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1. It contains the following elements Menu bar Provides access to all the application features Toolbar Shortcuts for the most common menu commands Service Structure Displays the list of configured components in Orbacus Notify Object Properties Displays the current property settings for the object selected in the Service Structure tree 755 CHAPTER 5 Orbacus Notify Console Status bar Displays the host and port at which the console is connected to Orbacus Notify and also displays information regarding currently executing operations 756 The Orbacus Notify Console Menus The Orbacus Notify Console Menus The File Menu The File Menu contains operations that manage the console windows New Window Creates a new console window connected to the same instance of Orbacus Notify Close Closes the current console window Quit Quits the application The Edit Menu The Edit Menu contains context sensitive operations which administer the various objects within Orbacus Notify These objects include channels admins proxies and filters Create Create a new object from the selected factory In this context the term factory refers to any object which includes factory methods for the creation of other objects For example an admin object is a factory for both proxy and filter creation Destroy Destroys the selected object Properties Displays a properties dialog for the selected object The
2. Background page 159 Information Managed by the IMR page 160 IMR Security page 163 Usage page 164 Windows NT Native Service page 166 Configuration Properties page 168 Connecting to the Service page 169 Utilities page 170 Getting Started with the Implementation Repository page 173 CHAPTER 7 The Implementation Repository 158 Programming Example page 176 Background Overview How It All Works Background The Orbacus Implementation Repository IMR provides support for the indirect binding of persistent object references The key advantage of indirect binding is that it loosens the coupling between clients and servers so that the location of the server can change without affecting the client In practical terms this is accomplished by providing the client with an IOR that actually refers to the IMR rather than to the server itself The IMR also provides the ability to start servers on demand using the Object Activation Daemon OAD The CORBA specification does not standardize how servers and the IMR interact it only suggests functionality for vendors to implement Hence the interface between servers and the IMR is strictly proprietary Due to the proprietary interface between servers and the IMR servers using the IMR must be developed using Orbacus for C or Java However the interaction between clients and the IMR is strictly specified by the GIOP specification so any client t
3. Usage page 189 Windows NT Native Service page 191 Configuration Properties page 193 Persistence page 194 Connecting to the Service page 195 Using the Naming Service with the IMR page 196 Bindings page 197 187 CHAPTER 9 Orbacus Names Name Resolution page 199 Programming Example page 200 188 Usage C Java Options Usage Orbacus includes functionally equivalent implementations of the Naming Service in C and Java nameserv h help v version i ior n no updates s start d database FILE l limit COUNT t timeout MINS c callback timeout SECS com ooc CosNaming Server h help v version i ior n no updates s start d database FILE l limit COUNT t timeout MINS c callback timeout SECS h Display the command line options supported by the help server v Display the version of the server version i Prints the stringified IOR of the server to standard ior output no updates Disables automatic updates i e callbacks that notify interested clients of changes to the naming service s start Use this option only when starting a persistent server using a new database d FILE database FILE Enables persistence for the server All of the bindings created by the server will be saved to the specified file If you are starting the se
4. CHAPTER 1 Introduction to JThreads C Overview What is JThreads C 578 JThreads C is the short form of Java like Threads for C JThreads C is a high level thread abstraction library that gives C programmers the look amp feel of Java threads Java supports multi threaded programming using the classes java lang Thread and java lang ThreadGroup the interface java lang Runnable and the synchronized keyword together with the methods wait notify and notifyAll in java lang Object Let s have a look how JThreads C translates this to C The Java classes java lang Thread and java lang ThreadGroup are directly translated into the C classes uTCThread and JTCThreadGroup The only difference is that the JThreads C classes have stc as a prefix instead of the Java package java lang The Java interface java lang Runnable is implemented as the abstract C class JTCRunnable which contains the pure virtual method run Support for the synchronized keyword is slightly more difficult since it is not possible to add new keywords to C JThreads C solves this using the classes gTCMonitor and JTCSynchronized Instances of JTCSynchronized Can be used as a replacement for the synchronized keyword provided that an instance of stcMonitor was created for the object to be synchronized JTCMonitor also provides the methods wait notify and notifyAll There are some features of Java s thread model tha
5. StructuredProxyPushConsumer m SequenceProxyPushConsumer ProxyPullConsumer m StructuredProxyPullConsumer SequenceProxyPullConsumer Figure 9 Notification Service CosNotifyChannelAdmin Object Management Hierarchy Note the objects marked with these are Notification Service equivalents of the Event Service counterparts Also note the interfaces added by the Notification Service The cosNotifyChannelAdmin EventChannelFactory addresses the lack of factory issue in the Event Service while several proxy interfaces have been added to support structured event delivery 699 CHAPTER 3 Notification Service Concepts Event Delivery 700 Event Header Event Body The Notification Service supports the delivery of events in a CORBA Any aS does the Event Service In addition the Notification Service introduces the concept of structured events and sequence events Structured Events Structured events are represented with the CosNotification StructuredEvent type as shown in Figure 10 gt domain_name type_name event_name ohf_name ohf_value ohf_name ohf_value ohf name ohf value gt fd_name fd_value fd_name fd_value fd_name fd_value remainder_of_body gt Figure 10 CosNotification StructuredEvent Fixed Header Variable Header Filterable Fields Remaining Body The OMG Notification Service The two main co
6. MinorNoUsableProfile No usable profile in IOR MinorMessageSizeLimit Maximum message size exceeded MinorThreadLimit Can t create new thread 408 CORBA System Exceptions COMM_FAILURE Minor Exception Code MinorRecv recv failed MinorSend send failed MinorRecvZero recv returned zero MinorSendZero send returned zero MinorSocket socket failed MinorSet sockopt setsockopt failed MinorGet sockopt getsockopt failed MinorBind bind failed MinorListen listen failed MinorConnect connect failed MinorAccept accept failed MinorSelect select failed MinorGethostname gethostname failed MinorGethostbyname gethostbyname failed MinorWSAStartup WSAStartup failed MinorWSACleanup WSACleanup failed MinorNoGIOP Not a GIOP message MinorUnknownMessage Unknown GIOP message MinorWrongMessage Wrong GIOP message MinorMessageError Got a message error message MinorFragment Invalid fragment message MinorUnknownReqId Unknown request ID MinorVersion Incompatible GIOP version MinorPipe Creation of pipe failed MinorSet SoTimeout setSoTimeout failed 409 CHAPTER 20 Exceptions and Error Messages MARSHAL Minor Exception Code 410 MinorNoValueFactory
7. BAD_PARAM Minor Exception Code page 405 NO_MEMORY Minor Exception Code page 407 IMP_LIMIT Minor Exception Code page 408 COMM_FAILURE Minor Exception Code page 409 MARSHAL Minor Exception Code page 410 NO_IMPLEMENT Minor Exception Code page 412 NO RESOURCES Minor Exception Code page 413 BAD_INV_ORDER Minor Exception Code page 414 TRANSIENT Minor Exception Code page 415 INTF_REPOS Minor Exception Code page 416 OBJECT_NOT_EXIST Minor Exception Code page 417 INV_POLICY Minor Exception Code page 418 INITIALIZE Minor Exception Code CORBA System Exceptions MinorORBDest royed ORB already destroyed 403 CHAPTER 20 Exceptions and Error Messages UNKNOWN Minor Exception Code MinorUnknownUserException Unknown user exception 404 BAD_PARAM Minor Exception Code CORBA System Exceptions MinorValueFactoryError Failure to register unregister or lookup value factory MinorRepositoryIdExists Repository ID already exists in Interface Repository MinorNameExists Name already used in Interface Repository MinorInvalidContainer Target is not a valid container MinorNameClashInInheritedContext Name clash in inherited context MinorBadAbstract InterfaceType Incorrect type for abstract interface MinorBadSchemeName Bad scheme name MinorBadAddress Bad address MinorBadSchemeSpecificPart Bad scheme specific part MinorOther Other
8. h help Display the command line options supported by the service i install Install the service The service must be started manually 3 start install Install and start the service u uninstall Uninstall the service d debug Run the service in debug mode In order to use Orbacus Balancer as a native Windows NT service first add the desired configuration properties to the HKEY_LOCAL_MACHINE NT registry key see Using the Windows NT Registry on page 71 for more details For example add the ooc balancer admin_endpoint and ooc balancer forward_endpoint properties so that the service will use non default ports Next the service should be installed with ntbalancerservice i This adds the orbacus Balancer entry to the Services dialog in the Control Panel To start the service select the orbacus Balancer entry and press Start If the service is to be started automatically when the machine is booted select the orbacus Balancer entry then click Startup Next select Automatic for the Startup Type and press OK Alternatively the service could have been installed using the s option which configures the service for automatic start up ntbalancerservice s If you want to remove the service run Usage ntbalancerservice u Note If the executable for the service is moved it must be uninstalled and re installed Any trace information provided by the ser
9. Destroying a Constraint Value A selected mapping filter constraint value pair is destroyed by choosing the Pair Edit Destroy menu operation A confirmation is displayed before the constraint value pair is removed 776 In this appendix APPENDIX A CosEventChannelA dmin Reference This appendix describes the CosEventChannelAdmin module This appendix contains the following section Module CosEventChannelAdmin page 778 CHAPTER A CosEventChannelAdmin Reference Module CosEventChannelAdmin Overview Exceptions 778 This module contains channel administration interfaces These interfaces support the creation of the various Event Service type admin and proxy objects AlreadyConnected exception AlreadyConnected Thrown by a consumer or supplier proxy to indicate that a client is already registered The proxy interfaces permit only one connection at a time TypeError exception TypeError Certain proxy implementations may impose additional requirements on pull suppliers and push consumers that are allowed to connect If the object does not support these requirements the TypeError exception is raised Module CosEventChannelAdmin Interface CosEventChannelAdmin ProxyPushConsumer Synopsis Operations interface ProxyPushConsumer inherits from CosEventComm PushConsumer A push supplier uses this interface to register with an event channel connect_push_supplier
10. Servers are registered with a name that is unique within the domain and the host corresponding to the OAD that is responsible for the server Since the name is unique within the domain it is not currently possible to register the same server with multiple OADs The server name that is registered in the IMR can be any string but it must be the same as the name used by the server i e the name specified by the orBServeriad option or equivalent property The attributes of a server that are stored by the IMR are summarized below host The host corresponding to the OAD that is responsible for the server exec The path of server executable the exe extension must be included on Windows platforms If this attribute is not set then the IMR will not activate the server args The arguments to be supplied when starting the server executable Note that orBServerId server id is automatically appended to the arguments before the server process is started rundir The directory that the server process will be started from If this attribute is not set then the server process will be started from the root directory For Windows platforms the full path must be specified in the exec attribute even if this attribute is set Information Managed by the IMR mode The activation mode The possible values are shared only one server process is created which is used by all clients and persistent the server pro
11. The next step in connecting a consumer to an event channel is to obtain the appropriate proxy supplier from the consumer admin object Like the supplier example this is where the consumer specifies the delivery model and type of events it wishes to receive It is important to note that the type of proxies used by suppliers and consumers are independent of each other Hybrid delivery models are supported for example a pull consumer can receive events from a push supplier Also the type of event specified by the proxies are independent due to the event translation capabilities of the channel For example structured events inserted into a CORBA Any by the supplier are received as structured events by a structured consumer 1 This example like the supplier uses the push delivery model and structured events The corresponding C code is di Ce CosNotifyChannelAdmin ProxyID proxyId CosNotifyChannelAdmin ProxySupplier_var proxySupplier consumerAdmin gt obtain notification push_supplier CosNotifyChannelAdmin STRUCTURED_EVENT proxyId CosNotifyChannelAdmin StructuredProxyPushSupplier_var structuredProxyPushSupplier CosNotifyChannelAdmin StructuredProxyPushSupplier _narrow proxySupplier 1 Try running different combinations of the demo suppliers and consumers which accompany the Orbacus Notify distribution see notify demo simple For example try running the SequencePullSupplier and the AnyPushConsumer
12. master s Run the server in slave mode slave a Run the IMR in administrative mode The IMR will an Se PAbive run in non administrative mode by default d DIRECTORY Specifies the directory in which the IMR maintains database DIRECTORY its database files If not specified the current working directory is used 164 Usage A INFO admin endpoint INFO Specifies the IMR s administrative endpoint settings This is the endpoint that the OADs and IMR enabled servers use to communicate with the IMR For security reasons access to this endpoint can be restricted If not specified iiop port 9999 is used F INFO forward endpoint INFO Specifies the IMR s public endpoint which is used by clients for server requests If not specified iiop port 9998 is used S INFO slave endpoint INFO Specifies the endpoint used by the OAD Note that all of the OADs in a domain must use the same endpoint If not specified iiop port 9997 is used L INFO locator endpoint INFO Specifies the endpoint used by the Initial Service Locator see The Initial Service Locator on page 153 If not specified iiop port 2809 is used a Note that only one of the m or s options may be specified Also if neither the m or s option is specified then the server is started in dual mode 165 CHAPTER 7 The Implementation Repository Windows NT Native Service
13. 57 58 return status Be Include the header file that declares the Orbacus Balancer utility initialization function This header file also includes the header file OB BalancerUtil h which contain the definitions of the utility objects The header file o0B Balancer_skel h must be included for the implementation of the LoadBalancing LoadAlert interface An implementation of the LoadBalancing LoadAlert interface that delegates to the LoadAlert utility object Invoke LoadBalancing Util LBUtil_init This function initializes the utility objects and must be called before initializing the ORB 295 CHAPTER 14 Orbacus Balancer 296 The remainder of the main function is the same as in section Non adaptive Load Balancing on page 289 Now we write the run function do ff Caer 2n cum CORBA ORE mp tata OrD aine aroe eNA r AEV St 4 if argc 2 5 return EXIT_FAILURE 6 const char memberId argv 1 T 8 CORBA Object_var poaObj 9 orb gt resolve_initial_references RootPOA 0 PortableServer POA_var rootPoa il PortableServer POA _narrow poaOb 2 3 PortableServer POAManager_var manager 4 rootPoa gt the_POAManager 5 6 LoadBalancing MemberPolicyValue_var value 7 new LoadBalancing MemberPolicyValue 8 value gt group_id CORBA string_dup Hello J value gt member_id CORBA string_dup memberId 20 CORBA Any any 20 any lt lt value _retn
14. 583 CHAPTER 2 Hello World 584 At first sight this application seems to indicate a problem Can the application terminate due to return from main before the thread gets a chance to run The answer is No because the destructor for JTCInitialize doesn t return until all of the threads have terminated The stcInitialize destructor allows JThreads C applications to have the same behavior as multi threaded Java applications Hello World with Runnable Hello World with Runnable 10 11 Java provides the Runnable interface so that an application developer may use threads without using inheritance The JThreads C equivalent of the Runnable interface is the class JTCRunnable The Hello World example using Runnable in Java looks like this 1 public class HelloWorld implements Runnable a i 3 Dolie wore sawn 4 5 System out println Hello World 6 7 8 static public void main String args 9 WO Thread t new Thread new HelloWorld AL al ie SSesSwee iiy 12 is A class HelloWorld is declared that implements the interface Runnable A new thread is created with a Runnable object as the parameter which in this case is an instance of the HelloWorld Class The thread is started Since the Thread object was created with a Runnable object parameter the run method of this Runnable is invoked 585 CHAPTER 2 Hello World The Java version can be translated directly int
15. Adaptive strategy which attempts to keep the member loads within a given tolerance This strategy takes an aggressive approach to load re balancing The configuration properties for this strategy are as follows Type CORBA ULong Members with loads less than the average minus the tolerance are selected in round robin order Members with loads greater than the average plus the tolerance are re balanced If there are no members with loads less than the average minus the tolerance then members with loads within tolerance of the average are selected in round robin order The default value for this property is O This alleviates the member selection problem 1 on page 269 and 3 on page 270 See load per client on page 278 See reject load on page 279 279 CHAPTER 14 Orbacus Balancer dampening multiplier See dampening multiplier on page 279 280 Connecting to the Service Connecting to the Service Servers that use Orbacus Balancer must be configured with the service s initial reference The object key of the service is Balancer hence a URL style object reference of the service running on host 1bhost at port 10000 would be corbaloc lbhost 10000 Balancer Using this object reference a server can configure the Orbacus Balancer initial reference with the property ooc orb service Balancer corbaloc lbhost 10000 Balancer An alternative to using the above property is to use the oRBInitR
16. In the reply handler implementation the user must instantiate a callback object and pass it to the ORB in the deferred AMI request or sendc_ call The ORB can then use this callback object to inform the client application that the request has completed This callback object must be derived from the generated aMI_EchoHandler Class This is shown in the C and Java code examples that follow The following code snippet shows the client application making the AMI deferred call for the Reply Handler implementation The EchoHandler_impl class must be implemented by the user For a complete example please see the code in the ob demo AMI echo_reply_router directory of the Orbacus for C distribution jon CORBA PolicyList policies policies length 2 WN policies 0 rootPOA create_id_assignment_policy PortableServer USER_ID 4 policies 1 TOOELOAS gt create_lifespan_policy PortableServer PERSISTENT 5 PortableServer POA_var handlerPOA rootPOA gt create_POA myHandlerPOA manager policies 6 CORBA Object_var obj orb gt string_to_object relfile Echo ref 7 Echo_var echo Echo _narrow obj 8 EchoHandler_imp1l handler new EchoHandler_impl handlerPOA PortableServer ServantBase_var servant handler 0 PortableServer ObjectId_var id PortableServer string_to_ObjectId myHandlerServant handlerPOA gt activate_object_with_id id servant 2 AMI_EchoHandler
17. local interface AcceptorInfo Information on an OCI Acceptor object Objects of this type must be narrowed to an Acceptor information object for a concrete protocol implementation for example to OCI TIOP AcceptorInfo in case the plug in implements IIOP See Also Interface OCI Acceptor id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag describe string describe Returns a human readable description of the transport Returns The description add_accept_cb void add_accept_cb in AcceptCB cb Add a callback that is called whenever a new connection is accepted If the callback has already been registered this method has no effect Parameters cb The callback to add remove_accept_cb void remove_accept_cb in AcceptCB cb Remove an accept callback If the callback was not registered this method has no effect 479 CHAPTER E Open Communications Interface Reference Parameters cb The callback to remove 480 Module OCI Interface OCI AcceptCB Synopsis local interface AcceptCB An interface for an accept callback object See Also Interface OCI AcceptorInfo Operations accept_cb void accept_cb in TransportInfo transport_info Called after a new connection has been accepted If the application wishes to reject the connection CORBA NO_PERMISSION may be raised Parameters transport_info
18. 5 org omg PortableServer POAHelper narrow obj 6 org omg PortableServer POAManagerFactory factory 7 rootPOA the_the_POAManagerFactory 8 com ococ OBPortableServer POAManagerFactory pmFactory 9 com ooc OBPortableServer POAManagerFactoryHelper narrow fac tory 0 org omg PortableServer POAManager myPOAManager null 1 org omg CORBA Policy pl new Policy 0 3 4 myPOAManager 5 pmFactory create_POAManager MyPOAManager pl 6 7 catch org omg PortableServer POAManagerFactoryPackage Man agerAlreadyExists ex 8 9 do something 20 21 catch org omg CORBA PolicyError ex 22 23 do something 24 Resolve the POA Manager Factory Create a new POA Manager with the name MyPOAManager The ORB processes any configuration properties that were defined for the POA Manager and may raise the oct InvalidParam exception if an error was found in the POA Manager s endpoint configuration POA Manager Policies Using POA Managers The POA Manager Factory interface allows a set of vendor specific policies to be used to configure the new POA Manager For Orbacus the proprietary policies are if ODIL module OBPortableServer local interface POAManagerFactory PortableServer POAManagerFactory EndpointConfigurationPolicy create_endpoint_configuration_policy in string value raises CORBA PolicyError CommunicationsConcurrencyPolicy create_communications_concurrency_policy in
19. 721 CHAPTER 4 Programming Example Resolve Event Channel Factory Obtain Notification Channel Supplier Consumer y A Obtain Supplier Admin Obtain Consumer Admin y y Obtain Proxy Consumer Obtain Proxy Supplier e Delivery Model e Delivery Model e Push e Push e Pull e Pull e Client Type e Client Type e Any e Any Structured e Structured e Sequence e Sequence Push Callback on Disconnect Yes Pull Push Implement Supplier Callback on Disconnect y Implement Consumer p Connect to Proxy Consumer 722 Connect to Proxy Supplier Figure 16 Connecting to a Notification Channel Pull Resolving the Event Channel Factory Obtaining an Event Channel 2 3 5 6 Connecting to a Notification Channel Before an application can obtain an event channel it must first resolve the NotificationService initial reference The result is an object of type CosNotifyChannelAdmin EventChannelFactory The C and Java code follows hd Cet CORBA Object_var obj orb gt resolve_initial_references NotificationService C OSS CosNotifyChannelAdmin EventChannelFactory_var eventChannelFactory CosNotifyChannelAdmin EventChannelFactory _narrow obj D Java org omg CORBA Object obj orb resolve_initial_references NotificationService EventChannelFactory eventCh
20. A servant class for 1 can then be defined using the I_skel_tie template 1 CH 2 typedef POA_I_tie lt I_impl_tie gt I_impl The servant class I_imp1 is defined as a template instance of Poa_I_tie parameterized with t_impl_tie 99 CHAPTER 5 CORBA Objects The tie template generated by the IDL compiler contains functions that permit you change the instance denoted by the tie Lo eC 2 template lt class T gt 3 Clase POA I tie public POAT a 5 jewloilaes 6 Laces a T _tied_object 8 void _tied_object T amp obj S void _tied_object T obj CORBA Boolean release true 10 Ne abe jak 7 9 The _tied_object function permits you to retrieve and change the implementation instance that is currently associated with the tie The first modifier function calls delete on the current tied instance before accepting the new tied instance if the release flag is currently true the release flag for the new tied instance is set to false The second modifier function also calls delete on the current tied instance before accepting the new instance but sets the release flag to the passed value Delegation using Java For every IDL interface the IDL to Java mapping generates an operations interface containing methods for the IDL attributes and operations This operations interface is also used to support delegation based servant implementation For an interface 1 the following additional class is generated
21. B Default Consumer Admin Properties Order Policy Priority Order v Discard Policy Any Order v Max Events per Consumer 0 Timeout msec 0 0 Priority 0 Maximum Batch Size 1 Pacing Interval msec 0 0 Retry Timeout msec 1000 0 Retry Multiplier 1 0 Max Retries 0 Max Retry Timeout msec 160000 0 Request Timeout msec 5000 0 Figure 26 Admin QoS Properties This dialog is activated from the Edit Properties operation when an admin object is selected in the Service Structure tree 763 CHAPTER 5 Orbacus Notify Console 764 Mapping Filters Priority and lifetime mapping filters may be assigned to or removed from consumer admin objects in the Mapping Filters tab of the Admin Properties dialog Figure 27 Figure 27 Consumer Admin Mapping Filters Subscription Offered Types For consumer admins subscription event types are managed in the Subscription Types tab of the Admin Properties dialog Figure 28 Similarly for supplier admins offered event types are managed in the Managing Admins Offered Types tab of the Admin Properties dialog Note that only one of the Subscription Types or Offered Types tab is available depending on whether a consumer or supplier admin is selected from the Service Structure Tree B Consumer Admin 1 Properties Add Event Types Figure 28 Admin Subscription Offer Types Destroying an Admin A selected admin is destroyed by choo
22. CodeSets const ServiceId CodeSets 1 TAG_INTERNET_IOP const ProfileId TAG_INTERNET_IOP 0 TAG_MULTIPLE_COMPONENTS const ProfileId TAG_MULTIPLE_COMPONENTS 1 TransactionService const ServiceId TransactionService 0 IOR struct IOR string type_id sequence lt TaggedProfile gt profiles ServiceContext struct ServiceContext ServiceId context_id sequence lt octet gt context_data TaggedComponent struct TaggedComponent ComponentId tag sequence lt octet gt component_data TaggedProfile struct TaggedProfile ProfileId tag sequence lt octet gt profile_data Aliases Module IOP Componentld typedef unsigned long ComponentId MultipleComponentProfile typedef sequence lt TaggedComponent gt MultipleComponentProfile Profileld typedef unsigned long Profileld ServiceContextList typedef sequence lt ServiceContext gt ServiceContextList Serviceld typedef unsigned long Serviceld 571 CHAPTER C FSSL Reference Module OB Interface Index Constants 572 ConnectionReusePolicy The connection reuse policy ProtocolPolicy The protocol policy ReconnectPolicy The reconnect policy TimeoutPolicy The timeout policy CONNECTION_REUSE_ POLICY const CORBA PolicyType CONNECTION_REUSE_POLICY 3 This policy type identifies the connection reuse policy PROTOCOL_POLICY const CORBA PolicyType PROTOCOL_POLICY 2 This policy type i
23. CommunicationsConcurrencyPolicy This example shows how to create a new POA Manager with the concurrency model set to threaded The C version is presented first followed by the Java version do off Cae 2 CORBA Object_var poaObj 3 orb gt resolve_initial_references RootPOA 4 OBPortableServer POA_var rootPOA 5 OBPortableServer POA _narrow poa0bj 6 POAManagerFactory_var factory rootPOA gt the_POAManagerFactory 7 OBPortableServer POAManagerFactory_var pmFactory 8 OBPortableServer POAManagerFactory _narrow factory 9 POAManager_var myPOAManager Policyiest pil pl length 1 pl 0 pmFactory gt iS l create_communications_concurrency_policy 3 OBPortableServer COMMUNICATIONS_CONCURRENCY_POLICY_THREADED try myPOAManager create_POAManager MyPOAManager pl catch const POAManagerFactory ManagerAlreadyExists amp ex do something m DOO MOANA MO N N And now the same example in Java 321 CHAPTER 16 Using Policies 322 oma numb WN FE CO Sa ab 20 21 BO 23 24 25 Java org omg CORBA Object obj orb resolve_initial_references RootPOA org omg PortableServer POA rootPOA org omg PortableServer POAHelper narrow obj org omg PortableServer POAManagerFactory factory rootPOA the_the_POAManagerFactory com ooc OBPortableServer POAManagerFactory pmFactory com ooc OBPortableServer POAManagerFact
24. Hello World Application Client Side Usage Setting Identity First a context must be created as in the server case Next a context policy must be created with the context id Policies are a standard CORBA mechanism for controlling operational behaviour and are considered to be immutable objects That is once they have been created they may not be changed The set of policies associated with an object reference are also considered to be immutable Hie Catt CORBA Policy_var contextPolicy fsslManager gt create_context_policy id Java org omg CORBA Policy contextPolicy fsslManager create_context_policy id The CORBA standard provides three methods to associate policies with object references ORB Level Policies The ORB level policies are managed using the ORB Policy Manager which is resolved through the initial reference ORBPolicyManager Hi Cast CORBA PolicyManager_var policyManager CORBA PolicyManager _narrow CORBA Object_var orb gt resolve_initial_references ORBPolicyManager Java org omg CORBA PolicyManager policyManager org omg CORBA PolicyManagerHelper narrow orb resolve_initial_references ORBPolicyManager Through this interface the current set of ORB level policies can be examined and changed The set of ORB level policies will be associated with every new object reference that is created by that ORB 534 Object Level Policies Thread Level Policie
25. Programming Example Programming Example Below is a simple example in Java that demonstrates how to obtain an InterfaceDef object and display its contents 1 Java 2 import org omg CORBA 3 es 4 5 org omg CORBA ORB initialize the ORB 6 org omg CORBA Object obj get object reference somehow 7 8 org omg CORBA Object defObj obj _get_interface_def 9 if defObj null 4 i System err println No Interface Repository available 2 System exit 1 3 ff 4 5 InterfaceDef def InterfaceDefHelper narrow defOb 4 6 org omg CORBA InterfaceDefPackage FulliInterfaceDescription desc vi def describe_interface 8 aioe ap 20 System out printin name desc name 21 System out printin id desc id 22 System out printin defined_in desc defined_in 23 System out printin version desc version 24 System out printin operations 25 for i 0 i lt desc operations length i 26 27 Syo cen out printime desc operations i name 28 29 System out printin attributes SOMO Gai mcm Gese attr i butes lengen a IE 31 32 System out println i desc attributes ilk nane oo 34 System out printin base_interfaces 35 for i 0 i lt desc base_interfaces length i 36 37 System out printime desc base_interfaces i 38 265 CHAPTER 13 The Interface Repository 5 8 9 13 15 16 17 19 39 266 After initializing the O
26. String dnl chain 1 subject_DN String dn2 ca_ subject_DN if dn1l equals dn2 return true return false 549 CHAPTER 2 Extending the Hello World Application Server Side main 550 First initialize the ORB fii Chest ime Main int arge Greiss eey char int status EXIT_SUCCESS CORBA TORB var orb try orb CORBA ORB_init argc argv status run orb argc argv catch const CORBA Exception amp ex cere lt lt x lt lt chal status EXIT_FAILURE if CORBA is_nil orb CEY orb gt destroy catch const CORBA Exception amp ex cere lt lt 6x lt lt Enel status EXIT_FAILURE return status Complete Example Java public static void main String args int status 0 org omg CORBA ORB orb null java util Properties props System getProperties props put org omg CORBA ORBClass com ooc CORBA ORB props put org omg CORBA ORBSingletonClass com ooc CORBA ORB try orb org omg CORBA ORB init args props status run orb args catch Exception ex ex printStackTrace status 1 if orb null Ery com ooc CORBA ORB orb destroy catch Exception ex ex printStackTrace status 1 System exit status 551 CHAPTER 2 Extending the Hello World Application run 552 Next obtain a reference to the FSSL Context Manager Hi CAs aL G
27. StructuredPushSupplier AnyPullSupplier Figure 11 Event Translation Example Event Channel 702 The OMG Notification Service Filtering The Notification Service defines a set of interfaces in the cosNotifyFilter module which support event filtering In the same way event channels are created from the EventChannelFactory filters are created from the FilterFactory The default filter factory is available from the CosNotifyChannelAdmin EventChannel interface Each filter contains a list of constraints where each constraint is composed of a list of event types and a single boolean constraint expression the filter structure is illustrated in Figure 12 Filter Constraint Event Types domain name type name domain name type name Constraint Expression Constraint Event Types domain name type name domain name type name Constraint Expression Figure 12 Filter Composition 703 CHAPTER 3 Notification Service Concepts 704 The constraint expression conforms to some constraint grammar and specifies restrictions based on the data in the event filterable fields Notify supports the default constraint grammar as specified in 1 For an event to match a constraint it must match one or more of the event types within that constraint and the constraint expression must eva
28. The TransportInfo for the new connection 481 CHAPTER E Open Communications Interface Reference Interface OCI AccFactory Synopsis Attributes Operations 482 local interface AccFactory An interface for an AccFactory object which is used by CORBA servers to create Acceptors See Also Interface OCI Acceptor Interface OCI AccFactoryRegistry id readonly attribute PluginId id The plugin id tag readonly attribute Profileld tag The profile id tag create_acceptor Acceptor create_acceptor in ParamSeq params raises InvalidParam Create an Acceptor using the given configuration parameters Refer to the plug in documentation for a description of the configuration parameters supported for a particular protocol Parameters params The configuration parameters Returns The new Acceptor Raises InvalidParam If any of the parameters are invalid change_key void change_key inout IOP IOR ior in ObjectKey key Change the object key in the IOR profile for this given protocol Module OCI Parameters ior The IOR key The new object key get_info AccFactoryInfo get_info Returns the information object associated with the Acceptor factory Returns The Acceptor 483 CHAPTER E Open Communications Interface Reference Interface OCI AccFactoryInfo Synopsis local interface AccFactoryInfo Information on an OCI AccFactory object See A
29. The data associated with the thread specific storage key Throws JTCSystemCallException Indicates a failed system call set static void set JTCThreadKey key void data Associates data with a thread specific storage key Parameters key The thread specific storage key data The data to associate with the key Throws JTCSystemCallException Indicates a failed system call 655 CHAPTER A Class Reference JTCThreadDeath Overview This exception is thrown when a thread is terminated by JTCThread stop If this exception is caught it must be re thrown to ensure correct termination of the thread 656 JTCException Overview Constructors Member Functions With the exception of JTcThreadDeath JTCException Is the base class of all JThreads C exception classes JTCException JTCException const char note long error 0 Constructs a JTCException with the message in note and the error type in error Parameters note A description of the error error An exception specific error code getError long getError const Returns the exception specific error code Currently only JTCSystemCallException has a specific error code Returns The error code getType virtual const char getType const Returns a string representation of the exception type This is the name of the exception class This member is not available in Java Returns The class name getMessage const char g
30. This is the same as the C version above Initial Services The Initial Service Locator In addition to providing the Orbacus Implementation Repository the IMR server see Chapter 7 acts as an initial service locator That is assuming that the IMR server is properly configured the name of the host running the IMR server is the only information needed to find a particular initial service To locate an initial service with name foo the IMR server must first be configured with the initial reference of this service This may be done with the oRBInitRef command line option or the ooc orb service configuration property see Chapter 4 for details Next the client that wishes to connect to foo must be configured with the default initial reference specifying the host running the IMR server The ORBDefaultInitRef command line option or the ooc orb default_init_ref configuration property may be used to configure the default initial reference For example given that the IMR server is running on imr host then the client can be started with the option ORBDe fault InitRef corbaloc imr host When the client is configured with this default initial reference it may invoke resolve_initial_references foo on the ORB to obtain a reference to foo 153 CHAPTER 6 Locating Objects The IORDump utility Overview Orbacus provides the iordump utility to decode stringified ORs and to print out their components in human readable form
31. Usage Orbacus includes functionally equivalent implementations of the Event Service in C eventserv Se e v wetesicial i mier Ie ciyjseclseiiai ce u untyped service and Java com ooc CosEvent Server Se oenyo mm versie miir le ei jsecl seiyaee u untyped service Options h Display the command line options supported by the help server v Display the version of the server version i Print the stringified IOR of the server to standard output LOr t Run a typed event service typed service u Run an untyped event service This is the default untyped service behavior 238 Usage Windows NT Native Service The C version of Orbacus Events is also available as a native Windows NT service nteventservice h help i install s start install u uninstall d debug h Display the command line options supported by the server help i Install the service The service must be started manually install s Install and start the service start install u Uninstall the service uninstall d Run the service in debug mode debug In order to use the Event Service as a native Windows NT service it is first necessary to add the ooc event endpoint property to the HKEY_LOCAL_MACHINE NT registry key see Using the Windows NT Registry on page 71 for more details Next the service should be installed with
32. Using the Windows NT Registry in the Orbacus manual for more details Next the service is installed with 676 Configuration Properties Orbacus Notify ntnotservice i This adds the Orbacus Notify entry to the services dialog in the Control Panel To start Orbacus Notify select the Orbacus Notify entry and press Start If the service is to be started automatically when the machine is booted select the Orbacus Notify entry then click startup Next select Startup Type Automatic and press OK If you want to remove the service run ntnotservice u Note If the executable for Orbacus Notify is moved it must be uninstalled and re installed Any trace information provided by the service is placed in the Windows NT Event Viewer with the title NotifyService In addition to the standard Orbacus configuration properties Orbacus Notify also supports the following properties Table 1 Configuration Properties Property Value Description ooc notification dbodir directory Specifies the directory in which Orbacus Notify stores its databases This property must be set either in a configuration file or on the command line otherwise Orbacus Notify will not start 677 CHAPTER 2 Configuration and Startup Table 1 Configuration Properties Property Value Description ooc notification dispatch_strategy threaded thread_pool Orbacus Notify supports two different models for
33. 22 CORBA Policy_var memberPolicy 29 orb gt create_policy LoadBalancing MEMBER_POLICY_ID any 24 25 CORBA PolicyList pl1 3 26 pl length 3 oa pl 0 rootPOA gt create_lifespan_policy 28 PortableServer PERSISTENT 29 pl 1 rootPOA gt create_id_assignment_policy 30 PortableServer USER_ID Bil pl 3 memberPolicy 22 PortableServer POA_var helloPOA 29 rootPOA gt create_POA hello manager pl 34 3S Hello_imp1l helloImpl new Hello_imp1 helloPOA 36 PortableServer ServantBase_var servant helloImpl er PortableServer 0bjectId_var oid 38 PortableServer string_to_ObjectId hello 39 helloPOA gt activate_object_with_id oid servant 40 Hello_var hello helloImpl gt _this 41 42 53 25 33 55 58 62 63 65 Programming Example 42 CORBA Object_var obj 43 orb gt resolve_initial_references Balancer 44 LoadBalancing GroupFactory_var factory 45 LoadBalancing GroupFactory _narrow ob 4 46 47 obj orb gt resolve_initial_references LoadUpdater 48 LoadBalancing Util LoadUpdater_var updater 49 LoadBalancing Util LoadUpdater _narrow ob 50 Sil obj orb gt resolve_initial_references LoadAlert 52 LoadBalancing Util LoadAlert_var alert 53 LoadBalancing Util LoadAlert _narrow ob 54 55 LoadAlert_impl loadAlertImpl new LoadAlert_impl alert 56 PortableServer ServantBase_var alertServant l
34. 4 5 data_ len_ c 6 i 8 synchronized public void writeBuffer 9 20 System out write data_ 0 len_ 21 System out flush 22 len_ 0 23 3 4 Two data members are defined e data_is a character array which holds the buffered characters jen_ is the current length of the buffer i e the number of valid characters in the buffer pointed to by data_ In contrast to the C version of this program it s not necessary to have a max_ data member since data_ length can be used instead 6 14 If no buffer has been created yet or if the buffer is full i e if Len_ is equal to data_ length a new larger buffer is allocated This is similar to the C version 15 A character is added to the buffer and 1en_ is incremented by one 590 Synchronization 18 22 Like in the C example the writeBuffer method prints 1en_ characters from the buffer on standard output and then resets 1en_ to zero What is different The only conceptual change to make the program thread safe was to add the synchronized keyword to the definitions of addchar and writeBuffer In Java every object implicitly has an associated monitor On entry to a synchronized method the monitor belonging to the object is locked preventing other threads from entering any other synchronized method of the object On exit the monitor is unlocked thus allowing access by other threads This makes sure that the scenario described above won t ever arise
35. 733 CHAPTER 4 Programming Example 734 And in Java Java org omg CORBA IntHolder proxyId new org omg CORBA IntHolder N ProxySupplier proxySupplier consumerAdmin obtain_notification_push_supplier ClientType STRUCTURED_EVENT proxyId StructuredProxyPushSupplier structuredProxyPushSupplier E gia RO OO Ty Os ae 1G 0 StructuredProxyPushSupplierHelper narrow i proxySupplier Variable to hold the ID later assigned to the proxy by Orbacus Notify Obtain a proxy push supplier specifying the type This example wants a structured event proxy push supplier Valid types are ANY_EVENT STRUCTURED_EVENT SEQUENCE_EVENT Narrow the proxy supplier to the appropriate type specified in the previous call Equivalent objects and methods exist for pull model consumers Connecting to a Notification Channel Connecting to a Proxy Implementing the Servant The final step in connecting a consumer to an event channel is to connect to the proxy This is similar to connecting the supplier with one major difference a push consumer must implement the appropriate CORBA servant to support the event delivery A push consumer must assume the role of CORBA server since it has to process incoming requests namely handle events pushed by the channel The implementation of the push consumer servant is discussed next Hi St class StructuredPushConsumer_impl public CosNotifyComm_StructuredPushConsumer_skel C
36. Alias for a sequence of Connector factories AcceptorSeq typedef sequence lt Acceptor gt AcceptorSeq Alias for a sequence of Acceptors AcceptCBSeq typedef sequence lt AcceptCB gt AcceptCBSeq Alias for a sequence of accept callback objects AccFactorySeq typedef sequence lt AccFactory gt AccFactorySeq Alias for a sequence of AccFactory objects Version const string Version 1 0 The OCI version If an interface or implementation changes in an incompatible way this version will be changed 453 CHAPTER E Open Communications Interface Reference Enums Structs Exceptions 454 SendReceiveMode enum SendReceiveMode SendOnly ReceiveOnly SendReceive Indicates the send receive capabilities of an OCI component Profilelnfo struct ProfileInfo ObjectKey key octet major octet minor ProfileId id unsigned long index TaggedComponentSeq components Basic information about an IOR profile Profiles for specific protocols contain additional data For example an IIOP profile also contains a hostname and a port number Members key The object key major The major version number of the ORB s protocol For example the major GIOP version if the underlying ORB uses GIOP minor The minor version number of the ORB s protocol For example the minor GIOP version if the underlying ORB uses GIOP id The id of the profile that contains this information in
37. Suspend Resume Refresh Properties Figure 22 Popup Menu This popup menu is a shortcut to the menu commands and contains appropriate operations for the selected object channel admin proxy or filter based on its current state Creation Wizards Creation Wizards The Orbacus Notify Console guides users through the creation of various items through the use of object creation wizards A sample wizard dialog is shown in Figure 23 Add Create Wizard excess e EN _EBocn Nem rinish concen Figure 23 Sample Creation Wizard The initial wizard dialog is displayed by invoking the Create operation on a selected object The wizards provide instructions related to the setup of various objects within Orbacus Notify 759 CHAPTER 5 Orbacus Notify Console Managing Notification Channels Creating a New Channel To create a new channel simply choose the EventChannelFactory and select the Edit Create operation The Event Channel Creation Wizard then steps through the creation of the channel Notification Channel Properties The Edit Properties menu operation for a selected channel displays a tabbed property dialog in which various channel properties may be edited All the properties in this dialog are set initially when the channel is created with the channel creation wizard 760 Managing Notification Channels QoS Properties The channel QoS Properties tab in the Event Channel Properti
38. The Event Channel 246 The Event Service distributes data in the form of events The term event in this context refers to a piece of information that is contributed by an event source An event channel instance accepts this information and distributes it to a list of objects that previously have connected to the channel and are listening for events The Event Service specification defines two distinct kinds of event channels untyped and typed Whereas an untyped event channel forwards every event to each of the registered clients in the form of a CORBA Any a typed event channel works more selectively by supporting strongly typed events which allow for data filtering We will only discuss the untyped event channel here For information on typed event channels and more details on the Event Service in general please refer to the official Event Service specification 9 Event Service Concepts Event Suppliers and Consumers Applications participating in generating and accepting events are called suppliers and consumers respectively Suppliers and consumers each come in two different versions namely push suppliers and pull suppliers and push consumers and pull consumers What s the difference between pushing events and pulling events Let s have a look at the consumer side first Some consumers must be immediately informed when new events become available on an event channel Such consumers usually act as push consumers They impleme
39. Unable to locate value factory MinorDSIResultBeforeContext DSI result cannot be set before context MinorDSIInvalidParameterList DSI argument list does not describe all parameters MinorLocalObject Attempt to marshal local object MinorWcharSentByClient wchar data sent by client on GIOP 1 0 connection MinorWcharSentByServer wchar data returned by server on GIOP 1 0 connection MinorReadOverflow Input stream buffer overflow MinorReadBooleanOverflow Overflow while reading boolean MinorReadCharOverflow Overflow while reading char MinorReadWCharOverflow Overflow while reading wchar MinorReadOctetOverflow Overflow while reading octet MinorReadShortOverflow Overflow while reading short MinorReadUShortOverflow Overflow while reading ushort MinorReadLongOverflow Overflow while reading long MinorReadULongOverflow Overflow while reading ulong MinorReadLongLongOverflow Overflow while reading longlong MinorReadULongLongOverflow Overflow while reading ulonglong MinorReadF loatOverflow Overflow while reading float MinorReadDoubleOverflow Overflow while reading double MinorReadLongDoubleOverflow Overflow while reading longdouble MinorReadSt ringOverflow Overflow while reading string MinorReadSt ringZeroLength Encountered zero length string
40. 1 It is fully backwards compatible with the OMG Event Service specification 2 providing a smooth migration path for applications that use an event service Some highlights of Orbacus Notify are e Written in C for maximum performance e Multi threaded architecture e Event filtering e Any structured and sequence event types e Push and pull suppliers and consumers e Quality of Service QoS parameters to control event queueing and event lifetime e Persistent and best effort event and channel reliability QoS parameters e Subscription sharing between channels and clients Orbacus Notify also features the Orbacus Notify Console a graphical user interface which is written in Java for maximum portability The user interface supports the maintenance of e Event channels Supplier and consumer admins e Proxy consumers and suppliers e All QoS parameters e Filters and constraint expressions e Event subscription and offer information The Orbacus Notify manual provides a brief overview of Event and Notification Service concepts However this document is not a substitute for the OMG Event Service and Notification Service specifications Please consult 1 and 2 for a detailed description of these services Overview The manual also includes a discussion of configuration issues an introduction to application development with examples in C and Java and detailed descriptions of the Orbacus Notify
41. 2 Instead of directly using operations like select Orbacus uses a Reactor to provide for flexible integration with existing event loops and to allow the installation of user supplied event handlers See The Reactor on page 360 for more information 351 CHAPTER 18 Concurrency Models 352 The maximum nesting level for the reactive concurrency model is usually much higher than for threaded concurrency models The reason is that the maximum nesting level for threaded models is determined by the maximum number of threads allowed per process whereas the reactive concurrency model is only limited by the maximum stack size per process Multi Threaded Concurrency Models Multi Threaded Concurrency Models In this section This section covers the following concurrency models Threaded Clients and Servers page 354 Thread per Client Server page 356 Thread per Request Server page 357 Thread Pool Server page 358 Leader_Follower page 359 353 CHAPTER 18 Concurrency Models Threaded Clients and Servers 354 For a threaded client outgoing requests are sent by the user thread but a separate receiver thread for handling replies is allocated for each connection to a server The separate receiver thread allows messages to be received and buffered for later retrieval by the user thread with DII operations such as get_response Of poll_response Like a threaded client a threaded server uses a separate
42. Abstract Syntax Notation One see 14 DER Distinguished Encoding Rules for ASN 1 see 4 DES Data Encryption Standard see 12 IDEA International Data Encryption Algorithm see 11 MD5 RSA Data Security Inc s MD5 message digest algorithm see 8 PEM Internet Privacy Enhanced Mail see 14 17 PKCS 8 Private Key Information Syntax Standard see 18 RC2 RC4 Rivest s Ciphers variable key size encryption algorithms see 11 RSA The RSA public key cryptosystem see 3 DSS The Digital Signature Standard see 11 SHA Secure Hash Algorithm see 7 559 CHAPTER A FSSL Definitions 560 Supported Toolkits OpenSSL IAIK iSaSiLk JSSE APPENDIX B Toolkits Supported by FSSL Both FreeSSL for C and Java require third party SSL toolkits to operate DISCLAIMER IONA Technologies does not assume any responsibility for the purchase or licensing of any third party product that is required to work with a particular version of the SSL plug in Any licensing issues that arise as a result of the use of any third party product is the sole responsibility of the purchaser FreeSSL for C requires OpenSSL 0 9 7g This is a public domain implementation of the Secure Sockets Layer version 3 0 Please see http www openssl org for more information on this product FreeSSL for Java supports version 3 04 of the IAIK iSaSiLk SSL toolkit and version 3 0 or equivalent Applet Edition of the IAIK JC
43. Clients do not need to implement this interface to simply pull events disconnect_sequence_pull_consumer void disconnect_sequence_pull_consumer Terminates communication between the target consumer and its supplier Also frees resources allocated by the consumer Module CosNotifyComm Interface CosNotifyComm SequencePullSupplier Operations interface SequencePullSupplier inherits from CosNotifyComm NotifySubscribe The SequencePullSupplier interface is implemented and registered connected by clients who wish to have sequences of structured events pulled from them by the channel pull_structured_events CosNotification EventBatch pull_structured_events in long max_number raises CosEventComm Disconnected This method blocks the calling thread until the supplier has data available or an exception is raised Parameters max_number Indicates the maximum number of events to return Returns A sequence of structured events try_pull_structured_events CosNotification EventBatch try_pull_structured_events in long max_number out boolean has_event raises CosEventComm Disconnected This method does not block and can be used to poll a pull supplier for events Parameters max_number Indicates the maximum number of events to return has_event Set to TRUE if there is at lease one event is available FALSE otherwise Returns A sequence of structured events if has_event is TRUE undefi
44. CosNotifyChannelAdmin SupplierAdmin 747 CHAPTER 4 Programming Example Destroying a Filter 748 all inherit the cosNotifyFilter FilterAdmin interface and can have filter objects associated with them In this example the filter is added on the consumer side by associating it with the supplier proxy Adding a filter to the proxy looks like Hy Chee CosNotifyChannelAdmin_ProxySupplier_var proxySupplier proxySupplier gt add filter filter Java ProxySupplier proxySupplier proxySupplier add_filter filter The add_filter operation adds the given filter to the list of filter objects already associated with the target proxy or admin object It returns an ID of type CosNotifyFilter FilterID which is unique amongst all filter objects associated with the particular target proxy or admin Note that the scope of a filter ID is limited to the scope of the admin or proxy to which the filter is assigned The cosNotifyFilter Filter interface includes a method destroy which destroys the target filter object Filters are not strictly owned by a single admin or proxy object Rather a filter is created from a filter factory and may be added to one or more admin or proxy objects For this reason clients must be careful when destroying a filter object as it may be referenced by other admins and or proxies within the service It is recommended that filters not be shared amongst admins or proxies This exa
45. For some applications the blocking request mechanism is not suitable An alternative is to implement a distributed callback mechanism allowing applications to make requests on a peer and have that peer notify it asynchronously of the result This introduces significant complexity since the application must now deal with issues related to peer registration persistence managing peer object references peer unavailability etc The effort required to handle such matters may dwarf the application s true purpose The OMG Event Service was designed to decouple communications between peer applications for which the synchronous request model and distributed callback scheme was too restrictive or too complex The Event Service introduced the concept of the event channel an entity to which peers could connect to supply and consume events Clients of the Event Service are classified as suppliers consumers or both depending on how they connect to an event channel Figure 2 illustrates a simplified delivery model Direction of Event Flow gt Supplier Event Channel Figure 2 Basic Event Service Communications Model Still the event service suffers from some serious drawbacks Lack of Reliability The event service makes no guarantees with regards to event delivery or connection persistence Any level of reliability is vendor specific 688 Overview Lack of Structured Events and Event Filtering In the event service th
46. If more than one thread is waiting and notifyal1 is used then all threads are woken but the order in which the waiting threads return from their call to wait is random Remember that only one thread at a time can return from wait since returning from wait requires the monitor s lock to be acquired This is not possible if another thread has previously returned from wait and has not yet released the monitors lock by exiting the synchronized method For this example notify is used as we know that there is going to be only one waiting thread However it doesn t matter whether notify or notifyAll is used because if more than one thread is waiting the number of characters is reset to zero once a thread has returned from wait When the other threads subsequently return from wait they will wait again because of the while loop 601 CHAPTER 3 Working With Threads Using Wait Notify with C Let s see how this example translates to JThreads C 1 void writeBuffer ay 3 JTCSynchronized synchronized this 4 while len_ lt 80 5 6 ey F 8 wait 9 10 catch const JTCInterruptedException EL 12 L3 14 cout write data_ len lt lt flush T5 len_ 0 le jj 3 As in the Java example the writeBuffer method must be synchronized Calling wait notify Or notifyAll without having the monitor locked results in the exception JTCI1legalMonitorStateException being thrown 4 Like in the Java example the while loop i
47. It also provides operations for the management of IOR profiles See Also Interface OCI AccFactoryRegistry Interface OCI AccFactory Interface OCI Transport id readonly attribute PluginId id The plugin id tag readonly attribute Profileld tag The profile id tag handle readonly attribute Handle handle The handle for this Acceptor Like with the handle for Transports the handle may only be used with operations like select A handle value of 1 indicates that the protocol plug in does not support selectable Transports close void close Closes the Acceptor accept or listen may not be called after close has been called Raises COMM_FAILURE In case of an error shutdown void shutdown Module OCI Shutdown the Acceptor After shutdown the socket will not listen to further connection requests Raises COMM_FAILURE In case of an error listen void listen Sets the acceptor up to listen for incoming connections Until this method is called on the acceptor new connection requests should result in a connection request failure Raises COMM_FATLURE In case of an error accept Transport accept in boolean block Used by CORBA servers to accept client connection requests It returns a Transport object which can be used for sending and receiving octet streams to and from the client Parameters block If set to TRUE the oper
48. John Wiley amp Sons Inc PUB 46 1 National Bureau of Standards FIPS PUB 46 1 Data Encryption Standard January 1988 573 574 13 14 15 16 17 18 CCITT Recommendation X 208 Specification of Abstract Syntax Notation One ASN 1 1988 RFC 1421 Linn J Privacy Enhancement for Internet Electronic Mail Part Message Encryption and Authentication Procedures RFC 1421 February 1993 RFC 1422 Kent S Privacy Enhancement for Internet Electronic Mail Part Il Certificate Based Key Management RFC 1422 February 1993 RFC 1423 Balenson D Privacy Enhancement for Internet Electronic Mail Part IIl Algorithms Modes and Identifiers RFC 1423 February 1993 RFC 1424 Kaliski B Privacy Enhancement for Internet Electronic Mail Part IV Key Certification and Related Services RFC 1424 February 1993 PKCS 8 Private Key Information Syntax Standard An RSA Laboratories Technical Note Version 1 2 Revised November 1 1993 Part Ill JThreads In this part This part contains the following chapters Introduction to JThreads C page 577 Hello World page 581 Working With Threads page 587 Memory Management page 611 Class Reference page 617 References page 87 CHAPTER 1 Introduction to JThreads C This chapter gives a short overview of JThreads In this chapter This chapter contains the following section Overview page 578
49. MinorReadSt ringNullChar Encountered null char in string CORBA System Exceptions MinorReadSt ringNoTerminator Terminating null char missing in string MinorReadWSt ringOverflow Overflow while reading wstring MinorReadWSt ringZeroLength Encountered zero length wstring MinorReadWSt ringNullWChar Encountered null char in wstring MinorReadWStringNoTerminator Terminating null char missing in wstring MinorReadFixedOverflow Overflow while reading fixed MinorReadFixedInvalid Invalid encoding for fixed value MinorReadBooleanArrayOverflow Overflow while reading boolean array MinorReadCharArrayOverflow Overflow while reading char array MinorReadWCharArrayOverflow Overflow while reading wchar array MinorReadOctetArrayOverflow Overflow while reading octet array MinorReadShortArrayOverflow Overflow while reading short array MinorReadUShortArrayOverflow Overflow while reading ushort array MinorReadLongArrayOverflow Overflow while reading long array MinorReadULongArrayOverflow Overflow while reading ulong array LongLongArrayOverflow MinorRead Overflow while reading longlong array MinorReadULongLongArrayOverflow Overflow while reading ulonglong array MinorRead FloatArrayOverflow Overflow while reading float array MinorRead DoubleArrayOverflow Overflow while readi
50. Set up the parameters that will be passed to the poller function Check the poller for the status of the deferred call This function will update any parameters with data that was expected from the deferred call Note that a timeout value of 1 will cause the client code to wait forever 341 CHAPTER 17 Asynchronous Method Invocation Java 342 For complete code please see the EchoClient java file in the ob demo AMI echo_poll_router directory of the Orbacus for Java distribution 5 org omg CORBA Object obj orb string_to_object relfile Echo ref echo Echo ec echo EchoHelper narrow obj echo AMI_EchoPoller poller ec sendp_echo_message Hello org omg CORBA StringHolder reply new org omg CORBA StringHolder poller echo_message 1 reply Create the Echo object based on the IOR in the Echo ref file Make the deferred call which returns an amt_EchoPoller object based on the generated class Note that the user does not have to override this class as must be done for the Reply Handler implementation Set up the parameters that will be passed to the poller function Check the poller for the status of the deferred call This function will update any parameters with data that was expected from the deferred call Note that a timeout value of 1 will cause the client code to wait forever Configuring Clients and Servers Configuring Clients and Servers Configuring router lists Clien
51. Supplier was disconnected from event channel gi 8 g CEY 20 Fadl Thread sleep 1000 a2 29 catch InterruptedException ex 24 25 260 4 8 The current date and time is inserted into the Any 253 CHAPTER 12 Orbacus Events 254 10 17 19 25 4 8 13 19 The event data in this example date and time are pushed to the event channel From the push supplier s view the event channel is just a consumer implementing the PushConsumer interface After sleeping for one second the steps above are repeated The example s pull supplier works similarly to the push supplier except that the event channel explicitly polls the supplier for new events This is done by either pull of try_pull The pull supplier doesn t see anything from the event channel but an object implementing the Pullconsumer interface The following example shows the basic layout of a pull supplier Lo Vif were 2 public Any pull 3 f 4 java util Date date new java util Date 5 String s PullSupplier says date toString 6 i Any any orb create_any 8 any insert_string s g return any public Any try_pull BooleanHolder has_event has_event value true return pull SO OD dy GE oe Cs I he Date and time are inserted into the any In this example new event data can be provided at any time so try_pull always sets has_event to true in order to signal that an event is available
52. connection It is used so that a member s load can be adjusted without having to wait for the next load update It is also used to estimate the effect of load re balancing The default value for this property is O This alleviates the member selection problem 1 on page 269 critical load Type CORBA ULong A member with a load greater than crit ical load is re balanced if there exists a member with a load that is less than critical load minus load per client This property has a default value of O which disables load re balancing This alleviates the member selection problem 3 on page 270 278 reject load dampening multiplier min dispersion tolerance load per client reject load Usage Type CORBA ULong A connection request will be rejected if all members have a load greater than the reject load property This property has a default value of O which means that connections will never be rejected Type CORBA Float A dampening technique is used to smooth out spikes that may occur in the reported loads of members The load of a member is calculated using the dampening multiplier property as follows load mult old_load 1 mult new_load where mult is the value of the dampening multiplier property This property must be greater than or equal to O and less than 1 The default value of O which disables dampening This alleviates member selection problems 1 on page 269 and 2 on page 270
53. each name consists of one or more components like a file is fully specified by its path in a filesystem Each name component consists of two strings id and kind which could be likened to a file s name and its extension Generally the filesystem analogy works very well when describing the Naming Service structures 197 CHAPTER 9 Orbacus Names 198 A new Naming Service entry i e a binding is created with the following operations if DI void bind in Name n in Object obj raises NotFound CannotProceed InvalidName AlreadyBound void bind_context in Name n in NamingContext nc raises NotFound CannotProceed InvalidName AlreadyBound NamingContext new_context NamingContext bind_new_context in Name n raises NotFound CannotProceed InvalidName AlreadyBound bind registers a new object with the Naming Service whereas a new context is registered with bind_context For each operation an object reference and a Name are expected as parameters New naming context objects are created with new_context Of bind_new_context bind_context and bind_new_context throw an AlreadyBound exception if the name is already in use in the target context To create a new binding without being concerned if the specified binding already exists use the following operations fi UDI void rebind in Name n in Object obj raises NotFound CannotProceed InvalidName void rebind_context in Name n in NamingContext nc
54. file list FILE Write a list of all generated files to file FILE dll import DEF Put DEF in front of every symbol that needs an explicit DLL import statement 37 CHAPTER 3 Generating Code with Orbacus with interceptor args Generate code with support for arguments result and exception list values for interceptors no local copy To ensure strict compliance with CORBA s location transparency semantics the default behavior of the translator is to generate code that copies valuetype argument and result values for collocated invocations Specify this option to disable strict compliance and generate more efficient code case sensitive The semantics of OMG IDL forbid identifiers in the same scope to differ only in case This option relaxes these semantics but is only provided for backward compatibility with non compliant IDL with async Generate code with support for Asynchronous Method Invocation AMI 38 Translating IDL to Java Translating IDL to Java Synopsis Description Options for jidl jidl options idl files Translates IDL files into Java files For every construct in the IDL file that maps to a Java class or interface a separate class file is generated Directories are automatically created for those IDL constructs that map to a Java package e g a module jidal can also add comments from the IDL file starting with to the generated Java files This allows you to use
55. gt the_POAManager woMAAtnauw amp WDN FE CORBA Any any CORBA PolicyList policies 1 policies length 1 any lt lt CORBA Any from_boolean false policies 0 orb gt create_policy OBPortableServer INTERCEPTOR_CALL_POLICY_ID any PortableServer POA_var myPOA OO 7 oy Cn a 6 No Ee rootPOA gt create_POA MyPOA manager policies Obtain references to the root POA and its POA manager Create a policy set consisting of the OBPortableServer InterceptorCallPolicy policy The OBPortableServer InterceptorCallPolicy policy is given a value of false so that server side interceptors will be disabled Create a new POA using the policy set created above 319 CHAPTER 16 Using Policies And now the same example in Java 1 Java 2 org omg CORBA Object obj 3 orb resolve_initial_references RootPOA 4 org omg PortableServer POA rootPOA 5 org omg PortableServer POAHelper narrow obj 6 org omg PortableServer POAManager manager vi rootPOA the_POAManager 8 9 org omg CORBA Any any orb create_any 0 org omg CORBA Policy policies new org omg CORBA Policy 1 1 any insert_boolean false 2 policies 0 orb create_policy 3 com ooc OBPortableServer INTERCEPTOR_CALL_POLICY_ID value any 4 5 org omg PortableServer POA myPOA 6 rootPOA create_POA MyPOA manager policies 1 16 This is equivalent to the C version 320 Programming Examples
56. next five icons correspond to the New Context New Binding Cut Copy Paste and Delete items as described in The Edit Menu on page 216 The Simple List and Details items from the View menu are the next two icons in the toolbar They determine whether the binding table displays only the ID and Kind fields or if Orbacus Names is available also the date and time the binding was last modified The last item in the menubar corresponds to the Refresh operation from the View menu The Popup Menu The Popup Menu When selecting an item in the binding table or a tree node with the right mouse button a popup menu with a choice of operations is displayed as shown in Figure 8 Open Context Cut Copy Paste Change ID Change Kind Change IOR Delete Unlink Save IOR to File Figure 8 A popup menu offers important operations This is another convenient alternative for executing frequently used operations 223 CHAPTER 10 Orbacus Names Console 224 CHAPTER 11 Orbacus Properties The CORBA Property Service permits you to annotate an object with extra attributes called properties that were not defined by the object s IDL interface Properties can represent any value because they make use of the CORBA any data type Orbacus Properties is compliant with 10 This chapter does not provide a complete description of the service It only provides an overview suitable to get you started For more information
57. no skeletons Don t generate skeleton classes no type codes Don t generate type codes and insertion and extraction functions for the Any type Use of this option will cause the translator to generate more compact code no virtual inheritance Don t use virtual C inheritance If you use this option you cannot use multiple interface inheritance in your IDL code and you also cannot use multiple C inheritance to implement your servant classes s tie Generate tie classes for delegate based interface implementations Tie classes depend on the corresponding skeleton classes i e you must not use no skeletons in combination with tie fwd Generate separate header files for forward declarations impl Generate example servant implementation classes An input file Foo idl will generate the files Foo_impl h and Foo_impl cpp These files will not be overwritten therefore you must first remove the existing files before new ones can be generated You must not use no skeletons in combination with this option impl all Similar to impi but function signatures are generated for all inherited operations and attributes You must not use no skeletons in combination with this option c suffix SUFFIX Use surrix as the suffix for source files The default value is cpp h suffix SUFFIX Use surFrx as the suffix for header files The default value is h 36 Translating IDL to C stub suffix SUFFIX Us
58. org omg CORBA BAD_PARAM ex 24 2 This object does not implement a NamingContext 26 Try to resolve the name of a particular service If a service of the specified name is not known to the ORB an InvalidName exception is thrown The service type was known Now the object reference has to be narrowed to the particular service type If this fails the service is not available 149 CHAPTER 6 Locating Objects And here s the C equivalent to the Java version above ho ff Car 2 CORBA Object_var obj 3 CosNaming NamingContext_var ctx 4 a EPER 6 F obj orb gt resolve_initial_references NameService 8 9 catch CORBA ORB InvalidName 0 il An error occured service is not available 2 3 4 if CORBA is_nil ob 5 6 The object reference is invalid 7 8 9 ctx CosNaming NamingContext _narrow ob 4 20min CORBA ESENCE valet 22 This object does not implement NamingContext 150 Initial Services Configuring the Initial Services When an application uses initial services that are not locality constrained the application must register the object references for these objects with the ORB Orbacus supports the standard orBInitRef and oRBDefault InitRef command line options for registering initial service object references ORBInitRef name URL ORBDefaultInitRef URL For example starting an application as shown below will enable the client to resolve the NameSer
59. please refer to the specification In this chapter This chapter contains the following sections Usage page 226 Connecting to the Service page 227 Using the Property Service with the IMR page 228 Creating Properties page 229 Querying for Properties page 230 Deleting Properties page 232 Programming Example page 233 1 Note that the Property Service has nothing to do with the properties used for configuration purposes Configuration properties are described in ORB Properties on page 58 225 CHAPTER 11 Orbacus Properties Usage Orbacus includes functionally equivalent implementations of the Property Service in C and Java C propserv h help v version i ior Java com ooc CosPropertyService Server h help v version i ior Options h Display the command line options supported by the help server v Display the version of the server version i Prints the stringified IOR of the server to standard ior output Configuration Properties In addition to the standard configuration properties described in Chapter 4 Orbacus Properties also supports the following properties ooc property endpoint ENDPOINT Specifies the endpoint configuration for the service Note that this property is only used if the coc orb oa endpoint property is not set CLASSPATH Requirements Orbacus Properties for Java requires the clas
60. since it is impossible for two threads to enter the addchar method simultaneously 591 CHAPTER 3 Working With Threads Thread Safe Version in C Thread safe C example JThreads C supports monitors with two classes JTCMonitor and JTCSynchronized The JTCcSynchronized Class uses the initialization is acquisition concept to acquire the monitor s lock The associated monitor s lock is acquired on construction and released on destruction Here is the thread safe C version of the example 1 class CharacterBuffer public JTCMonitor a i 3 char data_ 4 int kenty 5 int max 6 yo peubiac 8 9 CharacterBuffer 0 data_ 0 len_ 0 max_ 0 1 2 3 4 CharacterBuffer 5 6 delete data_ 7 8 g woid addChar char ma 20 Za JTCSynchronized synchronized this 22 if len_ gt max_ 28 24 char newData new char len_ 128 25 memcpy newData data_ len_ 26 delete data_ 27 data_ newData 28 max_ 128 29 30 data_ len_ c Sil Be 592 21 35 33 34 38 36 ST 38 Synchronization void writeBuffer JTCSynchronized synchronized this c out writel data_ len lt lt flush len_ 0 39 py The class CharacterBuffer is now derived from JTCMonitor In Java this is not necessary since all Java objects inherit implicitly from java lang Object which provides the monitor functionality The addChar and writeBuffer methods a
61. subgroups Returns true if the thread group has been destroyed false otherwise destroy void destroy Destroys this thread group and all of its subgroups The thread group must not contain any active threads Throws JTCI1legalThreadStateExcept ion If the thread group has active threads or has already been destroyed setMaxPriority void setMaxPriority int pri Sets the maximum priority that threads in the thread group and its subgroups may have Threads in the thread group that have higher priority are not affected That is their priorities are not lowered parentOf bool parentOf JTCThreadGroupHandle g Returns true if the thread group is the parent of thread group g Returns true if this thread is a parent of g false otherwise activeCount int activeCount const Returns the number of active threads in this thread group and all of its subgroups Returns The number of active threads activeGroupCount int activeGroupCount const Returns the number of active thread groups in this thread group Returns The number of active thread groups enumerate int enumerate JTCThreadHandle list int len bool recurse true const Copies pointers to each active thread in this thread group to the array list activeCount can be used to get an estimate of how big the array should be If more than len active threads are present the remaining threads are silently ignored The reason that the developer canno
62. useful to enable connection tracing diagnostics With diagnostics enabled the ORB will display its endpoint information allowing you to confirm that the application s endpoints are configured correctly Diagnostics can be enabled using the oRBtrace_connect ions command line option or using the equivalent property coc orb trace connections See Configuring the ORB and Object Adapter on page 57 for more information on configuration properties For a complete description of the available transport plug ins and their options see Chapter 19 Using POA Managers Command line Options and Endpoints Transport plug ins may support command line options and it is important to understand the effects of using those options They can be summarized as follows e Using a plug in s command line options will always add a new endpoint configuration i e command line options do not override an existing endpoint configuration e Command line options only configure endpoints for the Root POA Manager The first item is the most significant Let s consider some examples which will serve to explain this issue First assume that there is no endpoint configuration property for the Root POA Manager and that we use the following command line options IIOPhost host abc com IIOPport 1234 The IIOP plug in will convert these command line options into the following configuration property ooc orb oa endpoint iiop host host abc com
63. wowoMAtawn Fb WN FP oss ShutdownObject_impl1 CORBA ORB_ptr orb orb_ CORBA ORB _duplicate orb virtual void deactivate throw CORBA SystemException orb_ gt shutdown false osne G e Se 2 a A servant class for shutdownObject is defined For more information on how to implement servant classes see Chapter 5 An ORB is needed to call shutdown The constructor initializes the ORB member deactivate CallS shutdown on the ORB Note that shutdown is called with the argument false to avoid a deadlock A false argument instructs shutdown to terminate request processing without waiting for executing operations to complete A true argument instructs shutdown to return only once all operations have completed If shutdown were called with a true argument in this example it would deadlock That is because shutdown true would be invoked from within an operation and therefore could not ever return The client can use the deactivate call as shown below Hi Cat ShutdownObject_var shutdownObj Get a reference somehow shutdownObj gt deactivate In this chapter CHAPTER 5 CORBA Objects This chapter describes how to create and use CORBA servant objects This chapter contains the following sections Overview page 92 Implementing Servants page 94 Creating Servants page 103 Activating Servants page 107 Deactivating Servants page 112 Factory Objects page 114
64. 0 Specifies the load update frequency for the LoadUpdater object in milliseconds The default is 1000 1 second A value of O means that no load updates will be sent to the service 287 CHAPTER 14 Orbacus Balancer Programming Example Implementing a Load Balanced Server In this section 288 In this section we will show how to modify the C version of the Hello World server see Chapter 2 for load balancing First we will present the modifications necessary for non adaptive load balancing then the necessary modifications for adaptive load balancing will be presented This is followed by a description of the steps necessary to configure the service for the load balanced Hello World servers This section covers the following topics Non adaptive Load Balancing page 289 Adaptive Load Balancing page 294 Running the Load Balanced Servers page 298 Programming Example Non adaptive Load Balancing 15 The Hello World server presented in Chapter uses the Root POA to activate its Hello servant However a member POA must have a member policy the uszR_1D ID assignment policy value and the PERSISTENT lifespan policy value Hence the Hello World server must be modified so that the Hello servant is activated using a POA with the above policies Furthermore the Hello servant is no longer activated under the Root POA so it becomes necessary for it to override the _default_poa met
65. 6 Locating Objects Obtaining Object References Using CORBA an object can obtain a reference to another object in a multitude of ways One of the most common ways is by receiving an object reference as the result of an operation as demonstrated by the following example iL ff mips 2 interface A 3 4 4 33 5 6 interface B vt 8 A getA eS We 2 4 An interface a is defined 6 9 An interface B is defined with an operation returning an object reference to an A 126 2 5 7 28 14 17 19 22 24 27 Obtaining Object References On the server side a and sB can be implemented in C as follows l ff Cape 2 class A_impl public POA_A 3 public PortableServer RefCountServantBase A g Se e 6 T elesse B iol paolie EOA y 8 public PortableServer RefCountServantBase oF 0 iN aio a dL 2 public 2 4 B_imp1 5 6 a_ new A_impl 7 8 9 B_impl 20 ZL a_ gt _remove_ref 22 23 24 virtual A ptr getA throw CORBA SystemException 25 26 rectam en eels 27 Ze ie The servant class A_imp1 is defined which inherits from the skeleton class Poa_A and the class RefCount ServantBase which provides a reference counting implementation The servant class B_imp1 inherits from the skeleton class poa_sB and the reference counting class RefCount ServantBase An instance of the servant class A_imp1 is created in the constructor for B_impl In the destructor for B_imp1 the reference cou
66. Acceptor An interface for an Acceptor object which is used by CORBA servers to accept chent connection requests Figure 1 Documentation generated with the IDL to HTML translator The formatting syntax supported by nid and ria1 is similar to that used by javadoc The following keywords are recognized 47 CHAPTER 3 Generating Code with Orbacus 48 author author Denotes the author of the interface exception exception name description Adds an exception description to the exception list of an operation member member name description Adds a member description to the member list of a struct union enum or exception type param parameter name description Adds a parameter description to the parameter list of an operation return description Adds descriptive text for the return value of an operation see reference Adds a See also note since since text Comment related to the availability of new features version version The interface s version number Like javadoc hidl and ridi use the first sentence in the documentation comment as the summary sentence This sentence ends at the first period that is followed by a blank tab or line terminator or at the first e ridl understands most basic HTML tags and produces an equivalent format in the generated RTF files The following HTML tags are supported lt B gt lt BR gt lt CODE gt lt DD gt lt DL gt lt DT gt lt EM gt lt HR gt lt I gt lt LI gt
67. Console and proprietary Orbacus Notify features 673 CHAPTER 1 Introduction 674 In this chapter CHAPTER 2 Configuration and Startup This chapter describes how to start Orbacus Notify and lists various configuration properties This chapter contains the following sections Orbacus Notify page 676 Orbacus Notify Console page 683 Startup Example page 684 675 CHAPTER 2 Configuration and Startup Orbacus Notify Synopsis notserv v version h help i ior d dbdir Options v version Reports the Orbacus Notify version number h help Displays notserv command information i ior Prints IOR on standard output d dbdir Specifies the path to the database directory e g dbdir lt database directory gt Windows NT Native Service Orbacus Notify is also available as a native Windows NT service ntnotservice h help i install u uninstall d debug Options h help Displays command line options supported by the server i install Install the service The service must be started manually s start install Install the service The service will be started automatically u uninstall Uninstall the service d debug Run the service in debug mode In order to use Orbacus Notify as a native Windows NT service it is first necessary to add the NotificationService initial reference to the HKEY_LOCAL_MACHINE NT registry key see
68. Exception N N h Se status EXIT_FAILURE N N w N o 290 15 Programming Example 24 bf CORE ANH pu cmeniniela nck 25 26 try Pail 28 orb gt destroy 29 30 catch const CORBA Exception amp Sil 32 status EXIT_FAILURE 33 34 25 36 return status Si jf Include the header file that declares the Orbacus Balancer initialization function This header file also includes the header files oB Balancer h and OB BalancerPolicyTypes h which contain the definitions necessary for non adaptive load balancing Invoke LoadBalancing LB_init This function initializes the server for load balancing and must be called before initializing the ORB 291 CHAPTER 14 Orbacus Balancer The remainder of the main function is similar to that of Chapter Now we write the run function Lo ff Ci Zenit sum CORBA r ORBIpPE N OLD Anea roe eN AIEN Ss 4 4 if argc 2 5 return EXIT_FAILURE 6 const char memberId argv 1 i 8 g CORBA Object_var poaObj orb gt resolve_initial_references RootPOA 0 PortableServer POA_var rootPoa iL PortableServer POA _narrow poa0Ob 2 3 PortableServer POAManager_var manager 4 rootPoa gt the_POAManager 5 6 LoadBalancing MemberPolicyValue_var value vi new LoadBalancing MemberPolicyValue 8 value gt group_id CORBA string_dup Hello J value gt member_id CO
69. Figure 30 B Any Pull Supplier 0 Properties Mapping Filters Lifetime Mapping Filter lt None gt v Priority Mapping Filter lt None gt v Figure 30 Supplier Proxy Mapping Filters Subscription Offer Types For supplier proxies subscription event types are managed in the Subscription Types tab of the Proxy Properties dialog Figure 31 Similarly for consumer proxies offered event types are managed in the 767 CHAPTER 5 Orbacus Notify Console Offered Types tab of the Proxy Properties dialog Note that only one of the Subscription Types or Offered Types tab is available depending on whether a consumer or supplier proxy is selected from the Service Structure Tree B Any Pull Supplier 0 Properties Add Event Types Domain Name Type Name am Figure 31 Proxy Subscription Offer Types Destroying a Proxy Like channels and admins a selected proxy is destroyed by choosing the Edit Destroy menu operation A confirmation is displayed before the proxy is removed Any filters created from the selected proxy are not destroyed Instead the destroyed proxy is removed from the filter s subscriber list 768 Managing Filters Managing Filters Creating a New Filter Filter Properties Destroying a Filter Filters can be created from any of the following objects e admin proxy e FilterFactory Once an object matching one of the abov
70. IPOATie java the tie class that inherits from rpoa and delegates all requests to an instance of toperations 100 Implementing Servants To implement our servant class using delegation we need to write a class that implements the toperations interface I oy Om HW NM H PrPrRPR oO WNRO RR U e The servant class I_imp1_tie is defined to implement the roperations interface I_impl_tie must implement all of 1 s operations including inherited operations Java public class I_impl_tie implements IOperations public void op_a public void op_b public void op_i Figure 4 illustrates the relationship between the classes generated by the IDL to Java translator and the servant implementation classes IPOA _impl IPOATie gt l delegates to lOperations l_impl_tie Figure 4 Class Hierarchy for Inheritance and Delegation Implementation in Java 101 CHAPTER 5 CORBA Objects 102 2 7 9 14 16 21 As noted earlier Java s lack of multiple inheritance makes it impossible to inherit an implementation from another servant class Using tie classes however does allow implementation inheritance but only in certain situations For example let s implement each of our sample interfaces using delegation 1 Java 2 public class A_impl implements AOperations S at 4 public void op_a 5 6
71. Implementation Repository 176 12 16 Programming Example In this section we will show how to modify the C version of the Hello World server see Chapter 2 to use a persistent object reference This will allow the server to use the IMR for indirect binding Modifications to the Java version of the server are similar The code for both the C and Java persistent Hello World servers may be found in the demo hello_imr directories of the Orbacus for C and Java distributions The Hello World server presented in Chapter uses the Root POA to activate its Hello servant Since the Root POA uses the TRANSTENT life span policy the object reference it creates will not be persistent Hence the Hello World server must be modified so that the Hello servant is activated using a child POA with the pERsIsTEnt life span policy The new child POA will also use the USER_1D object identification policy so that the mkre utility may be used Further the Hello servant is no longer activated under the Root POA so it becomes necessary for it to override the _default_POA method The modified servant s class declaration is shown below lo ff Case 2 3 include lt Hello_skel h gt 4 5 class Hello impl public POA Hello 6 public PortableServer RefCountServantBase o 8 PortableServer POA_var poa_ 9 0 public 1i 2 Hello_impl PortableServer POA ptr 3 4 virtual void say_hello throw CORBA SystemException 5 6
72. Interface CosNotifyComm Interface CosNotifyComm NotifyPublish NotifySubscribe PushConsumer PullConsumer PullSupplier PushSupplier StructuredPushConsumer StructuredPullConsumer StructuredPullSupplier StructuredPushSupplier SequencePushConsumer SequencePullConsumer CONTENTS 803 804 805 806 810 812 814 815 816 817 818 819 820 821 822 823 824 825 826 829 831 834 837 838 839 840 841 842 843 844 845 846 847 848 849 850 xvii CONTENTS Interface CosNotifyComm SequencePullSupplier Interface CosNotifyComm SequencePushSupplier Appendix F CosNotifyFilter Reference Module CosNotifyFilter Interface CosNotifyFilter Filter Interface CosNotifyFilter MappingFilter Interface CosNotifyFilter FilterFactory Interface CosNotifyFilter FilterAdmin Appendix G OBNotify Reference Module OBNotify Notify Bibliography Index xviii 851 852 853 854 858 862 866 867 869 870 873 875 List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Documentation generated with the IDL to HTML translator Servants Proxies and the Object Adapter Class Hierarchy for Delegation Implementation in C Class Hierarchy for Inheritance and Delegation Implementation in Java Entering an IOR The Ping Window A closer look at the toolbar A popup menu offers important operations Reactive Server Figure 10 Reactive Client Serv
73. Ki FSSL ContextID id fsslManager gt create_context chain FSSL OctetSeq_var FSSL load_file client key FSSL PassPhrase_var FSSL string_to_PassPhrase blahblah FSSL TrustDecider_var new TrustDecider_impl caCert FSSL CipherSeq_var FSSL get_RSA_ciphers Java Create the client context int id fsslManager create_context chain com ooc FSSL FSSL load_file client key com ooc FSSL FSSL string_to_PassPhrase blahblah new ClientTrustDecider caCert com ooc FSSL FSSL get_RSA_ciphers After that the context should be set as the default context for all object references Lil Cts Ey Set this as the default context for all object references fi fsslManager gt set_context id Java Set this as the default context for all object references hi fsslManager set_context id 545 CHAPTER 2 Extending the Hello World Application After this has been done the remainder of run will be the same as the original demo ie Get hello object CORBA Object_var obj orb gt string_to_object relfile Hello ref if CORBA is_nil ob 4 cerr lt lt argv 0 lt lt cannot read IOR from Hello ref lt lt endl return EXIT_FAILURE Hello_var hello Hello _narrow obj assert CORBA is_nil hello Main loop Hi cout lt lt Enter bh for hello on VY for exes ehar
74. MinorInvalidAbstractInterfaceInheritance Invalid abstract interface inheritance MinorInvalidValueInheritance Invalid valuetype inheritance MinorInvalidServiceContextId Invalid service context ID MinorObject IsNull Object parameter to object_to_ior is null MinorInvalidComponentId Invalid component ID MinorInvalidProfileId Invalid profile ID MinorDuplicatePolicyType Duplicate policy types MinorDuplicateDeclarator Duplicate declarator MinorInvalidValueModifier Invalid valuetype modifier MinorDuplicateValueInit Duplicate valuetype initializer MinorAbstractValueInit Abstract valuetype cannot have initializer 405 CHAPTER 20 Exceptions and Error Messages 406 MinorDuplicateBaseType Base type appears more than once MinorSingleThreadedOnly ORB does not support multiple threads MinorNameRedefinitionInImmediateScope Invalid name redefinition in an immediate scope MinorInvalidValueBoxType Invalid type for valuebox MinorInvalidLocalInterfaceInheritance Invalid local interface inheritance MinorConstantTypeMismatch Constant type doesn t match definition CORBA System Exceptions NO MEMORY Minor Exception Code MinorAllocationFailure Memory allocation failure 407 CHAPTER 20 Exceptions and Error Messages IMP_LIMIT Minor Exception Code
75. ORB and Object Adapter Value timeout gt 1 Sets the oB ConnectTimeoutPolicy at the ORB level See Appendix B for more information on this policy The default value is 1 Value true false Sets the oB ConnectionReusePolicy at the ORB level See Appendix B for more information on this policy The default value is true Value true false Sets the oB InterceptorPolicy at the ORB level See Appendix B for more information on this policy The default value is true Value true false Sets the oB LocateRequestPolicy at the ORB level See Appendix B for more information on this policy The default value is false Value strict relaxed Sets the op LocationTransparencyPolicy at the ORB level See Appendix B for more information on this policy The default value is relaxed Value string Sets the oB ProtocolPolicy at the ORB level See Appendix B for more information on this policy Value transparent no_rebind no_reconnect Sets the Messaging RebindPolicy at the ORB level The default value is transparent Value timeout gt 1 Sets the oB RequestTimeoutPolicy at the ORB level See Appendix B for more information on this policy The default value is 1 61 CHAPTER 4 ORB and Object Adapter Initialization ooc orb policy retry ooc orb policy retry interval ooc orb policy retry max ooc orb policy retry remote 0oc orb policy sync_scope ooc orb policy t
76. Oe mem So Oo eS ON Re SS Any anyLong orb create_any Any AnyString orb create_any Any anyShort orb create_any anyLong insert_long 123451 anyString insert_string Foo anyShort insert_short short 0 Ery set define_property LongProperty anyLong set define_property StringProperty anyString set define_property ShortProperty anyShort catch ReadOnlyProperty ex An error occurred catch ConflictingProperty ex An error occurred catch UnsupportedProperty ex An error occurred catch UnsupportedTypeCode ex An error occurred catch InvalidPropertyName ex An error occurred PropertiesHolder ph new PropertiesHolder PropertiesIteratorHolder ih new PropertiesIteratorHolder set get_all_properties 0 ph ih PropertyHolder h new PropertyHolder while ih value next_one h The next property is now stored in h value ih value destroy Get a Property Service reference and check for errors 29 31 36 38 63 65 73 75 Programming Example The PropertySetDefFactory object is used to create a PropertySetDef instance Note that PropertySetDef iS a subclass of PropertySet Each property consists of a name and a value in the form of a CORBA Any Three properties are defined The first has the name LongProperty and stores a long value The second one is called StringProperty and stores a stri
77. Windows NT service it is first necessary to add the ooc naming endpoint configuration property to the HKEY_LOCAL_MACHINE NT registry key see Using the Windows NT Registry on page 71 for more details If the service is to be persistent the path to the database file must be stored in the following property 1 HKEY_LOCAL_MACHINE Software 00C Properties ooc naming database Next the service should be installed with ntnameservice i This adds the Orbacus Naming Service entry to the services dialog in the Control Panel To start the naming service select the Orbacus Naming Service entry and press start If the service is to be started automatically when the machine is booted select the orbacus Naming Service entry 1 Please note that services do not have access to network drives so the path to the database must be on a local hard drive 191 CHAPTER 9 Orbacus Names 192 then click startup Next select startup Type Automatic and press oK Alternatively the service could have been installed using the s option which configures the service for automatic start up ntnameservice s If you want to remove the service run ntnameservice u Note If the executable for the Naming Service is moved it must be uninstalled and re installed Any trace information provided by the service will be placed in the Windows NT Event Viewer with the title NamingService To enable tracing information add the desired trace configuration
78. a null pointer Some CORBA _ var types have built in conversion operators to a C reference type i e some _var types for type T have a conversion operator to Ts This message appears if an application uses this conversion operator on an uninitialized _var type Null pointer was passed as string parameter or return value According to the IDL to C mapping specification no null pointers may be passed as string parameters or return values This message appears if an application tries to do sO Null value passed as parameter This message indicates that an application attempted to pass a null value across an IDL interface Non Compliant Application Asserts Message Description Self assignment caused a dangling pointer This message appears if the content of a _var type is assigned to itself For example the following code will lead to this error message Somehow get a pointer to a variable struct AVariableStruct_var var AVariableStruct ptr var Bm WHY var ptr This will result in a dangling pointer because var will free its own content on assignment Replacement of Any content by its own value caused a dangling pointer This message appears if there is an attempt to replace the content of an Any by its own value For example char s CORBA string_dup Hello world CORBA Any any any lt lt s WN rR 4 any lt lt s Inserting s into any twice wi
79. a supplier is already connected the AlreadyConnected exception is raised Parameters pull_supplier A reference to the supplier object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pulling events from the connected supplier If the connection is already suspended the Connect ionAlreadyInactive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target to resume pulling events from the connected supplier If the connection is not suspended the Connect ionAlreadyAct ive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised Interface Module CosNotifyChannelAdmin CosNotifyChannelAdmin StructuredProxyPullConsumer Operations interface StructuredProxyPullConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm StructuredPullConsumer The structuredProxyPullConsumer interface manages connections from suppliers who wish to have structured events pulled from them by the channel connect_structured_pull_supplier void connect_structured_pull_supplier in CosNotifyComm StructuredPullSupplier pull_supplier raises CosEventChannelAdmi
80. argc char argv Initializes the JThreads C library and interprets arguments starting with JTC Throws JTCSystemCallException Indicates a failed system call JTCInitializeError Indicates a that an invalid option or option argument was specified Member Functions waitTermination void waitTermination Waits for all threads to terminate initialized static bool initialized Determines if the JThreads C library has been initialized Returns true if JThreads C has been initialized and false otherwise 619 CHAPTER A Class Reference JTCAdoptCurrentThread Overview Constructors 620 When integrating with third party libraries it is often necessary to call JThreads C methods from a thread that was not created using JThreads C In this situation the thread must create an instance of JTCAdopt Current Thread prior to using any other JThreads C classes Failure to instantiate JTCAdoptCurrent Thread Will result in undefined behavior JTCAdoptCurrentThread JTCAdopt Current Thread Informs the JThreads C library about the existence of this thread Throws JTCSystemCallException Indicates a failed system call JTCThread Overview Constructors This class is used to create a new thread of execution The thread functionality can be added by either deriving a class from gTcThread and overriding the run method or by passing an object of a class derived from JTCRunnable to the
81. based implementation Implementing Servants For our interface r it is therefore necessary to implement all operations in a single servant class I_imp1 regardless of whether those operations are defined in 1 or in an interface from which 1 is derived 1 Java 2 public class I_impl extends IPOA 3 4 public void op_a 5 6 a 8 Publick vone GSA 9 10 w IZ public void op_i 13 14 AS ji 2 15 The servant class 1_imp1 is defined which implements op_i as well as the inherited operations op_a and op_b 97 CHAPTER 5 CORBA Objects Implementing Servants using Delegation Sometimes it is not desirable to use an inheritance based approach for implementing an interface This is especially true if the use of inheritance would result in overly complex inheritance hierarchies for example because of use of an existing class library that requires extensive use of inheritance Therefore another alternative is available for implementing servants which does not use inheritance A special class known as a tie class can be used to delegate the implementation of an interface to another class 1 Delegation using C The Orbacus IDL to C translator can automatically generate a tie class for an interface in the form of a template class A tie template class is derived from the corresponding skeleton class and has the same name as the skeleton with the suffix _tie appended For the interface 1 from the C example abo
82. c do cout a WS We Clin SS es if c h hello gt say_hello while cin good amp amp e x return EXIT_SUCCESS 546 The Trust Decider Complete Example Java if Get hello object He CORBA Object_var obj orb gt string_to_object relfile Hello ref if CORBA is_nil ob 4 cerr lt lt argv 0 lt lt cannot read IOR from Hello ref lt lt endl return EXIT_FAILURE Hello_var hello Hello _narrow obj assert CORBA is_nil hello ih Main loop Vi covit lt Enter nh for hello of x for exits Nota charic do Cowie lt lt We le Cilia SS Op if c h hello gt say_hello while cin good amp amp c x return EXIT_SUCCESS The TrustDecider implementation for the demo will be extremely simple It will trust only those certificates directly signed by the provided CA To implement the TrustDecider the class FSSL_TrustDecider must be implemented In addition on the client side only the server will be trusted il Ce class TrustDecider_impl public FSSL TrustDecider 547 CHAPTER 2 Extending the Hello World Application 548 Java class ClientTrustDecider extends com ooc CORBA LocalObject implements com ooc FSSL TrustDecider Next the private members and constructor i Ore FSSL Certificate_var ca public TrustDecider_impl FSSL Certificate_var ca ca_ FSSL Certificate _duplic
83. created with the Constraint Creation Wizard 773 CHAPTER 5 Orbacus Notify Console Expression Properties The constraint expression is accessed with the Expression Properties tab shown in Figure 34 This dialog supports in place editing of the constraint expression Constraints which do not conform to the constraint grammar cannot be entered Mapping Constraint 0 Properties x Expression Event Types Result to Set Expression EERS blah foo Figure 34 Constraint Expression Properties 774 Managing Mapping Filter Constraint Value Pairs Event Type Properties The list of event types for a constraint is accessed with the Event Type Properties tab shown in Figure 35 To add a new event type click the Add button which adds a new blank event type to the list All event types in the list may be edited in place To remove a selected event type click the Remove button Mapping Constraint 0 Properties x Event Types Event Types Domain Name Type Name somedomain sometype Figure 35 Constraint Event Type Properties 775 CHAPTER 5 Orbacus Notify Console Result to Set Properties The value to be returned by a mapping filter on a match with a constraint may be edited in the Result to Set Properties tab Figure 36 Mapping Constraint 0 Properties x Result to Set Result to Set o Figure 36 Constraint Result to Set Properties
84. directional functionality Initially however only bi directional IIOP is supported In Figure 16 a server is shown that is capable of receiving both bi directional IIOP connections and regular IIOP connections Server OCI OCcl Bi dir IOP OCI IOP A Requests amp Requests Callbacks Callbacks OCI OCI IIOP IOP OCI Bi dir Client B Client A Figure 16 Connection Requirements Any callback requests from the Server to Client A will travel down the existing connection already established by the client On the other hand any callback requests from the Server to Client B require a new IIOP connection to be established from the server to the client Peers The Bi directional OCI Plug in The Bi directional plug in requires each peer in a bi directional connection to have a unique identifier called the peer ID Currently this identifier is just a simple ISO LATIN1 string In IIOP terms a unique endpoint is derived from the hostname port combination However since the Bi directional OCI plug in has no knowledge of the underlying protocol a separate identification scheme is currently required and must be provided by the application It is therefore the application s responsibility to ensure that each server and client has a unique peer ID In IIOP object references can be made persistent i e valid across process restarts by ensuring that the process is resta
85. directory DIR single file FILE Create a single file called FILE rtf with index Create index entries font PARA NAME font size PARA SIZE Specify the font name or size for a particular paragraph type The paragraph types and their default values are shown below Type Font Size body roman Times New Roman 12pt Translating IDL to RTF Type Font Size entry swiss Tahoma 12pt extra same as body 12pt heading swiss Arial 18pt index same as heading 15pt literal roman Courier New 10pt symbol roman Symbol 12pt 43 CHAPTER 3 Generating Code with Orbacus Generating C from an Interface Repository Synopsis irgen name base Description irgen generates C code directly from the contents of an Interface Repository See The IDL to C Translator and the Interface Repository on page 45 for an example Options for irgen h help v version no skeletons no type codes locality contrained no virtual inheritance tie impl impl all c suffix SUFFIX h suffix SUFFIX skel suffix SUFFIX header dir DIR other header dir DIR output dir DIR file list FILE dll import DEF with interceptors args no local copy These options are the same as for the idl command The argument to irgen is the pathname to use as the base name of the output filenames For example if the pathname yo
86. error the Orbacus library dumps a core Unix only and prints the file and line number where the error was detected You can use the core dump in order to track down the problem with a debugger The following error messages can appear Application requested a feature that has not yet been implementedThis is not an application error This error message appears if an application attempts to use a feature that has not yet been implemented in Orbacus In this case the only thing that can be done is to wait for the next Orbacus version that has this particular feature implemented Application used a deprecated feature that is not implemented anymoreThis is not an application error This error message appears if an application attempts to use a feature that is no longer implemented in Orbacus In this case the only thing that can be done is to avoid using this particular feature Application used wrong memory allocation functionlf this message appears an incorrect memory allocation function has been used A common mistake that leads to this error is to use malloc strdup and free or the new and delete operator instead of CORBA string_alloc and CORBA string_dup and CORBA string_free for string memory management Message Description was deallocated again Memory that was already deallocated This message indicates multiple memory deallocations For example if CORBA string_free Is called twice on the same string this messag
87. expanding an item will refresh the item In addition to the operations offered by the menu bar some frequently needed functions are available by icons located in the toolbar The toolbar contains all of the items of the Edit menu and the Refresh item of the View menu The toolbar is shown below Cif al sje gt m fe 9 The Menus When selecting an OAD server or POA with the right mouse button a popup menu with a choice of operations will be displayed as shown below Create Modify Delete Cut Paste Start Stop Reset Refresh This popup menu provides the same operations as the toolbar 185 CHAPTER 8 The Implementation Repository Console 186 In this chapter CHAPTER 9 Orbacus Names A CORBA object is often represented by an object reference in the form of a stringified IOR a lengthy string that is difficult to read and cumbersome to use It is much more natural to think of an object in terms of its name which is a core feature of the CORBA Naming Service In the Naming Service objects are registered with a unique name which can later be used to resolve their associated object references Orbacus Names is compliant with 10 This chapter does not provide a complete description of the service It only provides an overview suitable to get you started For more information please refer to the specification This chapter contains the following sections
88. file idl See Chapter 13 for more information on the Interface Repository 45 CHAPTER 3 Generating Code with Orbacus Include Statements Using include statements Restrictions 46 If you use the include statement in your IDL code the Orbacus IDL to C translator iai does not create code for included IDL files Instead the translator inserts the appropriate include statements in the generated header files There are several restrictions on where to place the include statements in your IDL files for this feature to work properly include may only appear at the beginning of your IDL files All include statements must be placed before the rest of your IDL code e Type definitions such as interface or struct definitions may not be split among several IDL files In other words no include statement may appear within such definitions If you do not want these restrictions to be applied you can use the translator option a11 with ial With this option the IDL to C translator treats code from included files as if the code appeared in your IDL file at the position where it is included This means that the compiler will not place include statements in the automatically generated header files regardless of whether the code comes directly from your IDL file or from files included by your IDL file Note that when generating code from an Interface Repository using irgen the translator behaves identically to
89. following structure corbaloc iiop version host port object key The components of the URL are as follows iiop This is the default protocol for corbaloc URLs and therefore is optional version The IIOP version number in major minor format The default iS 1 0 host The hostname of the server port The port on which the server is listening The default is 2089 object key A stringified object key The specification allows a URL to contain multiple addresses but the semantics are vendor specific In Orbacus each address is used in turn until one is found that works or until the ORB has tried them all and failed to contact the object The rir protocol is a shortcut for the ORB operation resolve_initial_references The corbaloc URL for the rir protocol has the following structure corbaloc rir id The components of the URL are as follows e rir The protocol e iq The identifier of the service to be resolved The identifier NameService is used if id is not supplied Some examples of corbaloc URLs are corbaloc nshost 10000 NameService corbaloc myhost 10000 MyObjectId corbaloc rir NameService 139 CHAPTER 6 Locating Objects See The BootManager on page 144 for information on how a server can support corbaloc URLs 140 Object Reference URLs corbaname URLs A corbaname URL provides additional flexibility by incorporating use of the Naming Service in
90. from main so that resources used by the ORB are properly released To destroy the ORB in C invoke destroy on the ORB Hi Cast CORBA ORB_var orb Initialize the orb Mil ax orb gt destroy And in Java Java org omg CORBA ORB orb Initialize the orb M pas orb destroy Server Event Loop Server Event Loop A server s event loop is entered by calling PoaManager activate on each POA Manager and then calling ORB run For example in Java Java org omg CORBA ORB orb Initialize the orb org omg PortableServer POAManager manager Get Root POA manager manager activate orb run And in C Hil Cast CORBA ORB_var orb Initialize the orb PortableServer POAManager_var manager Get the Root POA manager manager gt activate Clas S runi You can deactivate a server by calling ORB shutdown which causes ORB run to return For example consider a server that can be shut down by a client by calling a deactivate operation on one of the server s objects First the IDL code A Woy interface ShutdownObject void deactivate 89 CHAPTER 4 ORB and Object Adapter Initialization 90 2 3 9 12 14 17 On the server side ShutdownObject can be implemented like this IU CIF class ShutdownObject_impl public POA_ShutdownObject public PortableServer RefCountServantBase CORBA ORB_var orb_ public
91. given time MaxSuppliers suppliers gt O The maximum number of suppliers that can be connected to a channel at any given time The default value is O for all properties meaning that no limit applies to that property 715 CHAPTER 3 Notification Service Concepts Subscription Sharing 716 Subscription sharing is a standard mechanism for suppliers to publish the types of events that they will supply and for consumers to subscribe to event types that they wish to receive The information can be used by suppliers and consumers to decide whether they wish to supply events or consume events on a notification channel The Notification Service supports subscription sharing between channels and channel clients through the following interfaces i module CosNotifyComm interface NotifyPublish void offer_change in CosNotification EventTypeSeq added in CosNotification EventTypeSeq removed raises InvalidEventType NotifyPublish interface NotifySubscribe void subscription_change in CosNotification EventTypeSeq added in CosNotification EventTypeSeq removed raises InvalidEventType NotifySubscribe Supplier admins and proxy consumers inherit the NotifyPublish interface Suppliers may use the offer_change method to notify the channel that it is about to start supplying new event types or is about to stop supplying an existing type The channel maintains an a
92. hello Hello _narrow ob OrANaA OO fFWN FE Ko 328 2 3 5 11 13 14 16 Programming Examples Obtain the object reference from some means here using a file Create the BidirectionalPolicy with a value of BOTH to enable BiDir Add the Bidirectional Policy to the object and make sure to catch the return object reference Narrow the object to the specific type for method invocation And now the Java version Java org omg CORBA Object obj orb string_to_object relfile Hello ref org omg CORBA Any any orb create_any org omg BiDirPolicy BidirectionalPolicyValueHelper insert any org omg BiDirPolicy BOTH value org omg CORBA Policy policies new org omg CORBA Policy 1 policies 0 orb create_policy 10 org omg BiDirPolicy BIDIRECTIONAL POLICY_TYPE value any I 12 obj obj _set_policy_override policies 13 org omg CORBA SetOverrideType ADD_OVERRIDE 14 15 Hello hello HelloHelper narrow ob 4 Own one Ww Ww e Koj This is equivalent to the C version 329 CHAPTER 16 Using Policies 330 CHAPTER 17 Asynchronous Method Invocation This chapter describes how to design asynchronous non blocking clients In this chapter This chapter contains the following sections Introduction page 332 AMI Router page 333 Router Usage page 334 Router Administration Properties page 335 AMI Reply Handler Implementation page 337 AMI Poller Implementation page
93. hostname of the machine in which mkref is executed 171 CHAPTER 7 The Implementation Repository port The forward port of the imr server If not set then mkref will use 9998 server name The name of the server as registered in the IMR object id The Object ID used by the object poal poa2 poan The POA which creates the object where poal is a child of the Root POA poa2 is a child of poal and so on Upgrading the IMR Database 172 The imrdbupgrade utility is used to upgrade an earlier version of the IMR database Command line usage is as follows imrdbupgrade database directory The database directory parameter is used to specify the IMR database directory Getting Started with the Implementation Repository Getting Started with the Implementation Repository To use the IMR several steps must be taken These steps are presented below and are explained by way of example In this example we assume that Orbacus has been installed in the directory usr local Orbacus and the executables imr imradmin and mkref all exist in a directory that is in the search path 1 Determine the physical architecture In this example we have a network with three hosts master slavel and slave2 The host master is used to run only the IMR The hosts slavel and slave2 are used to run individual CORBA servers Create a configuration file for the IMR and OADs First create a configuration file
94. ia1 with the a11 option In other words the irgen command does not place include statements in the generated files but rather generates code for all IDL definitions in the Interface Repository 1 Preprocessor statements like define or ifdef may be placed before your include statements Documenting IDL Files Documenting IDL Files Overview Example Syntax With the Orbacus IDL to HTML and IDL to RTF translators nial and ridl you can easily generate HTML and RTF files containing IDL interface descriptions The translators generate a nicely formatted file for each IDL module and interface Figure 1 shows an HTML example IDL Documentation for OCI Netscape BEE File Edit View Go Communicator Help LW2 ste265 SH ps JEE Ae tocstonfie CimvenpieeaoOn y Module OCI The Open Communications Interface OCI The definitions in this module provide a uniform interface to network protocols This allows for easy plug in of new protocols or other communication mechanisms into ORBs that implement the OCI Furthermore protocol implementations need only to be written once and can then be reused with all OCI compliant ORBs For more information please see the OCI documentation Module Index IIOP This module contains interfaces to gather information on the IIOP OCI plug in Interface Index AccRegistry A registry for Acceptors AcceptCB An interface for an accept callback object
95. initialize JTCThreadHandle t new HelloWorld i a Sleeuce p ic gt jJeum return 0 wO O r o A a WN FE 7 The join method is used to wait for the thread to die However this example has a bug The join method can throw the exception JTCInterruptedException Therefore this example should be re written as follows I aime A meena Glin Aeey olea erae S i 4 JICInitialize initialize 5 JTCThreadHandle t new HelloWorld 6 E Siezwic 9 i do 8 9 EEY E gt Jorim catch const JTCInterruptedException amp while t gt isAlive return 0 to 0S I aunt WHE SO 9 15 join is called on the thread which should wait until the thread has terminated However if gtcInterruptedException is thrown we ignore it 609 CHAPTER 3 Working With Threads 17 This makes sure that the loop is only terminated if no JTCInterruptedException was thrown i e if the thread is not alive anymore 610 CHAPTER 4 Memory Management This chapter discusses the memory management features JThreads C such as reference counting and handle classes In this chapter This chapter contains the following sections Reference Counting page 612 Introducing Handles page 613 The JTCHandleT Template page 615 Rules of Thumb page 616 CHAPTER 4 Memory Management Reference Counting Avoiding memory leaks 612 You may have thought that the Hello World examples fro
96. is O which produces no output A level of 1 or higher produces lifecycle information e g creation and destruction of load balanced groups adding and removing members and setting load balancing strategies Value evel gt O Usage Defines the output level for diagnostic messages related to the load balancing of members The default level is O which produces no output Levels greater than O produce different degrees of output 277 CHAPTER 14 Orbacus Balancer Built in Load Balancing Strategies In this section we present the load balancing strategies that are provided with Orbacus Balancer Note that the default strategy is the round robin strategy random Non adaptive strategy where members are selected at random There are no configuration properties for this strategy round robin Non adaptive strategy where members are selected in round robin order There are no configuration properties for this strategy least load Adaptive strategy where the least loaded members are chosen in round robin order The configuration properties for this strategy are as follows tolerance Type CORBA ULong Members with a load difference that is less than tolerance are considered to have the same load The default value for this property is O This alleviates the member selection problem 1 on page 269 load per client Type CORBA ULong The load per client property is an estimate of the load for a given client
97. is returned remove_filter void remove_filter in FilterID filter raises FilterNotFound Remove a filter from the target object the filter itself is not destroyed If the specified filter is not found a FilterNotFound exception is raised Parameters filter The ID of the filter to remove get_filter Filter get_filter in FilterID filter raises FilterNotFound Retrieves a reference for the filter with the given filter ID from the target object Parameters filter The ID of the filter to locate Returns A reference to a filter object is returned If a filter with a given ID could not a be found a FilterNotFound exception is raised get_all_filters FilterIDSeq get_all_filters Retrieve a list of all filters associated with the target object Returns 867 CHAPTER F CosNotifyFilter Reference A list of filter IDs is returned remove_all_filters void remove_all_filters Remove all filters associated with the target object 868 In this appendix APPENDIX G OBNotity Reference This appendix describes the OBNotify module This appendix contains the following section Module OBNotify page 870 869 APPENDIX G OBNotify Reference Module OBNotify Constants 870 This module contains proprietary Orbacus Notify QoS settings Pulllnterval const string PullInterval PullInterval The amount of time the service pauses between pull requests The value of
98. itself and vendor specific information from the underlying SSL toolkit The default value is O 517 CHAPTER 1 Using FreeSSL for Orbacus Server Installation The server side FSSL plug in is installed as shown below ooc oci server fssliop Note that FSSL servers must also install the client side plug in 518 Endpoint Configuration Endpoint Configuration Options The configuration options for an FSSL endpoint are shown below fssliop backlog N bind ADDR host ADDR ADDR numeric port N backlog N Specifies the length of the queue for incoming connection requests Note that the operating system may override this setting if the value exceeds the maximum allowed bind ADDR Specifies the hostname or dotted decimal address of the network interface on which to bind the socket If not specified the POA Manager will bind its socket to all available network interfaces This property is useful in situations where a host has several network interfaces but the POA Manager should only listen for connections on a particular interface host ADDR ADDR Specifies a list of one or more hostnames and or dotted decimal addresses representing the addresses that should be advertised in IORs numeric If set and if host is not specified then the canonical dotted decimal address is advertised in ORs The default behavior is to use the canonical hostname if possible p
99. lbhost 10000 Balancer member1 7 Create object references for use by the clients To create an object reference run lbmkref H lbhost 10001 Hello IDL Hello 1 0 Hello gt Hello ref Note that the object references created by the load balanced servers can also be used by the clients After all members have been registered and the load balancing strategy is configured it is recommended to restart the service in non administrative mode This will prevent any accidental or unauthorized modifications 299 CHAPTER 14 Orbacus Balancer 300 In this chapter CHAPTER 15 Orbacus Watson Orbacus Watson is a loadable module that provides request tracing capabilities based on Portable Interceptors Method names parameter and return values exceptions and a call stack can be visualized The module can be loaded dynamically at application startup when shared libraries are used or linked statically to an application This chapter contains the following sections Tracing Levels page 302 Installing Watson in C page 303 Installing Watson in Java page 304 Configuration Properties page 305 301 CHAPTER 15 Orbacus Watson Tracing Levels The level of request tracing is controlled by the properties described in the next section The default value for all tracing levels is O 0 no tracing 1 displays name request id return exception status of operation 2 displays parameters and return
100. lbmkref H host port group id repository id object id host The host that the balancer server is running on The default value is the canonical hostname of the machine in which 1bmkref is executed port The forward port of the service group id The ID of the load balanced group repository id The Repository ID of the new object reference object id The Object ID of the new object reference 285 CHAPTER 14 Orbacus Balancer Utility Objects LoadAlert LoadCalculator LoadUpdater 286 To take advantage of the features of the adaptive load balancing strategies a load balanced server must send load updates to the appropriate load balanced groups and respond to load alerts Orbacus Balancer provides utility objects that the developer may use to help implement this functionality The utility objects provided by Orbacus Balancer are part of the LoadBalancing Util module and are provided as initial services see The BootManager on page 144 Each utility object is described below For further detail refer to Appendix F and for an example refer to Adaptive Load Balancing on page 294 The LoadAlert object is used to manage load alerts sent by the service The name of the LoadAlert initial service is LoadAlert The LoadCalculator object is used by the LoadUpdater object see below to calculate the current load of the server which will be used as the load of each member reg
101. length pos attribute unsigned long pos The position counter Note that the buffer s length and the position counter don t depend on each other There are no restrictions on the values permitted for the counter This implies that it s even legal to set the counter to values beyond the buffer s length advance void advance in unsigned long delta Increment the position counter Parameters delta The value to add to the position counter rest_length unsigned long rest_length Module OCI Returns the rest length of the buffer The rest length is the length minus the position counter s value If the value of the position counter exceeds the buffer s length the return value is undefined Returns The rest length is_full boolean is_full Checks if the buffer is full The buffer is considered full if its length is equal to the position counter s value Returns TRUE if the buffer is full FALSE otherwise 457 CHAPTER E Open Communications Interface Reference Interface OCI Plugin Synopsis Attributes Operations 458 local interface Plugin The interface for a Plugin object which is used to initialize an OCI plug in id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag init_client void init_client in ParamSeq params Initialize the client side of the plug in Parameters params Plug in specific paramete
102. load alerts The Orbacus Balancer utility objects will be used to help implement this functionality The modified server program is shown below 294 womAAtauwF WN FE Oy a 60 gt a gt 6 q 8 9 20 2i 22 29 24 25 26 27 28 29 30 31 22 29 alert_ Hf Cae include include include include include lt OB CORBA h gt lt OB Balancer_init h gt lt OB BalancerUtil_init h gt lt OB Balancer_skel h gt lt Hello_impl h gt class LoadAlert_impl virtual public POA_LoadBalancing LoadAlert virtual public PortableServer RefCountServantBase public LoadBalancing Util LoadAlert_var alert_ LoadAlert_impl LoadBalancing Util LoadAlert_ptr alert LoadBalancing Util LoadAlert _duplicate alert virtual void alert throw CORBA SystemExcept ion alert_ gt alert he aijele ieibiol CORMVAG FORNEY jee alice Clore p int main int argc char argv int status EXIT_SUCCESS CORBA ORB_var orb 8 25 37 Programming Example 34 try 35 36 LoadBalancing LB_init 37 KoadBalkinerngii EINE EEUE E 38 orb CORBA ORB_init argc argv 39 statusi rUn Oro argen arov 40 41 catch const CORBA Exception amp 42 43 status EXIT_FAILURE 44 45 46 if CORBA is_nil orb 47 48 try 49 50 orb gt destroy Sul 52 catch const CORBA Exception amp 5B 54 status EXIT_FAILURE 55 56
103. method has no effect Parameters cb The callback to add remove_connect_cb void remove_connect_cb in ConnectCB cb Remove a connect callback If the callback was not registered this method has no effect Parameters cb The callback to remove Module OCI Interface OCI ConFactoryRegistry Synopsis Operations local interface ConFactoryRegistry A registry for Connector factories See Also Interface OCI Connector Interface OCI ConFactory add_factory void add_factory in ConFactory factory raises FactoryAlreadyExists Adds a Connector factory to the registry Parameters factory The Connector factory to add Raises FactoryAlreadyExists If a factory already exists with the same plugin id as the given factory get_factory ConFactory get_factory in PluginId id raises NoSuchFactory Returns the factory with the given plugin id Parameters id The plugin id Returns The Connector factory Raises NoSuchFactory If no factory was found with a matching plugin id get_factories ConFactorySeq get_factories Returns all registered factories Returns The Connector factories 475 CHAPTER E Open Communications Interface Reference Interface OCI Acceptor Synopsis Attributes Operations 476 local interface Acceptor An interface for an Acceptor object which is used by CORBA servers to accept client connection requests
104. name 63 ooc orb trace connections 64 ooc orb trace retry 64 ooc orb use_type_code cache 63 ooc property port 226 Property Service 225 R Reactor 360 Recursion 215 RTF 47 S Servants 94 T Activation 107 C 104 Deactivation 112 Delegation 98 Inheritance 95 Java 105 Toolbar 184 222 U URL 137 138 corbaloc 139 corbaname 141 file 142 relfile 143 W W WwW indows NT Registry 71 indows Reactor 362 INDEX 877 INDEX 878
105. object A nil reference is permitted Module CosNotifyChannelAdmin Interface CosNotifyChannelAdmin ProxyPullSupplier Operations interface ProxyPullSupplier inherits from CosNotifyChannelAdmin ProxySupplier CosNotifyComm PullSupplier The ProxyPullSupplier interface supports connections by consumers who wish to pull unstructured events from the channel connect_any_pull_consumer void connect_any_pull_consumer in CosEventComm PullConsumer pull_consumer raises CosEventChannelAdmin AlreadyConnected Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters pull_consumer A reference to the consumer object A nil reference is permitted 817 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin StructuredProxyPullSupplier Operations 818 interface StructuredProxyPullSupplier inherits from CosNotifyChannelAdmin ProxySupplier CosNotifyComm StructuredPullSupplier The structuredProxyPullSupplier interface supports connections by consumers who wish to pull structured events from the channel connect_structured_pull_consumer void connect_structured_pull_consumer in CosNotifyComm StructuredPullConsumer pull_consumer raises CosEventChannelAdmin AlreadyConnected Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters p
106. object of the class implementing 1 s operations must be passed to the servant s constructor lo ff Case 2 I_impl_tie impl new I_impl_tie 3 POA I tie lt I_impl_tie gt tie_pointer 4 new POA I_tie lt I_impl_tie gt impl A new I_impl_tie is created with new An instance of poa_I_tie parameterized with I_impl_tie is created taking imp1 as a parameter All operation calls to tie will then be delegated to impl In this example the lifetime of imp1 is coupled to the lifetime of the servant tie That is when the tie is destroyed delete imp1 is called by the tie s destructor In case you don t want the lifetime of imp1 to be coupled to the lifetime of the tie for example because you want to create a servant on the stack and not on the heap making it illegal to call delete on the tie use the following code if CE 2 TI_impl_tie impl 3 POA_I_tie lt I_impl_tie gt tie 4 new POA I_tie lt I_impl_tie gt amp impl false A new I_imp1_tie is created this time on the stack not on the heap An instance of Poa_t_tie is created The false parameter tells tie not to call delete On impl Creating Servants Creating Servants using Java Every tie class generated by the IDL to Java translator has two constructors Java public class IPOATie extends IPOA public IPOATie IOperations delegate public IPOATie IOperations delegate POA poa The second constructor allows a POA instanc
107. of policies For the purposes of the SSL plug in the context policy is not considered to be a thread level policy 535 CHAPTER 2 Extending the Hello World Application Full Example The following is the full example Ht Caer FSSL CertificateSeq myCerts 2 myCerts length 2 myCerts 0 fsslManager gt create_certificate FSSL OctetSeq_var FSSL loadFile client der myCerts 1 fsslManager gt create_certificate FSSL OctetSeq_var FSSL loadFile CAcert der FSSL ContextID id fsslManager gt create_context myCerts FSSL OctetSeq_var FSSL loadFile clientkey der FSSL PassPhrase_var FSSL string_to_PassPhrase foobar myTrustDecider FSSL CipherSeq_var FSSL getDefaultCiphers CORBA PolicyManager_var policyManager CORBA PolicyManager _narrow CORBA Object_var orb gt resolve_initial_references ORBPolicyManager CORBA PolicyList pl 1 pl length 1 pl 0 fsslManager gt create_context_policy id policymanger gt add_policy_overrides pl Java com ooc FSSL Certificate myCerts new com ooc FSSL Certificate 2 myCerts 0 fsslManager create_certificate com ooc FSSL FSSL load_file client dert myCerts 1 fsslManager create_certificate com ooc FSSL FSSL load_file ca der int id fsslManager create_context myCerts com ooc FSSL FSSL load_file clientkey der com ooc FSSL FSSL string_to_P
108. of false OBPortableServer Communication sConcurrencyPolicy See ooc orb oa conc_model on page 65 and ooc orb poamanager manager conc_model on page 67 OBPortableServer EndpointConfig urationPolicy See ooc orb poamanager manager endpoint on page 67 OBPortableServer GlOPVersionPol icy See ooc orb poamanager manager version on page 67 311 CHAPTER 16 Using Policies Programming Examples This section provides several examples of setting policies programmatically Please note however that policies used to configure the ORB can easily be set at the ORB level without requiring changes to the application through the use of configuration properties See ORB Properties on page 58 for more information For the sake of clarity the psuedo code examples in this section lack exception handling In this section This section contains the following examples Connection Reuse Policy page 313 Retry Policy page 316 Timeout Policy page 318 Interceptor Call Policy page 319 CommunicationsConcurrencyPolicy page 321 EndpointConfigurationPolicy page 323 GlOPVersionPolicy page 325 Bidirectional Policy page 327 312 Programming Examples Connection Reuse Policy Connection Reuse Policy at ORB Level 2 3 4 5 The following examples demonstrate how to set OB ConnectionReusePolicy at both the ORB level and the object level in C and Java
109. omg PortableServer POAHelper narrow orb resolve_initial_references RootPOA org omg PortableServer POAManager manager rootPOA the_POAManager org omg PortableServer POA persistentPOA null try org omg CORBA Policy policies new org omg CORBA Policy 2 policies 0 rootPOA create_lifespan_policy org omg PortableServer LifespanPolicyValue PERSISTENT policies 1 rootPOA create_id_assignment_policy org omg PortableServer IdAssignmentPolicyValue USER_ID persistentPOA rootPOA create_POA PersistentPOA manager policies catch org omg PortableServer POAPackage AdapterAlreadyExists ex ex printStackTrace throw new RuntimeException catch org omg PortableServer POAPackage InvalidPolicy ex ex printStackTrace throw new RuntimeException AsyncEchoHandler asyncHandler new AsyncEchoHandler rootPOA echo AMI_EchoHandler handler asyncHandler _this orb org omg CORBA Object obj orb string_to_object relfile Echo ref echo Echo ec echo EchoHelper narrow ob ec sendc_echo_message handler Hello 339 CHAPTER 17 Asynchronous Method Invocation 340 15 16 17 18 19 Create a persistent POA for the reply handler This is important as it allows the router to deliver the reply in the event that the client goes down and comes back up Servers should also use persistent POAs for the same reason Instantiate a new AsyncEchoHandler object using o
110. on a per channel admin proxy basis c 710 The OMG Notification Service Table 4 QoS Properties Property Value Description EventReliability BestEffort EventReliability is set on the channel Persistent object and determines whether the delivery of all events on the channel will be Persistent Or BestEffort The default iS BestEffort ConnectionReliability BestEffort ConnectionReliability applies to Persistent channel admin and proxy objects and the re establishment of supplier and consumer connections The default is BestEffort MaxEventsPerConsumer events gt 0 The MaxEvent sPerConsumer property is used to limit the number of events that will be queued in a ProxySupplier The default is O meaning no limit OrderPolicy AnyOrder OrderPolicy determines the order in FifoOrder which events are queued for delivery to a PriorityOrder consumer AnyOrder means that any DeadlineOrder ordering policy FifoOrder PriorityOrder Of DeadlineOrder may be used The default is PriorityOrder DiscardPolicy AnyOrder DiscardPolicy applies when a queue FifoOrder reaches a limit specified by LifoOrder MaxEvent sPerConsumer admin property PriorityOrder and specifies the order in which events DeadlineOrder should be discarded The default is RejectNewEvents AnyOrder meaning that any event may be discarded on overflow MaximumBatchSize size gt 0 Indicates the maximum number of events that will be delivered in a sequen
111. on page 282 Utilities on page 283 Programming Example on page 288 267 CHAPTER 14 Orbacus Balancer Basic Concepts 268 Let us assume that we wish to provide a library service that is made available through a set of objects These objects being a set of book objects and a library object that manages the book objects Furthermore it is desired that connections made with each of these objects be load balanced The replicated objects for each book and the replicated library objects are managed in the service by a single entity that is called a load balanced group Each member of the load balanced group must provide a replica of each object for the library service each member must provide a replica of each book object and a replica of the library object All of the replicas provided by a member must be activated on a single POA with a member policy which uniquely identifies the member within the service the usER_1D ID assignment policy value and the PERSISTENT lifespan policy value Such a POA will be referred to as a member POA and the corresponding server will be referred to a oad balanced server Object references created by a member POA will refer to the service instead of the member POA within the load balanced server When a client makes a request on an object using a reference create by a member POA the service e receives the request e determines the load balanced group e selects a m
112. on the base interval each subsequent retry is multiplied by the backoff _factor This property is used for both the unlimited_ping and the limited_ping retry policies Value Integer n gt 0 Default 6 The maximum number of times the backoff factor is applied to the base retry interval This property is used for both the unlimited_ping and the limited_ping retry policies 335 CHAPTER 17 Asynchronous Method Invocation ooc router retry_policy interval_ limit ooc router decay_policy decay_ seconds ooc router resume_policy resume _seconds 336 Value Integer n gt 0 The maximum number of retry attempts made This property is used for limited_ping retry policy only Value Integer n gt 0 Default o The time in seconds for which a destination registration is valid If this is set to zero 0 the registration remains valid until the destination explicitly unregisters itself with a call to unregister_destination Value Integer n gt 0 Default 1200 20 minutes The time in seconds after which a suspended destination should be resumed If this is set to zero 0 the registered destination can only be resumed with an explicit call to resume_dest ination Note Orbacus 4 3 1 does not allow this value to be set to zero 0 This is required due to the lack of persistence in the AMI Router in the 4 3 1 version of Orbacus AMI Reply Handler Implementation AMI Reply Handler Implementation C
113. on them by the channel connect_any_push_consumer void connect_any_push_consumer in CosEventComm PushConsumer push_consumer raises CosEventChannelAdmin AlreadyConnected CosEventChannelAdmin TypeError Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters push_consumer A reference to the consumer object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pushing events to the connected consumer If the connection is already suspended the Connect ionAlreadyInact ive exception is raised If the target object is not connected to a supplier the Notconnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target object to resume pushing events to the connected consumer If the connection is not suspended the Connect ionAlreadyAct ive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised 823 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin StructuredProxyPushSupplier Operations 824 interface StructuredProxyPushSupplier inherits from CosNotifyChannelAdmin ProxySupplier CosNotifyComm StructuredPushSupplier The structuredPr
114. orb Get a reference to the ORB somehow 3 Java io BufferedReader in new java io BufferedReader 4 new java io FileReader object ref 5 String ref in readLine 6 org omg CORBA Object obj orb string_to_object ref 7 B b BHelper narrow obj 3 5 The stringified object reference is read 6 string_to_object creates an object reference from the string 7 Use BHelper narrow to narrow the return value of string_to_object to B 136 Using a URL 8 13 15 16 Stringified Object References It is sometimes inconvenient or impossible for clients to have access to the same filesystem as the server in order to read a stringified object reference from a file A more flexible method is to publish the reference in a file that is accessible by clients as a URL Your clients can then use HTTP or FTP to obtain the contents of the file freeing them from any local filesystem requirements This strategy only requires that your clients know the appropriate URL and is especially suited for use in applets Note This example is shown only in Java because of Java s built in support for URLs but the strategy can also be used in C 1 Java 2 lt dimporl jave io 7 3 import java net 4 5 String location http www mywebserver object ref 6 org omg CORBA ORB orb Get a reference to the ORB somehow a 8 URL url new URL location 9 URLConnection conn url openConnection 10 BufferedReader
115. page 75 1 Note that these properties have nothing to do with the Property Service as described in Appendix B 57 CHAPTER 4 ORB and Object Adapter Initialization ORB Properties ooc config 0oc oci client 00c oci server 00c oci plugin name ooc orb client_shutdown_timeout 58 Value filename Selects the default configuration file This property is only available in Java applications and is equivalent to the oRBACUS_CONFIG environment variable in C See Using a Configuration File on page 70 for more information on configuration files Value string Specifies a comma separated list of client side transport plug ins to be installed The plug ins are installed in the order they appear in the list The default value is iiop Value string Specifies a comma separated list of server side transport plug ins to be installed The plug ins are installed in the order they appear in the list The default value is iiop Value string Specifies a plug in s shared library C or initialization class Java In most cases this property is not necessary because the ORB attempts to locate the library or class using a well known name In C the well known name is 1ibocI_name so UNIX 1iboct_name s1 HP UX or ocI_name a11 Windows where name is the plug in name e g iiop The ORB searches for this shared library in the library search path Similarly in Java the ORB searches the class
116. path for a class named com ooc OCI name Value timeout gt O If the client is not able to gracefully disconnect from the server in timeout seconds a connection shutdown is forced If this property is set to zero then the client will not force a connection shutdown If the property is not set a default timeout value of two seconds is used ooc orb client_timeout ooc orb conc_model ooc orb default_init_ref ooc orb default_wcs ooc orb extended_wchar ooc orb giop max_message_size Configuring the ORB and Object Adapter Value timeout gt 0 The client actively closes a connection that has been idle for timeout seconds once that connection has no more outstanding replies Note that the application must use the threaded client side concurrency model if connection timeouts are desired If this property is set to zero or not set at all then the client does not close idle connections Note that a policy can also be set on the ORB or on individual object references See OB ACMTimeoutPolicy on page 309 for more information Value reactive threaded Selects the client side concurrency model The reactive concurrency model is not currently available in Orbacus for Java The default value is threaded for both C and Java applications See Chapter 18 for more information on concurrency models Value URL Specifies a partial URL If an application calls the ORB operation resolve_initial_references and
117. private key must be converted from PEM format to PKCS 8 DER format gt openssl pkcs8 outform DER in newreq pem out newkey der topk8 Finally the new certificate and the CA s certificate must be converted from PEM to DER encoding gt openssl x509 outform DER in newcert pem out newcert der gt openssl x509 outform DER in demoCA cacert pem out cacert der This must be done to create two sets of certificates and private keys one set for the server and one set for the client Store the client set in client der and client key Store the server set in server der and server key The CA s certificate should be in ca der When creating certificates it s necessary to provide identity information For the Server use Server for the common name section of the certificate s Subject field This will be used later for trust decisions For this toolkit an application must be written to generate the certificates Since this is beyond the scope of the manual the reader is advised to consult the application fssl demo hello GenCerts java bundled with the FreeSSL for Java distribution Complete Example Client Side main First initialize the ORB Hl Cet int Main iMeancge chars angi ehars int status EXIT_SUCCESS CORBA ORB_var orb EEY orb CORBA ORB_init argc argv status run orb argc argv catch const CORBA Exception amp ex Cer lt 6x lt lt endl status EXIT_FAILURE if CORBA is_n
118. program to a JThreads C program include lt JTC JTC h gt class HelloWorld al 2 3 public JTCThread A 5 publie 6 Wises ll WALC wink 7 8 cout lt lt Hello World lt lt endl 9 IE Neubin ime arge Chari argv JICInitialize initialize JTCThread t new HelloWorld E gt Sheeucie p return 07 woMWAtInunbt WNHE CO All JThreads C programs must include the header file stc atc h which contains among other useful things all of the necessary JThreads C class definitions Just like in the Java example a class HelloWorld is defined This class is derived from gTcThread instead of the Java equivalent java lang Thread A run method is defined which prints Hello World on standard output System out is replaced by the familiar C iostreams object cout A main method is defined not as a static class member as in the Java example but as the standard C global main function main creates an object of type HelloWorld and calls the start method which starts a new thread of execution The only other change is that the JThreads C thread library must be initialized in main This is done by creating an instance of the class JTCInitialize 1 You might think that the Hello World program has a memory leak because the thread object is created with new but never deleted with delete but this is not the case See Reference Counting on page 612 for more information
119. raises NotFound CannotProceed InvalidName Use the unbind operation to delete a particular binding ie E void unbind in Name n raises NotFound CannotProceed InvalidName Name Resolution Name Resolution Besides registering objects an equally important task of the Naming Service is name resolution A name is passed to the resolve Or resolve_str operation and an object reference is returned if the name exists if WI Object resolve in Name n raises NotFound CannotProceed InvalidName Object resolve_str in StringName n raises NotFound CannotProceed InvalidName The resolve and resolve_str operations are only useful when a particular name is known in advance Sometimes it is necessary to ask for a list of all bindings registered with a particular naming context The list operation returns a list of bindings TO typedef sequence lt Binding gt BindingList void list in unsigned long how_many out BindingList bl out BindingIterator bi If the number of bindings is especially large the BindingIterator interface is provided so that you don t have to query for all available bindings at once Simply get a certain number of bindings specified with how_many and get the rest if any using the BindingIterator TO interface BindingIterator boolean next_one out Binding b boolean next_n in unsigned long how_many out BindingList bl voididestroy O Make sure that you destroy the iterator object
120. register the plug in prior to ORB initialization Ue OCI register_plugin fssliop OCI_init_fssliop endif 521 CHAPTER 1 Using FreeSSL for Orbacus URL Support 522 The FSSL plug in supports corbaloc URLs with the following protocol syntax corbaloc fssliop host port object key The components of the URL are as follows fssliop This selects the FSSL plug in host The hostname or IP address of the server port The port on which the server is listening object key A stringified object key Contexts Contexts What is a Context A context comprises three pieces of information identity trust decision and a set of cipher suites This information is necessary to establish an SSL connection from a client to a server and to allow a server to accept new SSL connections from clients For anonymous communications only the set of cipher suites is necessary Context Creation Contexts are managed via a context manager A reference to the context manager is obtained by resolving the FSSLContextManager initial reference To create a new context FSSL Manager create_context is called This returns the ID of the newly created context i Cat FSSL ContextID id fsslManager gt create_context myChain myKey myPassPhrase myDecider myCiphers Java int id fsslManager create_context myChain myKey myPassPhrase myDecider myCiphers Contexts can also be created usin
121. requests out 2 In this chapter CHAPTER 16 Using Policies This chapter describes the policies used to configure the ORB and to create a new POA These policies are derived from the interface CORBA Policy This chapter contains the following sections Overview page 308 Supported Policies page 309 Programming Examples page 312 307 CHAPTER 16 Using Policies Overview 308 The ORB and its services may allow the application developer to configure the semantics of its operations This configuration is accomplished in a structured manner through interfaces derived from the interface CORBA Policy There are two basic types of policies those used to configure the ORB and those used to create a new POA Furthermore the configuration of ORB policy objects is accomplished at two levels e ORB Level These policies override the system defaults The ORB has an initial reference oRBPolicyManager A PolicyManager has a set of operations through which the current set of overriding policies can be obtained and new policies can be applied Object Level The object interface contains operations to retrieve and set policies for itself Policies applied at the object level override those applied at the thread level or the ORB level For more information on Policies the PolicyManager interface and the CORBA Object policy operations see 8 and 4 Supported Policies Supported Policies The followi
122. returns a Transport object which can be used for sending and receiving octet streams to and from the server Returns The new Transport object Raises TRANSIENT If the server cannot be contacted COMM_FAILURE In case of other errors connect_timeout Transport connect_timeout in unsigned long timeout Similar to connect but it is possible to specify a timeout On return the caller can test whether there was a timeout by checking whether a nil object reference was returned 467 CHAPTER E Open Communications Interface Reference 468 Parameters timeout The timeout value in milliseconds Returns The new Transport object Raises TRANSIENT If the server cannot be contacted COMM_FAILURE In case of other errors get_usable_profiles ProfileInfoSeq get_usable_profiles in IOR ref in CORBA PolicyList policies From the given IOR and list of policies get basic information about all profiles for which this Connector can be used Parameters ref The IOR from which the profiles are taken policies The policies that must be satisfied Returns The sequence of basic information about profiles If this sequence is empty there is no profile in the IOR that matches this Connector and the list of policies equal boolean equal in Connector con Find out whether this Connector is equal to another Connector Two Connectors are considered equal if they are interchangeable Paramet
123. scheduling push and pull requests on clients The best dispatch model depends on how Orbacus Notify is to be used e threaded Each push supplier and pull consumer proxy has a thread invoking requests on the client supplier or consumer Each proxy transfers or receives events independent of the other If there is a large number of consumers or suppliers this can result in a large number of active threads This model is useful for environments where communication latency varies from client to client and or the host system can process multiple threads efficiently On systems where threads are expensive it may be preferable to use thread_pool When using the threaded dispatch model pull consumer proxies invoke pull on pull suppliers e thread_pool All channels share a pool of threads that invoke requests on the client supplier or consumer There is a fixed number of threads dispatching requests on clients placing an limit on the number of concurrent push pull requests This model is useful for environments where it is desirable to place an upper bound on the number of active threads The number of threads in the pool are controlled by the dispatch_threads property When using the thread_pool dispatch model pull consumer proxies invoke try_pull on pull suppliers ooc notification dispatch_threads threads gt O Specifies the number of threads for the thread_pool dispatch strategy The defaul
124. sequence of admin name value pairs set_admin void set_admin in AdminProperties admin raises UnsupportedAdmin Sets the administrative properties for the target object If any of the properties in admin are unsupported the UnsupportedAdmin exception is raised Parameters admin A sequence of name value pairs defining the administrative properties to be set on the target object 804 In this appendix APPENDIX D CosNotifyChannelAd min Reference This appendix describes the CosNotifyChannelAdmin module This appendix contains the following section Module CosNotifyChannelAdmin page 806 805 CHAPTER D CosNotifyChannelAdmin Reference Module CosNotifyChannelAdmin Aliases Structs 806 This module contains the definitions of the primary Notification Service interfaces These interfaces allow suppliers and consumers to connect to a channel ProxylD typedef long ProxyID Alias for a proxy ID ProxylIDSeq typedef sequence lt ProxyID gt ProxyIDSeq Alias for a sequence of Proxy IDs AdminID typedef long AdminID Alias for an admin ID AdminIDSeq typedef sequence lt AdminID gt AdminIDSeq Alias for a sequence of Admin IDs ChannellD typedef long ChannelID Alias for a channel ID ChannellDSeq typedef sequence lt ChannelID gt ChannelIDSeq Alias for a sequence of channel IDs AdminLimit struct AdminLimit CosNotification PropertyName name CosNotifica
125. target object 789 CHAPTER B CosEventComm Reference Interface CosEventComm PushSupplier Synopsis interface PushSupplier This interface is implemented by a push supplier which wishes to receive notification when it is disconnected Operations disconnect_push_supplier void disconnect_push_supplier This method terminates event communication and releases resources allocated by the target object 790 Module CosEventComm Interface CosEventComm PullSupplier Synopsis Operations interface PullSupplier This interface is implemented by a pull supplier so that the channel my pull events pull any pull raises Disconnected This method blocks the calling thread until the supplier has data available or an exception is raised Returns An event in a CORBA Any try_pull any try_pull out boolean has_event raises Disconnected This method does not block and can be used to poll a pull supplier for events Parameters has_event Set to TRUE if there is an event available raLsE otherwise Returns An event in a corBa Any if has_event is TRUE undefined if has_event is FALSE disconnect_pull_supplier void disconnect_pull_supplier This method terminates event communication and releases resources allocated by the target object 791 CHAPTER B CosEventComm Reference Interface CosEventComm PullConsumer Synopsis interface PullConsumer This interface is implemente
126. than 56 bits FSSL get_RSA_ciphers returns a sequence of all RSA RSA cipher suites FSSL get_DSS_ciphers returns a sequence of all DSS DSS cipher suites and FSSL_get_ADH_ciphers returns a sequence of all ADH cipher suites If none of these helper methods supplies the desired functionality it is possible to manually construct a sequence of the cipher suites as follows HA Ca FSSL CipherSeq ciphers 2 ciphers length 2 ciphers 0 FSSL RSA_WITH_RC4_128_MD5 ciphers 1 FSSL RSA_WITH_RC4_128_SHA 525 CHAPTER 1 Using FreeSSL for Orbacus Trust Decision 526 Java com ooc FSSL Cipher ciphers com ooc FSSL Cipher RSA_WITH_RC4_128_MD5 value com ooc FSSL Cipher RSA_WITH_RC4_128_SHA value The application itself must be responsible for a determination of whether a certificate chain is trusted or not To do this the application should provide an implementation of the TrustDecider interface interface TrustDecider boolean is_trusted in CertificateSeq chain hi The is_trusted method is called when each new connection is established or accepted The trust decider can assume that the provided certificate chain is valid and good That means that each certificate in the chain is signed by the next certificate and the last is self signed If true is returned then the chain is trusted and the connection may continue If false is returned then the connection is rejected Contexts This exampl
127. the channel push_structured_event void push_structured_event in CosNotification StructuredEvent notification raises CosEventComm Disconnected Suppliers invoke this operation to pass structured event data to consumers If communication is disconnected the Disconnected exception is raised Parameters notification The structured event being pushed to the consumer disconnect_structured_push_consumer void disconnect_structured_push_consumer Terminates communication between the target consumer and its supplier Also frees resources allocated by the consumer 845 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm StructuredPullConsumer Operations 846 interface StructuredPullConsumer inherits from CosNotifyComm NotifyPublish The structuredPullConsumer interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel Clients do not need to implement this interface to simply pull events disconnect_structured_pull_consumer void disconnect_structured_pull_consumer Terminates communication between the target consumer and its supplier Also frees resources allocated by the consumer Module CosNotifyComm Interface CosNotifyComm StructuredPullSupplier Operations interface StructuredPullSupplier inherits from CosNotifyComm NotifySubscribe The structuredPullSupplier interface is im
128. the request sending direction and the results are received in the in direction For a server application requests from clients are coming in and replies with results or exceptions are sent out Setting one of the more specific properties ooc watson trace requests in and ooc watson trace requests out overrides the corresponding value for this direction set by ooc watson trace requests 305 CHAPTER 15 Orbacus Watson Sample Configuration File 306 Applications using Orbacus Watson can simply be started by specifying a configuration file with appropriate property settings with the orBconfig command line option server ORBconfig watson cfg The following example file shows how to set properties for C and Java applications Register ORB initializer for watson Orbacus Java org omg PortableInterceptor ORBInitializerClass com ooc watson R IORBInitializer_impl Load module watson Orbacus C Disable if module was build statically to avoid error message from the ORBs ModuleManager ooc orb modules watson On Windows enable one of the following properties if you built with DLLs For debug builds ooc orb module watson watson412d d11 For non debug builds ooc orb module watson watson412 d11 Set request tracing levels more specific settings in and out override the general setting in the first of these lines ooc watson trace requests 3 ooc watson trace requests in 1 ooc watson trace
129. the specified host add server server name exec host Register a server under the OAD specified by host with the given exec attribute add poa server name poa name Register a POA for the specified server remove oad host Unregister an OAD remove server server name Unregister a server remove poa se rver name poa name Unregister a POA get oad status host Get the status of an OAD get server info Server name Get the attributes and state information for a server get poa status Server name poa name Get the status of a POA list oads List all OADs list servers List all servers list poas server name List all POAs tree Display all OADs servers and POAs in a tree like format tree oad host Display an OAD and its associated servers and POAs in a tree like format tree server Server name Display a server and its associated POAs in a tree like format Making References Utilities set server Server name exec host args rundir mode activate_poas update_timeout failure_timeout max_spawns value Set an attribute of a server e g set server srv max_spawns 2 sets the max_spawns attribute for the server srv to 2 start server Server name Start a server stop server Server name Stop a server reset server
130. this property is of type TimeBase TimeT with a default of 1 second RetryTimeout const string RetryTimeout RetryTimeout Specifies the initial amount of time as a TimeBase TimeT that the service will wait before retrying a failed client communications attempt The default value is 1 second RetryMultiplier const string RetryMultiplier RetryMultiplier After each consecutive expiration of the retry timeout the timeout value will be multiplied by this factor This value is a double and has a valid range of 1 0 to 2 0 inclusive The default value is 1 0 MaxRetries const string MaxRetries MaxRetries The maximum number of retries that will be performed before the proxy ceases making requests to the connected consumer or supplier The proxy then disconnects and destroys itself The default value is O which means unlimited retry MaxRetryTimeout const string MaxRetryTimeout MaxRetryTimeout The upper limit aS a TimeBase TimeT for increasing the retry interval After this duration has been reached the retry interval will stay constant until success or until OBNot ify MaxRetries has been reached The default value is 60 seconds RequestTimeout const string RequestTimeout RequestTimeout Module OBNotify The amount of time TimeBase TimeT permitted for a blocking request on a client to return before a timeout The default value is 5 seconds 871 APPENDIX G OBNotify Reference 872 Notit
131. to as its forward endpoint be accessible outside of the network firewall Otherwise anyone can mimic the IMR and cause an OAD to run any command they decide For additional security the information managed by the IMR may only be modified when the IMR is running in administrative mode That is e OAD registration and removal e server registration and removal e modification of server attributes and e POA registration and removal are only possible when the IMR is running in administrative mode An attempt to modify the information managed by the IMR when it is not running in administration mode will result in a CORBA NO_PERMISSION exception 163 CHAPTER 7 The Implementation Repository Usage The IMR and OAD are currently implemented using Orbacus for C but Orbacus for Java servers can also be launched by the IMR Both the IMR and OAD are contained in the IMR server which may be started in one of three modes master Start only the IMR slave Start only the OAD dual Start both the IMR and OAD Command line usage is as follows imr h help v version m master s slave a administrative d database A admin endpoint F forward endpoint S slave endpoint L locator endpoint h Display the command line options supported by the help server v Display the version of the server version m Run the server in master mode
132. to the event channel Similarly the consumer uses the push model to receive events from the same channel Each event represents a letter of the alphabet in both upper and lower case forms see Figure 15 gt Structured Push Push Push Structured Push Event Channel Supplier Consumer 720 Figure 15 Orbacus Notify Example Note that this example is taken from the C demos which accompany the Orbacus Notify distribution see notify demo simple StructuredPushSupplier cpp and notify demo simple StructuredPushConsumer cpp or the equivalent Java demos which accompany the Orbacus Notify Console distribution notify demo simple StructuredPushSupplier java and notify demo simple StructuredPushConsumer java In this example the supplier and consumer create the channel admin and proxy objects Alternatively an Orbacus Notify client could use an already existing object either through a published IOR or via the unique ID assigned to such objects within Orbacus Notify For clarity appropriate exception handling and error checking is not included in the code snippets Connecting to a Notification Channel Connecting to a Notification Channel This section describes how suppliers and consumers connect to a notification channel so that they may transfer events Figure 16 illustrates how the supplier and consumer connect to an event channel in this example Each of these steps are described next
133. transmitted in any form or by any means photocopying recording or otherwise without prior written consent of IONA Technologies PLC No third party intellectual property right liability is assumed with respect to the use of the information contained herein IONA Technologies PLC assumes no responsibility for errors or omissions contained in this book This publication and features described herein are subject to change without notice Copyright 2001 2006 IONA Technologies PLC All rights reserved All products or services mentioned in this manual are covered by the trademarks service marks or product names as designated by the companies who market those products Updated 07 Feb 2006 Contents List of Figures Part Using Orbacus Chapter 1 Introduction to Orbacus Overview Chapter 2 Getting Started The Hello World Example Application Defining the Example in IDL Implementing the Example in C Implementing the Server Writing the Server Program Implementing the Client Compiling and Linking Running the Application Implementing the Example in Java Implementing the Server Implementing the Client Compiling Running the Application Summary Where To Go From Here Chapter 3 Generating Code with Orbacus Orbacus Translators Translating IDL to C Translating IDL to Java Translating IDL to HTML Translating IDL to RTF Generating C from an Interface Repository xix RW CONTENTS The IDL to C Translator a
134. type_mask Dispatch events Parameters type_mask If not zero this operation will return once all registered event handlers that match the type mask have unregistered Returns TRUE if all event handlers that match the type mask have unregistered or FALSE If event dispatching has been interrupted interrupt_dispatch void interrupt_dispatch 445 CHAPTER C Reactor Reference 446 Interrupt event dispatching After calling this operation interrupt will return with FALSE dispatch_one_event boolean dispatch_one_event in long timeout Dispatch at least one event Parameters timeout The timeout in milliseconds A negative value means no timeout i e the operation will not return before at least one event has been dispatched A zero timeout means that the operation will return immediately if there is no event to dispatch Returns TRUE if at least one event has been dispatched or FALSE otherwise event_ready boolean event_ready Check whether an event is available Returns TRUE if an event is ready or FALSE otherwise APPENDIX D Logger Reference This appendix describes the Orbacus Logger interfaces In this appendix This appendix contains the following sections Interface OB Logger page 448 Interface OB WLogger page 449 447 CHAPTER D Logger Reference Interface OB Logger local interface Logger The Orbacus message logger interface Ope
135. void connect_push_supplier in CosEventComm PushSupplier push_supplier raises AlreadyConnected Registers a push supplier implementation with the event channel A push supplier need not implement a CosEventComm PushSupplier object to successfully push events on the channel This is only necessary if the supplier wishes for notification when it is disconnected by the channel If this notification is not required a nil object reference may be given Parameters push_supplier A reference to a push supplier implementation or a nil object reference 779 CHAPTER A CosEventChannelAdmin Reference Interface CosEventChannelAdmin ProxyPullSupplier Synopsis Operations 780 interface ProxyPullSupplier inherits from CosEventComm PullSupplier A pull consumer uses this interface to register with an event channel connect_pull_consumer void connect_pull_consumer in CosEventComm PullConsumer pull_consumer raises AlreadyConnected Registers a pull consumer implementation with the event channel A pull consumer need not implement a cosEventComm PullConsumer object to successfully pull events from a channel This is only necessary if the consumer wishes for notification when it is disconnected by the channel If this notification is not required a nil object reference may be passed Parameters pull_consumer A reference to a pull consumer implementation or a nil object reference Module CosEv
136. when it is no longer needed 199 CHAPTER 9 Orbacus Names Programming Example 200 Orbacus includes simple C and Java examples that demonstrate how to use the CORBA Naming Service These examples are located in the folder naming demo We will concentrate on the Java example but the C example works similarly The example expects a Naming Service server to be already running and that the server s initial reference can be resolved by the ORB Because of its volume we have split the code into several parts for the discussion below Initialization Programming Example The first code fragment deals with initializing the ORB iS 00 gt J ay OF oS Go SD Oh Oo NF oS TWWWWWWWNNNNN DY NYDN DN ND oO OF 1 amp 4 OS to Oo so oe WN eS SS Java java util Properties props System getProperties props put org omg CORBA ORBClass com ooc CORBA ORB props put org omg CORBA ORBSingletonClass com ooc CORBA ORBSingleton org omg CORBA ORB orb null try Orb OPB initlargs props org omg CORBA Object poaObj null try poaObj orb resolve_initial_references RootPOA catch org omg CORBA ORBPackage InvalidName ex throw new RuntimeException li POA rootPOA POAHelper narrow poa0bj POAManager manager rootPOA the_POAManager org omg CORBA Object obj null Ery obj orb resolve_initial_references NameService catch org omg CORBA ORBPackage InvalidName ex t
137. wi 8 9 public class B_impl implements BOperations 0 1 public void op_b 2 3 4 5 6 public class I_impl extends B_impl implements IOperations 7 8 public void op_a 9 20 21 22 public void op_i 23 24 Be I Class A_imp1 is defined as implementing aoperations Class B_imp1 is defined as implementing Boperations Class I_imp1 inherits the implementation of op_b from B_imp1 and provides an implementation of op_a and op_i Since a Java class can only extend one class it s not possible for r_imp1 to inherit the implementations of both op_a and op_b Creating Servants Creating Servants Servants are created the same way in both C and Java once your servant class is written you simply instantiate a servant with new 1 You can also instantiate servants on the stack However this only works only for some POA policies so servants are usually instantiated on the heap 103 CHAPTER 5 CORBA Objects Creating Servants using C 104 2 3 Here is how to create servants using C Y ics 2 I_impl servant_pointer new I_impl 3 I_impl another_servant_pointer new I_impl Two servants are created with new Note that this merely instantiates the servants but does not inform the ORB that these servants exist yet The ORB server side run time only learns of the existence of the servants once you activate them In case the servant class was written using the delegation approach an
138. 166 The imr server is also available as a native Windows NT service ntimrservice h help i install s start install u uninstall d debug h Display the command line options supported by help the service i Install the service The service must be started instali manually s Install and start the service start install u Uninstall the service uninstall d Run the service in debug mode debug In order to use the IMR server as a native Windows NT service first add the desired configuration properties to the HKEY_LOCAL_MACHINE NT registry key see Using the Windows NT Registry on page 71 for more details For example add the ooc imr admin_endpoint ooc imr forward_endpoint and ooc imr slave_endpoint properties so that the IMR and OAD will use non default endpoint settings Next the service should be installed with ntimrservice i This adds the orbacus Implementation Repository entry to the Services dialog in the Control Panel To start the service select the orbacus Implementation Repository entry and press start If the service is to be started automatically when the machine is booted select the orbacus Implementation Repository entry then click startup Next select startup Type Automatic and press ox Alternatively the service could have been installed using the s option which configures the service for automatic start up Windows NT Native
139. 224 0 0 0 through 239 255 255 255 By default multicast is not used 383 CHAPTER 19 The Open Communications Interface Command line Options 384 no loopback Specifies that loopback mode of the socket shall be disabled in multicast mode This prevents sending multicast packets back to the local socket For Java this functionality is only available from JDK 1 4 0 on ttl N Specifies the time to live value 0 255 of multicast packets sent System defaults apply if not specified numeric If set and if host is not specified then the canonical dotted decimal address is advertised in IORs The default behavior is to use the canonical hostname if possible port N Specifies the port number on which to bind the socket If no port is specified an unused one will be selected automatically by the operating system Use this option if you plan to publish an IOR e g in a file a naming service etc and you want that IOR to remain valid across executions of your server Without this option your server is likely to use a different port number each time the server is executed This option must be specified if multicast is used transport timeout N Specifies the time in seconds after which inactive connections are reaped The default value is 60 seconds Note When using multicast all servers which belong to the same multicast group must specify the same host add
140. 341 Configuring Clients and Servers page 343 331 CHAPTER 17 Asynchronous Method Invocation Introduction Overview In this section 332 Asynchronous Method Invocation AMI allows the design of asynchronous non blocking clients without change to server side design This allows a client to invoke a request on a server and immediately return without waiting for the request to be serviced The response will be delivered to the client at a later time through either a callback mechanism initiated by the ORB AMI Reply Handler implementation or a polling mechanism initiated by the client AMI Polling implementation The Orbacus 4 3 AMI implementation is based on OMG s CORBA 3 0 2 specification specifically Chapter 22 CORBA Messaging Section II Messaging Programming Model for the client side code generation while the message delivery is done through an AMI Router Quality of Service QoS policies are not currently supported though they will be incorporated into a future release of the product when the routing capability is enhanced The AMl enabled client code is generated by using the with async option for the Orbacus code generators Also the target IDL file must include the AMI idl file Modifying an application s client code to use AMI is discussed in the following sections The AMI echo demos located in the directory ob demo AMI will be used as the basis for this discussion This section c
141. 41 ooc event trace events 242 ooc event trace lifecycle 242 ooc event typed_service 242 ooc ifr options 261 ooc ifr port 261 ooc imr dbdir 168 276 287 ooc imr trace oad 168 276 287 ooc naming callback_ timeout 193 ooc naming database 193 ooc naming no_updates 193 ooc naming port 193 ooc naming timeout 193 ooc naming trace_level 193 ooc oci client 58 ooc oci plugin 58 ooc oci server 58 ooc orb client_timeout 59 ooc orb conc_model 59 ooc orb default_init_ref 59 ooc orb default_wcs 59 ooc orb extended_wchar 59 ooc orb giop max_message_ size 59 ooc orb id 60 ooc orb module name 60 ooc orb modules 60 ooc orb native_cs 60 ooc orb native_wcs 60 ooc orb oa conc_model 65 ooc orb oa endpoint 66 ooc orb oa numeric 67 ooc orb oa thread_pool 66 ooc orb oa version 66 00c orb poamanager manager conc_model 67 ooc orb poamanager manager endpoint 67 ooc orb poamanager manager version 67 ooc orb policy connection_reuse 61 ooc orb policy connect_timeout 61 ooc orb policy interceptor 61 ooc orb policy locate_request 61 ooc orb policy location_transparency 61 ooc orb policy protocol 61 ooc orb policy rebind 61 X ooc orb policy request_timeout 61 X11 Reactor 361 ooc orb policy retry 62 ooc orb policy retry interval 62 ooc orb policy retry max 62 ooc orb policy retry remote 62 ooc orb policy sync_scope 62 ooc orb policy timeout 62 ooc orb server_name 62 ooc orb server_shutdown_timeout 63 ooc orb server_timeout 63 ooc orb service
142. 6 CORBA String_var s orb gt object_to_string Nelib a const char refFile Hello ref 8 ofstream out refFile ollie lt lt lt lt Eimelilp 20 out close Pal 22 manager gt activate 23 Gra gt seuin p 24 25 return EXIT_SUCCESS 26 Using the ORB reference resolve_initial_references is invoked to obtain a reference to the Root POA The Root POA is used to obtain a reference to its POA Manager A servant of type Hello_imp1 is created and assigned to a ServantBase_var variable The servant is then used to incarnate a CORBA object using the _this operation ServantBase_var and Hello_var like all _var types are smart pointer i e servant and hello will release their assigned object automatically when they go out of scope The client must be able to access the implementation object This can be done by saving a stringified object reference to a file which can then be read by the client and converted back to the actual object reference The operation object_to_string converts a CORBA object reference into its string representation 15 CHAPTER 2 Getting Started 22 23 The server must activate the POA Manager to allow the Root POA to start processing requests and then inform the ORB that it is ready to accept requests 1 If your application contains more than one object you do not need to save object references for all objects Usually you save the reference of one obje
143. 75 for more information 55 CHAPTER 4 ORB and Object Adapter Initialization Object Adapter Initialization In Orbacus the object adapter is not initialized until the Root POA is first resolved For example J Gee CORBA Object_var poaObj orb gt resolve_initial_references RootPOA Java org omg CORBA Object poaObj orb resolve_initial_references RootPOA Upon completion the ORB will have created the Root POA and its POA Manager and will have initialized the ORB s server side functionality 56 Configuring the ORB and Object Adapter Configuring the ORB and Object Adapter Overview In this section Orbacus applications can tailor the behavior of the ORB and object adapters using a collection of properties These properties can be defined in a n T umber ways using the Windows Registry Windows NT C using a configuration file using system properties Java using command line options programmatically at run time he Orbacus configuration properties are described in the following sections Unless otherwise noted every property can be used in both C and Java applications This section contains the following subsections ORB Properties page 58 OA Properties page 65 Command line Options page 68 Using a Configuration File page 70 Using the Windows NT Registry page 71 Defining Properties page 72 Precedence of Properties page 74 Advanced Property Usage
144. 91 CHAPTER 5 CORBA Objects Overview 92 A CORBA object is an object with an interface defined in CORBA IDL CORBA objects have different representations in clients and servers e A server implements a CORBA object in a concrete programming language for example in C or Java This is done by writing an implementation class for the CORBA object and by instantiating this class The resulting implementation object is called a servant e Aclient that wants to make use of an object implemented by a server creates an object that delegates all operation calls to the servant via the ORB Such an object is called a proxy When a client invokes a method on the local proxy object the ORB packs the input parameters and sends them to the server which in turn unpacks these parameters and invokes the actual method on the servant Output parameters and return values if any follow the reverse path back to the client From the client s perspective the proxy acts just like the remote object since it hides all the communication details within itself A servant must somehow be connected to the ORB so that the ORB can invoke a method on the servant when a request is received from a client This connection is handled by the Portable Object Adapter POA as shown in Figure 2 Client Server Servant Proxy POA C ORB Figure 2 Servants Proxies and the Object Adapter Overview The Portable Object Adapter i
145. ADDR Specifies the hostname or dotted decimal address of the network interface on which to bind the socket If not specified the socket will be bound to all available interfaces This option is useful in situations where a host has several network interfaces but the server should only listen for connections on a particular interface buffer size N Sets the size of the socket s receive buffer Note that this is only a hint to the operating system To determine the actual size use the trace option when installing the plug in The default value is operating system dependent host ADDR ADDR Specifies a list of one or more hostnames and or dotted decimal addresses representing the addresses that should be advertised in ORs Multiple addresses are represented as multiple tagged profiles If host is not specified the canonical hostname is used This option must be specified if multicast is used message timeout SEC Specifies the expiration time in seconds for incomplete messages Because the plug in may fragment a request into multiple packets it is possible for some packets to be lost If no more packets have arrived for an incomplete message after the specified timeout the message is discarded The default value is 15 seconds multicast Specifies that multicast should be used If this option is set the host and port options must also be specified and the host must be an IP address in the multicast range
146. ATION_TRANSPARENCY_STRICT ensures strict location transparency is followed LOCATION_TRANSPARENCY_RELAXED relaxes the location transparency guarantees for performance reasons Specifically for collocated method invocations the dispatch concurrency model will be ignored and policy overrides are not removed The default value is LOCATION_TRANSPARENCY_RELAXED 434 Module OB Interface OB ProtocolPolicy Attributes Operations local interface ProtocolPolicy inherits from CORBA Policy The protocol policy This policy specifies the order in which profiles should be tried value readonly attribute OCI PluginIdSeq value If a ProtocolPolicy is set then the value specifies the list of plugins that may be used The profiles of an IOR will be used in the order specified by this policy If no profile in an IOR matches any of the plugins specified by this policy a CORBA TRANSIENT exception will be raised By default the ORB chooses the protocol to be used contains boolean contains in OCI PluginId id Determines if this policy includes the given plugin id 435 CHAPTER B Orbacus Policy Reference Interface OB RequestTimeoutPolicy local interface RequestTimeoutPolicy inherits from CORBA Policy The request timeout policy This policy can be used to specify a maximum time limit for requests See Also Interface OB TimeoutPolicy Attributes value readonly attribute unsigned long value If an
147. Admin Obtains the IDs of all consumer admin objects associated with the target object Returns A sequence of admin IDs get_all_supplieradmins AdminIDSeq get_all_supplieradmins Obtains the IDs of all supplier admin objects associated with the target object Returns A sequence of admin IDs 833 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin EventChannelFactory Operations 834 interface EventChannelFactory The EventChannelFactory interface contains operations which support the creation and management of Notification Service event channels create_channel EventChannel create_channel in CosNotification QoSProperties initial_qos in CosNotification AdminProperties initial_admin out ChannelID id raises CosNotification UnsupportedQoS CosNotification UnsupportedAdmin Creates a new channel Parameters initial_gos A sequence of QoS properties to be assigned to the new channel initial_admin A sequence of administrative properties to be assigned to the new channel id The ID assigned to the channel by the target object is returned in this parameter Returns A reference to the newly created channel is returned If any of the QoS properties in initial_Qos are not supported an Unsupporteddos exception is raised If any of the administrative properties in initial_admin are not supported an UnsupportedAdmin exception is raised get_all_channels Cha
148. B_init Enter the CORBA event loop This loop will also dispatch X11 events Alternatively the standard X11 event loop may be called which will also dispatch CORBA events 361 CHAPTER 18 Concurrency Models The Windows Reactor Using a Windows Reactor is very similar to using a X11 Reactor if Cat include lt Windows h gt 1 2 3 4 include lt OB CORBA h gt 5 include lt OB Logger h gt 6 include lt OB Properties h gt y include lt OB OBWindows h gt 8 9 int main int argc char argv 0 il HINSTANCE hInstance GetModuleHandle 0 2 3 OB Reactor_var reactor OB GetWindowsReactor hInstance 4 5 CORBA ORB_var OBCORBA ORB_init argc argv 6 OB r Propet ics camii OB Loggen MN ieeveiwore p T 8 POA initialization not shown 9 20 orb gt run 2i 22 Cleanup not shown 200m 2 7 Include header files 13 Use the Windows application instance to get a Windows Reactor 15 16 Initialize the ORB using the Orbacus specific OBCORBA ORB_init 20 Enter the CORBA event loop which now also dispatches Windows events The standard Windows event loop may also be called which will then also dispatch CORBA events 362 In this chapter CHAPTER 19 The Open Communications Interface The Open Communications Interface OCI defines common interfaces for pluggable protocols TCP IP is one possible candidate for an OCI plug in Since Orbacus uses GIOP suc
149. C Encoding MD5 RSA _WITH_3DES EDE_CBC_SHA const Cipher RSA_WITH_3DES_EDE_CBC_SHA 10 Key Exchange Algorithm RSA Symmetric Encryption Algorithm DEC 168 MAC Encoding SHA RSA_WITH_DES CBC_SHA const Cipher RSA_WITH_DES_CBC_SHA 9 Key Exchange Algorithm RSA Symmetric Encryption Algorithm DEC 56 MAC Encoding SHA RSA _WITH_IDEA_CBC_SHA const Cipher RSA_WITH_IDEA_CBC_SHA 7 Key Exchange Algorithm RSA Symmetric Encryption Algorithm IDEA 128 MAC Encoding SHA RSA _WITH_RC4_128 MD5 const Cipher RSA_WITH_RC4_128_MD5 4 Key Exchange Algorithm RSA Symmetric Encryption Algorithm RC4 128 MAC Encoding MD5 RSA_WITH_RC4_128 SHA const Cipher RSA_WITH_RC4_128_SHA 5 Key Exchange Algorithm RSA Symmetric Encryption Algorithm RC4 128 Aliases Module FSSL MAC Encoding SHA CertificateSeq typedef sequence lt Certificate gt CertificateSeq Alias for an X509 Certificate Chain Cipher typedef unsigned long Cipher An alias for a cipher suite CipherSeq typedef sequence lt Cipher gt CipherSeq Alias for a sequence of Ciphers ContextID typedef unsigned long ContextID Alias for Context ID OctetSeq typedef sequence lt octet gt OctetSeq Alias for sequences of octets PassPhrase typedef sequence lt octet gt PassPhrase Alias for a PassPhrase PrivateKey typedef sequence lt octet gt PrivateKey Alias for a PrivateKey 569 CHAPTER C FSSL Reference Module IOP Constants Structs 570
150. CORBA Object_var myObj obj gt _set_policy_overrides pl CORBA ADD_OVERRIDE Java org omg CORBA Any any orb_ create_any any insert_ulong com ooc OCI IIOP PLUGIN_ID value org omg CORBA Policy pl new org omg CORBA Policy 1 pl 0 orb create_policy com ooc OB PROTOCOL_POLICY_ID value any com ooc CORBA Delegate delegate com ooc CORBA Delegate org omg CORBA portable Object Impl myObj _get_delegate org omg CORBA Object obj delegate set_policy_overrides myObj pl org omg CORBA SetOverrideType ADD_OVERRIDE If it is necessary to revert to a secure transport again for establishing further connections for instance case of a client creating successive connections to secure and insecure servers simply reapply the OCI FSSLIOP PLUGIN_ID protocol policy as needed 539 CHAPTER 2 Extending the Hello World Application Complete Example Certificates OpenSSL iSaSiLk 540 First the certificates must be created for both the client and the server For a real world application the certificates will most likely be provided by an actual certificate authority However for the purposes of this demo we ll generate the certificates by hand First create a certificate authority gt cd tmp gt CA sh newca Next create a certificate request and sign the request using the new certificate authority Use passphrase blahblah gt CA sh newreq gt CA sh sign Next the
151. Control Menu This menu contains operations which control the operation of Orbacus Notify Shutdown Shutdown Orbacus Notify Suspend This operation is available for proxy push supplier and proxy pull consumer objects It interrupts event flow between the selected proxy and the connected supplier or consumer Resume This operation causes previously suspended proxies to resume pushing or pulling events 757 CHAPTER 5 Orbacus Notify Console The View Menu The Help Menu The Popup Menu 758 This menu contains operations which allow the user to configure the console display Show ToolBar Toggles between a visible and hidden toolbar Show StatusBar Toggles between a visible and hidden statusbar Explicit Refresh Toggles the refresh mode of the Service Structure tree If set then the contents of the tree are not automatically refreshed on tree node expansion Refresh Obtains an updated list of items from Orbacus Notify and updates the console display accordingly This option is useful if the list of items has been changed by another Orbacus Notify client This menu is used to access the on line help facilities Help Contents Displays the main help contents page From here the user can navigate the entire on line help system About Displays version and copyright information Right clicking on the various items in the console displays a context sensitive popup menu as shown in Figure 22 Create Destroy
152. D_OVERRIDE 3 Use the RETRY_STRICT mode that is retry only if the exception completion status is COMPLETED_NO 4 Wait 500 milliseconds between successive retries Retry a maximum of 5 times 6 Allow retries on exceptions that are generated remotely in addition to locally generated exceptions 13 14 Set the policy on the object by using the _set_policy_overrides method This method returns a new object that has the set of policies applied 316 Programming Examples And now the same example in Java oo 7 00n PWN FE errero NEBE O is 14 15 16 Java com ooc OB RetryAttributes attrib new com ooc OB RetryAttributes attrib mode com ooc OB RETRY_STRICT value attrib interval 500 attrib max 5 attrib remote true org omg CORBA Any any orb create_any com ooc OB RetryAttributesHelper insert any attrib org omg CORBA Policy policies new org omg CORBA Policy 1 policies 0 orb create_policy com ococ OB RETRY_POLICY_ID value any org omg CORBA Object newObj obj _set_policy_override policies org omg CORBA SetOverrideType ADD_OVERRIDE 1 16 This is equivalent to the C version Note that you can also set the retry policy at the ORB level 317 CHAPTER 16 Using Policies Timeout Policy 318 2 6 7 8 1 10 This example shows how to configure timeouts at the object level As usual the C version is presented first followed by the Java version Hf Cie CO
153. E This is an excellent SSL toolkit available from the IAlK Java Group Please see http jce iaik tugraz at for more information on this product FreeSSL for Java supports the JSSE toolkit JSSE is available from Sun and is bundled with JDK 1 4 and above Please see http java sun com for more information on this product 561 CHAPTER B Toolkits Supported by FSSL 562 APPENDIX C FSSL Reference This appendix documents the FSSL interfaces In this appendix This appendix contains the following sections Module CORBA page 564 Module FSSL page 565 Module IOP page 570 Module OB page 572 563 CHAPTER C FSSL Reference Module CORBA Interface Index Current Provides information on the current connection Policy Provides information on the current policy Aliases PolicyList typedef sequence lt Policy gt PolicyList PolicyType typedef unsigned long PolicyType PolicyTypeSeq typedef sequence lt PolicyType gt PolicyTypeSeq 564 Module FSSL Overview Interface Index Constants Module FSSL The FSSL plug in interfaces This module allows for the configuration of the Secure Sockets Layer OCI plug in Certificate X509 Certificate Interface ContextPolicy Context Policy Interface Current Provides information on the current connection Manager Manager Interface TrustDecider TrustDecider Interface allows users to provide custom certificate chain trust algo
154. E Software 00C Properties Windows NT C only For example a property defined using a command line option overrides the same property defined in a configuration file Configuring the ORB and Object Adapter Advanced Property Usage Examples With the methods for ORB initialization discussed in the previous sections the command line arguments are not processed until a call to CORBA ORB_init C OBCORBA ORB_init C or org omg CORBA ORB init Java Hence the set of properties that will be used by the ORB is not available until after the ORB is initialized This poses a problem if the properties need to be validated prior to ORB initialization If you need access to an ORB s property set before it is initialized then you may elect to use the Orbacus specific operations OB ParseArgs C or com ooc CORBA ORB ParseArgs Java The following examples check the value of the coc orb conc_model property to ensure that it is set to threaded If not the code chooses the threaded concurrency model i ff CMe 2 include lt OB Logger h gt 3 include lt OB Properties h gt 4 5 OB Properties_var dflt OB Properties getDefaultProperties 6 OB Properties_var props new OB Properties dflt 7 OB ParseArgs argc argv props OB Logger _nil 8 const char orbModel props gt getProperty ooc orb conc_model 9 if strcemp orbModel threaded 0 1 1 props gt setPro
155. Event QoS properties Property Value Description EventReliability BestEffort EventReliability when set on a per event Persistent basis sets a different reliability for the target event than that specified at the channel admin proxy level Note that it is not permitted to specify per event Persistent event reliability over a channel with BestEffort event reliability By default the reliability of event delivery is determined by the EventReliability setting of the channel Priority 32767 lt priority The order in which events are delivered to a lt 32767 consumer can be specified based on the priority of an event The lowest priority is 32 767 and 32 767 is the highest The default priority is O Timeout TimeBase TimeT Timeout states a relative expiry time after which an event can be discarded By default events have no relative expiry time StopTime TimeBase UtcT StopTime states an absolute expiry time after which an event can be discarded By default events have no absolute expiry time StartTime TimeBase UtcT StartTime States an absolute earliest delivery time after which the event can be delivered The StartTime property provides the ability to hold an event until a specified time and be eligible for delivery only after that time By default events are eligible for transmission as soon as they are received by the service QoS Properties The following QoS properties are set
156. EventType Reports changes in the event offering to consumers If one or more of the event type names being added or removed is syntactically incorrect the InvalidEventType exception is raised Parameters added A list of new event types being added to those currently offered removed A list of event types no longer being supplied 839 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm NotifySubscribe Operations 840 interface NotifySubscribe The NotifySubscribe interface provides a method which consumers can use to inform suppliers of the event types of interest subscription_change void subscription_change in CosNotification EventTypeSeq added in CosNotification EventTypeSeq removed raises InvalidEventType Reports changes in the event subscription to suppliers If one or more of the event type names being added or removed is syntactically incorrect the InvalidEventType exception is raised Parameters added A list of new event types being added to the current subscription removed A list of event types being removed from the subscription Module CosNotifyComm Interface CosNotifyComm PushConsumer interface PushConsumer inherits from CosNotifyComm NotifyPublish CosEventComm PushConsumer The PushConsumer interface is implemented and registered connected by clients who wish to have unstructured events pushed on them by the channel 841 CHAPTER E CosNotifyComm Referen
157. EventType eventTypes new EventType 1 22 eventTypes 0 eventType 23 24 ConstraintExp constraint new ConstraintExp 25 constraint event_types eventTypes 26 constraint constraint_expr constraintStrings i 27 28 constraints i constraint I Nt 2 15 See 2 15 above 17 26 See 17 22 above 28 See 24 25 above 746 Adding a Filter to an Admin or Proxy Filtering Create Filter Creating a filter is straightforward UG Chat filter filterFactory gt create_filter EXTENDED_TCL Java filter filterFactory create_filter EXTENDED_TCL The single argument to the create_filter method specifies the constraint grammar This example uses EXTENDED_TcL which is the default grammar supported by all compliant notification services Add Constraints to the Filter Once the filter and constraints are available the constraints are added to the filter Again this is straightforward Ue Ce CosNotifyFilter_ConstraintInfoSeq_var info filter gt add_constraints constraints Java ConstraintInfo info filter add_constraints constraints The return value of the add_constraints operation is a Sequence in which each element contains one of the input constraint expressions and the unique identifier for that expression assigned by Orbacus Notify The IDL interfaces CosNotifyChannelAdmin ProxyConsumer CosNotifyChannelAdmin ProxySupplier CosNotifyChannelAdmin ConsumerAdmin
158. Example in Java The object reference is narrowed to a reference to a Hello object A simple Java cast is not allowed here because it is possible that the client will need to ask the server whether the object is really of type Hello The say_hello operation is invoked causing the server to print Hello World on standard output 27 CHAPTER 2 Getting Started Compiling Steps To compile the application Ensure that your CLASSPATH environment variable includes the current working directory as well as the Orbacus for Java classes i e the OB jar file as shown below Platform Command UNIX CLASSPATH your_orbacus_directory lib OB jar SCLASSPATH export CLASSPATH Windows set CLASSPATH your_orbacus_directory lib OBE jar SCLASSPATH 28 Replace your_orbacus_directory with the name of the directory where Orbacus is installed To compile the implementation classes and the classes generated by the Orbacus IDL to Java translator use javac or the Java compiler of your choice javac hello java Implementing the Example in Java Running the Application Steps To run the application complete the following steps 1 Start the Hello World Java server by entering the following command in a command prompt java hello Server 2 Start the Hello World Java client by entering the following command java hello Client Again make sure that your CLASSPATH environm
159. Factory ChannelAlreadyExists CosTypedEventChannelAdmin TypedEventChannel get_channel_by_id in OBEventChannelFactory ChannelId id raises OBEventChannelFactory ChannelNotAvailable OBEventChannelFactory ChannelIdSeq get_channels void shutdown At start up the untyped Event Service creates a single channel having the identifier DefaultEventChanne1 and the typed Event Service creates a single channel having the identifier Default TypedEventChannel A channel s identifier also serves as its object key therefore a channel can be located using a corbaloc URL see corbaloc URLs on page 139 For example a channel with the identifier TelemetryData can be located on the host myhost at port 2098 using the following URL corbaloc myhost 2098 TelemetryData To obtain the object reference of a channel factory use a corbaloc URL with the object key as shown in Table 2 on page 243 For example assuming the untyped Event Service is running on host myhost at port 2098 here is how a C application can obtain the object reference of the channel factory and create a channel with the identifier Telemet ryData Ue Cast CORBA Object_var obj orb gt string_to_object corbaloc myhost 2098 DefaultEventChannelFactory OBEventChannelFactory EventChannelFactory_var factory OBEventChannelFactory EventChannelFactory _narrow ob CosEventChannelAdmin EventChannel_var channel factory gt c
160. Fields contain two name value pairs for the lower and upper case versions of alphabetic character The first step in applying a filter is to obtain a reference to the Default Filter Factory Note that every object of type CosNotifyChannelAdmin EventChannel includes a reference to the DefaultFilterFactory 1g Sane interface EventChannel readonly attribute CosNotifyFilter FilterFactory default_filter_factory he In C the reference is obtained as follows hil Cr CosNotifyFilter_FilterFactory_var filterFactory eventChannel gt default_filter_factory And in Java Java FilterFactory filterFactory eventChannel default_filter_factory This section presents the creation of a simple filter as implemented by the FilteredConsumer demo 12 13 15 Filtering Create Filter Constraints Creating filter constraints involves populating a sequence of type CosNotifyFilter ConstraintExpSeq The details are presented below lo off CSP 2 const CORBA_ULong numConstraints 5 3 const char constraintStrings aA i 5 Supper A 6 Slower e 7 Slower i 8 Supper 0 g Supper U O he dL 2 CosNotifyFilter_ConstraintExpSeq constraints numConstraints constraints length numConstraints 3 4 5 for CORBA_ULong i 0 i lt numConstraints i S i F 8 constraints i event_types length 1 constraints i event_types 0 domain_name 9 CORBA
161. Hi Cast CORBA ORB_var orb Get the ORB somehow CORBA Object_var obj orb gt resolve_initial_references POACurrent PortableServer Current_var current PortableServer Current _narrow ob if CORBA is_nil current Got Current object OK You can keep the reference to the current object in a variable and use it from within any executing operation in a servant There is no need to refresh the current reference for the current operation not even for threaded servers The ORB takes care of ensuring that operation invocations on the current object return the correct data 122 Factory Objects In Java the code to obtain the current reference looks like this Java org omg CORBA ORB orb Get the ORB somehow org omg CORBA Object obj orb resolve_initial_references POACurrent org omg PortableServer Current current org omg PortableServer CurrentHelper narrow obj if current null Got Current object OK 123 CHAPTER 5 CORBA Objects 124 CHAPTER 6 Locating Objects This chapter describes how to locate CORBA servant objects In this chapter This chapter contains the following sections Obtaining Object References page 126 Lifetime of Object References page 130 Stringified Object References page 134 Object Reference URLs page 138 The BootManager page 144 Initial Services page 148 The IORDump utility page 154 125 CHAPTER
162. ION_POLICY_1_2 value try myPOAManager pmFactory create_POAManager MyPOAManager pl catch org omg PortableServer POAManagerFactoryPackage Manager AlreadyExists ex do something catch org omg CORBA PolicyError ex do something Programming Examples Bidirectional Policy BidirectionalPolicy Server This example shows how to create a new POA with the BidirectionalPolicy Implementation enabled to allow negotiation of Bidirectional connection reuse The C example is presented first followed by the Java version Wil Gee CORBA Object_var obj orb gt resolve_initial_references RootPOA PortableServer POA_var rootPOA PortableServer POA _narrow ob 4 PortableServer POAManager_var manager rootPOA gt the_POAManager oOo Oo J oy oF e Ww he CORBA Any any CORBA PolicyList policies 1 policies length 1 any lt lt BiDirPolicy BOTH policies 0 orb gt create_policy BiDirPolicy BIDIRECTIONAL _POLICY_TYPE any PortableServer POA_var myPOA rootPOA gt create_POA MyPOA manager policies Oy C8 gt D E O 2 7 Obtain the reference to the RootPOA and RootPOAManager 9 14 Create a new BidirectionalPolicy containing the value of BiDirPolicy BOTH to enable Bidirectional connection reuse negotiation 16 17 Create the new POA with this policy to enable BiDir negotiation on requests destined for this POA 327 CHAPTER 16 Usi
163. It then returns the actual event data Programming Example After examining the most important aspects of the event suppliers code we are now going to analyze the consumers code The push consumer with its push operation is shown first Java public void push Any any try String s any extract_string System out printin s oo 100 PWN FE wo catch MARSHAL ex er e o Ignore unknown event data RR Wd The push consumer s push operation is called with the event wrapped in a CORBA any In this code fragment it is assumed that the any contains a string with date and time information In case the Any contains another data type a MARSHAL exception is thrown This exception can be ignored here because other events aren t of interest After extracting the string it is displayed in the console window 255 CHAPTER 12 Orbacus Events 256 15 23 In contrast to the push consumer the pull consumer has to actively query the event channel for new events This is how the pull consumer loop looks 1 Java 2 while supplier_ null 3 4 4 Any any null 5 6 try a 8 any supplier_ pull G 0 catch Disconnected ex il 2 Supplier was diconnected from event channel 3 4 5 GEY 6 7 String s any extract_string 8 System out println s S 20 catch MARSHAL ex 2il 22 Ignore unknown event data 29 24 A CORBA any is prepared for later use Usi
164. JTCSynchronized const JTCRWMutex amp mon ReadWriteLockType type Acquires the mutex s lock The destructor releases the mutex s lock 647 CHAPTER A Class Reference Throws JTCSystemCallException Indicates a failed system call 648 JTCSyncT Overview This class is a template version of the gtcSynchronized Class The JtcSyncT template is more efficient than the atcsynchronized class however it is more difficult to use The template s constructor invokes the lock method on the parameter class and the destructor invokes the unlock method This template may also be instantiated with the classes JTCMonitor JTCMutex and JTCRecursiveMutex Constructor JTCSyncT JTCSyncT const T amp mon Acquires the monitor s lock The destructor releases the monitor s lock Throws JTCSystemCallException Indicates a failed system call 649 CHAPTER A Class Reference JTCReadLock Overview Constructor 650 This class is used to acquire and release a read lock To create a synchronized method an instance of this class should be created with the JTCRWMutex as the constructor argument The constructor acquires the lock and the destructor releases the lock JTCReadLock JTCReadLock const JTCRWMutex amp mon Acquires the mutex s lock for reading The destructor releases the mutex s lock Throws JTCSystemCallException Indicates a failed system call JTCWriteLock Overview This class is
165. JTcThread constructor JTCThread JTCThread JTCRunnableHandle target const char name 0 Create a new thread object with a target object and a name Parameters target The object whose run method is invoked when start is called If no object is specified the run method of the thread object must be overridden in a derived class name The name of the thread If no name is specified a default name is used This default name is the string thread concatenated with the thread id A thread id is a system specific identifier generated by the operating system when a new thread is created Application developers are encouraged to use the urcThreadtd Class to refer to thread ids Throws JTCSystemCallException Indicates a failed system call JTCThread JTCThread const char name Create a new thread object with a name Parameters name The name of the thread Throws JTCSystemCallException Indicates a failed system call JTCThread JTCThread JTCThreadGroupHandle amp group JTCRunnableHandle target const char name 0 621 CHAPTER A Class Reference Create a new thread object belonging to a group with a target object and a name Parameters group The thread group target The object whose run method is invoked when start is called If no target object is specified the run method of the thread object must be overridden in a derived class name The name of the thread If no name is specified a de
166. L This URL is the same as the file URL except that it takes a relative file name instead of an absolute file name 143 CHAPTER 6 Locating Objects The BootManager Consider the following corbaloc URL corbaloc myhost 10000 MyObjectId In this example MyoObjectId is the complete object key Normally object keys require more information than a simple name to uniquely identify a POA and a servant within the POA The CORBA specification does not standardize how a server can configure these simple object keys therefore each ORB implementation must provide a proprietary solution In Orbacus the BootManager provides the mapping from a simple object key to a complete object reference 144 The BootManager BootManager Interface Here is the IDL interface for the BootManager module OB local interface BootManager exception NotFound exception AlreadyExists void add_binding in PortableServer ObjectId oid in Object obj raises AlreadyExists void remove_binding in PortableServer ObjectId oid raises NotFound For the complete IDL description please see Appendix A 145 CHAPTER 6 Locating Objects How the BootManager Works 146 When an Orbacus server receives a request the ORB verifies that the key has the ORB s internal format If not the ORB will ask the BootManager if it has a mapping for the foreign key If a match is found the ORB will return a location
167. LICY_ID boolAny 8 CORBA Object_var newObj 9 obj gt _set_policy_overrides policies CORBA ADD_OVERRIDE 2 7 This is the same as in the example for the ORB level Set the policy on the object by using the _set_policy_overrides method This method returns a new object that has the set of policies applied 314 Programming Examples And here is the same example in Java 1 Java 2 org omg CO 3 boolAny in 4 org omg Co 5 policies 0 6 orb create_pol RBA Any boolAny orb create_any sert_boolean false RBA Policy policies new org omg CORBA Policy 1 Licy com ooc OB CONNECTION_REUSE_POLICY_ID value 7 boolAny 8 org omg CO 9 obj _se 10 org RBA Object newObj t_policy_override policies omg CORBA SetOverrideType ADD_OVERRIDE 1 10 This is equivalent to the C version 315 CHAPTER 16 Using Policies Retry Policy This example shows how to configure retries at the object level The C version is presented first followed by the Java version Lo Wy Care 2 OB RetryAttributes attrib 3 attrib mode OB RETRY_STRICT 4 attrib interval 500 5 attrib max 5 6 attrib remote true 7 8 CORBA Any any OM any lt lt attrib 10 CORBA Policylist policies 1 11 policies length 1 12 policies 0 orb gt create policy OB RETRY_POLICY_ID any 13 CORBA Object_var newObj 14 obj gt _set_policy_overrides policies CORBA AD
168. Methods Chapter 4 Memory Management Reference Counting Introducing Handles The JTCHandleT Template Rules of Thumb Appendix A Class Reference xiv JTClnitialize JTCAdoptCurrentThread JTCThread JTCRunnable JTCThreadGroup JTCHandleT JTCMonitor JTCMonitorT JTCRecursiveMutex JTCMutex JTCRWMutex JTCSynchronized JTCSyncT JTCReadLock JTCWriteLock JTCThreadld JTCThreadKey JTCTSS JTCThreadDeath JTCException JTCInterruptedException JTClillegalThreadStateException JTClllegalMonitorStateException JTClillegalArgumentException JTCSystemCallException JTCUnknownThreadException JTCOutOfMemoryError 600 604 608 611 612 613 615 616 617 618 620 621 629 630 635 638 640 642 644 646 647 649 650 651 652 653 654 656 657 659 660 661 662 663 664 665 CONTENTS JTCInitializeError 666 JThreads Bibliography 667 Part IV Orbacus Notification Chapter 1 Introduction 671 Overview 672 Chapter 2 Configuration and Startup 675 Orbacus Notify 676 Orbacus Notify Console 683 Startup Example 684 Chapter 3 Notification Service Concepts 687 Overview 688 The OMG Event Service 690 Delivery Models 691 Object Management Hierarchy 694 Event Delivery 696 The OMG Notification Service 697 Delivery Models 698 Object Management Hierarchy 699 Event Delivery 700 Event Translation 702 Filtering 703 Mapping Filters 707 Quality of Service 709 Proprietary QoS Properties 713 Administrative Pr
169. Module LoadBalancing Util Interface Load Interface Load Interface Load Orbacus Bibliography Balancing Util LoadAlert Balancing Util LoadCalculator Balancing Util LoadU pdater Part II FreeSSL Chapter 1 Using FreeSSL for Orbacus What is SSL Installation Endpoint Configuration Command Line Options Static Linking URL Support Contexts Chapter 2 Extending the Hello World Application Server Side Usage xii 485 486 487 488 489 490 491 492 493 494 499 500 501 502 504 505 506 507 508 509 513 514 517 519 520 521 522 523 529 530 CONTENTS Client Side Usage 534 Determining Peer Identity 537 Preventing Connections to Secure Insecure Servers 539 Complete Example 540 Client Side 541 Server Side 550 Appendix A FSSL Definitions 559 Appendix B Toolkits Supported by FSSL 561 Appendix C FSSL Reference 563 Module CORBA 564 Module FSSL 565 Module IOP 570 Module OB 572 FSSL Bibliography 573 Part Ill JThreads Chapter 1 Introduction to JThreads C 577 Overview 578 Chapter 2 Hello World 581 Hello World in Java 582 Hello World in C 583 Hello World with Runnable 585 Chapter 3 Working With Threads 587 Synchronization 588 Thread Safe Version in Java 590 Thread Safe Version in C 592 Block Synchronization 594 Static Monitors 597 xiii CONTENTS The Wait Notify and NotifyAll Methods The Stop and Suspend Methods The Join and IsAlive
170. NC TUn CORBAD ORB ptr orb int argc char arov OBCORBA ORB_var oborb OBCORBA ORB _narrow orb Obtain the ORB s property set OB Properties_var props oborb gt properties ty Resolve the FSSL Context Manager CORBA Object_var fsslManagerObj orb gt resolve_initial_references FSSLContextManager FSSL Manager_var fsslManager FSSL Manager _narrow fsslManagerOb Java Sieciesle Manat run org omg CORBA ORB orb String args throws org omg CORBA UserException Obtain the ORB s property set java util Properties props com ooc CORBA ORB orb properties Hi Resolve the FSSL Context Manager com ooc FSSL Manager fsslManager com ooc FSSL ManagerHelper narrow orb resolve_initial_references FSSLContextManager Complete Example Next the certificate chain for the server must be created This is exactly the same procedure as for the client Lie Cie Ei Create the servers certificate chain Ee FSSL Certificate_var serverCert fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file server der FSSL Certificate_var caCert fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file ca der FSSL CertificateSeq chain chain length 2 chain 0 serverCert chain 1 caCert Java Hil Create the server certificate chain com ooc FSSL Certificate s
171. NECTION_REUSE_POLICY_ID 1330577411 This policy type identifies the connection reuse policy CONNECT_TIMEOUT_POLICY_ID const CORBA PolicyType CONNECT_TIMEOUT_POLICY_ID 1330577416 This policy type identifies the connect timeout policy INTERCEPTOR_POLICY_ID const CORBA PolicyType INTERCEPTOR_POLICY_ID 1330577415 This policy type identifies the interceptor policy LOCATE_REQUEST_POLICY_ID const CORBA PolicyType LOCATE_REQUEST_POLICY_ID 1330577418 This policy type identifies the locate request policy LOCATION_TRANSPARENCY_POLICY_ID const CORBA PolicyType LOCATION_TRANSPARENCY_POLICY_ID 1330577414 This policy type identifies the location transparency policy LOCATION_TRANSPARENCY_RELAXED const short LOCATION_TRANSPARENCY_RELAXED 1 The LOCATION_TRANSPARENCY_RELAXED LocationTransparencyPolicy value LOCATION_TRANSPARENCY_STRICT const short LOCATION_TRANSPARENCY_STRICT 0 The LOCATION_TRANSPARENCY_STRICT LocationTransparencyPolicy value PROTOCOL _POLICY_ID const CORBA PolicyType PROTOCOL_POLICY_ID 1330577410 This policy type identifies the protocol policy REQUEST TIMEOUT POLICY_ID const CORBA PolicyType REQUEST_TIMEOUT_POLICY_ID 1330577417 This policy type identifies the request timeout policy Structs Module OB RETRY_ALWAYS const short RETRY_ALWAYS 2 The RETRY_ALWAYS RetryPolicy value RETRY_NEVER const short RETRY_NEVER 0 The RETRY_NEVER RetryPolicy value RETRY_
172. NotifyChannelAdmin ConsumerAdmin Attributes Operations 826 interface ConsumerAdmin inherits from CosNotification QoSAdmin CosNotifyComm NotifySubscribe CosNotifyFilter FilterAdmin CosEventChannelAdmin ConsumerAdmin The ConsumerAdmin interface supports the creation of proxy suppliers MyID readonly attribute AdminID MyID The ID assigned to the target admin object by the channel MyChannel readonly attribute EventChannel MyChannel A reference to the parent channel MyOperator readonly attribute InterFilterGroupOperator MyOperator The InterFilterGroupOperator to be used when combining filter results from the target admin object and its child proxies priority_filter attribute CosNotifyFilter MappingFilter priority_filter Reference to an optional priority mapping filter lifetime_filter attribute CosNotifyFilter MappingFilter lifetime_filter Reference to an optional lifetime mapping filter pull_suppliers readonly attribute ProxyIDSeq pull_suppliers A list of pull suppliers managed by the target admin object push_suppliers readonly attribute ProxyIDSeq push_suppliers A list of push suppliers managed by the target admin object get_proxy_supplier ProxySupplier get_proxy_supplier in ProxyID proxy_id Module CosNotifyChannelAdmin raises ProxyNotFound Obtains a reference to a proxy supplier with the given proxy ID Parameters proxy_id The ID of the proxy to locate A consume
173. ORBA_ORB_var orb_ CORBA_BOA_var boa_ public w O I oo GT e WN FE StructuredPushConsumer_imp1 CORBA_ORB_ptr orb CORBA_BOA_ptr boa orb_ CORBA_ORB _duplicate orb boa_ CORBA_BOA _duplicate boa virtual StructuredPushConsumer_impl orn uu bWNE 9 20 void 21 push_structured_event 22 const CosNotification_StructuredEvent amp event 23 24 cout lt lt Pushed lt lt endl 25 if DisplayEvent event 26 throw CosEventComm Disconnected 27 28 735 CHAPTER 4 Programming Example 2 3 5 6 9 18 20 27 29 34 36 41 736 29 void 30 disconnect_structured_push_consumer Sil 32 orb_ gt disconnect this 2B bes gt deactivate_impl CORBA ImplementationDef _nil 34 35 36 void oF offer_change const CosNotification_EventTypeSeq amp added 38 const CosNotification_EventTypeSeq amp removed 39 40 Event offering has changed 41 A fhe New class defining our servant Note the derivation from CosNotifyComm_StructuredPushConsumer_skel which is generated by the IDL compiler from CosNotifyComm idl Keep a reference to the ORB and the BOA Constructor and destructor Store our reference to the ORB and BOA in _var types for automatic memory management Implement the push_structured_event method This method is invoked each time the channel pushes an event in this example the consumer displays the event The DisplayEvent routine returns tru
174. Orbacus User Guide Version 4 3 1 IONA Technologies PLC Orbix IONA Enterprise Integrator Enterprise Integrator Orbix E2A Application Server Orbix E2A XMLBus XMLBus are trademarks or registered trademarks of IONA Technol ogies PLC and or its subsidiaries Orbacus and JThreads C are trademarks or registered trademarks of IONA Tech nologies Inc IONA IONA Technologies the IONA logo Making Software Work Together IONA e Busi ness Platform and Total Business Integration are trademarks or registered trademarks of IONA Technologies PLC and or its subsidiaries Java and J2EE are trademarks or registered trademarks of Sun Microsystems Inc in the United States and other countries CORBA is a trademark or registered trademark of the Object Management Group Inc in the United States and other countries All other trademarks that appear herein are the property of their respective owners While the information in this publication is believed to be accurate IONA Technologies PLC makes no warranty of any kind to this material including but not limited to the implied warranties of merchantability and fitness for a particular purpose IONA Technologies PLC shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing performance or use of this material COPYRIGHT NOTICE No part of this publication may be reproduced stored in a retrieval system or
175. Orbacus db This file is placed in the usr local Orbacus etc directory 2 Start the service in administrative mode balancer ORBconfig usr local Orbacus etc balancer conf administrative 3 Create the load balanced group Before starting the load balanced servers the associated load balanced group must be created This can be done using the 1badmin utility as follows lbadmin ORBInitRef Balancer corbaloc lbhost 10000 Balancer create group Hello Where 1bhost is the host running the service 4 Add the members The members can be added to the group explicitly using the add member command of the 1badmin utility or they can be added automatically when the load balanced servers are started Note that members cannot be added automatically by the load balanced servers if the service is not running in administrative mode 5 Configure the load balancing strategy The set strategy Of set custom strategy commands of the lbadmin utility may be used to configure the group s load balancing strategy For example to use the least load Strategy lbadmin ORBInitRef Balancer corbaloc lbhost 10000 Balancer 298 Programming Example set strategy least load tolerance 5 load per client 5 Note that the strategy may also be changed after the load balanced servers are started 6 Start the load balanced servers For example to start a server for the member with ID member1 run server ORBInitRef Balancer corbaloc
176. POLICY_ID const CORBA PolicyType RETRY_POLICY_ID 1330577412 This policy type identifies the retry policy RETRY_STRICT const short RETRY_STRICT 1 The RETRY_STRICT RetryPolicy value TIMEOUT_POLICY_ID const CORBA PolicyType TIMEOUT_POLICY_ID 1330577413 This policy type identifies the timeout policy RetryAttributes struct RetryAttributes short mode unsigned long interval unsigned long max boolean remote The retry information 429 CHAPTER B Orbacus Policy Reference Interface OB ConnectTimeoutPolicy local interface ConnectTimeoutPolicy inherits from CORBA Policy The connect timeout policy This policy can be used to specify a maximum time limit for connection establishment See Also Interface OB TimeoutPolicy Attributes value readonly attribute unsigned long value If an object has a connect TimeoutPolicy set and a connection cannot be established after value milliseconds a CORBA NO_RESPONSE exception is raised The default value is 1 which means no timeout 430 Module OB Interface OB ConnectionReusePolicy local interface ConnectionReusePolicy inherits from CORBA Policy The connection reuse policy This policy determines whether connections may be reused or are private to specific objects Attributes value readonly attribute boolean value If an object has a Connect ionReusePolicy set with value set to FALSE then other object references will not be p
177. Product objects either because the programmer who wrote the client forgot to invoke dest roy or because the client program crashed before it had a chance to clean up You should keep these issues in mind when designing your own factory objects 1 Two possible strategies for handling this issue include time outs in which a servant that has not been used for some length of time is automatically released and expiration in which an object reference is only valid for a certain length of time after which a client must obtain a new reference The implementation of these solutions is beyond the scope of this manual 119 CHAPTER 5 CORBA Objects Obtaining the POA for a Servant 120 As mentioned in the previous sections every servant inherits a _default_poa function from its skeleton class The default implementation of this function returns the Root POA If you instantiate servants on anything but the Root POA you must override the function in the servant otherwise calls to _this will create incorrect object references Usually this involves remembering the POA reference for a servant in a private member variable and returning that reference from a call to _default_poa If all servants for objects of a particular interface type use the same POA you can use a static member variable In C you can use an approach similar to the following Ii CE class Product_impl public virtual POA_Product public virtual PortableServer
178. PropertyErrorSeq error An InvalidProperties exception indicates that specified properties were not valid and could not be used to create the strategy Module LoadBalancing Interface LoadBalancing LoadAlert interface LoadAlert Implemented by a server that wishes to receive load alerts a signal to redirect requests back to the Balancer Operations alert void alert Redirect the next request back to the Balancer 499 CHAPTER F Orbacus Balancer Reference Interface LoadBalancing Strategy Operations 500 interface Strategy Used to choose the next member to service a new client connection The Balancer provides several implementations of the Strategy interface get_name string get_name Retrieve the name of the strategy get_properties PropertySeq get_properties Get the property set of the strategy adjust void adjust in MemberDataSeq members Update the members get_next MemberId get_next raises MemberNotFound Get an un loaded member push_load void push_load in MemberId member_id in unsigned long load raises MemberNotFound StrategyNotAdaptive Update the load of a member destroy void destroy Destroy the strategy Module LoadBalancing Interface LoadBalancing StrategyProxy Operations interface StrategyProxy Acts as a proxy for the load balancing strategy get_name string get_name Retrieve the name of the strategy get_p
179. RB and obtaining an object reference we invoke _get_interface_def on the object If no interface definition could be found _get_interface_def returns nil Narrow the object reference to InterfaceDef We now have a reference to an object in the IFR that describes the most derived type of our object reference Request a complete description of the interface Print information about the interface including the names of its operations and attributes A complete example of how to use the IFR can be found in the ob demo repository subdirectory 1 Recent versions of the IDL to Java mapping introduced the _get_interface_def operation which returns org omg CORBA Ob ject instead of org omg CORBA InterfaceDef Portable Java applications should use _get_interface_def In C the operation is _get_interface In this chapter CHAPTER 14 Orbacus Balancer Orbacus Balancer provides load balancing of client connections across a group of replicated objects The load balancing service provided by Orbacus Balancer is transparent and interoperable with any CORBA client However the interface between the servers and the service is strictly proprietary This chapter contains the following sections Basic Concepts on page 268 Load Balancing Strategies on page 269 Service Security on page 272 Usage on page 273 Connecting to the Service on page 281 Load Balanced IMR enabled Servers
180. RBA Any ULongAny ULongAny lt lt CORBA ULong 1000 CORBA PolicyList policies 1 policies length 1 policies 0 orb gt create policy OB TIMEOUT_POLICY_ID ULongAny 7 CORBA Object_var newObj 8 obj gt _set_policy_overrides policies CORBA ADD_OVERRIDBE Oo fF WN F We want to set the timeout to a value of 1000 milliseconds Set the policy on the object by using the _set_policy_overrides method This method returns a new object that has the set of policies applied And now the same example in Java Lo J Dawa 2 org omg CORBA Any ULongAny orb create_any 3 ULongAny insert_ulong 1000 4 org omg CORBA Policy policies new org omg CORBA Policy 1 5 policies 0 6 orb create_policy com ooc OB TIMEOUT_POLICY_ID value 7 ULongAny 8 org omg CORBA Object newObj 9 obj _set_policy_override policies 10 org omg CORBA SetOverrideType ADD_OVERRIDE This is equivalent to the C version Note that you can also set the timeout policy at the ORB level Programming Examples Interceptor Call Policy 2 7 9 15 17 18 This example shows how to create a new POA with server side interceptors disabled The C version is presented first followed by the Java version il CBRE CORBA Object_var obj orb gt resolve_initial_references RootPOA PortableServer POA_var rootPOA PortableServer POA _narrow ob PortableServer POAManager_var manager rootPOA
181. RBA string_dup memberId 20 CORBA Any any ale any lt lt value _retn 22 CORBA Policy_var memberPolicy 23 orb gt create_policy LoadBalancing MEMBER_POLICY_ID any 24 292 4 6 16 23 25 33 35 40 Programming Example 25 CORBA PolicyList pl 3 26 ple leno hie 20 pl 0 rootPOA gt create_lifespan_policy 28 PortableServer PERSISTENT 29 pl 1 rootPOA gt create_id_assignment_policy 30 PortableServer USER_ID Sil pl 3 memberPolicy oe PortableServer POA_var helloPOA 33 rootPOA gt create_POA hello manager pl 34 35 Hello_imp1l helloImpl new Hello impl helloPOA 36 PortableServer ServantBase_var servant helloImpl Si PortableServer ObjectId_var oid 38 PortableServer string_to_ObjectId hello 39 helloPOA gt activate_object_with_id oid servant 40 Hello_var hello helloImpl gt _this 41 42 manager gt activate 43 orb gt run 44 45 return EXIT_SUCCESS 46 Check the arguments for the member ID Create the member policy The group ID will be He11o and the member ID is an argument of the program Create the member POA Create the Hello servant and activate it on the member POA The remainder of the run function is similar to that of Chapter 293 CHAPTER 14 Orbacus Balancer Adaptive Load Balancing To use adaptive load balancing the Hello server must send load updates to the service and react to
182. RBA System Exceptions INTF_REPOS Error accessing interface repository BAD_CONTEXT Error processing context object OBJ_ADAPTER Failure detected by object adapter DATA_CONVERS ION Error in data conversion OBJECT_NOT_EXIST Non existent object references should be discarded TRANSACTION_REQUIRED Active transaction context required TRANSACTION_ROLLEDBACK Transaction has rolled back or is marked to be rolled back IVALID_TRANSACTION Invalid transaction context NV_POLICY Invalid Policy CODESET_INCOMPATIBLE Incompatible client and server native code sets REBIND Thrown on a OBJECT_FORWARD or LOCATION_FORWARD status depending on the RebindPolicy TIMEOUT Time to live period was exceeded TRANSACTION_UNAVATLABLE Transaction service context could not be processed TRANSACTION_MODE Mismatch between TransactionPolicy and current transaction mode BAD_OQOS Object cannot support the required QOS In the following subsections the minor exception codes are presented Minor codes that are Orbacus specific are presented as MinorCodeName that is are tagged with the superscript This section describes the following minor exception codes INITIALIZE Minor Exception Code page 403 UNKNOWN Minor Exception Code page 404 401 CHAPTER 20 Exceptions and Error Messages 402
183. RC4_40_MD5 17 Key Exchange Algorithm DH Symmetric Encryption Algorithm RC4 40 MAC Encoding MD5 Module FSSL DH_anon_WITH_3DES_EDE_CBC_SHA const Cipher DH_anon_WITH_3DES_EDE_CBC_SHA 21 Key Exchange Algorithm DH Symmetric Encryption Algorithm DES 168 MAC Encoding SHA DH_anon_WITH_DES CBC_SHA const Cipher DH_anon_WITH_DES_CBC_SHA Key Exchange Algorithm DH 20 Symmetric Encryption Algorithm DES 56 MAC Encoding SHA DH_anon_WITH_RC4_128 MD5 const Cipher DH_anon_WITH_RC4_128_MD5 Key Exchange Algorithm DH 18 Symmetric Encryption Algorithm RC4 128 MAC Encoding MD5 RSA_EXPORT_WITH_DES40 CBC_SHA const Cipher RSA_EXPORT_WITH_DES40_CBC_SHA 8 Key Exchange Algorithm RSA Symmetric Encryption Algorithm DES 40 MAC Encoding SHA RSA_EXPORT_WITH_NULL_MD5 const Cipher RSA_EXPORT_WITH_NULL_MD5 Key Exchange Algorithm RSA Symmetric Encryption Algorithm NULL MAC Encoding MD5 Il m RSA_EXPORT_WITH_NULL_SHA const Cipher RSA_EXPORT_WITH_NULL_SHA Key Exchange Algorithm RSA Symmetric Encryption Algorithm NULL MAC Encoding MD5 Il N RSA_EXPORT_WITH_RC2_CBC_40 MD5 const Cipher RSA_EXPORT_WITH_RC2_CBC_40_MD5 6 567 CHAPTER C FSSL Reference 568 Key Exchange Algorithm RSA Symmetric Encryption Algorithm RC2 40 MAC Encoding MD5 RSA_EXPORT_WITH_RC4_ 40 MD5 const Cipher RSA_EXPORT_WITH_RC4_40_MD5 3 Key Exchange Algorithm RSA Symmetric Encryption Algorithm RC4 40 MA
184. RS Excingmaupi ts 1 20 2il constraints i event_types 0 type_name 22 CORBASSCEINOSGUGICA A i 29 24 constraints i constraint_expr 25 CORBA_string_dup constraintStrings i BG jf Constraint expressions In this example events which represent vowels are interesting The constraint Supper A can be interpreted as match events which have a filterable field named upper and a value of eA Initialize the sequence to hold numconstrainsts expressions Iterate over the constraintStrings array assigning each element to a separate constraint expression 745 CHAPTER 4 Programming Example 17 22 Event types are characterized by the domain_name and type_name fields A constraint is the intersection of a single constraint expression and one or more event types For this example we are only interested in events with filterable data section elements that satisfy our constraint expression Any event type will satisfy these constraints 24 25 Specify the constraint expression 1 Java 2 final int numConstraints 5 3 String constraintStrings A i 5 Supper A 6 Slower e i Slower Tinm 8 Supper 0O 9 Supper U O Hg F 2 ConstraintExp constraints 5 new ConstraintExp numConstraints 4 5 forint i 0 7 i lt p umConstraints 7 t i 4 a EventType eventType new EventType 8 eventType domain_name 9 eventType type_name 20 2k
185. RefCountServantBase PortableServer POA_var poa_ papke void Product_impl PortableServer POA_ptr poa poa_ PortableServer POA _duplicate poa virtual PortableServer POA_ptr _default_POA return PortableServer POA _duplicate poa_ O amt aed es Wa 2 e Se 2 a The constructor accepts a POA reference and remembers that reference in a private member variable The _default_poa function returns the servant s POA In Java the approach is very similar Factory Objects 121 CHAPTER 5 CORBA Objects Getting the POA for a Currently Executing Request The ORB provides access to an object of type PortableServer Current Jit wpa module PortableServer interface Current CORBA Current exception NoContext POA get_POA raises NoContext ObjectId get_object_id raises NoContext J This interface provides access to the POA and the object ID for an executing request Note that these operations must be invoked only from within the context of an executing operation inside a servant otherwise they raise NoContext The Current object provides a useful way to obtain access to a servant s POA and object ID without having to store the POA reference in a member variable at the cost of being accessible only from within an operation implementation You can obtain a reference to the Current object from resolve_initial_references In C the code looks something like this C
186. Reference 832 A reference to the newly created consumer admin is returned new_for_suppliers SupplierAdmin new_for_suppliers in InterFilterGroupOperator op out AdminID id Creates a new supplier admin Parameters op The InterFilterGroupOperator to apply between filter results from the target object and subsequently created proxy objects id The id assigned to the new supplier admin by the event channel Returns A reference to the newly created supplier admin is returned get_consumeradmin ConsumerAdmin get_consumeradmin in AdminID id raises AdminNotFound Obtains a reference to a consumer admin from an admin ID Parameters id The ID of the admin for which a reference is required The ID is originally assigned by the channel on creation of the admin Returns A reference to the consumer admin with the given ID If no matching admin object is found an AdminNotFound exception is raised get_supplieradmin SupplierAdmin get_supplieradmin in AdminID id raises AdminNotFound Obtains a reference to a supplier admin from an admin ID Parameters id The ID of the admin for which a reference is required The ID is originally assigned by the channel on creation of the admin Returns A reference to the supplier admin with the given ID If no matching admin object is found an AdminNotFound exception is raised get_all_consumeradmins AdminIDSeq get_all_consumeradmins Module CosNotifyChannel
187. Server name Reset a server Note that the imradmin utility also needs to be configured with the IMR initial reference see Connecting to the Service on page 169 The host argument is optional If host is not specified the local host name is used The server name argument refers to the name of the server The format of the poa name argument is poal poa2 poa3 where poal is a child of the Root POA poa2 is a child of poai and poa3 is a child of poa2 Refer to Information Managed by the IMR on page 160 for further details In very rare circumstances it s possible for the IMR and OAD to become confused as to the state of a server In this case it might be necessary to manually reset the state of the server using the reset server command It is also necessary to use this command if the server continually crashes on startup and has reached the maximum number of retries specified by its max_spawns attribute This prevents the OAD from continually starting the same broken server The mkref utility creates IMR based object references for use by clients Since the Object ID is required to create a reference this utility can only be used to create references for objects created by POAs using the USER_ID object identification policy Its usage is shown below mkref H host poal poa2 poan P port server name object id host The host that the imr server is running on The default value is the canonical
188. Service ntimrservice s If you want to remove the service run ntimrservice u Note If the executable for the service is moved it must be uninstalled and re installed Any trace information provided by the service is be placed in the Windows NT Event Viewer with the title 1mrservice To enable tracing information add the desired trace configuration property i e one of the ooc imr trace properties or one of the coc orb trace properties to the HKEY_LOCAL_MACHINE NT registry key with a REG_sz value of at least 1 167 CHAPTER 7 The Implementation Repository Configuration Properties In addition to the standard configuration properties described in Chapter 4 the IMR also supports the following properties Property Value Description ooc imr mode master slave dual Specifies the mode in which the imr server will be started ooc imr administrative true false If set to true then run the IMR in administrative mode For details refer to the a command line option ooc imr dbdir directory Equivalent to the a command line option ooc imr admin_endpoint info Equivalent to the a command line option ooc imr forward_endpoint info Equivalent to the F command line option ooc imr slave_endpoint info Equivalent to the s command line option ooc imr locator_endpoint info Equivalent to the L command line option ooc imr trace peer_status level gt 0 Defines the output level for IMR diagnostic message
189. Service 9 specification for details 232 Programming Example Programming Example The Property Service test suite which is part of the Orbacus distribution provides a good example of how to create properties and query for their values The code below is based on excerpts of this test suite which is located in the directory property test We will concentrate on an example in Java here As with the previous examples the Java code is very similar to what is necessary in C The example demonstrates how to create properties and how to get a list of all the properties defined within a PropertySet 1 Java 2 3 org omg CORBA Object obj null 4 D Ery 6 a obj orb resolve_initial_references PropertyService 8 9 catch org omg CORBA ORBPackage InvalidName ex 0 il An error occurred Property Service is not available 2 3 4 if obj null 5 6 The object reference is invalid gi 8 9 PropertySetDefFactory factory null 20 try all 4 22 factory PropertySetDefFactoryHelper narrow obj 200 24 catch org omg CORBA BAD_PARAM ex ye YL 26 This object does not implement the Property Service Pail jt 28 29 PropertySetDef set factory create_propertysetdef w 233 CHAPTER 11 Orbacus Properties 5 27 234 iS fs ES PS Ge PS FE TS PS DeO woo o O e WN Ee Ow Sa ony Cony Lon fen on Cony Cony toni Cony Vony Tn e Cea Gal Gn Tony tenn on ah Cas Om GW hr OS OO 1 6 OF amp WO Ne
190. Setting a policy at the ORB level means that the ORB will honor this policy for all newly created objects Existing objects maintain their current set of policies Setting a policy at the object level overrides any ORB level policies applied to that object Setting the connection reuse policy to false at the ORB level means that the ORB will create a new connection from the client to the server for each new proxy object instead of reusing existing ones Setting the connection reuse policy to false at the object level means that the client does not reuse connections to the server only for a particular proxy object If the connection reuse policy is set to true at some later point communications channels that were previously created with a connection reuse policy set to false will not be reused That is the connection reuse policy is sticky in the sense that the reuse policy that was in effect at the time that a communications channel is created stays with it Setting the reuse policy at the object level means that for a client the ORB will not reuse the communications channel that is associated with the proxy object Our first example shows how the connection reuse policy can be set at the ORB level First in C Hil Case CORBA Any boolAny boolAny lt lt CORBA Any from_boolean 0 CORBA PolicyList policies policies length 1 policies 0 orb gt create_policy OB CONNECTION_REUSE_POLICY_ID boolAny CORBA Objec
191. SiLk see 6 The SSL protocol ensures that the connection between communicating parties is reliable The integrity of the message data is verified using a keyed Message Authentication Code MAC The sender of a message uses a secure one way hash function e g SHA MD5 to compute a unique MAC for the message The receiver uses the same function to compute its own MAC and then compares what it computed against the MAC computed by the sender This means that corrupted or deliberately changed messages can be detected because the two MACs will not match Cipher Suites A cipher suite 1 defines The public key algorithm used for peer authentication and key exchange The symmetric algorithm used for data encryption The secure hash function for MAC computation During the initial handshake the client offers its set of supported cipher suites in its preferred order The server responds by selecting one of the suites or raising a handshake failure if they have none in common The following table summarizes the algorithms used by each cipher suite for key exchange symmetric cryptography and MAC calculation Note that the SSL plug in only supports the RSA and ADH suites Table 1 Supported Cipher Suites Name Key Alg Symmetric Alg MAC Calc FSSL_RSA_EXPORT_WITH_NULL_MD5 RSA None MD5 FSSL_RSA_EXPORT_WITH_NULL_ SHA RSA None SHA FSSL_RSA_EXPORT_WITH_RC4_40_ MD5 RSA RC4 40 bits MD5 FSSL_RSA_WITH_ RC4_128 MD5 RSA RC4 128 bi
192. Static Linking page 521 URL Support page 522 Contexts page 523 513 CHAPTER 1 Using FreeSSL for Orbacus What is SSL Overview How Does It Work 514 The Secure Sockets Layer SSL protocol developed by Netscape Communications Corporation provides communications privacy over a network It is designed to prevent eavesdropping tampering and message forgery The FreeSSL plug in enables secure communications using the Orbacus ORB in both Java and C The plug in supports SSLv3 as defined in 1 SSL uses symmetric cryptography for data communication e g DES In symmetric cryptography both parties use the same key to encrypt and decrypt data This is different than asymmetric cryptography in which different keys are used for encryption and decryption The advantage of using symmetric cryptography for securing message traffic is that it operates much faster than asymmetric cryptography thereby minimizing the overhead incurred by the use of a secure communication protocol Asymmetric cryptography also known as public key cryptography e g RSA DSS is still used in the SSL protocol for authentication and key exchange Using public key cryptography each party has an associated public and private key Data encrypted with the public key can only be decrypted with the private key and vice versa This allows a party to prove its identity by encrypting the data with its private key As no other party has access to
193. Structure Event Header Event Body Filtering In this example the filter object is treated much like an event channel in that it is not necessarily created during each execution of the demo If the demo application determines that it must create a filter it does so and publishes the IOR for the filter Subsequent executions of the demo then attempt to re use this filter Obtaining a filter from its IOR is straightforward Ii Cre CORBA_Object_var obj Get object from filter IOR CosNotifyFilter_Filter_var filter CosNotifyFilter_Filter _narrow ob Java org omg CORBA Object obj Get object from Filter TOR Filter filter FilterHelper narrow ob The structure of the demo events see Figure 20 is presented before discussing filter creation domain_name alpha type_name character Fixed Header event_name Hh Variable ae Header d lt fi I di fi 1 h ai a Gaa Filterable fd_name upper fd_value H Fields m lt Remaining Body d lt Figure 20 Demo Event Structure 743 CHAPTER 4 Programming Example Obtaining a Reference to the Filter Factory Obtaining a Filter 744 For demonstration purposes all events share the same domain_name and type_name field values The event_name field is a concatenation of the filterable field values The Variable Header and Remaining Body of the event structure are left empty The Fi terable
194. The Orbacus Notify Console Main Window Popup Menu Sample Creation Wizard Notification Channel QoS Properties Notification Channel Admin Properties Admin QoS Properties Consumer Admin Mapping Filters Admin Subscription Offer Types Proxy QoS Properties Supplier Proxy Mapping Filters Proxy Subscription Offer Types Constraint Expression Properties Constraint Event Type Properties Constraint Expression Properties Constraint Event Type Properties Constraint Result to Set Properties 702 703 705 708 720 722 726 731 742 743 755 758 759 761 762 763 764 765 766 767 768 770 771 774 775 776 Part Using Orbacus In this part This part contains the following chapters Introduction to Orbacus page 3 Getting Started page 7 Generating Code with Orbacus page 33 ORB and Object Adapter Initialization page 53 Locating Objects page 125 The Implementation Repository page 157 The Implementation Repository Console page 181 Orbacus Names page 187 Orbacus Names Console page 211 Orbacus Properties page 225 Orbacus Events page 237 The Interface Repository page 257 Orbacus Balancer page 267 Orbacus Watson page 301 Using Policies page 307 Asynchronous Method Invocation page 331 Concurrency Models page 347 The Open Communications Interface page 363 Exceptions and Error Messages page 399 Boot Manager Reference page 423 Orbacus Polic
195. The sequence of Connectors equivalent boolean equivalent in IOR iorl in IOR ior2 Checks whether two IORs are equivalent taking only profiles into account matching this Connector factory Parameters ior1 The first IOR to check for equivalence ior2 The second IOR to check for equivalence Returns TRUE if the IORs are equivalent FALSE otherwise hash unsigned long hash in IOR ref in unsigned long maximum Calculates a hash value for an IOR Parameters ref The IOR to calculate a hash value for maximum The maximum value of the hash value Returns The hash value get_info ConFactoryInfo get_info Returns the information object associated with the Connector factory Returns The Connector factory information object 473 CHAPTER E Open Communications Interface Reference Interface OCI ConFactoryInfo Synopsis Attributes Operations 474 local interface ConFactoryInfo Information on an OCI ConFactory object See Also Interface OCI ConFactory id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag describe string describe Returns a human readable description of the transport Returns The description add_connect_cb void add_connect_cb in ConnectCB cb Add a callback that is called whenever a new connection is established If the callback has already been registered this
196. TypeSeq Alias for a sequence of event types Constants Module CosNotification NamedPropertyRangeSeq typedef sequence lt NamedPropertyRange gt NamedPropertyRangeSeq Alias for a sequence of named property ranges PropertyErrorSeq typedef sequence lt PropertyError gt PropertyErrorSeq Alias for a sequence of property errors EventBatch typedef sequence lt StructuredEvent gt EventBatch Alias for a sequence of structured events EventReliability const string EventReliability EventReliability Specifies event reliability The valid values are BestEffort and Persistent BestEffort const short BestEffort Reliability property value 0 Persistent const short Persistent 1 Reliability property value ConnectionReliability const string ConnectionReliability ConnectionReliability Specifies connection reliability The valid values are BestEffort and Persistent Priority const string Priority Priority Indicates the relative priority of the event compared to other events in the channel Can take on any value between 32 767 and 32 767 with 32 767 being the lowest priority 32 767 being the highest and O being the default LowestPriority const short LowestPriority 32767 Priority property value 795 CHAPTER C CosNotification Reference 796 HighestPriority const short HighestPriority 32767 Priority property value DefaultPriority const short DefaultPriority 0 Priori
197. Util Interface LoadBalancing Util LoadCalculator Operations local interface LoadCalculator Interface for the calculation of the server load The LoadCalculator is used by the LoadUpdater to calculate the current load of the server which will be used as the load of each member registered with the LoadUpdater The implementation provided by the Balancer calculates the load based on the number of active requests since the last invocation of calculate_load See Also Interface LoadBalancing Util _LoadUpdater calculate_load unsigned long calculate_load Calculate the load 507 CHAPTER F Orbacus Balancer Reference Interface LoadBalancing Util LoadUpdater Operations 508 local interface LoadUpdater Interface to manage load updates sent to the Balancer At regular intervals set by the update frequency the LoadUpdater gets the load from the LoadCalculator and pushes it to the load balanced group of each registered member See Also Interface LoadBalancing Util LoadCalculator get_update_frequency unsigned long get_update_frequency Retrieve the load push frequency set_update_frequency void set_update_frequency in unsigned long millis Set the load push frequency set_load_calculator void set_load_calculator in LoadCalculator calc Set the load calculator register_member void register_member in MemberId member_id in GroupId group_id raises GroupNotFou
198. Will result in an informative error message from the ORBs ModuleManager upon application startup if the module was linked statically 303 CHAPTER 15 Orbacus Watson Installing Watson in Java Since Orbacus Watson is based on Portable Interceptors it is installed using the standard mechanism for installing interceptors Specifically a property is defined which specifies the name of a class to be loaded org omg PortableInterceptor ORBInitializerClass com ooc watson RI ORBInitializer_impl Note that the property has no associated value as the name of the class to be loaded is part of the property name 304 Configuration Properties Configuration Properties The behavior of the Orbacus Watson module is controlled by the following properties Property Description ooc watson trace requests lt level gt This property sets the indicated tracing level for the in and out direction The default value is O ooc watson trace requests in lt level gt This property sets the indicated tracing level only for the in direction The default value is O ooc watson trace requests out lt level gt This property sets the indicated tracing level only for the out direction The default value is O The information displayed in the in and out directions differ for the different roles an application takes in CORBA For a client application making a CORBA request the out direction corresponds to
199. _suppliers Creates a new SupplierAdmin object Returns An object reference to the new admin is returned destroy void destroy Destroys an EventChannel and all associated admin and proxy objects 785 CHAPTER A CosEventChannelAdmin Reference 786 In this appendix APPENDIX B CosEventComm Reference This appendix describes the CosEventComm module This appendix contains the following section Module CosEventComm page 788 787 CHAPTER B CosEventComm Reference Module CosEventComm Exceptions 788 This module contains the basic Event Service compatible interfaces supporting the exchange of events between a supplier and consumer Note that a channel acts as both supplier and consumer of events through its proxy interfaces Disconnected exception Disconnected This exception is raised by an operation if event communication has been disconnected Module CosEventComm Interface CosEventComm PushConsumer Synopsis Operations interface PushConsumer This interface is implemented by a push consumer to receive event data push void push in any data raises Disconnected A supplier invokes the push operation to transfer an event to a consumer Parameters data The event is encapsulated in a CORBA Any disconnect_push_consumer void disconnect_push_consumer This method terminates event communication and releases resources allocated by the
200. _var handlerRef handler gt _this 3 echo gt sendc_echo_message handlerRef Hello 4 while handler gt receptions lt 1 orb gt perform_work 337 CHAPTER 17 Asynchronous Method Invocation 338 1 5 8 12 13 14 15 Create a persistent POA for the reply handler This is important as it allows the router to deliver the reply in the event that the client goes down and comes back up Servers should also use persistent POAs for the same reason Create the Echo object based on the IOR in the Echo ref file Instantiate a new EchoHandler_imp1 object using the new persistent POA This class must be created by the user and derived from the generated POA_AMI_EchoHandler Sample code for an EchoHandler_imp1 can be found in the Echo_imp1 cpp file located in the ob demo AMI ech_reply_router demo folder Make the deferred call passing the handler as the first parameter Wait for the response to come back This is simply how this demo was implemented How the callback is handled is application dependent Java AMI Reply Handler Implementation The following code snippet shows the client application making the AMI deferred call for the Reply Handler implementation The asyncEchoHandler class must be implemented by the user For a complete example please see the code in the ob demo AMI echo_reply_router directory of the Orbacus for Java distribution oO org omg PortableServer POA rootPOA org
201. ableServer RefCountServantBase 4 G jetlollikes i 8 virtual void destroy throw CORBA SystemException G 10 PortableServer POA_var poa _default_POA iil PortableServer ObjectId_var id poa gt servant_to_id this 12 poa gt deactivate_object id 13 hi The servant class Product_imp1 is defined as an implementation of the Product interface In addition Product_imp1 inherits from RefCount ServantBase which makes the servant reference counted The destroy operation deactivates the servant with the POA As a result the POA will release all references it maintains to the servant Since there are no other references to the servant left the servant s reference count will drop to zero and thus the servant is destroyed 11 14 Factory Objects Next we ll implement the factory Io ff Csr 2 class Factory impi public virtual POA Factory Si 4 public 5 6 vireualFEroductiptr i createProduct throw CORBA SystemException 8 9 Product_imp1 impl new Product_impl orb_ 10 PortableServer ServantBase_var servant impl A PortableServer POA_var poa Get servant s POA 12 PortableServer ObjectId_var id Assign an ID 13 poa gt activate_object_with_id id impl 14 return impl gt this 15 he The servant class Factory_imp1 is defined as an implementation of the Factory interface A new reference counted Product servant is instantiated The serva
202. ableServer InterceptorCallPolicy local interface InterceptorCallPolicy inherits from CORBA Policy The interceptor call policy This policy controls whether the server side interceptors are called for a particular POA Attributes value readonly attribute boolean value The InterceptorCallPolicy value If a POA has an InterceptorCallPolicy set and value is FALSE then any installed server side interceptors are not called for requests on this POA Otherwise interceptors are called for each request The default value is TRUE 440 BiDirPolicy Constants Typedefs BiDirPolicy BIDIRECTIONAL_POLICY_TYPE const CORBA PolicyType BIDIRECTIONAL_POLICY_TYPE 37 This policy type identifies the BiDirectional GIOP CORBA 3 compliant protocol policy NORMAL const BidirectionalPolicyValue NORMAL 0 This value indicates normal disabled BiDir GIOP functionality BOTH const BidirectionalPolicyValue BOTH 1 This value indicates enabled BiDir GIOP functionality typedef unsigned short BidirectionalPolicyValue 441 CHAPTER B Orbacus Policy Reference 442 In this appendix APPENDIX C Reactor Reference This appendix describes the Orbacus Reactor interfaces This appendix contains the following section Module OB page 444 443 CHAPTER C Reactor Reference Module OB Aliases Constants Native Types 444 Handle typedef long Handle An event handler s handle Mas
203. ack model replies from AMI routers should be implemented using persistent POAs This allows routers to deliver requests and or replies in the event that an application is terminated and Configuring Clients and Servers restarted at a later time Applications that do not use persistent POAs will generate a different object reference when restarted and the router will be unable to deliver the request and or reply 345 CHAPTER 17 Asynchronous Method Invocation 346 In this chapter CHAPTER 18 Concurrency Models This chapter describes how an Object Request Broker handles communication and request execution using single and multi threaded concurrency models This chapter contains the following sections Concurrency Models page 348 Single Threaded Concurrency Model page 350 Multi Threaded Concurrency Models page 353 The Reactor page 360 347 CHAPTER 18 Concurrency Models Concurrency Models What is a Concurrency Model Why different Concurrency Models Orbacus Concurrency Models Overview 348 A concurrency model describes how an Object Request Broker ORB handles communication and request execution There are two main categories of concurrency models single threaded concurrency models and multi threaded concurrency models Single threaded concurrency models describe how an ORB behaves while a request is sent or received in a single threaded environment For example one model i
204. actory Registry and concrete implementations of Acceptor Factory must be registered with the Acceptor Factory Registry OCI Reference OCI for the Application Programmer OCI Reference This chapter does not contain a complete reference of the OCI It only explains OCI basics and in the remainder of this chapter how it is used from the application programmer s point of view for the most common tasks For more information on how to use the OCI to write your own protocol plug ins and for a complete reference please refer to Appendix E The following sections only apply to the standard Orbacus IIOP plug in For other plug ins please refer to the plug in s documentation A Converter Class for Java page 368 Getting Hostnames and Port Numbers page 369 Determining a Server s IP Address page 373 367 CHAPTER 19 The Open Communications Interface A Converter Class for Java As you will see in the following examples the OCI info objects return port numbers as IDL unsigned short values and IP addresses as an array of 4 IDL unsigned octet values This works fine for C but in Java this causes a problem because there are no unsigned types in Java The Java mapping simply maps unsigned types to signed types Consider for example the IP address 126 127 128 129 In Java the OCI will return this as 126 127 128 127 because 128 and 129 if bit wise mapped to the Java byte type are 128 and 127 To a
205. acus Events The default level is O which produces no output A level of 1 or higher produces event processing information and a level of 2 or higher produces event creation and destruction information ooc event trace lifecycle LEVEL Defines the output level for lifecycle diagnostic messages printed by Orbacus Events The default level is O which produces no output A level of 1 or higher produces lifecycle information e g creation and destruction of Suppliers and Consumers ooc event typed_service true false Equivalent to the t command line option CLASSPATH Requirements Orbacus Events for Java requires the classes in oB jar and oBEvent jar 242 Connecting to the Service Connecting to the Service The object key of the Event Service depends on whether it is running as a typed or untyped service The object keys and corresponding interface types are shown in Table 2 Table 2 Object Keys and Interface Types Object Key Interface Type Event Service DefaultEventChannel CosEvent ChannelAdmin EventChannel Typed Event Default TypedEvent Channel CosTypedEventChannelAdmin Service TypedEventChannel The object key can be used when composing URL style object references For example the following URL identifies the untyped event service running on host evhost at port 10000 corbaloc evhost 10000 DefaultEventChannel Refer to Chapter 6 for more information on URLs and configur
206. ad to application misbehavior 579 CHAPTER 1 Introduction to JThreads C 580 In this chapter CHAPTER 2 Hello World We begin with the first program most programmers start with A program that displays the text Hello World and then exits However our example is different from the typical Hello World program in that itis multi threaded That is our version starts a new thread whose sole purpose is to print Hello World on the display This chapter contains the following sections Hello World in Java page 582 Hello World in C page 583 Hello World with Runnable page 585 581 CHAPTER 2 Hello World Hello World in Java In Java this program can be written as 582 1 mf 2 4 5 6 7 8 9 10 Lt L2 1S J public class HelloWorld extends Thread public void run System out println Hello World static public void main String args Thread t new HelloWorld TESE ALENT A class HelloWorld is defined extending the class java lang Thread A run method is defined displaying Hello World on standard output A static main method is defined which creates an object of type Hel loWorld The start method is called which starts a new thread of execution This thread then invokes the run method of the Helloworla object Hello World in C Hello World in C 6 9 12 19 Let s convert the Java
207. aises COMM_FAILURE In case of an error get_info TransportiInfo get_info Returns the information object associated with the Transport Returns The Transport information object 463 CHAPTER E Open Communications Interface Reference Interface OCI TransportInfo Synopsis Attributes Operations 464 local interface TransportInfo Information on an OCI Transport object Objects of this type must be narrowed to a Transport information object for a concrete protocol implementation for example to OCI TIOP Transport Info in case the plug in implements IIOP See Also Interface OCI Transport id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag connector_info readonly attribute ConnectorInfo connector_info The ConnectorInfo object for the Connector that created the Transport object that this TransportInfo object belongs to If the Transport for this TransportInfo was not created by a Connector this attribute is set to the nil object reference acceptor_info readonly attribute AcceptorInfo acceptor_info The AcceptorInfo object for the Acceptor that created the Transport object that this TransportInfo object belongs to If the Transport for this TransportInfo was not created by an Acceptor this attribute is set to the nil object reference describe string describe Returns a human readable description of the transp
208. alarsr 6 buffer_ addChar str_ characterAt i F 8 The for loop is now placed in a code block synchronized with the CharacterBuffer s monitor lock This will make sure that the characters are put into the buffer in the proper sequence 595 CHAPTER 3 Working With Threads 596 This is called a synchronized code block in contrast to a synchronized method The example translates to JThreads C as follows Ll class Weiter public JiCcihread 2 3 CharacterBuffer buffer_ 4 const ehar str gt 5 joulolics wi 8 Writer CharacterBuffer buffer const char str 9 0 buffer_ buffer Al str Str 2 3 4 virtual void run 5 6 Fi JTCSynchronized synchronized buffer_ 8 int len strlen str_ 9 for int r Q0 1 lt Llen 7 17t 20 puffer S adadCharc istr 17 Ail 22 BS WP 16 21 Instead of using this buffer_ is used for synchronization Static Monitors Static Monitors Synchronized static monitors In Java it is possible to have static methods which are synchronized Here is an example public class StaticCounter static long counter_ public static synchronized void increment counter_ omit num F amp F WN FE public static synchronized void decrement SCouimree A public static synchronized long value return counter_ woMAtI aot WHE OO This class allows global access to a protected counter This class must be synchronized beca
209. aloc URLs always have empty repository IDs The Bi directional OCI Plug in The Bi directional OCI Plug in Note This Bidir implementation is deprecated with the addition of the CORBA 3 compliant version of BiDir GIOP New users requiring BiDir functionality should use the new BiDir GIOP interface as described in Chapter 16 Overview The Orbacus Bi directional plug in offers a solution for distributed systems where security restrictions interfere with a client s ability to receive callbacks This capability is especially useful in two common situations e Firewalls prevent the server from establishing a separate connection back to the client Browser restrictions prevent an applet from accepting connections Note This plug in does not implement the Bi directional IIOP standard defined by CORBA 2 3 This plug in uses a proprietary protocol that is not interoperable with other ORBs In this section This sections covers the following topics How Does it Work page 390 Peers page 391 Client Installation page 392 Server Installation page 393 Endpoint Configuration page 394 Command line Options page 395 Configuration Properties page 396 Static Linking page 397 URL Support page 398 389 CHAPTER 19 The Open Communications Interface How Does it Work 390 The Bi directional plug in uses a layered design that theoretically enables any connection oriented OCI plug in to support bi
210. ameter is required Because the bi directional plug in is layered on another plug in the underlying plug in must be installed first For example to install bi directional IIOP the IIOP plug in is installed first and then the bi directional plug in is installed ooc oci server iiop bidir protocol iiop Note that a bi directional application generally needs to install both the client and server side plug ins 393 CHAPTER 19 The Open Communications Interface Endpoint Configuration 394 There are two distinct types of bi directional endpoints one which creates a real endpoint using the underlying plug in and one which only listens for callbacks on existing outgoing bi directional connections The latter type will be referred to as a callback endpoint A server will typically create the first type of endpoint a security restricted client will only create the second type since listening on a real port is often forbidden or pointless if a firewall prevents incoming connections The implication of creating a callback endpoint is that a server wishing to call back to a client will only be able to do so if there is an existing bi directional connection from the client to the server If not the server will receive a TRANSIENT exception The configuration options for a bi directional endpoint are shown below Note that the plug in identifier for endpoint configuration purposes is formed by combining bidi
211. amp Associates Inc 1997 2 Doug Lea Concurrent Programming in Java Addison Wesley Longman Inc 1997 3 Why JavaSoft is Deprecating Thread stop Thread suspend and Thread resume Sun Microsystems Inc 4 Bjarne Stroupstrup The C Programming Language Third Edition Addison Wesley Longman Inc 1997 1 Available from http java sun com products jdk 1 2 docs guide misc threadPrimitiveDeprecation html 667 CHAPTER B 668 Part IV Orbacus Notification In this part This part contains the following chapters Introduction page 671 Configuration and Startup page 675 Notification Service Concepts page 687 Programming Example page 719 Orbacus Notify Console page 753 CosEventChannelAdmin Reference page 777 CosEventComm Reference page 787 CosNotification Reference page 793 CosNotifyChannelAdmin Reference page 805 CosNotifyComm Reference page 837 CosNotifyFilter Reference page 853 OBNotify Reference page 869 Notify Bibliography page 873 CHAPTER 1 Introduction This chapter gives a brief overview of Orbacus Notify In this chapter This chapter contains the following section Overview page 672 671 CHAPTER 1 Introduction Overview What is Orbacus Notify Features Graphical Interface About this Document 672 Orbacus Notify is an implementation of the Object Management Group OMG Notification Service specification
212. anager already set inorInvalidUseOfDSIArguments Invalid use of DSI arguments MinorInvalidUseOfDSIContext Invalid use of DSI context inorRequestAlreadySent DII request has already been sent inorRequestNot Sent DII request has not been sent yet MinorResponseAlreadyReceived DII response has already been received MinorSynchronousRequest Operation not supported on synchronous DII request MinorInvalidPICall Invalid Portable Interceptor call MinorServiceContextExists A service context already exists with the given ID MinorPolicyFactoryExists A factory already exists for the given PolicyType MinorNoCreatePOA Cannot create POA while undergoing destruction MinorBadConcModel Invalid concurrency model MinorORBRunning ORB run already called TRANSIENT Minor Exception Code CORBA System Exceptions MinorRequestDiscarded Request has been discarded MinorNoUsableProfileInIOR No usable profile in IOR MinorRequestCancelled Request has been cancelled MinorPOADest royed POA has been destroyed MinorConnectFailed Request has been cancelled MinorCloseConnection Got a close connection message MinorActiveConnect ionManagement Active connection management closed connection MinorForcedShutdown Forced connection shutdown because of timeout MinorLocat ionForwardHopCoun
213. andle Whenever a handle is destroyed the destructor of the handle decrements the reference count of the thread object it points to by 1 For the example above this means that if you replace JTCThreaa by JTCThreadHandle the reference count of the thread object will be 2 instead of 1 after the new because the handle increased the counter by 1 After the thread has terminated the counter is still 1 and thus the thread object is not deleted so that it is safe to use operations like isAlive or join on the thread object When the handle is destroyed at the end of the main function the handle s destructor decrements the thread object s counter by 1 so that the thread object is then also deleted The JTCHandleT Template The JTCHandleT Template Handle classes JThreads C provides the following handle classes JTCThreadHandle as a replacement for JTCThread JTCRunnableHandle as a replacement for sTcRunnable gTCThreadGroupHandle as a replacement for gTcThreadGroup These classes are all typedefs for a more general handle type written as a C template typedef JTCHandleT lt JTCThread gt JTCThreadHandle typedef JTCHandleT lt JTCRunnable gt JTCRunnableHandle typedef JTCHandleT lt JTCThreadGroup gt JTCThreadGroupHandle In case you want to access methods from classes derived from JTCThread or from JTCRunnable you must define your own handle type As an example let s go back to Implementing a Thr
214. annelFactory EventChannelFactoryHelper narrow obj oof WN FE Resolve the NotificationService initial reference Narrow the reference to the appropriate type The object reference to the cosNot ifyChannelAdmin EventChannelFactory is used to create an event channel Another option is to ask for an existing channel using an ID previously assigned by Orbacus Notify io y IDH 2 interface EventChannelFactory a i 4 os 5 EventChannel get_event_channel in ChannelID id raises ChannelNotFound 6 wo Te This example creates the channel if necessary and publishes the IOR of the newly created channel otherwise an already published IOR is used to get a channel reference Note that only one of the supplier or consumer actually creates the channel depending on which is started first It then publishes the IOR for the newly created channel for use by its peer 723 CHAPTER 4 Programming Example In C the channel is created as follows Hi Cat CosNotification QoSProperties initialQoS CosNotification AdminProperties initialAdmin CosNotifyChannelAdmin ChannelID channelld CosNotifyChannelAdmin EventChannel_var eventChannel eventChannelFactory gt create_channel initialQoS initialAdmin channelTIqd In Java 1 Java 2 Property initialQoS new Property 0 3 Property initialAdmin new Property 0 4 org omg CORBA IntHolder channelId new org omg CORBA IntHolder EventCha
215. apping Constraint 0 Properties x Expression Event Types Result to Set Expression blah foo Figure 32 Constraint Expression Properties 770 Destroying a Filter Constraint Managing Filter Constraints This dialog supports in place editing of the constraint expression Constraints which do not conform to the constraint grammar cannot be entered Event Type Properties The list of event types for a constraint is accessed with the Event Type Properties tab shown in Figure 33 Event Types Event Types Domain Name Type Name somedomain sometype Figure 33 Constraint Event Type Properties To add a new event type click the Add button which adds a new blank event type to the list All event types in the list may be edited in place To remove a selected event type click the Remove button A selected filter constraint is destroyed by choosing the Edit Destroy menu operation A confirmation is displayed before the constraint is removed 771 CHAPTER 5 Orbacus Notify Console Managing Mapping Filters Creating a New Mapping Filter Mapping Filter Properties Destroying a Mapping Filter 772 Mapping filters may only be created from the FilterFactory Existing mapping filters may be assigned to the following objects from the appropriate properties dialog e consumer admin e supplier proxy To create a new mapping filter select the FilterFac
216. arnates a particular CORBA object Activation of a servant assigns an object identifier to the servant That object identifier is also embedded in every object reference that is created for an object and serves to link the object reference with its servant The POA s IdAssignmentPolicy value controls whether object IDs are assigned by the POA or the server application code The systEm_t1pD policy value directs the ORB to assign a unique object identifier to the CORBA object represented by the servant the USER_1D policy value requires the server application code to supply an ID that must be unique within the servant s POA Servants can be activated implicitly or explicitly Implicit activation takes place when you create the first object reference for a servant Explicit activation requires a separate API call Typically you will use implicit activation for transient objects and explicit activation for persistent objects The ImplicitActivationPolicy controls whether explicit or implicit is in effect Explicit activation requires the No_IMPLICIT_ACTIVATION policy value on the servant s POA whereas implicit activation requires the IMPLICIT_ACTIVATION policy value 107 CHAPTER 5 CORBA Objects Implicit Activation of Servants using C The following code shows how to implicitly activate a servant ff Cae amp one baale 3S I yer iy impl gt _this A new servant imp1 is created 3 The new servant is activated implicitly b
217. art of the Orbacus core library The IIOP plug in supports the standard iiop format for corbaloc URLs as described in corbaloc URLs on page 139 379 CHAPTER 19 The Open Communications Interface The UDP OCI Plug in The UDP plug in provides unreliable unicast and multicast functionality suitable for applications which can tolerate the potential for lost messages Only oneway operations are supported For configuration purposes the identifier of the UDP plug in is udp In this section This sections covers the following topics Client Installation page 381 Server Installation page 382 Static Linking page 386 URL Support page 387 Narrowing UDP Object References page 388 380 The UDP OCI Plug in Client Installation The client side UDP plug in is installed as shown below ooc oci client udp buffer size N packet delay MSEC packet size N no loopback ttl N trace N The following options are supported buffer size N Sets the size of the socket s send buffer Note that this is only a hint to the operating system To determine the actual size use the trace option The default value is operating system dependent packet delay MSEC Specifies the delay in milliseconds between packets In some cases sending packets too quickly can cause more packets to be dropped The default value is O packet size N Sets the size of a packet in bytes If necessar
218. ass windows Use the Windows Look amp Feel if available motif Use the Motif Look amp Feel if available mac Use the Macintosh Look amp Feel if available h Display the command line options supported by the help program CLASSPATH Requirements The Orbacus IMR Console requires the classes in OB jar OBIMR jar and OBUtil jar Implementation Repository In order to locate an IMR Service the application uses the initial IMR Service Lookup Service as provided to the ORB with options such as ORBservice or ORBconfig If the service is not found an error is displayed and the IMR Console exits 182 The Menus The File Menu The Edit Menu The Menus The menus provide access to all of the features of the application In addition the most common actions are also available in the toolbar as well as in a popup menu that is displayed when pressing the right mouse button over an item in the binding table or context tree The File menu contains the Exit menu item which is used to exit the Orbacus IMR Console The operations in the Edit menu provide the means for manipulating OADs servers and POAs Create Create a new OAD server or POA Modify Modify the selected object Delete Delete the selected object Cut Move the selected server to the clipboard Paste Insert the server contained in the clipboard under the selected OAD Start Start the selected server Stop Stop
219. assPhrase foobar myTrustDecider com ooc FSSL FSSL get_default_ciphers org omg CORBA PolicyManager policyManager org omg CORBA PolicyManagerHelper narrow orb resolve_initial_references ORBPolicyManager org omg CORBA Policy pl new org omg CORBA Policy 1 pl 0 fsslManager create_context_policy id policyManager add_policy_overrides pl 536 Client Side Usage Determining Peer Identity Before the client can determine the identity of the peer it must first get the OCI FSSLIOP Transportinfo The client accomplishes this by calling _non_existent on the object reference to force the connection and then narrowing the OCI Transportinfo Lt Cart OCI FSSLIOP TransportInfo_var fssliopInfo if obj gt _non_existent OCI TransportInfo_var info obj gt _get_oci_transport_info fssliopInfo OCI FSSLIOP TransportInfo _narrow info j Java com ooc OCI FSSLIOP TransportInfo fssliopInfo null if obj _non_existent org omg CORBA portable ObjectImpl objImpl org omg CORBA portable ObjectImp1 obj com ooc CORBA Delegate objDelegate com ooc CORBA Delegate objImpl _get_delegate com ooc OCI TransportInfo info objDelegate get_oci_transport_info fssliopInfo com ooc OCI FSSLIOP Transport InfoHelper narrow info Once a reference to the FSSLIOP transport information is aquired OCI FSSLIOP Transportinfo certificate_chain can be used to
220. at It is available in a C and a Java version Its usage is shown below iordump options f FILE IOR com ooc OB IORDump options f FILE IOR 1 h help Show available options V version Show Orbacus version f FILE Read IORs from file instead of command line IOR List of ORs The Java version is available in oB jar Sample output for the demo hello The following command example iordump f Hello ref 154 The IORDump utility prints IOR 1 byteorder little endian type_id IDL Hello 1 0 Profile 1 iiop iiop_version 1 2 hosts 192 16820 1 port 17000 object_key 37 Ai ye a ANS 49 AS BO AP LOOM 55 55 53 54 55 45 Ooo Si Sbe E GA iii iii 1G eA 7S 6S 0 RootPOA O 202 254 186 190 GO 215 205 ex 0 0 0 0 0 Marara y Native char codeset TSO 8859 1 1987 Latin Alphabet No 1 Char conversion codesets TSO 646 1991 IRV International Reference Version X Open UTF 8 UCS Transformation Format 8 UTF 8 Native wchar codeset fISsO IEC L0ed6 1219937 UCsS 2 Level i Wchar conversion codesets ISO IEC 10646 1 1993 UTF 16 UCS Transformation Format 16 bit form 155 CHAPTER 6 Locating Objects 156 In this chapter CHAPTER 7 The Implementation Repository This chapter describes how the Orbacus Implementation Repository IMR works and how to use it This chapter contains the following sections
221. ate Throws JTCSystemCallException Indicates a failed system call join void join long millis Waits for the thread to terminate for at most millis milliseconds Throws JTCSystemCallException Indicates a failed system call JTCIllegalArgumentException Thrown if the value of millis is negative join void join long millis int nanos Waits for the thread to terminate for at most millis milliseconds and nanos nanoseconds Throws JTCSystemCallException Indicates a failed system call JTCIllegalArgumentException Thrown if the value of millis is negative or if the value of nanos is not in the range O 999999 setPriority void setPriority int newPri Sets the thread priority to a new value Parameters newPri The new thread priority Throws JTCSystemCallException Indicates a failed system call getPriority int getPriority const Returns the priority of the thread Returns The thread priority Throws JTCSystemCallException Indicates a failed system call enumerate static int enumerate JTCThreadHandle list int len Copies each active thread from this thread s thread group and subgroups into the array list If more than len items are present the list is truncated Parameters list The array into which all threads from this thread s group and subgroups are copied len The number of gTcThreadHandle elements in list Returns The number of threads returned in list currentThrea
222. ate ca Java private com ooc FSSL Certificate ca_ ClientTrustDecider com ooc FSSL Certificate ca ca_ ca Next is_trusted must be implemented ie Cass virtual CORBA Boolean is_trusted const FSSL CertificateSeq amp chain Java public boolean is_trusted com ooc FSSL Certificate chain This method should ensure that the CA in the certificate chain is the CA provided by the constructor To do that it should be verfied that the CA has signed the last certificate in the chain since CA certificates are self signed and that the subject distinguished names are the same In addition the common name portion of the server side certificate will be examined to Complete Example ensure that only the server is accepted Note that for a real world example more than just the common name should be validated since it s possible that the common name is the same for two certificates Lie Cast CORBA String_var serverDN chain 0 gt subject_DN if strstr serverDN CN Server 0 return false if chain length 2 amp amp chain 1 gt is_signed_by ca_ CORBA String_var dnl chain 1 gt subject_DN CORBA String_var dn2 eca gt subject_DN if strcmp dn1 dn2 0 return true return false Java String serverDN chain 0 subject_DN if serverDN indexOf CN Server 1 return false if chain length 2 amp amp chain 1 is_signed_by ca_
223. atically destroys itself after all threads have terminated and all sub groups are destroyed A newly created thread group inherits its parent s daemon status The root thread group is a non daemon thread group JTCThreadGroup JTCThreadGroup const char name Creates a new thread group with the provided name The new thread group s parent is that of the current thread Parameters name The name of the thread group Throws JTCI1llegalThreadSt ateExcept ion Thrown if the parent thread group has been destroyed JTCThreadGroup JTCThreadGroup JTCThreadGroup group const char name Creates a new thread group with the provided name and parent thread group Parameters group The parent of the thread group name The name of the thread group Throws JTCI1legalThreadSt ateExcept ion Thrown if the parent thread group has been destroyed getName const char getName const Returns the name of the thread group Returns The name of the thread group getParent JTCThreadGroupHandle getParent const Returns the parent of the thread group If the thread group is the root thread group the handle contains a null pointer Returns The parent of the thread group isDaemon bool isDaemon const Returns the daemon flag for this thread group If the daemon flag is true the thread group is destroyed once all threads are terminated and sub groups are empty Returns The value of the daemon flag setDaemo
224. ation blocks until a new connection has been accepted If set to FaLsE the operation returns a nil object reference if there is no new connection ready to be accepted Returns The new Transport object Raises COMM_FAILURE In case of an error connect_self Transport connect_self Connect to this acceptor This operation can be used to unblock threads that are blocking in accept Returns The new Transport object Raises TRANSIENT If the server cannot be contacted COMM_FAILURE In case of other errors 477 CHAPTER E Open Communications Interface Reference 478 add_profiles void add_profiles in ProfileInfo profile_info inout IOR ref Add new profiles that match this Acceptor to an IOR Parameters profile_info The basic profile information to use for the new profiles ref The IOR get_local_profiles ProfileInfoSeq get_local_profiles in IOR ref From the given IOR get basic information about all profiles for which are local to this Acceptor Parameters ref The IOR from which the profiles are taken Returns The sequence of basic information about profiles If this sequence is empty there is no profile in the IOR that is local to the Acceptor get_info AcceptorInfo get_info Returns the information object associated with the Acceptor Returns The Acceptor information object Module OCI Interface OCI AcceptorInfo Synopsis Attributes Operations
225. bacus Properties 225 Usage 226 Connecting to the Service 227 Using the Property Service with the IMR 228 Creating Properties 229 Querying for Properties 230 Deleting Properties 232 Programming Example 233 Chapter 12 Orbacus Events 237 Usage 238 Windows NT Native Service 239 Configuration Properties 241 Connecting to the Service 243 Using the Event Service with the IMR 244 Event Service Concepts 245 The Event Channel 246 Event Suppliers and Consumers 247 Event Channel Policies 249 Event Channel Factories 250 Programming Example 253 Chapter 13 The Interface Repository 257 Usage 258 Windows NT Native Service 259 Configuration Properties 261 Connecting to the Interface Repository 262 Configuration Issues 263 Interface Repository Utilities 264 Programming Example 265 Chapter 14 Orbacus Balancer 267 Basic Concepts 268 Load Balancing Strategies 269 vii CONTENTS Service Security Usage Windows NT Native Service Configuration Properties Built in Load Balancing Strategies Connecting to the Service Load Balanced IMR enabled Servers Utilities Service Administration Making References Utility Objects Utility Object Configuration Properties Programming Example Non adaptive Load Balancing Adaptive Load Balancing Running the Load Balanced Servers Chapter 15 Orbacus Watson Tracing Levels Installing Watson in C Installing Watson in Java Configuration Properties Sample Configuration File Chapter 16 Using Policies Over
226. bject operator T amp operator Retrieve a C reference to the referenced object Returns A C reference to the object 637 CHAPTER A Class Reference JTCMonitor Overview Methods 638 This class provides the functionality of Java monitors In order to implement synchronized methods the monitor s lock must be acquired for example by creating an instance of the atcSynchronized class at the top of the synchronized method with the monitor as the argument to the constructor The monitor s wait method can be used to release the monitor s lock and to wait for notifications The notify and notifyAll methods can be used to wake one or all waiting monitors respectively wait void wait Waits for notification by another thread The calling thread must own the monitor s lock The monitor s lock is released and the thread waits for notification by another thread via a call to either notify or notifyAll The thread then waits until it can regain ownership of the monitor s lock and then resumes execution Throws JTCIllegalMonitorStateException If the monitor is not locked by the calling thread JTCSystemCallException Indicates a failed system call wait wait long timeout Waits for notification by another thread The calling thread must own the monitor s lock The monitor s lock is released and the thread waits for notification by another thread via a call to either notify or notifyAl11 or
227. bjects related to the current request get_oci_transport_info TransportInfo get_oci_transport_info This method returns the Transport information object for the Transport used to invoke the current request get_oci_acceptor_info AcceptoriInfo get_oci_acceptor_info This method returns the Acceptor information object for the Acceptor which created the Transport used to invoke the current request Module OCI IIOP Module OCI IlOP Aliases Constants This module contains interfaces to support the IIOP OCI plug in InetAddr typedef string InetAddr Alias for an IP address This alias will be used for address information from the various information classes It can be an IPv4 or IPv6 address string PLUGIN_ID const PluginId PLUGIN_ID iiop The identifier for the lt SmallCaps gt ORBacus IIOP plug in 487 CHAPTER E Open Communications Interface Reference Interface OCI IIOP TransportInfo Synopsis local interface TransportInfo inherits from OCI TransportInfo Information on an IIOP OCI Transport object See Also Interface OCI Transport Interface OCI TransportInfo Attributes addr readonly attribute InetAddr addr The local IP address port readonly attribute unsigned short port The local port remote_addr readonly attribute InetAddr remote_addr The remote IP address remote_port readonly attribute unsigned short remote_port The remote port 488 Mod
228. catch java io IOException ex ex printStackTrace return 1 manager activate ule wie 2 return 0 A reference to the Root POA is obtained using the ORB reference and the Root POA is used to obtain a reference to its POA Manager A servant of type Hello_imp1 is created and is used to incarnate a CORBA object The CORBA object is released automatically when it is not used anymore The object reference is stringified and written to a file The server enters its event loop to receive incoming requests 25 CHAPTER 2 Getting Started Implementing the Client Client java Save this to a file with the name Client java in the directory hello i ff IENA 2 package hello 3 4 public class Client 5 4 6 public static void main String args 7 8 Same as for the server 9 0 1 static int run org omg CORBA ORB orb 2 3 org omg CORBA Object obj null 4 Ery 5 6 String refFile Hello ref y java io BufferedReader in new java io BufferedReader 8 new java io FileReader refFile 9 String ref in readLine 20 obj orb string_to_object ref 21 22 catch java io IOException ex 29 24 ex printStackTrace 25 return 1 26 27 28 Hello hello HelloHelper narrow ob 29 30 hello say_hello Sil 32 returno Be Sah 6 9 This code is the same as for the server 14 26 The stringified object reference is read and converted to an object 26 28 30 Implementing the
229. cations Interface OCI and is installed at runtime through configuration For more general information on Orbacus configuration and the OCI please see the Orbacus User Guide The client side FSSL plug in is installed as follows ooc oci client fssliop seed FILE backend IMPL trace N The following options are supported seed FILE FreeSSL for C only If specified FreeSSL will use the contents of the file filename as random data to seed the OpenSSL PRNG Psuedo Random Number Generator This may be necessary if the operating system doesn t have its own random data generator usually dev random If no random data generator is found and this property is not specified FreeSSL will use a generic seeding algorithm backend IMPL FreeSSL for Java only The Java version supports multiple third party SSL toolkits which are identified to the plug in during installation Support for different third party SSL toolkits is provided through multiple back end libraries where each library includes an implementation of the FSSLImpl interface The backend option accepts the name of the class implementing the FSSLImpl interface By default the IAIK toolkit is used Please see Appendix B for information on the supported SSL toolkits and the related back end library In this manual we will assume that the IAIK toolkit is being used trace N Sets the level of diagnostic output generated by the plug in
230. ce Interface CosNotifyComm PullConsumer interface PullConsumer inherits from CosNotifyComm NotifyPublish CosEventComm PullConsumer The PullConsumer interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel Clients do not need to implement this interface to simply pull events 842 Module CosNotifyComm Interface CosNotifyComm PullSupplier interface PullSupplier inherits from CosNotifyComm NotifySubscribe CosEventComm PullSupplier The PullSupplier interface is implemented and registered connected by clients who wish to have unstructured events pulled from them by the channel 843 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm PushSupplier interface PushSupplier inherits from CosNotifyComm NotifySubscribe CosEventComm PushSupplier The PushSupplier interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel Clients do not need to implement this interface to simply push events 844 Module CosNotifyComm Interface CosNotifyComm StructuredPushConsumer Operations interface StructuredPushConsumer inherits from CosNotifyComm NotifyPublish The structuredPushConsumer interface is implemented and registered connected by clients who wish to have structured events pushed on them by
231. ce OBPortableServer InterceptorCallPolicy BiDirPolicy Appendix C Reactor Reference Module OB Interface OB Reactor Appendix D Logger Reference Interface OB Logger Interface OB WLogger Appendix E Open Communications Interface Reference Module OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI Buffer Plugin Transport TransportInfo CloseCB Connector ConnectorInfo ConnectCB ConFactory ConFactory nfo ConFactoryRegistry Acceptor AcceptorInfo AcceptCB AccFactory AccFactorylnfo CONTENTS 431 432 433 434 435 436 437 438 439 440 441 443 444 445 447 448 449 451 452 456 458 459 464 466 467 469 471 472 474 475 476 479 481 482 484 xi CONTENTS Interface OCI Interface OCI Module OCI IIOP Interface OCI Interface OCI Interface OCI Interface OCI Interface OCI AccFactoryRegistry Current IOP TransportInfo IOP Connector nfo I1OP ConFactorylnfo IIOP Acceptorlnfo IIOP AccFactorylnfo Appendix F Orbacus Balancer Reference Module LoadBalancing Interface Load Interface Load Interface Load Interface Load Interface Load Balancing LoadAlert Balancing Strategy Balancing StrategyProxy Balancing Group Balancing GroupFactory
232. ce of structured events The default is 1 PacingInterval TimeBase TimeT PacingInterval is the maximum period of time a channel will collect events into a sequence before delivering the sequence The default is O meaning that a sequence of events is transmitted when ready 711 CHAPTER 3 Notification Service Concepts Note For a more extensive description of the above listed properties please refer to 1 712 The OMG Notification Service Proprietary QoS Properties Properties for Retry Handling of a Failed Event Communication While the Notification Service specification 1 defines a wide range of QoS properties there are some important features which remain undefined For example although the specification provides QoS properties to control priority expiry times and earliest delivery time for events it does not specify how an event communication failure is handled Similarly for pull events the specification does not define how often the pull should occur To address these deficiencies Orbacus Notify implements a number of proprietary features The IDL names for these features are specified in the OBNotify module Orbacus Notify includes several QoS properties which configure proprietary retry handling facilities A retry occurs when Orbacus Notify attempts to push an event and receives an exception thereby prompting it to retry sending the event at specified intervals Table 5 R
233. certificate file differs from DER certificate files Data from the PKCS12 files is loaded directly into an octet sequence using FSSL load_file and passed as a parameter to FSSL Manager create_pkcs12_context Hi Cit FSSL OctetSeq_var pkcs12_data FSSL ContextID id fsslManager gt create_pkcs12_context pkcs12_data myPassPhrase myDecider myCiphers FSSL load_file cert pl2 Java byte pkcs12_data com ooc FSSL FSSL load_file cert p12 int id fsslManager create_pkcs12_context pkcs12_data myPassPhrase myDecider myCiphers Contexts Passphrase The passphrase is an octet sequence Again a typical use case is that the passphrase is a string therefore a helper method FSSL_string_to_PassPhrase s provided i Ct FSSL PassPhrase_var myPassphrase FSSL string_to_PassPhrase foobar Java byte myPassphrase com ooc FSSL FSSL string_to_PassPhrase foobar Cipher Suites The context creation method is passed a sequence of cipher suite identifiers A common use case is to allow all non anonymous ciphers Therefore a helper method FSssL get_non_export_ciphers is provided UG Cree FSSL CipherSeq_var ciphers FSSL get_non_export_ciphers Java int ciphers com ooc FSSL FSSL get_non_export_ciphers Three other helper methods are also provided FSSL get_export_ciphers returns a sequence of all export RSA cipher suites ciphers using keys that are less
234. cess is started when the IMR starts and is used by all clients activate poas If this attribute is set to true default then all persistent POAs will be registered automatically If set to false then persistent POAs are not registered automatically update timeout The amount of time in milliseconds to wait for server status updates failure timeou The amount of time in seconds to wait for the t server to start max spawns The maximum number of tries to start the server The IMR also maintains various state information for each server The internal ID of the server e The status of the server process The valid values are forked starting running stopping and stopped e Whether or not the server was started manually e The number of times that the server process has been spawned Server processes inherit environment settings from the environment in which the OAD was started Hence path library path and class path environment variables can be used by the server application This is especially useful in the case of shared library and class path settings Note that the class path may also be set in the args attribute On Windows platforms the exec attribute may refer to an executable or batch file Make sure that the first line of the batch file contains echo off On UNIX platforms the exec attribute may refer to an executable or a shell script with interpreter as its f
235. char method This class does not work as we want it to however Suppose we start two new threads one to add 123 to the buffer and another one to add abc CharacterBuffer buffer new CharacterBuffer JTCHandleT lt Writer gt wl new Writer buffer 123 JTCHandleT lt Writer gt w2 new Writer buffer abc Wil S Sieeucie Pe w2 gt start Gy gS es SS 1 A CharacterBuffer is created 594 2 3 4 5 3 7 Block Synchronization Two writer threads are created one with 123 as argument and the other with abc Both threads use the same CharacterBuffer object The JTCHandleT template is explained in The JTCHandleT Template on page 615 It would be wrong to use just a plain C pointer writer here but for now let s just assume that sTcHandleT lt Writer gt and Writer are the same The two Writer threads are started Now consider the following scenario w1 runs first but after writing 12 into the buffer the operating system switches to the execution of w2 which writes abc After that w1 continues to write 3 The result is that the buffer now contains the character sequence 12abc3 instead of 123abc We can easily avoid this by rewriting the run method to lock the monitor of the CharacterBuffer object before starting to write into the buffer welolie vone arini synchronized buffer_ 1 2 3 4 5 oaae a 0 p a ser ileingiela p
236. cing The default value is O meaning no transaction tracing OOC database trace database level gt 0 Controls the level of diagnostic output related to database activity Set this value to 1 or greater to enable database activity tracing The default value is O meaning no tracing ooc database trace locks level gt 0 Controls the level of diagnostic output related to database locking Set this value to 1 or greater to enable database lock tracing The default value is O meaning no tracing ooc database max_retries retries gt 0 The maximum number of retries of a transaction before an abort When a transaction is aborted it is completely rolled back and a CORBA TRANSIENT exception is raised meaning the client should retry the request later A value of O means unlimited retries The default value is O 680 Table 1 Orbacus Notify Configuration Properties Property Value Description ooc database max_sleep_time time gt 0 The maximum amount of time to sleep in seconds between retries The time between successive retries grows exponentially until this value is reached that is 1 2 4 8 max_sleep_time Set this value to O to disable sleeping between retries The default value is 256 ooc database checkpoint_interval interval gt 0 The interval at which database checkpointing occurs in seconds in conjunction wi
237. const JTCInterruptedException amp if done_ break cout write data_ len_ len_ 0 lt a flush void terminate JTCSynchronized synchronized stnis done_ true Howay 6 11 20 34 36 56 41 50 50 51 53 54 58 63 The Stop and Suspend Methods The CharacterBuf fer Class is now also derived from sTcThread in order to provide the separate thread for printing the buffer s contents We added a done_ flag initially set to false in the constructor Nothing has changed in the addchar method The implementation is the same as in section The writeBuffer method is obsolete We now have a run method instead which prints the buffer s contents in an endless loop This is similar to the implementation shown in section However the while loop now not only checks whether 80 characters are available but also whether the done_ flag is set to true If the inner while loop was terminated because done_ was set to true break Is called This causes the thread to exit the outer while loop to return from the run method and to terminate If the inner while loop was terminated for any other reason there are 80 characters available now which are printed on standard output The terminate method serves as a replacement for stop It first acquires the monitor s lock with an instance of gTcsynchronize then sets the done_ flag to true and notifies the waiting thread 607 CHAPTER 3 Working With Th
238. ct Key 133 Object References 126 Objects Locating 125 Persistent 112 Transient 112 OCI 363 Acceptor 364 Acceptor Factory 364 Bi directional Plug in 389 Connector 364 Connector Factory 364 875 INDEX IIOP Plug in 375 380 389 Info Objects 365 Registries 364 Transport 364 ooc router decay_policy decay_ seconds 336 ooc router resume_policy resume_seconds 336 ooc router retry_policy 335 ooc router retry_policy backoff_ factor 335 ooc router retry_policy base_ interval 335 ooc router retry_policy interval_ limit 336 ooc router retry_policy max_backoffs 335 Open Communications Interface 363 Options hidl 41 irgen 44 jidl 39 ridl 42 ORB Configuration 58 Destruction 88 ORBacus Names 187 P POA 93 162 POA Manager 77 Root POA Manager 78 Policies 307 ACMTimeoutPolicy 309 BidirectionalPolicy 309 ConnectionReusePolicy 309 ConnectTimeoutPolicy 309 InterceptorCallPolicy 311 InterceptorPolicy 310 LocationTransparencyPolicy 310 ProtocolPolicy 310 RequestTimeoutPolicy 310 RetryPolicy 311 TimeoutPolicy 311 Popup Menu 223 Port 132 369 Portable Object Adapter 93 Programming Examples Event Service 253 Implementation Repository 176 288 Interface Repository 265 Name Service 200 OCI 367 Policies 312 Property Service 233 876 Properties ooc config 58 ooc event max_events 241 ooc event max_retries 241 ooc event port 241 ooc event pull_interval 241 ooc event retry_multiplier 241 ooc event retry timeout 2
239. ct which provides operations that can subsequently return references to other objects 16 Implementing the Example in C Implementing the Client Overview Client code 7 12 16 20 In several respects the client program is similar to the server program The code to initialize and destroy the ORB is the same Save the following code in a file Client cpp w 0O 1 O A fF WN FE o I o oe Wb H oS wo 20 2al 22 25 24 25 26 BY Lil Cabs include lt OB CORBA h gt include lt Hello h gt include lt fstream h gt Genie CORE Ayer O LiE moiety ey ime main akidie siateie char argvi l Same as for the server int run CORBA ORB_ptr orb const char refFile Hello ref ifstream in refFile char s 2048 im SS G CORBA Object_var obj orb gt string_to_object s j Hello_var hello Hello _narrow obj hello gt say_hello return 0 In contrast to the server the client does not need to include Hello_impl h Only the generated file Hello h is needed This code is the same as for the server The stringified object reference written by the server is read and converted to a CORBA Object object reference It s not necessary to obtain a reference to the Root POA or its POA Manager because they are only needed by server applications 17 CHAPTER 2 Getting Started 18 22 24 The _narrow operation generates a Hello object reference fr
240. currency model is chosen the ORB creates a new thread for each request This is shown in Figure 13 To E g a _ h be lt a a T T T T Client A Thread per Request Client B Server Figure 13 Thread per Request Server For simplicity there are no separate arrows for dispatch and thread creation in the diagram With the thread per request model requests are never delayed When they arrive a new thread is created and the request is executed in the user code using this thread On return the thread is destroyed Besides using a reactive client together with a reactive server the thread per request server in combination with a threaded client is the only other model that allows nested method calls with an unlimited nesting level The thread pool model also allows nested method calls but the nesting level is limited by the number of threads in the pool The thread per request concurrency model is inefficient The main problem results from the overhead involved in creating new threads namely one for each request 357 CHAPTER 18 Concurrency Models Thread Pool Server 358 The thread pool model uses threads from a pool to carry out requests so that threads have to be created only once and can then be reused for other requests Figure 14 shows an example with one client and a thread pool server with three threads in the pool Sender and
241. d Event offering has changed New class defining our servant Note the derivation from _StructuredPushConsumerimp1Base which is generated by the IDL compiler from CosNotifyComm idl See 5 6 above Constructor See 19 29 above See 31 36 above 737 CHAPTER 4 Programming Example 30 34 See 38 43 above Once the servant is implemented it is registered with the proxy supplier Hi Ci CosNotifyComm_StructuredPushConsumer_var structuredPushConsumer new StructuredPushConsumer_impl orb boa structuredProxyPushSupplier gt connect_structured_push_consumer structuredPushConsumer Java StructuredPushConsumer_impl structuredPushConsumer new StructuredPushConsumer_impl orb boa structuredProxyPushSupplier connect_structured_push_consumer structuredPushConsumer All that remains is to activate the BOA and the consumer is ready to receive events 738 Supplying Events Supplying Events Overview Push Supplier The mechanism of supplying events to a notification channel depends on the delivery model The Orbacus Notify C and Java demos implement push and pull suppliers with any structured and sequence events Implementing a push supplier is relatively easy since no CORBA servants are required for the most basic applications Once connected to the proxy the application can immediately start supplying events This example pushes events within the main subroutine as shown belo
242. d static JTCThread currentThread Returns a pointer to the currently executing thread object Returns The currently executing thread object sleep static void sleep long millis int nanos 0 Suspends execution of this thread for millis milliseconds and nanos nanoseconds Parameters 625 CHAPTER A Class Reference 626 millis The number of milliseconds to sleep nanos The number of nanoseconds to sleep Throws JTCSystemCallException Indicates a failed system call JTCIllegalArgumentException Thrown if the value of millis is negative or if the value of nanos is not in the range O 999999 JTCInterruptedException Thrown if the sleep call is interrupted yield static void yield Gives up the thread s current timeslice This can be called if you want to manually give other threads an opportunity to execute activeCount static int activeCount Returns the number of active threads in this thread s thread group and subgroups Returns The number of active threads in this thread s group and subgroups getld JTCThreadId getId const Returns the id of the thread Returns The thread id of the thread setAttrHook typedef void JTCAttrHook pthread_attr_t static void setAttrHook JTCAttrHook hook JTCAttrHook oldHook 0 Sets gets a hook that will be used to initialize custom POSIX thread attributes Note this method is only available for systems using POSIX threads Paramet
243. d shutdown should be called first 459 CHAPTER E Open Communications Interface Reference 460 Then dummy data should be read from the Transport using one of the receive operations until either an exception is raised or until connection closure is detected After that its safe to call close i e no messages can get lost Raises COMM_FAILURE In case of an error shutdown void shutdown Shutdown the Transport Upon a successful shutdown threads blocking in the receive operations will return or throw an exception After calling shutdown no operations on associated TransportInfo object may be called To fully close the Transport close must be called Raises COMM_FAILURE In case of an error receive void receive in Buffer buf in boolean block Receives a buffer s contents Parameters buf The buffer to fill block If set to TRUE the operation blocks until the buffer is full If set to FALSE the operation fills as much of the buffer as possible without blocking Raises COMM_FAILURE In case of an error receive_detect boolean receive_detect in Buffer buf in boolean block Similar to receive but it signals a connection loss by returning FALSE instead of raising ComM FAILURE Parameters buf The buffer to fill block If set to TRUE the operation blocks until the buffer is full If set to FALSE the operation fills as much of the buffer as possible withou
244. d by a pull consumer which wishes to receive notification when it is disconnected Operations disconnect_pull_consumer void disconnect_pull_consumer This method terminates event communication and releases resources allocated by the target object 792 In this appendix APPENDIX C CosNotification Reference This appendix describes the CosNotification module This appendix contains the following sections Module CosNotification page 794 793 CHAPTER C CosNotification Reference Module CosNotification Aliases 794 This module contains the definition of the structured event type and various definitions related to QoS and Administration properties Istring typedef string Istring PropertyName typedef Istring PropertyName Alias for a property name PropertyValue typedef any PropertyValue Alias for a property value PropertySeq typedef sequence lt Property gt PropertySeq Alias for a sequence of property name value pairs OptionalHeaderFields typedef PropertySeq OptionalHeaderFields Alias for event header optional header fields FilterableEventBody typedef PropertySeq FilterableEventBody Alias for event body filterable fields QoSProperties typedef PropertySeq QoSProperties Alias for Quality of Service properties AdminProperties typedef PropertySeq AdminProperties Alias for channel administration properties EventTypeSeq typedef sequence lt EventType gt Event
245. d by the push consumer Compared to the push consumer the pull consumer is the easier to implement and may be likened to the push supplier The most basic pull consumer need not implement a servant but may directly invoke the methods of the proxy pull supplier interface The any structured and sequence pull suppliers have separate IDL interfaces The structured pull consumer IDL is given below IDL interface StructuredPullConsumer NotifyPublish void disconnect_structured_pull_consumer 741 CHAPTER 4 Programming Example Filtering 742 So far this chapter has covered the details of connecting to an event channel and event delivery mechanisms One of the powerful features of Orbacus Notify is the ability to filter events on both the supplier and consumer side In particular filters may be applied to supplier and consumer admins and to supplier and consumer proxies This section extends the structured push consumer example by applying a filter to the supplier proxy FilteredConsumer cpp and FilteredConsumer java in the C and Java demos implement event filtering The steps in applying a filter are illustrated in Figure 19 Obtain reference to FilterFactory y Obtain a filter Create constraints AA Create filter y Add constraints to filter y Add filter to appropriate object proxy or admin Figure 19 Applying a Filter Demo Event
246. d its child proxy object are combined Members AND_opP Use logical AND semantics between admin and proxy filter results or_op Use logical OR semantics between admin and proxy filter results 809 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin ProxyConsumer Attributes Operations 810 interface ProxyConsumer inherits from CosNotification QoSAdmin CosNotifyFilter FilterAdmin ProxyConsumer interface Supports operations common to all proxy consumers MyType readonly attribute ProxyType MyType The type delivery model and event type of the proxy MyAdmin readonly attribute SupplierAdmin MyAdmin Reference to the parent supplier admin object obtain_subscription_types CosNotification EventTypeSeq obtain_subscription_types in ObtainInfoMode mode Obtains an aggregate list of all event types on the channel to which there is a subscription Parameters mode Determines how subscribed event types are returned Returns A sequence of event types representing all events currently subscribed to on the channel validate_event_qos void validate_event_qos in CosNotification QoSProperties required_qos out CosNotification NamedPropertyRangeSeq available_qos raises CosNotification UnsupportedQoS Checks for a conflict between per event QoS and the QoS settings of the target proxy If the target proxy cannot honor any of QoS properties in required_gos an Unsu
247. d retries RequestTimeout TimeBase TimeT The amount of time permitted for a blocking request on a client to return before a timeout The default value is 5 seconds Other Proprietary QoS Properties 714 This section describes other proprietary QoS properties available for Orbacus Notify Table 6 Propietary QoS Properties Property Value Description Pulllnterval interval gt 0 Orbacus Notify includes a PulliInterval property to specify how often events should be pulled from suppliers This property is applicable to the pull model and enables users to configure the frequency of pull requests made on suppliers The default value is 1 second Request Timeout TimeBase TimeT The Request Timeout property specifies the maximum time limit for requests made on pull suppliers and push consumers by their associated proxies The maximum value for this property is 10 minutes The default value is 5 seconds The OMG Notification Service Administrative Properties In addition to configurable QoS properties event channels also support the configuration of certain administrative properties There are three administrative properties each of type long which are supported by an event channel Table 7 Administrative Properties Property Value Description MaxConsumers consumers gt 0 The maximum number of consumers that can be connected to a channel at any
248. de oB corBA h which contains definitions for the standard CORBA classes as well as for other useful things 4 We must also include the Hello_imp1 class definition contained in the header file Hello_impl h 6 9 The say_hello function simply prints Hello World on standard output 12 Implementing the Example in C Writing the Server Program Overview main function Now we will write the server program To simplify exception handling and ORB destruction we will split the server into two functions main and run where main only creates the ORB and calls run Create a file with the name Server cpp and enter the code for the main function shown below oma fF WN FE OANA OF WNE OO NM NM NM NY WNHrROW iif Cabs include lt OB CORBA h gt include lt Hello_impl h gt include lt fstream h gt DMieeeun CORB Ave ORBE pile ey aloe iieiali alisie lt ijtefe ehar Eireteny int status EXIT_SUCCESS CORBA ORB var orb try orb CORBA ORB_init argc argv status run orb catch const CORBA Exceptions amp Status EXIT_PAITLURE 13 CHAPTER 2 Getting Started 14 2 5 16 17 19 22 24 34 36 24 alice ICORBA Gale piloro 25 26 try 2m 28 orb gt destroy 29 30 catch const CORBA Exception amp Sil 32 status EXIT_FAILURE 33 34 35 36 return status Si Several header files are included Of t
249. dentifies the protocol policy RECONNECT_POLICY const CORBA PolicyType RECONNECT_POLICY 4 This policy type identifies the reconnect policy TIMEOUT_POLICY const CORBA PolicyType TIMEOUT_POLICY 5 This policy type identifies the timeout policy FSSL Bibliography 1 7 10 11 12 The SSL Protocol Version 3 0 Transport Layer Security Working Group ANSI X3 106 American National Standard for Information Systems Data Link Encryption American National Standards Institute 1983 R Rivest A Shamir and L M Adleman A Method for Obtaining Digital Signatures and Public Key Cryptosystems Communications of the ACM v 21 n 2 Feb 1978 pp 120 126 CCITT Recommendation X 509 The Directory Authentication Framework 1988 SSLeay and SSLapps FAQ T J Hudson E A Young iSaSiLk 2 0 User Manual Institute for Appli Information Processing and Communications Graz University of Technology 1998 NIST FIPS PUB 180 1 Secure Hash Standard National Institute of Standards and Technology U S Department of Commerce DRAFT 31 May 1994 R Rivest RFC 1321 The MD5 Message Digest Algorithm April 1992 W Diffie and M E Hellman New Directions in Cryptography IEEE Transactions on Information Theory V IT 22 n 6 Jun 1977 pp 74 84 Marc Laukien Uwe Seimet Matthew Newhook and Mark Spruiell ORBacus For C and Java Object Oriented Concepts Inc Bruce Schneier Applied Cryptography
250. determine the identity of the caller Uy Chi FSSL CertificateSeq_var chain fssliopInfo gt certificate_chain Java com ooc FSSL Certificate chain fssliopInfo certificate_chain The negotiated cipher can be determined using the OCI FSSLIOP Transportinfo negotiated_cipher 537 CHAPTER 2 Extending the Hello World Application I se FSSL Cipher cipher fssliopInfo gt negotiated_cipher Java com ooc FSSL Cipher cipher fssliopInfo negotiated_cipher 538 Client Side Usage Preventing Connections to Secure Insecure Servers In developing your applications you may want to restrict the servers to which your proxy will connect For instance you may want to connect only with secure servers or alternatively only with insecure servers To do this a ProtocolPolicy policy must be used The ProtocolPolicy is used to restrict the protocol that will be used to establish communications By default after initializing the FreeSSL plug in a protocol policy with a value of OCI FSSLIOP PLUGIN_ID is set as an ORB level policy Therefore only secure connections will be established unless this is overridden To allow an object reference to use IIOP the protocol policy can be overridden on the reference as follows Ud Coe CORBA Any any any lt lt OCCIT ILINO P 8 r PLUGIN TD CORBA PolicyList pl 1 pl length 1 pl 0 orb gt create policy OB PROTOCOL_POLICY_ID any
251. dex The position index of this profile in an IOR components A sequence of tagged components FactoryAlreadyExists exception FactoryAlreadyExists PluginId id A factory with the given plugin id already exists Members id The plugin id NoSuchFactory exception NoSuchFactory PluginId id No factory with the given plugin id could be found Members id The plugin id InvalidParam exception InvalidParam string reason A parameter is invalid Members reason A description of the error Module OCI 455 CHAPTER E Open Communications Interface Reference Interface OCI Buffer Synopsis Attributes Operations 456 local interface Buffer An interface for a buffer A buffer can be viewed as an object holding an array of octets and a position counter which determines how many octets have already been sent or received The IDL interface definition for Buffer is incomplete and must be extended by the specific language mappings For example the C mapping defines the following additional functions Octet data Returns a C pointer to the first element of the array of octets which represents the buffer s contents Octet rest Similar to data this operation returns a C pointer but to the n th element of the array of octets with n being the value of the position counter length readonly attribute unsigned long length The buffer
252. dule LoadBalancing MemberDataSeq typedef sequence lt MemberData gt MemberDataSeq A sequence of member data TolerancePropertyValue typedef unsigned long TolerancePropertyValue The tolerance load balancing strategy property value The default value is O LoadPerClientPropertyType typedef unsigned long LoadPerClientPropertyType The load per client load balancing strategy property value The default value is O RejectPropertyValue typedef unsigned long RejectPropertyValue The reject load load balancing strategy property value The default value is O meaning no rejections DampeningMultiplierPropertyValue typedef float DampeningMultiplierPropertyValue The dampening multiplier load balancing strategy property value The default value is O which disables dampening CriticalLoadPropertyValue typedef unsigned long CriticalLoadPropertyValue The critical load load balancing strategy property value The default value is O which disables re balancing MEMBER _POLICY_ID const CORBA PolicyType MEMBER _POLICY_ID 1000 This policy type identifies the member policy TolerancePropertyName const string TolerancePropertyName tolerance The tolerance load balancing strategy property name Members with a load difference that is less than tolerance are considered to have the same load LoadPerClientPropertyName const string LoadPerClientPropertyName load per client 495 CHAPTER F Orbacus Balancer Referenc
253. e Enums Structs 496 The load per client load balancing strategy property name The load per client property is an estimate of the load produced by a client RejectLoadPropertyName const string RejectLoadPropertyName reject load The reject load load balancing strategy property name Only members with loads less than reject load are selected DampeningMultiplierPropertyName const string DampeningMultiplierPropertyName dampening multiplier The dampening multiplier load balancing strategy property name A dampening technique is used to smooth out spikes that may occur in the reported loads of members The load of a member is calculated using the dampening multiplier property as follows load mult old_load 1 mult new_load where mult is the dampening multiplier property value The dampening multiplier property must be greater than or equal to O and less than 1 CriticalLoadPropertyName const string CriticalLoadPropertyName critical load The critical load load balancing strategy property name Members with loads greater than or equal to the critical load are re balanced PropertyErrorCode enum PropertyErrorCode BAD_PROPERTY BAD_VALUE This enumeration contains the various load balancing strategy configuration property error codes Property struct Property PropertyName name PropertyValue value Exceptions A load balancing strategy configuration property Pr
254. e Event Loop Next we start listening for requests Java GEY al 2 3 4 manager activate 5 6 catch org omg PortableServer POAManagerPackage AdapterInactive 8 throw new RuntimeException 10 GEDE LONII 2 10 Everything is ready now so we can listen for requests by calling actiavate on the POA Manager and run on the ORB 208 Releasing Resources 2 9 16 26 Programming Example Some cleanup work should be done before exiting the program Every binding must be properly unbound and the ORB must be destroyed o y Jene 2 nc unbind cName 3 nc unbind bName 4 nc unbind aName 5 nc unbind alName 6 nc unbind a2Name fi nc unbind a3Name 8 nc unbind nc2Name 9 nc unbind nclName 0 1 catch RuntimeException ex 2 3 status 1 4 5 6 if orb null 7 8 try 9 20 orb destroy 2m 22 catch const RuntimeException ex 23 24 status 1 25 26 27 28 System exit status All bindings are unbound destroy is called on the ORB This releases the resources used by the ORB The complete example can be found in the folder naming demo included with the Orbacus distribution 209 CHAPTER 9 Orbacus Names 210 In this chapter CHAPTER 10 Orbacus Names Console Orbacus Names includes a graphical client for administering the service called the Orbacus Names Console The application can manage any CORBA compliant Naming Service but add
255. e OCI IIOP AccFactoryInfo Synopsis local interface AccFactoryInfo inherits from OCI AccFactoryInfo Information on an IIOP OCI Acceptor Factory object 492 In this appendix APPENDIX F Orbacus Balancer Reference This appendix describes the interfaces for the Orbacus Balancer This appendix contains the following sections Module LoadBalancing page 494 Module LoadBalancing Util page 505 493 CHAPTER F Orbacus Balancer Reference Module LoadBalancing Aliases 494 The definitions in this module provide the interface of the Orbacus Balancer Groupld typedef string GroupId A load balanced group ID GroupIdSeq typedef sequence lt GroupId gt GroupIdSeq A sequence of load balanced group IDs Memberld typedef string MemberId A member ID MemberldSeq typedef sequence lt MemberId gt MemberIdSeq A sequence of member IDs Objectld typedef PortableInterceptor ObjectId ObjectId An object ID PropertyName typedef string PropertyName A load balancing strategy configuration property name PropertyValue typedef any PropertyValue A load balancing strategy configuration property value PropertySeq typedef sequence lt Property gt PropertySeq A sequence of load balancing strategy configuration properties PropertyErrorSeq typedef sequence lt PropertyError gt PropertyErrorSeq A sequence of load balancing strategy configuration property errors Constants Mo
256. e TCP port e g 10001 Specifies the path to the service s database directory Replace lt database directory gt with the directory where the service should create its databases Provides a reference to the default event channel factory Replace lt host gt with your system s host name and lt port gt with the TCP port chosen above After Orbacus Notify has been properly built and installed there will be a notserv executable in the installation target directory For example on UNIX assuming the installation path was set to usr local the executable is usr local bin notserv And on Windows with the installation path set to c orbacus C Orbacus bin notserv exe You can start Orbacus Notify in two ways Starting the Orbacus Notify Console Startup Example e Specify the configuration file on the command line Unix usr local bin notserv ORBconfig tmp ob conf Windows C Orbacus bin notserv exe ORBconfig C temp ob conf e Specify the configuration file with an environment variable Unix ORBACUS_CONFIG tmp ob conf export ORBACUS_CONFIG usr local bin notserv Windows set ORBACUS_CONFIG C temp ob conf C Orbacus bin notserv exe The Java archive opNotify jar contains the Orbacus Notify Console For example on Unix assuming the installation path was set to usxr local the archive can be found at usr local lib OBNotify jar And on Windows assuming the installation path was set to c orbacus C O
257. e is the load for each member of the load balanced group Hence we must make certain approximations when making load re balancing decisions For these approximations to hold the following assumptions must made e The average load created by a client can be reliably estimated e The load created by a client does not deviate much from the average load e Dedicated hosts e Homogeneous hosts Since load re balancing decisions are based on approximations that will only be reasonable when certain conditions are meant there is always the chance of a load re balancing error Let us say that a load re balancing error occurs when the load that is transferred from the replica of one member to the replica of another causes the target member to become overloaded This situation is what we will call system instability In some cases the system may remain instable indefinitely For example if a single client is solely responsible for causing a high load then the client will likely be bounced from member to member Yet another source of load re balancing errors comes from the fact that a member cannot redirect a client until it receives a request When this occurs the member may no longer be overloaded This can be alleviated by associating an expire time with a load alert Some important things to note when choosing between adaptive and non adaptive load balancing strategies are e Non adaptive strategies impose very little overhead compared t
258. e leader_follower Value 1 0 1 1 or 1 2 Specifies the GIOP version to be used in object references generated by a particular POA Manager This option is useful for backward compatibility with older ORBs that reject object references using a newer version of the protocol The default value is determined by the value of ooc orb oa version 67 CHAPTER 4 ORB and Object Adapter Initialization Command line Options There are equivalent command line options for many of the Orbacus properties The options and their equivalent property settings are shown in the following table Refer to ORB Properties on page 58 for a description of the properties Option Property OAreactive ooc orb oa conc_model reactive OAthreaded ooc orb oa conc_model threaded OAthread_per_client ooc orb oa conc_model thread_per_client OAthread_per_request ooc orb oa conc_model thread_per_request OAthread_pool N ooc orb oa conc_model thread_pool ooc orb oa thread_pool n OAleader_follower N ooc orb oa conc_model leader_follower ooc orb oa leader_follower_pool Nn OAversion version ooc orb oa version version ORBDefaultInitRef URL ooc orb default_init_ref URL ORBid Id ooc orb id id ORBInitRef name ior ooc orb service name ior ORBnative_cs name ooc orb native_cs name ORBnative_wcs name ooc orb native_wcs name ORBnaming ior ooc orb service NameService or ORBpr
259. e lost when the service terminates It is also important to note that when using the service in its persistent mode you should always start the service on the same port see Chapter 4 for more information Connecting to the Service Connecting to the Service The object key of the Naming Service is NameService which identifies an object of type CosNaming OBNamingContext The OBNamingContext interface is derived from the standard interface CosNaming NamingContextExt and provides additional Orbacus specific functionality For a description of the oBNamingContext interface please refer to the documented IDL file naming idl OBNaming idl The object key can be used when composing URL style object references For example the following URL identifies the naming service running on host nshost at port 10000 corbaloc nshost 10000 NameService Refer to Chapter 6 for more information on URLs and configuring initial services 195 CHAPTER 9 Orbacus Names Using the Naming Service with the IMR The Naming Service may be used with the Implementation Repository IMR However if used with the IMR it is important to note that the corbaloc URL style object reference described in the previous section cannot be used If the IMR is used then the object reference for the Naming Service must be created using one of the following methods where NamingServer refers to the server name configured with the IMR e Start the Naming Service w
260. e structure of events is unknown to the event channel and consumers are forced to handle all events when only a small subset may be of interest The CPU time necessary to interpret and discard unwanted events may seriously impact consumer performance This is exacerbated when multiple suppliers are connected to a channel Lack of an Event Channel Factory The event service does not address the issue of channel creation Instead vendors are forced to define and implement proprietary interfaces for this purpose As a result event service clients become tied a particular vendor and are not easily ported to other event service implementations The OMG has adopted the Notification Service to address these issues while maintaining compatibility with the Event Service This chapter presents an overview of Event Service and Notification Service concepts 689 CHAPTER 3 Notification Service Concepts The OMG Event Service Overview In this section 690 This section explains many of the terms and concepts covered by the Event Service Section builds upon this discussion with a presentation of the ideas introduced by the OMG Notification Service Refer to specifications 1 and 2 for a complete discussion of the Event Service and Notification Service This section contains the following topics Delivery Models page 691 Object Management Hierarchy page 694 Event Delivery page 696 Delivery Models Overview Ca
261. e surFrx as the suffix for stub files The default value is an empty suffix skel suffix SUFFIX Use surFrIx as the suffix for skeleton files The default value is _skel all Generate code for included files instead of inserting include statements See Include Statements on page 46 no relative When generating code idl assumes that the same 1 options that are used with idi are also going to be used with the C compiler Therefore ial will try to make all include statements relative to the directories specified with 1 The option no relative suppresses this behavior in which case idl will not make include statements for included files relative to the paths specified with the 1 option header dir DIR This option can be used to make include statements for header files relative to the specified directory this header dir DIR Like the header dir option this option can be used to make include statements for header files relative to the specified directory However this option only applies to include statements for the header files of this IDL file other header dir DIR Like the header dir option this option can be used to make include statements for header files relative to the specified directory However this option only applies to include statements for the header files corresponding to IDL files that were included in this IDL file output dir DIR Write generated files to directory DIR
262. e time The corresponding value is of type long MaxConsumers const string MaxConsumers MaxConsumers The maximum number of consumers that can be connected to a channel at any one time The corresponding value is of type long MaxSupplier const string MaxSuppliers MaxSuppliers The maximum number of suppliers that can be connected to a channel at any one time The corresponding value is of type long Structs Module CosNotification Property struct Property PropertyName name PropertyValue value A generic name value property pair Members name The name of the property value The value of the property EventType struct EventType string domain_name string type_name Structure defining an event type The type of an event is governed by the domain_name and type_name Members domain_name Identifies the vertical industry domain in which the event is defined type_name Further classifies the event within the domain PropertyRange struct PropertyRange PropertyValue low_val PropertyValue high_val Structure used to indicate a range of acceptable values for an unnamed property NamedPropertyRange struct NamedPropertyRange PropertyName name PropertyRange range 799 CHAPTER C CosNotification Reference 800 Structure used to indicate a range of acceptable values for a named property PropertyError struct PropertyError QoSE
263. e to be supplied which will be used as the return value for the tie s _default_poa method If the POA instance is not supplied the _default_poa method will return the root POA of the ORB with which the tie has been associated This example demonstrates how to create servants using Java 1 Java 2 I_impl impl new I_impl 3 I_impl anotherImpl new I_impl 2 3 Two servants imp1 and anotherImp1 are created with new In case the servant class was written using the delegation approach an object implementing the toperations interface must be passed to the tie s constructor 1 Java 2 I_impl_tie impl new I_impl_tie 3 IPOATie tie new IPOATie impl 2 A new I_impl_tie is created An instance of TPoaTie is created taking imp1 as a parameter All operation calls to tie will then be delegated to imp1 105 CHAPTER 5 CORBA Objects The tie class also provides methods for accessing and changing the implementation object 1 Java 2 public class IPOATie extends IPOA Set 4 arose 5 public IOperations _delegate 6 public void _delegate IOperations delegate wi 5 This method returns the current delegate i e implementation object 6 This method changes the delegate object 106 Activating Servants Activating Servants Servants must be activated in order to receive requests from clients Servant activation informs the ORB run time which particular servant represents or inc
264. e trust decider only trusts those certificates directly signed by some mythical certificate authority CA X Hi Cia class MyTrustDecider public FSSL TrustDecider CA X certificate FSSL Certificate_var cert_ jubilee MyTrustDecider FSSL Manager_ptr fsslManager FSSL OctetSeq_var data FSSL load_file cax der cert_ fsslManager gt create_certificate data virtual CORBA Boolean is_trusted const FSSL CertificateSeq amp chain if chain length 2 return chain 1 gt is_signed_by cert_ return false 527 CHAPTER 1 Using FreeSSL for Orbacus 528 Java final class MyTrustDecider extends com ooc CORBA LocalObject implements com ooc FSSL TrustDecider Hi CA X certificate Ue com ooc FSSL Certificate cert_ MyTrustDecider com ooc FSSL Manager fsslManager cert_ fsslManager create_creatificate com ooc FSSL FSSL load_file cax der public bool is_trusted com ooc FSSL Certificate chain if chain length 2 return chain i is_signed_by cert_ return false In this chapter CHAPTER 2 Extending the Hello World Application In order to demonstrate how to use the FreeSSL plug in the standard Hello World application included with Orbacus in the subdirectory demo hello will be modified The complete source code for this example is included with the FreeSSL distribution in the directory fssI demo hello This chap
265. e types is selected invoke the Edit Create menu operation The Filter Creation Wizard then steps through the creation of the filter Note that all filters become property of the FilterFactory and have associations with zero one or many admins and or proxies There are no editable properties associated with a filter When a filter is selected in the Service Structure Tree the right hand panel displays the read only list of subscribers A selected filter is destroyed by choosing the Edit Destroy menu operation A confirmation is displayed before the filter is removed 1 Ifthe filter is created from an admin then the Filter Proxy Creation Wizard is used 769 CHAPTER 5 Orbacus Notify Console Managing Filter Constraints Creating a New Filter Constraint A filter constraint is created from a filter object To create a filter constraint from the console choose the appropriate filter and select Edit Create The Constraint Creation Wizard then steps through the creation of the filter constraint Filter Constraint Properties The Edit Properties menu operation for a selected filter constraint displays a tabbed property dialog in which various constraint properties may be edited All the properties in this dialog are set initially when the constraint is created with the Constraint Creation Wizard Expression Properties The constraint expression is accessed with the Expression Properties tab shown in Figure 32 M
266. e when an event containing the last letter of the alphabet is received prompting the consumer to disconnect from the channel On disconnection by the channel disconnect the servant and end the process Invoking deactivate_imp1 causes the BOA s impl_is_ready method to return Not implemented in this example This method communicates changes in the event type offering on the channel Sequences of event types being added and event types being removed are passed as parameters 1 For the details of DisplayEvent see any of the demos which accompany the Orbacus Notify distribution in notify demo simple 5 6 8 12 14 21 23 28 Connecting to a Notification Channel The corresponding Java code is presented below woMWAtnuwnbt WN FE OJ oh Clb tw he WWWWWWNHNNNNNN DN DN LDH Gi om GG hor G ow oO oy OF oe GW Nh FF o Java class StructuredPushConsumer_impl extends _StructuredPushConsumerImp1lBase private ORB orb_ private BOA boa_ StructuredPushConsumer_impl ORB orb BOA boa orb_ orb boa_ boa public void push_structured_event StructuredEvent event throws org omg CosEventComm Disconnected System out printin Pushed if StructuredPushConsumer displayEvent event throw new org omg CosEventComm Disconnected public void disconnect_structured_push_consumer orb_ disconnect this boa_ deactivate_impl null public void offer_change EventType added EventType remove
267. e will be displayed reference count of zero Object was deleted without an object This message appears if an object was deleted by calling delete on its object reference Never use the delete operator for that use CORBA release instead 419 CHAPTER 20 Exceptions and Error Messages Message Description Object was already deleted object reference count was already zero This message appears if the number of release operations on an object reference is greater than the number of _duplicate operations Sequence length was greater than maximum sequence length This message indicates that the application tried to set the length of a bounded sequence to a value greater than its maximum length Index for sequence operator or remove function was out of range This message appears if the argument to the sequence member functions operator Of remove exceeds the sequence length Buffer size not equal to sequence bound This message indicates that the application attempted to call allocbuf on a bounded sequence with an argument not equal to the sequence bound Null pointer was used to initialize T_var type This message indicates an attempt to initialize a _var type with a null pointer operator gt was used on null pointer or nil object reference This message indicates an attempt to use operator gt on an uninitialized _var type Application tried to dereference
268. e will result in a CORBA NO_PERMISSION exception Usage Usage Orbacus Balancer is currently only implemented using Orbacus for C but Orbacus for Java servers can also be load balanced Orbacus Balancer command line usage is as follows balancer h help v version a administrative d database A admin endpoint F forward endpoint h help Display the command line options supported by the server v version Display the version of the server a administrative Run the service in administrative mode The service will run in non administrative mode by default d DIRECTORY Specifies the directory in which the service maintains its database DIRECTORY database files If not specified then the current working directory is used A INFO admin endpoint INFO Specifies the service s administrative public endpoint settings This is the endpoint that the load balanced servers use to communicate with the service For security reasons access to this endpoint can be restricted F INFO forward endpoint INFO Specifies the services s public endpoint settings which is used by clients for server requests 273 CHAPTER 14 Orbacus Balancer Windows NT Native Service 274 The balancer server is also available as a native Windows NT service ntbalancerservice h help i install s start install u uninstall d debug
269. ead Termination Method on page 604 in which we defined a terminate method In case we actually want to call this method we cannot use JTCThreadHandle as shown below JTCThreadHandle t new CharacterBuffer Do something with the CharacterBuffer t gt terminate This does not work compiler will complain Just as you cannot use JTCThread to access methods from classes derived from gTCThread you Cannot use JTCThreadHandle for this either You must use the handle class for CharacterBuffer This can be done by using the JTCHandletT template typedef JTCHandleT lt CharacterBuffer gt CharacterBufferHandle CharacterBufferHandle t new CharacterBuffer Do something with the CharacterBuffer t gt terminate This works 615 CHAPTER 4 Memory Management Rules of Thumb Rules 616 Keep the following rules in mind when using JThreads C e Always use handle types instead of plain C pointers The only exception can be made if it is absolutely certain that after start is called on the thread object the C pointer is not used anymore e Never allocate thread objects runnable objects or thread group objects on the stack Always use new e Never attempt to delete thread objects runnable objects or thread group objects with delete They will be deleted automatically e Define your own handle types by using the sTcHandleT template whenever you must access methods of classes derived from JTCThread JTCThreadGrou
270. eated and is used to incarnate a CORBA object The object reference of the servant is stringified The stringified object reference is written to a file In Java the server code looks like this 1 Java 2 org omg CORBA ORB orb Get a reference to the ORB somehow B_impl bImpl new B_impl B b biImpl _this orb String ref orb object_to_string b new java io FileOutputStream object ref 3 4 5 6 java io PrintWriter out new java io PrintWriter 7 8 out println ref 9 out close A servant for the interface B is created and is used to incarnate a CORBA object The object reference of the servant is stringified The stringified object reference is written to a file 135 CHAPTER 6 Locating Objects Now that the stringified object reference resides in a file our clients can read the file and convert the string to an object reference I Cree CORBA ORB_var orb Get a reference to the ORB somehow ifstream in object ref String 7 aij SS Sip CORBA Object_var obj orb gt string_to_object s c_str B_var b B _narrow ob Ano PWD FE 3 5 The stringified object reference is read string_to_object creates an object reference from the string Since the return value of string_to_object is of type CORBA Object_ptr B _narrow must be used to get a B_ptr which is assigned to a self managed B_var in this example 1 Java 2 org omg CORBA ORB
271. ects a recursion The bindings contained in the naming context leading to the recursion is not saved Use Save IOR to File in order to create a file that contains the stringified IOR of the currently selected binding or context With Close Window the current window is closed Closing the last window causes the application to terminate Exit can be used to terminate the application regardless of how many windows are open 215 CHAPTER 10 Orbacus Names Console The Edit Menu 216 The operations in this menu provide the means for creating and deleting objects and for changing the Naming Service structure New Context New Binding Delete Link Unlink Cut Copy Paste Change ID Change Kind Change IOR Select all Invert Selection Creates a new naming context Creates a new binding for an object Deletes the selected items Creates a new binding for an existing naming context Unbinds the selected items Moves the selected items to the clipboard Copies the selected items to the clipboard Inserts the clipboard contents Edits the ID field of the selected item Edits the Kind field of the selected item Edits the IOR of the selected item Selects all items in the object table Inverts the current selection New contexts and bindings are created with the operations New Context and New Binding respectively If one of these functions is selected a new context or object binding with a unique name is added to the curre
272. ed OB_DLL When linking statically we need to explicitly register the plug in prior to ORB initialization OCI register_plugin udp OCI_init_udp endif URL Support The UDP OCI Plug in The UDP plug in supports corbaloc URLs with the following protocol syntax corbaloc udp host port object key The components of the URL are as follows uap This selects the UDP plug in host The hostname or IP address of the server port The port on which the server is listening object key A stringified object key 387 CHAPTER 19 The Open Communications Interface Narrowing UDP Object References 388 When an application calls narrow it may result in the ORB making a twoway call to the _is_a operation to determine whether narrow should succeed However twoway operations cannot be invoked on UDP object references therefore the application must take extra precautions It is only safe to use narrow when 5 the object reference has a non empty repository ID and 6 the repository ID matches the type being narrowed In all other cases the ORB will attempt to invoke _is_a Therefore if an application cannot be sure that narrow will succeed without invoking_is_a it should use the standard operation unchecked_narrow instead This operation assumes that the application is operating correctly and allows the narrow to succeed without using _is_a 1 Object references created from corb
273. ed for server registration and can only be used when starting the server for the first time ii Use the orBServerId command line option iii Use the ooc orb server_name configuration property This configuration property is equivalent to the orBServerId command line option and may be set in a configuration file or programmatically prior to initializing the ORB in a server In this example the IMR is responsible for starting the servers Hence when the server is started the oRBServertd option is automatically added to the argument list 8 Create object references for use by the clients A server can always be used to create references for its objects However if an object is created by a POA that uses the usER_1D object identification policy then the mkreg utility can also be used to create a reference for the object Using the mkreg utility is discussed below Assume each server has a single primary object Serverl uses Object 1 for its Object ID and server2 uses Object2 Also each server creates a persistent POA called main to hold its objects To create object references for these objects run the following on master mkref P 10001 Serverl Object1 Main gt Objectl ref mkref P 10001 Server2 Object2 Main gt Object2 ref After all OADs servers and POAs are registered it is recommended to restart the IMR in non administrative mode This will prevent any accidental or unauthorized modifications 175 CHAPTER 7 The
274. ed on a recursive TypeCode that has not yet been embedded An already embedded TypeCode was reused This message indicates that an application attempted to embed a recursive TypeCode that was already embedded LongDouble type is not supported on this platform This message appears when an application uses the CORBA LongDouble type on a platform which does not support this type APPENDIX A Boot Manager Reference This appendix describes the interfaces for the Orbacus Boot Manager In this appendix This appendix contains the following sections page 424 page 426 Interface OB BootManager Interface OB BootLocator 423 CHAPTER A Boot Manager Reference Interface OB BootManager local interface BootManager Interface to manage bootstrapping of objects Exceptions NotFound exception NotFound This exception indicates that a binding has not been found AlreadyExists exception AlreadyExists This exception indicates that a binding already exists Operations add_binding void add_binding in PortableServer 0bjectId oid in Object obj raises AlreadyExists Add a new binding to the internal table Parameters oid The object id to bind obj The object reference Raises AlreadyExists Thrown if binding already exists remove_binding void remove_binding in PortableServer ObjectId oid raises NotFound Remove a bi
275. ed to the buffer and 1en_ is incremented by one The writeBuffer method prints len_ characters from the buffer on standard output and then resets 1en_ to Zero The above class works fine as long as there is only a single thread of execution but it will not work properly in a multi threaded environment For example if two threads execute addchar simultaneously things can easily go wrong Let s assume that the first thread runs until after the delete data_ statement has been executed At this point the operating system switches from the execution of the first thread to the second Since max_ has not yet been incremented by the first thread the second thread also enters the conditional and accesses the data_ variable which now points to memory already deleted by the first thread This will most likely crash the program To solve the above problem Java uses a concept known as monitors This is described in the following sections 589 CHAPTER 3 Working With Threads Thread Safe Version in Java Thread safe Java example A thread safe Java version of the code in the previous section can be written as follows 1 public class CharacterBuffer 24 3 private char data_ null 4 private int len_ 0 5 6 synchronized public void addChar char c 7 8 if data_ null len_ data_ length 9 0 byte newData new byte len_ 128 T if data_ null 2 System arraycopy data_ 0 newData 0 len_ 3 data_ newData
276. ef command line option Refer to Chapter 6 for more information on URLs and configuring initial services 281 CHAPTER 14 Orbacus Balancer Load Balanced IMR enabled Servers Load balanced servers may also be IMR enabled servers For information on using the IMR refer to Chapter 7 Note that Orbacus Balancer and the IMR need no additional configuration Object references created by a member POA of an IMR enabled server will still refer to the associated load balanced group within Orbacus Balancer However when Orbacus Balancer selects a member implemented by a IMR enabled server to service a new connection the reference returned to the client will actually refer to the IMR instead of the member s server When the client makes a request using this reference the IMR receives the request activates the member s server if necessary using the OAD and returns a new object reference to the client that refers the server 282 Utilities Utilities In this section This section describes various load balancing utilities Service Administration page 284 Making References page 285 Utility Objects page 286 Utility Object Configuration Properties page 287 283 CHAPTER 14 Orbacus Balancer Service Administration The 1badmin utility provides complete control over Orbacus Balancer Its command interface is shown below h help Display this information list groups List the load balanced
277. egister to receive sequences of structured events For any such consumer this property defines the maximum period of time the channel will collect individual events into a sequence before delivering the sequence to the consumer The corresponding value is of type TimeBase TimeT StartTimeSupported const string StartTimeSupported StartTimeSupported Indicates whether or not the setting of start Time on a per message basis is supported The corresponding value is of type boolean StopTimeSupported const string StopTimeSupported StopTimeSupported Indicates whether or not the setting of stopTime on a per message basis is supported The corresponding value is of type boolean MaxEventsPerConsumer const string MaxEventsPerConsumer MaxEventsPerConsumer An administrative property can be set on a channel to bound the maximum number of events a given channel is allowed to queue at any given point in time However a single badly behaved consumer could result in the channel holding the maximum number of events it is allowed to queue for an extended period of time preventing further event communication through the channel This QoS property helps to avoid this situation by bounding the maximum number of events the channel will queue on behalf of a given consumer The corresponding value is of type long MaxQueueLength const string MaxQueueLength MaxQueueLength The maximum number of events that a channel will buffer at any on
278. ember of this group and e returns a new reference to the client that refers to the replica of the object that is provided by this member The client then establishes a connection with the server using the new object reference and communicates directly with the server without the intervention of the service Load Balancing Strategies Load Balancing Strategies Member Selection Each load balanced group within the service has an associated load balancing strategy The load balancing strategy determines which member will be used to service the next client connection The strategy is also responsible for load re balancing Load re balancing is done by issuing load alerts to overload members When a member receives a load alert it forwards the next client request back to the service There are two types of strategies adaptive and non adaptive When using an adaptive strategy a load balanced group must receive load updates from the members These loads are then used by the strategy to determine the next member to be used for a client connection Adaptive strategies can also provide load re balancing When using non adaptive strategies the service does not require load updates from the members and load re balancing is not possible Member selection and load re balancing are discussed in the following sections The advantages and disadvantages of the different types of load balancing strategies is also presented Non adaptive membe
279. ence counter for you Let s go back to the example from The Join and IsAlive Methods on page 608 There we told you that it is absolutely necessary to use JTCThreadHandle instead of JTCThread Now we will reveal the secret behind it Consider how we would have written the example without JTCThreadHandle int marmint targe mG Weatterer Faro JTCInitialize initialize Don t do this Use JTCThreadHandle instead of JTCThread JTCThread t new HelloWorld ic sieeve do try t gt join catch const JTCInterruptedException amp while t gt isAlive return 0 This example is wrong and the program will most certainly crash When the thread terminates its reference count is decremented from 1 to O and thus the thread object is deleted with delete However we are still trying to join with the thread and check whether it s still alive using isAlive even though the thread object has already been deleted 613 CHAPTER 4 Memory Management 614 So what we would have to do is increase the reference count by 1 after the new and to decrement it by 1 after the while loop This would make sure that the reference count drops to O after the join and isAlive methods were called This is exactly what handles are doing for you Whenever you assign a thread object to a handle it increases the reference count of the thread object by 1 The same is true if you assign a handle to another h
280. ent Parameters filterable_data The event to be evaluated in the form of a structured event Returns Returns TRUE if the event satistifes at least one constraint FALSE otherwise If the filterable data of the input event contains data that the match operation cannot handle an UnsupportedFilterableData exception is raised match_typed boolean match_typed in CosNotification PropertySeq filterable_data raises UnsupportedFilterableData Not implemented attach_callback CallbackID attach_callback in CosNotifyComm NotifySubscribe callback Allows objects supporting the NotifySubscribe interface proxy suppliers and consumer admins to register with the target filter object Registered objects are notified when the set of event types required by the filter constraints changes Parameters callback A reference to an object interested in subscription changes Returns Module CosNotifyFilter The target filter object assigns and returns a unique ID to each registered callback detach_callback void detach_callback in CallbackID callback raises CallbackNotFound Removes a callback previously registered with attach_callback Parameters callback The ID of the callback to be removed The callbackNotFound exception is raised of the target object does not contain a reference with the given ID get_callbacks CallbackIDSeq get_callbacks Retrieve a list of all callbacks registered with the targe
281. ent variable includes the oBE jar file You might also want to use a C server together with a Java client or vice versa This is one of the primary advantages of using CORBA if something is defined in CORBA IDL the programming language used for the implementation is irrelevant CORBA applications can talk to each other regardless of the language they are written in 29 CHAPTER 2 Getting Started Summary What have we learnt 30 At this point you might be inclined to think that this is the most complicated method of printing a string that you have ever encountered in your career as a programmer At first glance a CORBA based approach may indeed seem complicated On the other hand think of the benefits this kind of approach has to offer You can start the server and client applications on different machines with exactly the same results Regarding the communication between the client and the server you don t have to worry about platform specific methods or protocols at all provided there is a CORBA ORB available for the platform and programming language of your choice If possible get some hands on experience and start the server on one machine the client on another As you will see CORBA based applications run interchangeably in both local and network environments One last point to note you likely won t be using CORBA to develop systems as simple as our Hello World example The more complex your applicat
282. entChannel EventServicePOA For the typed Event Service the object reference must be created using one of the following methods e Start the Event Service with the options ORBServerlId EventServer typed service ior causing the Event Service to print its reference to standard output e Use the mkref utility mkref EventServer DefaultTypedEventChannel EventServicePOA Object references for the Orbacus proprietary factory objects can be created using the following commands mkref EventServer DefaultEventChannelFactory EventServicePOA mkref EventServer DefaultTypedEventChannelFactory Event ServicePOA When using the Event Service with the IMR the service must be started with the option ORBServerld EventServer where Event Server refers to the server name configured with the IMR When the IMR is configured to start the Event Service this option is automatically added to the service s arguments However when the Event Service is started manually the option must be present For further information on configuring a service with the IMR refer to Getting Started with the Implementation Repository on page 173 244 Event Service Concepts Event Service Concepts In this section This section contains the following topics The Event Channel page 246 Event Suppliers and Consumers page 247 Event Channel Policies page 249 Event Channel Factories page 250 245 CHAPTER 12 Orbacus Events
283. entChannelAdmin Interface CosEventChannelAdmin ProxyPullConsumer Synopsis Operations interface ProxyPullConsumer inherits from CosEventComm PullConsumer A pull supplier uses this interface to register with an event channel connect_pull_supplier void connect_pull_supplier in CosEventComm PullSupplier pull_supplier raises AlreadyConnected TypeError Registers a pull supplier implementation with the event channel A pull supplier must implement and register a CosEventComm Pull Supplier object so that the channel may successfully pull events from it Parameters pull_supplier A reference to a pull supplier implementation 781 CHAPTER A CosEventChannelAdmin Reference Interface CosEventChannelAdmin ProxyPushSupplier Synopsis Operations 782 interface ProxyPushSupplier inherits from CosEventComm PushSupplier A push consumer uses this interface to register with an event channel connect_push_consumer void connect_push_consumer in CosEventComm PushConsumer push_consumer raises AlreadyConnected TypeError Registers a push consumer implementation with the event channel A push consumer must implement and register a CosEvent Comm PushConsumer object so that the channel may successfully push events on it Parameters push_consumer A reference to a push consumer implementation Module CosEventChannelAdmin Interface CosEventChannelAdmin ConsumerAdmin Synopsis Ope
284. ented first followed by the Java version i ist 2 CORBA Object_var poaObj 3 orb gt resolve_initial_references RootPOA 4 OBPortableServer POA_var rootPOA 5 OBPortableServer POA _narrow poa0bj 6 POAManagerFactory_var factory rootPOA gt the_POAManagerFactory 7 OBPortableServer POAManagerFactory_var pmFactory 8 OBPortableServer POAManagerFactory _narrow factory 9 POAManager_var myPOAManager 0 Polieyiist pl 1 pl length 1 2 pl 0 pmFactory gt create_giop_version_policy 3 OBPortableServer GIOP_VERSION_POLICY_1_2 4 try 54 6 myPOAManager create_POAManager MyPOAManager pl P 8 catch const POAManagerFactory ManagerAlreadyExists amp ex om 20 do something 21 And now the same example in Java 325 CHAPTER 16 Using Policies 326 oma nanan fF WN FE ey eS wA SS OO 20 21 22 29 24 25 Java org omg CORBA Object obj orb resolve_initial_references RootPOA org omg PortableServer POA rootPOA org omg PortableServer POAHelper narrow obj org omg PortableServer POAManagerFactory factory rootPOA the_the_POAManagerFactory com ooc OBPortableServer POAManagerFactory pmFactory com ooc OBPortableServer POAManagerFactoryHelper narrow facto ry org omg PortableServer POAManager myPOAManager null org omg CORBA Policy pl new Policy 1 pl 0 pmFactory create_giop_version_policy com ooc OBPortableServer GIOP_VERS
285. entifies an object of type cosNotifyChannelAdmin EventChannelFactory The object key can be used when composing URL style object references For example the following URL identifies the notification service running on host nshost at port 10000 corbaloc nshost 10000 DefaultEventChannelFactory Orbacus Notify Console Orbacus Notify Console Synopsis java com ooc CosNotifyConsole Main There are no command line options specific to the Orbacus Notify Console 683 CHAPTER 2 Configuration and Startup Startup Example Starting Orbacus Notify 684 The following is an example for how to start Orbacus Notify and the Orbacus Notify Console using an Orbacus configuration file For more information on Orbacus configuration files please refer to Using a Configuration File on page 70 Note that it is also possible to use command line parameters instead of configuration files Create a file with the following contents and save it as tmp ob conf Unix or C temp ob conf Windows 1 ooc notification endpoint iiop port lt port gt ooc notification dbdir lt database directory gt 3 ooc orb service NotificationService corbaloc lt host gt lt port gt DefaultEventChannelFactory a Note that for layout reasons this configuration option spans two lines but in your configuration file only one single line must be used Specifies the endpoint configuration for the service Replace lt port gt with an arbitrary fre
286. eously See The X11 Reactor on page 361 e A special Reactor for use with Microsoft Windows 95 98 NT 2000 This Reactor handles Windows messages and CORBA network events simultaneously See The Windows Reactor on page 362 The default Reactor is the select Reactor If one of the other Reactors is to be used it must be initialized explicitly The X11 Reactor 1 7 11 13 15 17 22 The Reactor An application that wants to use the X11 Reactor can obtain a special X11 Reactor using 0B GetX11Reactor which it must pass to OBCORBA ORB_init Li Cae include lt X11 Intrinsic h gt include lt OB CORBA h gt include lt OB Logger h gt include lt OB Properties h gt include lt OB X11 h gt Oo 1 ot OF amp WwW NS Ee int main int argc char argv XtAppContext appContext Widget topLevel XtAppInitialize amp appContext MMiv Aplications Om Ol mecca CmuciiaCh vam Ol mula O ay OB Reactor_var reactor OB GetX11lReactor appContext CORBA ORB_var OBCORBA ORB_init argc argv OBI Propert resike onii OB e bogger mniula i mmisealcteons a D AO OO NS Gh 0 Se I S N POA initialization not shown N N Si SOrD gt eva p N N BS W Cleanup not shown N U Include header files Initialize the X11 application Use the X11 application context to obtain a X11 Reactor Initialize the ORB using the Orbacus specific OBCORBA OR
287. er Figure 11 Threaded Server Figure 12 Thread per Client Server Figure 13 Thread per Request Server Figure 14 Thread Pool Server Figure 15 OCI Class Diagram Figure 16 Connection Requirements Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Starting the Orbacus Notify Console Basic Event Service Communications Model Canonical Push Model Canonical Pull Model Hybrid Push Pull Model Hybrid Pull Push Model Mixed Suppliers and Consumers Event Service CosEventChannelAdmin Object Management Hierarchy Notification Service CosNotifyChannelAdmin Object Management Hierarchy Figure 10 CosNotification StructuredEvent 47 92 99 101 215 220 222 223 350 351 354 356 357 358 366 390 686 688 691 691 692 692 693 694 699 700 xix LIST OF FIGURES Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 XX Event Translation Example Filter Composition Admin and Proxy Filtering Mapping Filter Composition Orbacus Notify Example Connecting to a Notification Channel Connecting a Supplier to a Notification Channel Connecting a Consumer to a Notification Channel Applying a Filter Demo Event Structure
288. erface I extends org omg CORBA Object eh TOE MASAO u A The description for operation S param arg A dummy argument return A dummy string exception M IPackage E Raised under certain circumstances puole String S int arg throws M IPackage E Note that jid1 automatically inserts the fully qualified Java name for the exception E M IPackage E in this case These are the contents of IPackage E java Java package M IPackage IDL M 1I E 1 0 ii This comment describes exception E x final public class E extends org omg CORBA UserException public E 51 CHAPTER 3 Generating Code with Orbacus Now you can use javadoc to extract the comments from the generated Java files and produce nicely formatted HTML documentation For additional information please refer to the javadoc documentation 52 In this chapter CHAPTER 4 ORB and Object Adapter Initialization This chapter describes the initialization of client and server ORBs in various languages This chapter contains the following sections Initializing the C ORB page 54 Initializing the Java ORB page 55 Object Adapter Initialization page 56 Configuring the ORB and Object Adapter page 57 Using POA Managers page 77 ORB Destruction page 88 Server Event Loop page 89 53 CHAPTER 4 ORB and Object Adapter Initialization Initializ
289. erface Repository Utilities page 264 Programming Example page 265 CHAPTER 13 The Interface Repository Usage The Orbacus Interface Repository is currently only provided with Orbacus for C irserv h help v version d debug i ior DNAME DNAME DEF UNAME IDIR case sensitive FILE h Display the command line options supported by the server help v Display the version of the server version d Print diagnostic messages This option is for Orbacus internal debug debugging purposes only i Print the stringified IOR of the server to standard output ior DNAME Defines NAME aS DEF Or 1 if DEF is not provided This option is DNAME DEF passed directly to the preprocessor UNAME Removes any definition for name This option is passed directly to the preprocessor IDIR Adds pir to the include file search path This option is passed directly to the preprocessor case sensitive The semantics of OMG IDL forbid identifiers in the same scope to differ only in case This option relaxes these semantics but is only provided for backward compatibility with non compliant IDL FILE IDL files to be loaded into the repository 258 Usage Windows NT Native Service ntirservice h help i install s start install u uninstall d debug Display the command line options supported by the server install Ins
290. ermitted to use connections made on behalf of this object If set to TRUE then connections are shared The default value iS TRUE 431 CHAPTER B Orbacus Policy Reference Interface OB InterceptorPolicy Attributes 432 local interface InterceptorPolicy inherits from CORBA Policy The interceptor policy This policy can be used to control whether the client side interceptors are called value readonly attribute boolean value If an object reference has an InterceptorPolicy Set and value iS FALSE then any installed client side interceptors are not called Otherwise interceptors are called for each method invocation The default value is TRUE Module OB Interface OB LocateRequestPolicy Attributes local interface LocateRequestPolicy inherits from CORBA Policy The locate request policy This policy can be used to specify whether the ORB sends locate request messages value readonly attribute boolean value If an object has a LocateRequestPolicy set to false then the ORB will not send locate request messages for the object 433 CHAPTER B Orbacus Policy Reference Interface OB LocationTransparencyPolicy local interface LocationTransparencyPolicy inherits from CORBA Policy The location transparency policy This policy is used to control how strict the ORB is in enforcing location transparency This is useful for performance reasons Attributes value readonly attribute short value LOC
291. ers hook The function that will be called to retrieve the custom POSIX thread attributes before the creation of each thread Data Members oldHook Optional parameter in which the previously set hook is returned Applications should call this function within the new hook In essence hooks may be chained setRunHook typedef void JTCRunHook JTCThread static void setRunHook JTCRunHook hook JTCRunHook oldHook 0 Sets gets a run hook which may be used to setup any application specific information during thread creation The hook function must call thread gt run to actually run the thread Parameters hook The function that will be called on creation of the thread oldHook Optional parameter in which the previously set hook is returned Applications should call this function from within the new hook In essence hooks may be chained setStartHook typedef void JTCStartHook static void setStartHook JTCStartHook hook JTCStartHook oldHook 0 Sets gets a start hook which may be used to setup any thread specific information Parameters hook The function that will be called on creation of the thread oldHook Optional parameter in which the previously set hook is returned Applications should call this function from within the new hook In essence hooks may be chained JTC_MIN_PRIORITY const int JTC_MIN_PRIORITY A constant for the minimum priority a thread can have JTC_NORM_PRIORITY const
292. ers con The connector to compare with Returns TRUE if the Connectors are equal FALSE otherwise get_info ConnectorInfo get_info Returns the information object associated with the Connector Returns The Connector information object Module OCI Interface OCI ConnectorInfo Synopsis Attributes Operations local interface ConnectorInfo Information on a OCI Connector object Objects of this type must be narrowed to a Connector information object for a concrete protocol implementation for example to OCI TIOP ConnectorInfo in case the plug in implements IIOP See Also Interface OCI Connector id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag describe string describe Returns a human readable description of the transport Returns The description add_connect_cb void add_connect_cb in ConnectCB cb Add a callback that is called whenever a new connection is established If the callback has already been registered this method has no effect Parameters cb The callback to add remove_connect_cb void remove_connect_cb in ConnectCB cb Remove a connect callback If the callback was not registered this method has no effect 469 CHAPTER E Open Communications Interface Reference Parameters cb The callback to remove 470 Module OCI Interface OCI ConnectCB Synopsis local in
293. ers constraint_expression A reference to the filter constraint const raint_id The ID assigned to the filter constraint by the target object MappingConstraintPair struct MappingConstraintPair ConstraintExp constraint_expression any result_to_set The mapping filter constraint value pair Members 855 CHAPTER F CosNotifyFilter Reference Exceptions 856 const raint_expression A filter constraint result_to_set The result to return from a match operation which matches on the corresponding constraint MappingConstraintInfo struct MappingConstraintInfo ConstraintExp constraint_expression ConstraintID constraint_id any value Used to maintain an association between mapping filter constraints and constraint IDs Members constraint_expression A filter constraint constraint_id A unique ID assigned to the constraint value pair by the target mapping filter object value The result to return from a match operation which matches on the corresponding constraint UnsupportedFilterableData exception UnsupportedFilterableData Raised during a match operation if the input event contains data that the match operation is not designed to handle InvalidGrammar exception InvalidGrammar Raised during filter creation if an invalid constraint grammar is specified InvalidConstraint exception InvalidConstraint ConstraintExp constr Module Co
294. ertyName property_name boolean next_n in unsigned long how_many out PropertyNames property_names void destroy The iterators should always be destroyed when they are no longer needed Sometimes it is useful to know of how many properties a PropertySet consists of This information is provided by get_number_of_properties uy unsigned long get_number_of_properties Note that you have to be careful if you intend to use the return value of get_number_of_properties as the input value for the how_many parameter of get_all_properties in order to get a complete property list You always have to check the PropertiesIterator for properties that were not returned as part of the Properties sequence returned by get_all_properties otherwise you might miss a property that was defined by another process between your calls to get_number_of_properties and get_all_properties 231 CHAPTER 11 Orbacus Properties Deleting Properties If a property has become obsolete it can be deleted from the PropertySet with delete_property IDL void delete_property in PropertyName property_name raises PropertyNotFound InvalidProperty FixedProperty As you might have guessed by this operation s signature there are properties that cannot be deleted at all This kind of property is called a FixedProperty The Property Service defines several other special property types such as read only properties Please refer to the OMG Property
295. erverCert fsslManager create_certificate com ooc FSSL FSSL load_file server der com ooc FSSL Certificate caCert fsslManager create_certificate com ooc FSSL FSSL load_file ca der com ooc FSSL Certificate chain new com ooc FSSL Certificate 2 chain 0 serverCert chain 1 caCert 553 CHAPTER 2 Extending the Hello World Application 554 Once that has been done a context must be created For this demo all RSA ciphers can be used The implementation of the TrustDecider will come a little later Hi Catt Hi Create the server context Hu FSSL ContextID id fsslManager gt create_context chain FSSL OctetSeq_var FSSL load_file server key FSSL PassPhrase_var FSSL string_to_PassPhrase blahblah FSSL TrustDecider_var new TrustDecider_impl caCert FSSL CipherSeq_var FSSL get_RSA_ciphers Java Create the server context Hi int id fsslManager create_context chain com ooc FSSL FSSL load_file server key com ooc FSSL FSSL string_to_PassPhrase blahblah new ClientTrustDecider caCert com ooc FSSL FSSL get_RSA_ciphers Complete Example Once the SSL context has been created the POAManager can be initialized and the RootPOA resolved Lie Ct Create the POA Manager Hy PortableServer POAManager_var poaManager FSSL create_poa_manager RootPOAManager orb fsslManager id props Hi Resolve R
296. es The IIOP OCI Plug in If set and if host is not specified then the canonical numeric dotted decimal address is advertised in IORs The default behavior is to use the canonical hostname if possible port N Specifies the port number on which to bind the socket If no port is specified an unused one will be selected automatically by the operating system Use this option if you plan to publish an IOR e g in a file a naming service etc and you want that IOR to remain valid across executions of your server Without this option your server is likely to use a different port number each time the server is executed See Chapter 6 for more information 377 CHAPTER 19 The Open Communications Interface Command line Options The IIOP plug in supports the following command line options IIOPbacklog N Equivalent to the backlog endpoint option IIOPbind ADDR Equivalent to the bina endpoint option II0Phost ADDR ADDR Equivalent to the host endpoint option 110Pnumeric Equivalent to the numeric endpoint option IIOPport N Equivalent to the port endpoint option See Command line Options and Endpoints on page 85 for more information on the behavior of command line options 378 Static Linking URL Support The IIOP OCI Plug in There are no special requirements for linking the IIOP plug in statically in C since the plug in is p
297. es dialog is shown in Figure 24 E Event Channel 0 Properties Figure 24 Notification Channel QoS Properties This includes all QoS properties available for the channel including Orbacus Notify proprietary properties Note that Event Reliability and Connection Reliability are only set during channel creation and cannot be altered afterwards 761 CHAPTER 5 Orbacus Notify Console Destroying a Channel 762 Admin Properties The Admin Properties tab in the Event Channel Properties dialog shown in Figure 25 is used to set the maximum number of suppliers and consumers permitted per channel Event Channel 0 Properties x ee QS Properties Admin Properties Max Consumers 0 Max Suppliers 0 Figure 25 Notification Channel Admin Properties To destroy a channel simply select the channel and select the Edit Destroy menu operation A confirmation is displayed before the channel is removed Note that destroying a channel also destroys all admins and proxies associated with that channel Managing Admins Managing Admins Creating a New Admin Admin Properties To create a new supplier or consumer admin choose Edit Create on a selected event channel The Admin Creation Wizard then steps through the configuration of the new admin object QoS Properties Supplier and consumer admin QoS properties are configured in QoS Properties tab of the Admin Properties dialog shown in Figure 26
298. es the monitor lock which was acquired on entry to the writeBuffer method and waits for another thread to call either notify Or notifyAll on the monitor 5 9 It s possible that wait throws an InterruptedException Therefore this exception must be caught 600 11 12 The Wait Notify and NotifyAll Methods Now let s change the addchar method so that it calls notify whenever there are at least 80 characters in the buffer 1 synchronized public void addChar char c ABs 3 if data_ null len_ gt data_ length 4 5 byte newData new byte len_ 128 6 if data null Y System arraycopy data_ 0 newData 0 len_ 8 data_ newData 9 10 data_ len_ c alal iit Lem 80 12 PoE 1E Again addChar is declared synchronized so that the monitor lock is acquired This is a requirement for using wait notify Or notifyAll If after the addition of a new character the number of characters in the buffer is equal to or larger than 80 notify is called This wakes exactly one thread which is waiting using wait Waking in this context means that the wait Call of the waiting thread returns and implicitly locks the monitor again making sure that only one thread at a time can run the synchronized method The difference between notify and notifyAll is that notify only wakes one thread while notifyAll wakes all waiting threads If more than one thread is waiting and notify is used a random thread is woken
299. es the presence of an IFR PIDL interface Object InterfaceDef get_interface The exact semantics of get_interface can be a source of confusion In Orbacus as with most other ORBs the get_interface operation is a remote operation That is when a client invokes get_interface on an object reference the request is sent to the server The server knows the interface type of the object reference and interacts with the IFR to locate the appropriate CORBA InterfaceDef object to return to the client Therefore the server must be configured for the IFR It is not necessary to configure the client for the IFR if the client s only interaction with the IFR is via get_interface 263 CHAPTER 13 The Interface Repository Interface Repository Utilities irfeed IDL files can be loaded into the IFR at runtime using irfeed See the description of the irserv command for more information on the command line options irfeed h help v version d debug DNAME DNAME DEF UNAME IDIR FILE irdel Type definitions can be removed from the IFR using irdel See the description of the irserv command for more information on the command line options irdel h help v version name The name argument represents the scoped name of the type to be removed A scoped name has the form X Y Z For example an interface 1 defined in a module m can be identified by the scoped name M 1 264
300. ess of a client within a server method the following code can be used in a servant class method implementation Hi CBr CORBA Object_var baseCurrent orb gt resolve_initial_references OCICurrent OCI Current_var current Bm WD OCI Current _narrow baseCurrent 5 6 OCI TransportInfo_var info current gt get_oci_transport_info 7 OTN a s TOPs Transportinto ver itopinto 8 OCI IIOP TransportInfo _narrow info 9 0 if CORBA is_nil iiopInfo tL 4 2 OCI IIOP InetAddr remoteAddr iiopInfo gt remote_addr 3 CORBA UShort remotePort iiopInfo gt remote_port 4 5 cout lt lt Call from 6 lt lt remoteAddr 0 lt lt lt lt remoteAddr 1 lt lt 7 lt lt remoteAddr 2 lt lt lt lt remoteAddr 3 8 lt lt lt lt remotePort lt lt endl Q The OCI current object is requested and narrow d to the correct OCI Current type The info object for the transport is requested and narrow d to an IIOP transport info object The remainder of the example code is only executed if this was really an IIOP transport info object The address and the port of the client calling this operation are obtained and printed on standard output 371 CHAPTER 19 The Open Communications Interface The Java version looks as follows 1 Java 2 org omg CORBA Object baseCurrent 3 orb resolve_initial_references OCICurrent 4 com ooc OCI Cur
301. et of replicated objects and stateless servers e Fault Tolerance transparent failover by implementing multiple profile Interoperable Object References e Active Connection Management reclaim idle connections automatically conserving threads sockets memory and other important system resources e Security FreeSSL plug in provides secure authentication and encryption facilities See FreeSSL on page 511 CORBA features Platform support About this Document Overview e Concurrency Single and Multithreaded models to exploit power of multiprocessor hardware e Dynamic Loading Of Modules transparently install extensions and services such as transactions interceptors and protocol plug ins e Flexibility through pluggable transport protocols See The Open Communications Interface on page 363 e CORBA 2 5 support e CORBA Services Naming Events and Property services are part of the Orbacus product e Orbacus interoperates with the Orbix Notification Orbix Trader and Orbix Telecom Logging services e Portable Interceptors provide a hook for adding code that is called upon for each operation invocation e Portable Object Adapter provides high scalability for servers that contain very large numbers of objects Objects by Value reduce network traffic by turning a remote interaction into a local invocation e Dynamic Invocation and Dynamic Skeleton Interface send and receive re
302. etMessage const Returns a description of the exception This is the note parameter provided in the constructor Returns A description of the exception 657 CHAPTER A Class Reference Related Functions operator lt lt ostream amp operator lt lt ostream amp os const JTCException amp e Inserts a description of the error to the output stream os Parameters os The output stream in which to insert the thread id e The reference to the exception Returns The output stream os 658 JTClinterruptedException Overview This exception is thrown if a system call is interrupted Currently JTCMonitor wait and JTCThread sleep can throw this exception The semantics differ from Java in this respect An InterruptedException in Java is thrown if a thread is interrupted by java lang Thread interrupt Unfortunately it is impossible to implement this method in a portable fashion using the POSIX and WIN32 threading models 659 CHAPTER A Class Reference JTCillegalThreadStateException Overview This exception is thrown if a member function is called while the object is in an illegal state Currently JTCThread start the JTCThreadGroup JTCThreadGroup constructors and JTCThreadGroup destroy can throw this exception 660 JTClillegalMonitorStateException Overview This exception is thrown by sTcMonitor wait JTCMonitor notify or JTCMonitor notifyAl1 if the monitor s
303. etry Properties Property Value Description RetryTimeout TimeBase TimeT The RetryTimeout specifies the initial amount of time that Orbacus Notify waits before trying to resend an event after a communication failure with a client The default value is 1 second RetryMultiplier 1 0 lt multiplier The RetryMultiplier is the value by which the lt 2 0 current value of the RetryTimeout is multiplied to determine the next RetryTimeout value The Ret ryMultiplier may also be used to provide a backoff value if necessary The default value is 1 0 MaxRetryTimeo TimeBase TimeT The MaxRetryTimeout property is the maximum ut value or ceiling that the RetryTimeout can have This property applies to RetryTimeout values that are directly assigned by a developer as well as those that are generated from the multiplication of the RetryMultiplier and RetryTimeout The default value is 60 seconds 713 CHAPTER 3 Notification Service Concepts Table 5 Retry Properties Property Value Description The relationship among the above properties is defined as follows RetryTimeout x RetryMultiplier lt MaxRetryTimeout MaxRetries retries gt 0 The MaxRetries value is the maximum number of times that a failed event communication should be retried Once this number has been reached the proxy is destroyed and the communication terminated The default value is O meaning unlimite
304. fault name is used This default name is the string thread concatenated with the thread id A thread id is a system specific identifier generated by the operating system when a new thread is created Application developers are encouraged to use the utcThreadtd Class to refer to thread ids Throws JTCSystemCallException Indicates a failed system call JTCThread JTCThread JTCThreadGroupHandle amp group const char name 0 Create a new thread object belonging to a group with a name Parameters group The thread group name The name of the thread If no name is specified a default name is used This default name is the string thread concatenated with the thread id A thread id is a system specific identifier generated by the operating system when a new thread is created Application developers are encouraged to use the utcThreadtd Class to refer to thread ids Throws JTCSystemCallException Indicates a failed system call Member Functions getThreadGroup JTCThreadGroupHandle getThreadGroup Returns a thread group handle for the thread group object to which this thread object belongs 622 Returns A handle for the thread group object setName void setName const char name Sets the name of the thread object Parameters name The new name for the thread object If a nu11 pointer is used a default name is used This default name is the string thread concatenated with the thread id A thread id is a
305. ferred to the clipboard their contents are not evaluated before they are pasted It is during the Paste operation that the bindings of a context are duplicated This means that if new bindings are added to a context after a Cut or Copy operation these bindings will be present after pasting this context An item registered with the Naming Service has three modifiable attributes its ID its Kind and its IOR The ID and Kind attributes can be edited by simply double clicking the ID or Kind field in the table You can also change binding attributes with the corresponding menu operations Change ID Change Kind and Change IOR Entering a new IOR for an existing name effectively replaces an object registered with the Naming Service by another object with the same name Use Select all to select all of the entries in the binding table The current table selection can be inverted using Invert Selection 217 CHAPTER 10 Orbacus Names Console The View Menu The operations in this menu control the appearance of the console window as well as the presentation of the Naming Service data Toolbar Toggles the toolbar visibility Status Bar Toggles the statusbar visibility Error Window Toggles the error message window visibility Simple List Displays minimum object information Details Displays additional object information Sort Sets sorting mode for object list Refresh Updates the complete window contents A toolbar that gives access to freque
306. for the IMR containing the following imr conf ooc imr admin_endpoint iiop port 10000 ooc imr forward_endpoint iiop port 10001 ooc imr slave_endpoint iiop port 10002 ooc imr mode master ooc imr dbdir usr local Orbacus db This file is placed in the usr local Orbacus etc directory on host master Second create a configuration file for the OADs containing the following oad conf ooc orb service IMR corbaloc master 10000 IMR ooc imr slave_endpoint iiop port 10002 ooc imr mode slave ooc imr dbdir usr local Orbacus db This files is placed in the usr local Orbacus etc directory on hosts slavel and slave2 Start the IMR in administrative mode On host master run 173 CHAPTER 7 The Implementation Repository 174 imr ORBconfig usr local Orbacus etc imr conf administrative Start the OADs On host slave1 run imr ORBconfig usr local Orbacus etc oad conf On host slave2 run imr ORBconfig usr local Orbacus etc oad conf Each OAD automatically registers itself with the IMR Note that an OAD can also be registered manually using the imradmin utility For example to register the OAD on host slave1 run imradmin ORBInitRef IMR corbaloc master 10000 IMR add oad slavel Add each server to the IMR In our example we will run one server on each OAD The server names are Serverl and Server2 and are located in usr local bin on their respective hosts First we register the server
307. forward reply redirecting the client to the object reference supplied by the BootManager The BootManager Using the BootManager 3 6 3 6 The BootManager add_binding operation binds an object id to an object reference The BootManager remove_binding operation removes an existing binding The following example illustrates how a server can add a binding for the object id Myobject Id Hil CBRE CORBA Object_var obj Get a reference CORBA Object_var bmgrObj orb gt resolve_initial_references BootManager OB BootManager_var bootManager OB BootManager _narrow bmgrOb 4 PortableServer ObjectId_var objId PortableServer string_to_ObjectId MyObjectId bootManager gt add binding objId obj Oo I HD OF amp WwW N a Get a reference to the BootManager object by invoking resolve_initial_references on the ORB Create the object id Create the new binding And in Java Java org omg CORBA Object obj Get a reference org omg CORBA Object bmgrObj orb resolve_initial_references BootManager com ooc OB BootManager_var bootManager com ooc OB BootManagerHelper narrow bmgrObj byte objId MyObjectId getBytes bootManager add_binding objId obj 0 sd aS BS Get a reference to the BootManager object by invoking resolve_initial_references on the ORB Create the object id Create the new binding 147 CHAPTER 6 Locating Objects Init
308. g Started Running the Application Overview 20 Our Hello World application consists of two parts e The client program e The server program Start the server first since it must create the file He11o ref that the client needs in order to connect to the server As soon as the server is running you can start the client If all goes well the Hello World message will appear on the screen Implementing the Example in Java Implementing the Example in Java Generating Java from IDL In this section In order to implement this application in Java the interface specified in IDL is translated to Java classes similar to the way the C code was created Translate the code in Hello id1 to Java using the following command jidl package hello Hello idl This command generates several Java source files on which the actual implementation will be based Hello java HelloHelper java HelloHolder java HelloOperations java HelloPOA java _HelloStub java All these files are generated into a directory with the name hello This section discusses the following topics Implementing the Server page 22 Implementing the Client page 26 Compiling page 28 Running the Application page 29 21 CHAPTER 2 Getting Started Implementing the Server Implementation class Create a file Hello_imp1 java in the directory hello and enter the following code for the server s Hell
309. g a PKCS12 certificate file which contains a certificate chain and private key s To create a new context from a PKCS12 file FSSL Manager create_pkcs12_context is called Uy Case FSSL ContextID id fsslManager gt create_pkcs12_context pkcs12_certificate myPassPhrase myDecider myCiphers Java int id fsslManager create_pkcs12_context pkcs12_certificate myPassPhrase myDecider myCiphers To destroy a context call FSSL Manager dest roy_context Applications should be careful not to destroy contexts that are currently in use Ud Cast fsslManager gt destroy_context id 523 CHAPTER 1 Using FreeSSL for Orbacus Java fsslManager destroy_context id Certificates 524 New X 509 certificates are created using the operation FSSL Manager create_certificate An octet sequence containing a DER encoded certificate should be passed as an argument Ii Che FSSL Certificate_var myCertificate fsslManager gt create_certificate data Javat com ooc FSSL Certificate myCertificate fsslManager create_certificate data Since reading certificate data from a file is a typical use case a helper method FSSL load_file is provided This takes a file name as the argument and returns an octet sequence J Cat FSSL OctetSeq_var data FSSL load_file mycert der Java byte data com ooc FSSL FSSL load_file mycert der Handling certificate data from a PKCS12
310. ggregate list of all event types currently offered and when this changes it notifies consumers through the offer_change method The OMG Notification Service Consumer admins and proxy suppliers inherit the Not ifySubscribe interface Consumers may use the subscription_change method to subscribe unsubscribe to a set of channel events Again the channel maintains an aggregate list of all subscriptions and when this changes it notifies suppliers through the subscript ion_change method Subscription sharing allows sophisticated suppliers and consumers to dynamically control the types of events that flow through the channel This can increase channel efficiency since unwanted events are no longer produced 717 CHAPTER 3 Notification Service Concepts 718 CHAPTER 4 Programming Example This chapter describes a set of steps which implementa simple Orbacus Notify supplier and consumer In this chapter This chapter contains the following sections Introduction page 720 Connecting to a Notification Channel page 721 Supplying Events page 739 Consuming Events page 741 Filtering page 742 Disconnecting from a Notification Channel page 749 Building Orbacus Notify Clients page 751 719 CHAPTER 4 Programming Example Introduction This chapter describes a set of steps which implement a simple Orbacus Notify supplier and consumer The supplier uses the push model to present structured event data
311. groups create group group id Create a load balanced group destroy group group id Destroy a load balanced group get group info group id Get the attributes of a group get group ior group id repository id object id Get the IOR for use by a client set strategy group id lt strategy gt Use the specified built in strategy set custom strategy group id ior Use the given custom strategy list members group id Enumerate the members of the group add member group id member id Add a member to the group remove member group id member id Remove a member from the group shutdown Shutdown the service Where lt strategy gt can be random round robin least load Or min dispersion The least load strategy has the options tolerance tolerance load per client load_per_client critical load critical_load reject load reject_load dampening multiplier dampening_multiplier The min dispersion strategy has the options tolerance tolerance load per client reject load reject_load load_per_client dampening multiplier dampening_multiplier Making References Utilities The 1bmkref utility creates object references for use by clients of Orbacus Balancer Note that this can only be used to create object references when the service is configured to use the IIOP Its usage is shown below
312. gt WNHNNNNNN NN NH RO OO SE Sy Gr ab Ga ND te KS tS Sul 32 33 34 35 36 588 class CharacterBuffer chart data y Ime Mok int len jemulloyll a s CharacterBuffer data_ 0 len_ 0 CharacterBuffer delete data_ void addChar char c if len_ max_ char newData memcpy newData data_ delete data_ data_ newData max 128 data_ len_ c void writeBuffer cout write data_ len_ len 0 max_ 0 new char len_ 128 len_ lt lt se liuisiing 3 5 10 14 21 28 29 32 36 Mulit threading environment Monitors Synchronization Several data members are defined data_is a character pointer to the buffered characters max_is the maximum length of the buffer pointed to by data_ jen_ is the current length of the buffer i e the number of valid characters in the buffer pointed to by data_ len_ must be less than or equal to max_ The constructor initializes the class data members data_ max_ and len_ The destructor deletes data_ freeing the buffer memory If the buffer is full i e if ten_ is equal to max_ allocate more memory This is done by allocating a new larger character buffer copying the existing buffer contents into the new buffer deleting the old buffer and assigning the pointer to the new buffer to data_ Finally max_ must be updated to reflect the new buffer size A character is add
313. h a plug in then implements the IIOP protocol Other candidates are SCCP Signaling Connection Control Part part of SS 7 or SAAL Signaling ATM Adaptation Layer This chapter contains the following sections Interface Summary page 364 OCI Reference page 367 The IIOP OCI Plug in page 375 The UDP OCI Plug in page 380 The Bi directional OCI Plug in page 389 363 CHAPTER 19 The Open Communications Interface Interface Summary Buffer Transport Acceptor and Connector Acceptor and Connector Factories The Registries 364 An interface for a buffer A buffer can be viewed as an object holding an array of octets and a position counter which determines how many octets have already been sent or received The Transport interface allows the sending and receiving of octet streams in the form of Buffer objects There are blocking and non blocking send receive operations available as well as operations that handle time outs and detection of connection loss Acceptors and Connectors are Factories 2 for Transport objects A Connector is used to connect clients to servers An Acceptor is used by a server to accept client connection requests Acceptors and Connectors also provide operations to manage protocol specific IOR profiles This includes operations for comparing profiles adding profiles to IORs or extracting object keys from profiles Acceptor and Connector Factories are used by c
314. h Orbacus this part contains a Getting Started chapter explaining some Orbacus basics with a very simple example In this chapter CHAPTER 2 Getting Started This chapter introduces you to Orbacus using a well known application the Hello World application is presented here in a special client server version This chapter contains the following sections The Hello World Example Application page 8 Defining the Example in IDL page 9 Implementing the Example in C page 10 Implementing the Example in Java page 21 Summary page 30 Where To Go From Here page 31 CHAPTER 2 Getting Started The Hello World Example Application C and Java applications Many books on programming start with this tiny demo program In introductory C books you ll probably find the following piece of code in the very first chapter Hi Crt include lt iostream h gt WOE Wise Golte Clases cout lt lt Hello World lt lt endl return 0 Or in introductory Java books Java public class Greeter public static void main String args System out printlin Hello World These applications simply print Hello World to standard output and that is exactly what this chapter is about Printing Hello World with a CORBA based client server application In other words we will develop a client program that invokes a say_hello operation on an ob
315. h the 110Phost option specifies a hostname alias that is mapped by DNS to the canonical hostname See Command line Options and Endpoints on page 85 for more information on the 110Phost option 131 CHAPTER 6 Locating Objects Port Number 132 Each time a server is executed the Root POA manager selects a new port number on which to listen for incoming requests Since the port number is included in published object references subsequent executions of the server could invalidate existing object references To overcome this problem Orbacus provides the 110Pport option that causes the Root POA manager to use the specified port number You will need to select an unused port number on your host and use that port number every time the server is started See Command line Options and Endpoints on page 85 for more information on the 110Pport option Lifetime of Object References Object Key Each object created by a server is assigned a unique key that is included in object references published for the object Furthermore the order in which your server creates its objects may affect the keys assigned to those objects To ensure that your objects always have the same keys activate your objects using POAs with the PERSISTENT life span policy and the usER_ID object identification policy 133 CHAPTER 6 Locating Objects Stringified Object References The CORBA specification defines two operations on the ORB inte
316. hat is CORBA compliant may interact with the IMR When a server is using the IMR object references created by one of its persistent POAs refer to the IMR rather than to the server itself When the client makes a request using this reference the IMR receives the request activates the server if necessary using the OAD and returns a new object reference to the client that identifies the server at its current host and port The client then establishes a connection with the server using the new object reference and communicates directly with the server without the intervention of the IMR However should the server fail a well behaved client will contact the IMR again which may restart the server and allow the client to resume its activities 1 Binding refers to the process of opening a connection and associating an object reference with its servant 159 CHAPTER 7 The Implementation Repository Information Managed by the IMR OADs Servers 160 The IMR provides support for the indirect binding and automatic activation of servers within a given domain In order to provide this support the IMR manages three types of entities OADs servers and POAs An OAD is responsible for the activation of servers on a given host Each OAD is registered in the IMR using a host name The IMR also maintains the status of each OAD If the OAD is running and in a ready state it will have a status of up otherwise its status will be down
317. he address and port are obtained and displayed on standard output 374 The IIOP OCI Plug in The IIOP OCI Plug in Client Installation Server Installation In this section The IIOP plug in implements the Internet Inter ORB Protocol as described in 4 By default the ORB automatically installs the client and server i e Connector Factory and Acceptor Factory components of the IIOP plug in and IIOP is the default protocol used by the ORB For configuration purposes the identifier of the IIOP plug in is iiop The client side IIOP plug in is installed as shown below ooc oci client iiop no keepalive The following options are supported no keepalive Disable the use of TCP keepalives The server side IIOP plug in is installed as shown below oo0c oci server iiop This sections covers the following topics Endpoint Configuration page 376 Command line Options page 378 Static Linking page 379 375 CHAPTER 19 The Open Communications Interface Endpoint Configuration 376 The configuration options for an IIOP endpoint are shown below iiop bac klog N bind ADDR host ADDR ADDR multi profile no keepalive numeric port N backlog N Specifies the maximum length of the listen backlog queue Note that the operating system may have a smaller limit which will override this value If not specified a default value of 50 is
318. he router to standard ior output p Starts a persistent request router for use with the persistent AMI polling model w Sets the number of worker threads for processing workers WORKERS requests The value of WORKERS should be between 1 and 255 334 Router Administration Properties Router Administration Properties ooc router retry_policy ooc router retry_policy base_ interval ooc router retry_policy backoff_ factor ooc router retry_policy max_backoffs In addition to the standard configuration properties described in Chapter 4 the Orbacus AMI Router also supports the following properties for configuring router administration functionality Values immediate_suspend unlimited_ping limited_ping Default unlimited_ping Specifies the retry policy to use for the router If a router has a retry policy of immediate_suspend its state is set to SUSPENDED as soon as a message fails to be delivered to it Otherwise retry attempts are governed by additional configuration parameters given below Value Integer n gt 0 Default 5 This is the base number of seconds to wait between retry attempts This property is used for both the unlimited_ping and the limited_ping retry policies Value Decimal n gt 0 Default 2 The time between retry attempts is the product of the value of the base_interval multiplied by the value of the backoff_factor After the first retry attempt which is based solely
319. hese oB coRBA h provides the standard CORBA definitions and Hel1lo_imp1 h contains the definition of the Hello_imp1 class A forward declaration for the run function The first thing a CORBA program must do is initialize the ORB This operation expects the parameters with which the program was started These parameters may or may not be used by the ORB depending on the CORBA implementation Orbacus recognizes certain options that will be explained later The run helper function is called This code catches and prints all CORBA exceptions raised by orB_init or run If the ORB was successfully created it is destroyed This releases the resources used by the ORB If destroy raises a CORBA exception this exception is caught and printed The exit status is returned If there was no error EXIT_SUCCEss is returned Or EXIT_FAILURE otherwise run function 4 7 9 10 12 14 16 20 Implementing the Example in C Add the code for the run function to Server cpp i ff Gre 2 int run CORBA ORB_ptr orb sy 4 CORBA Object_var poaObj 5 orb gt resolve_initial_references RootPOA 6 PortableServer POA_var rootPoa i PortableServer POA _narrow poa0Ob 8 S PortableServer POAManager_var manager 0 rootPoa gt the_POAManager i 2 Hello_impl helloImpl new Hello_impl 3 PortableServer ServantBase_var servant helloImpl 4 Hello_var hello helloImpl gt _this 5
320. hich does not inherit from any other interface and from which no other interface inherits This means that the implementation class 1_imp1 only inherits from the skeleton class Poa_I and no implementation class inherits from I_imp1 It is not strictly necessary to have an implementation class for every interface For example it is sufficient to only have the class I_imp1 as long as I_imp1 implements all interface operations including the operations of the base interfaces I Cee class 1_impl s wirtual public POAT public virtual void op_a throw CORBA SystemException virtual void op_b throw CORBA SystemException virtual void op_i throw CORBA SystemException SO T oOo OF amp ND hi Now 1I_imp1 is only derived from Poa_z but not from the other servant classes I_imp1 must implement all operations from the interface 1 as well as the operations of all interfaces from which 1 is derived Several files are generated by the Orbacus IDL to Java translator for an interface 1 including 1 Java which defines a Java interface 1 containing public methods for the operations and attributes of 1 and IPOA java which is an abstract skeleton class that serves as the base class for servant classes In contrast to C Java s lack of multiple inheritance currently makes it impossible for a servant class to inherit operation implementations from other servant classes except when using delegation
321. his method since it destroys the target object and all objects it manages For example destroying an admin will destroy all proxies managed by that admin potentially cutting off active communication channels Similarly destroying a channel destroys all admins and proxies associated with that channel Disconnecting Passive Clients Disconnecting from a passive client push consumer or pull supplier is not as straight forward as disconnecting from an active client In the demo examples the passive servants disconnect by throwing the CosEventComm Disconnected exception from the push method when it detects the last event has been received On receipt of this exception Orbacus Notify invokes the appropriate servant disconnect method which initiates client process termination 750 Building Orbacus Notify Clients Building Orbacus Notify Clients The following sections describe how to build Orbacus Notify clients Compiling and Linking C Compiling and linking is to a large degree compiler and Clients platform dependent Many compilers require unique options to generate correct code Orbacus Notify clients at a minimum must link with the following e Orbacus Notify library 1ibcosNotify a Unix or CosNotify lib Windows e Orbacus library 1iboB a Unix or ob 1ib Windows See the Orbacus manual and README files which accompany the Orbacus distribution for various platform specific compilation instructions Co
322. hod The modified servant s class declaration is shown below i ff Case 2 include lt Hello_skel h gt 3 4 class Hello_impl public POA Hello 5 public PortableServer RefCountServantBase 6 i PortableServer POA_var poa_ 8 Se pullaics 10 11 Hello_impl PortableServer POA_ptr 12 1S virtual void say_hello throw CORBA SystemException 14 15 virtual PortableServer POA ptr _default_POA 1G js Private member to store the servant s default POA A constructor must be defined to allow the assignment of the servant s default POA Declaration of the _default_poa method 289 CHAPTER 14 Orbacus Balancer The remainder of the class declaration is unchanged The definition of the constructor and _default_Ppoa method follow I Cree Hello_impl Hello_impl PortableServer POA_ptr poa poa_ PortableServer POA _duplicate poa PortableServer POA_ptr Hello_impl _default_POA return PortableServer POA _duplicate poa_ The modified server program is shown below Ud Re include lt OB CORBA h gt include lt OB Balancer_init h gt include lt Hello_impl h gt aijele ieibiol COMING RORY jee alice Close p int main int argc char argv womAit numb WN FE int status EXIT_SUCCESS CORBA ORB_var orb try LoadBalancing LB_init orb CORBA ORB_init argc argv status run orb argc argv Ch os Or Be Co SS catch const CORBA
323. host O lt lt endl 6 cout lt lt porl U lt lt port endl 7 8 The list of registered acceptors is requested from the POA Manager The for loop iterates over all acceptors The info object for the acceptor is requested and narrowed to an IIOP acceptor info object The if block is only entered in case the info object really belongs to an IIOP plug in The hostname and port number are requested from the IIOP acceptor info object and printed on standard output 369 CHAPTER 19 The Open Communications Interface The Java version is basically equivalent to the C code and looks as follows Java com ooc OCI Acceptor acceptors oaManager get_acceptors i 2 p 3 4 for int i 0 i lt acceptors length i Sa 6 com ooc OCI AcceptorInfo info acceptors i get_info T com ooc OCI IIOP AcceptoriInfo iiopInfo 8 com ooc OCI IIOP AcceptorInfoHelper narrow info 9 if iiopInfo null String hosts iteopinio hosts short port Converter port iiopInfo port System out printin host host0 System out println port port OO dS eer a IS S 2 12 This is equivalent to the C version 13 The converter class is used to get a port number in int format 15 16 Like in the C version the hostname and port number are printed on standard output 370 OCI Reference Determining a Client s IP Address 2 4 6 8 10 12 18 To determine the IP addr
324. hread blocks until the mutex is unlocked If the current owner of the mutex attempts to re lock the mutex a deadlock may result unlock void unlock const This method is called by the owner of the mutex to release it The mutex must be locked and the calling thread must be the one that last locked the mutex If these conditions are not met undefined behavior will result JTCSynchronized Overview Constructor This class is used to acquire and release a monitor s lock To create a synchronized method an instance of this class should be created with the monitor as the constructor argument The constructor acquires the lock and the destructor releases the lock This class may also be used with the classes JTCMutex JTCRecursiveMutex and JTCRWMutex JTCSynchronized JTCSynchronized const JTCMonitor amp mon Acquires the monitor s lock The destructor releases the monitor s lock Throws JTCSystemCallException Indicates a failed system call JTCSynchronized JTCSynchronized const JTCMutex amp mon Acquires the mutex s lock The destructor releases the mutex s lock Throws JTCSystemCallException Indicates a failed system call JTCSynchronized JTCSynchronized const JTCRecursiveMutex amp mon Acquires the mutex s lock The destructor releases the mutex s lock Throws JTCSystemCallException Indicates a failed system call JTCSynchronized enum ReadWriteLockType read_lock write_lock
325. hrow new RuntimeException if obj null throw new RuntimeException 201 CHAPTER 9 Orbacus Names 202 10 22 24 32 34 47 37 38 29 NamingContextExt nc null 40 Eey nc NamingContextExtHelper narrow obj catch org omg CORBA BAD_PARAM ex throw new RuntimeException i SS ES ES PS SS lt O Olt Coho Usually the application is initialized in the main method For more information on ORB initialization see Chapter 4 In the next step we try to connect to the Naming Service by supplying NameService to resolve_initial_references If InvalidName is thrown there is no Naming Service available because the ORB doesn t know anything about this service If calling resolve_initial_references was successful the object reference is checked and narrowed in order to verify that it supports the interface CosNaming NamingContextExt If the narrow operation raises CORBA BAD_PARAM the object does not support the interface This is considered to be an error because we explicitly asked for a Naming Service instance Binding Programming Example In the next step some sample bindings are created and bound to the Naming Service y eNe 2 Named_impl impl A new Named_impl 3 Named_impl implA1l1 new Named_impl 4 Named_impl implA2 new Named_impl 5 Named_impl imp1A3 new Named_impl 6 Named_impl imp1R new Named_impl t Named_impl implC new Named_im
326. ial Services 148 The CORBA specification provides a standard way to bootstrap an object reference through the use of initial services which denote a set of unique services whose object references if available can be obtained using the ORB operation resolve_initial_references which is defined as follows iff DI module CORBA interface ORB typedef string ObjectId exception InvalidName Object resolve_initial_references in ObjectId identifier raises InvalidName Initial services are intended to have well known names and the OMG has standardized the names for some of the CORBAservices 9 For example the Naming Service has the name Nameservice and the Trading Service has the name TradingService Initial Services Resolving an Initial Service An example in which the ORB is queried for a Naming Service object reference will demonstrate how to use resolve_initial_references The example assumes that the ORB has already been initialized as usual First the Java version Tava org omg CORBA Object obj null org omg CosNaming NamingContext ctx null CEY obj orb resolve_initial_references NameService woMAAtnawF WN H catch org omg CORBA ORBPackage InvalidName ex An error occured service is not available if obj null The object reference is invalid CO oh Gb WN oS oO try 20 Pall ctx org omg CosNaming NamingContextHelper narrow ob 22 23 catch
327. ication may receive events Figure 18 outlines the process of connecting Consumer Obtain Consumer Admin y Obtain Proxy Supplier e Delivery Model e Push e Pull e Client Type e Any e Structured e Sequence Push Pull Callback on Disconnect Implement Consumer y Connect to Proxy Supplier lt Figure 18 Connecting a Consumer to a Notification Channel 731 CHAPTER 4 Programming Example Consumer Admin 732 a consumer to an event channel The first step in connecting a consumer is to obtain a consumer admin As mentioned earlier each event channel comes with default supplier and admin objects The example consumer uses the default consumer admin Hl Cate CosNotifyChannelAdmin ConsumerAdmin_var consumerAdmin eventChannel gt default_consumer_admin Java ConsumerAdmin consumerAdmin eventChannel default_consumer_admin As with supplier applications consumers may also create a new consumer admin object using the following jf IDL EventChannel ConsumerAdmin new_for_consumers in InterFilterGroupOperator op out AdminID id hi or use an admin with a given ID of type CosNotifyChannelAdmin AdminID Note that this is a unique ID assigned by Notify jf IDL EventChannel ConsumerAdmin get_consumeradmin in AdminID id raises AdminNotFound hi Proxy Supplier Connecting to a Notification Channel
328. ier void connect_sequence_pull_supplier in CosNotifyComm SequencePullSupplier pull_supplier raises CosEventChannelAdmin AlreadyConnected CosEventChannelAdmin TypeError Connects a supplier to the channel If a supplier is already connected the AlreadyConnected exception is raised Parameters pull_supplier A reference to the supplier object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pulling events from the connected supplier If the connection is already suspended the Connect ionAlreadyInactive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target object to resume pulling events from the connected supplier If the connection is not suspended the Connect ionAlreadyActive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised Module CosNotifyChannelAdmin Interface CosNotifyChannelAdmin ProxyPushSupplier Operations interface ProxyPushSupplier inherits from CosNotifyChannelAdmin ProxySupplier CosNotifyComm PushSupplier The ProxyPushSupplier interface manages connections from push consumers who wish to have unstructured events pushed
329. ier and consumer play active roles in this model Hybrid Pull Push Model In the Hybrid Pull Push model an event channel pulls events from suppliers and pushes them to consumers see Figure 6 Direction of Event Flow gt Pull Push Pull Supplier Event Channel Push Consumer Figure 6 Hybrid Pull Push Model The supplier and consumer are both passive in this model Combinations of the various models are also supported as illustrated in Figure 7 692 The OMG Event Service Direction of Event Flow Push Consumer Push Consumer Pull Consumer Push Supplier Pull Supplier Figure 7 Mixed Suppliers and Consumers Event Channel 693 CHAPTER 3 Notification Service Concepts 694 Object Management Hierarchy The relationship between Event Service objects is shown in Figure 8 An EventChannel SupplierAdmin m ConsumerAdmin ProxyPushSupplier ProxyPullSupplier ProxyPushConsumer ProxyPullConsumer Figure 8 Event Service CosEventChannelAdmin Object Management Hierarchy Event Service client ultimately connects to a proxy object reference so that it may supply or consume events A set of steps to obtain a proxy object reference are e Obtain an initial reference to an event channel this is outside the scope of the Event Service specification e Obtain the appropriate admin object from the channel Suppliers will want a Co
330. ifyFilter FilterFactory interface FilterFactory The FilterFactory interface includes operations which support the creation of filter objects and mapping filter objects Operations create _filter Filter create_filter in string constraint_grammar raises InvalidGrammar Creates a new filter object Parameters constraint_grammar The constraint grammar to be used for constraint expressions Returns A new filter object is returned If an unknown constraint grammar is specified an InvalidGrammar exception is raised create_mapping filter MappingFilter create_mapping_filter in string constraint_grammar in any default_value raises InvalidGrammar Creates a new mapping filter object Parameters const raint_grammar The constraint grammar to be used for constraint expressions default_value The default value returned by a match operation on the target mapping filter Returns A new filter object is returned If an unknown constraint grammar is specified an InvalidGrammar exception is raised 866 Module CosNotifyFilter Interface CosNotifyFilter FilterAdmin Operations interface FilterAdmin The FilterAdmin interface supports the management of filter objects add_filter FilterID add_filter in Filter new_filter Adds a filter to the target object Parameters new_filter The filter object to be added to the target object Returns The ID assigned to the filter by the target object
331. il orb Ery orb gt destroy catch const CORBA Exception amp ex cer lt ex lt lt endl status EXIT_FAILURE return status 541 CHAPTER 2 Extending the Hello World Application 542 Java Publbicwstakvc vend main String args int status 0 org omg CORBA ORB orb null java util Properties props System getProperties props put org omg CORBA ORBClass com ooc CORBA ORB props put org omg CORBA ORBSingletonClass com ooc CORBA ORB try orb org omg CORBA ORB init args props status run orb args catch Exception ex ex printStackTrace status 1 if orb null ERY com ooc CORBA ORB orb destroy catch Exception ex ex printStackTrace status 1 System exit status Complete Example run Next obtain a reference to the FSSL Context Manager ii CH int run CORBA 7ORB_ptr orb int argc char argv OBCORBA ORB_var oborb OBCORBA ORB _narrow orb fof Obtain the ORB s property set Hil OB Properties_var props oborb gt properties Hy Resolve the FSSL Context Manager CORBA Object_var fsslManagerObj orb gt resolve_initial_references FSSLContextManager FSSL Manager_var fsslManager FSSL Manager _narrow fsslManagerOb Java Sleslieae siete run org omg CORBA ORB orb String args throws org omg CORBA UserException Obtai
332. ile Comments in the IDL file are preserved and javadoc style keywords are supported The section Documenting IDL Files on page 47 provides more information h help v version d debug DNAME DNAME DEF UNAME IDIR all case sensitive These options are the same as for the idl command no sort Don t sort symbols alphabetically ignore case Sort case insensitive use tables Use tables for indices alt indent Use alternative indentation for argument lists The alternative format requires less horizontal space which is in particular useful if the names of the operation or arguments are long output dir DIR Write HTML files to the directory DIR 41 CHAPTER 3 Generating Code with Orbacus Translating IDL to RTF Description Options for ridl 42 ridl creates Rich Text Format RTF files from IDL files An RTF file is generated for each module and interface defined in an IDL file Comments in the IDL file are preserved and javadoc style keywords are supported The section Documenting IDL Files on page 47 provides more information h help v version d debug DNAME DNAME DEF UNAME IDIR all case sensitive These options are the same as for the idl command no sort ignore case use tables alt indent These options are the same as for the hidl command output dir DIR Write RTF files to the
333. ile Using a URL Object Reference URLs corbaloc URLs corbaname URLs file URLs relfile URLs The BootManager BootManager Interface How the BootManager Works Using the BootManager Initial Services Resolving an Initial Service Configuring the Initial Services The Initial Service Locator The IORDump utility CONTENTS 105 107 108 109 110 111 112 114 116 118 119 120 122 125 126 130 131 132 133 134 135 137 138 139 141 142 143 144 145 146 147 148 149 151 153 154 CONTENTS Chapter 7 The Implementation Repository 157 Background 159 Information Managed by the IMR 160 IMR Security 163 Usage 164 Windows NT Native Service 166 Configuration Properties 168 Connecting to the Service 169 Utilities 170 Getting Started with the Implementation Repository 173 Programming Example 176 Chapter 8 The Implementation Repository Console 181 Usage 182 The Menus 183 Chapter 9 Orbacus Names 187 Usage 189 Windows NT Native Service 191 Configuration Properties 193 Persistence 194 Connecting to the Service 195 Using the Naming Service with the IMR 196 Bindings 197 Name Resolution 199 Programming Example 200 Initialization 201 Binding 203 Exceptions 206 The Event Loop 208 Releasing Resources 209 Chapter 10 Orbacus Names Console 211 Usage 212 Naming Service Lookup 213 The Menus 214 The Edit Menu 216 The View Menu 218 vi CONTENTS The Tools Menu 220 The Toolbar 222 The Popup Menu 223 Chapter 11 Or
334. ilter Constraints page 770 Managing Mapping Filters page 772 753 CHAPTER 5 Orbacus Notify Console Overview The Orbacus Notify Console supports the management of all aspects of Orbacus Notify The Orbacus Notify Console includes the following functionality e Complete administration of channels admins and proxies e QoS configuration at the channel admin and proxy levels e Administration of filters e Administration of mapping filters e Administration of subscription sharing 754 Overview The Main Window The Orbacus Notify Console main window is shown in Figure 21 ORBacus Notify Console File Edit Control View Help esixe Service Structure bject Properties Event Channel Factory QoS Property Value f Event Channel 0 Default Consumer Admin B consumer Admin 1 S Any Pull Supplier 0 Default Supplier Admin Supplier Admin 1 Structured Push Consumer 0 f Event Channel 1 B Default Consumer Admin Lifetime Mapping Filter Priority Mapping Filter y Sequence Push Supplier 0 y Structured Pull Supplier 1 B Default Supplier Admin Q A any Push Consumer 0 f Forwarding Filter 0 Constraint 0 E Forwarding Filter 0 s Event Channel 2 Constraint 0 H Global Mapping Filter 0 a Global Mapping Filter 1 C Manning Constraint Host localhost Port 12101 Figure 21 The Orbacus Notify Console Main Window
335. imeout ooc orb raise_dii_exceptions ooc orb server_name 62 Value never strict always Sets the mode attribute of the oB RetryPolicy at the ORB level See Appendix B for more information on this policy The default value is strict Value timeout gt O Sets the interval attribute of the oB RetryPolicy at the ORB level See Appendix B for more information on this policy The default value is 0 Value timeout gt O Sets the max attribute of the oB RetryPolicy at the ORB level See Appendix B for more information on this policy The default value is 1 Value true false Sets the remote attribute of the oB RetryPolicy at the ORB level See Appendix B for more information on this policy The default value is false Value none transport server target Sets the Messaging SyncScopePolicy at the ORB level The default value iS transport Value timeout gt 1 Sets the oB TimeoutPolicy at the ORB level See Appendix B for more information on this policy The default value is 1 Value true false Determines whether system exceptions that occur during Dynamic Invocation Interface DII operations are raised immediately or are stored only in the CORBA Environment object This property is only available for Java applications The default value is true Note that specifying a value of false may result in unexpected behavior Value string ooc orb server_shutdown_timeou
336. in new BufferedReader 11 new InputStreamReader conn getInputStream 12 String ref in readLine 13 in close 14 15 org omg CORBA Object object orb string_to_object ref 16 B b BHelper narrow object location is the URL of the file containing the stringified object reference Read the string from the URL connection Convert the string to an object reference Narrow the reference to a B object 137 CHAPTER 6 Locating Objects Object Reference URLs 138 Prior to the adoption of the Interoperable Naming Service INS 10 the only standard format for stringified object references was the cumbersome tor format The INS introduced two new more readable formats for object references that use a URL like syntax Object reference URLs can be passed to string_to_object just like tor references The two new URL formats are described in detail in the specification but will be briefly discussed here The optional file URL format is also discussed as well as the proprietary relfile URL format corbaloc URLs Object Reference URLs The corbaloc URL supports any number of protocols the format of the URL depends on the protocol in use The general format of a corbaloc URL is shown below corbaloc protocol lt protocol specific gt Orbacus supports two standard protocols iiop and rir but additional protocols may be supported via transport plug ins The corbaloc URL for the iiop protocol has the
337. in the processing state at the same time However as stated above there can only ever be one leader The main advantage of this model is scalablilty It allows tight control over the number of threads used by each POAManager 359 CHAPTER 18 Concurrency Models The Reactor What is a Reactor Available Reactors 360 In reactive mode see Single Threaded Concurrency Model on page 350 Orbacus uses a so called Reactor for event dispatching 141 Simply speaking the Reactor is an instance in Orbacus a singleton where special objects so called event handlers can register if they are interested in specific events These events can be network events such as an event signaling that data are ready to be read from a network connection Again this chapter only applies to Orbacus when used with reactive concurrency models If you use Orbacus with any other concurrency model for example any of the multi threaded models the following examples are not applicable Also since Orbacus for Java currently doesn t support the reactive model at all the following only applies to Orbacus for C Currently there are three Reactors supported by Orbacus e The standard select Reactor which relies on the Berkeley Sockets select function e A special Reactor for use with the X11 Window System This Reactor handles X11 events which for example can trigger X11 callbacks and CORBA network events simultan
338. ineOrder 3 OrderPolicy property value indicating events should be buffered in the order of shortest expiry deadline first such that events that are destined to timeout soonest should be delivered first DiscardPolicy const string DiscardPolicy DiscardPolicy Discard policy determines the order in which events are discarded when the number of queued events exceeds MaxEvent sPerConsumer The OrderPolicy property values are alSo DiscardPolicy property values LifoOrder const short LifoOrder 4 DiscardPolicy property value The last event received will be the first discarded RejectNewEvents const short RejectNewEvents 5 DiscardPolicy property value The proxy consumers of the associated channel should reject attempts to send new events to the channel when such an attempt would result in a buffer overflow raising the system exception IMP1_LIMIT Note that this is the default setting for discard policy MaximumBatchSize const string MaximumBatchSize MaximumBatchSize This QoS property has meaning in the case of consumers that register to receive sequences of structured events For any such consumer this property indicates the maximum number of events that will be delivered within each sequence The corresponding value is of type long PacingInterval const string PacingInterval PacingInterval 797 CHAPTER C CosNotification Reference 798 This QoS property has meaning in the case of consumers that r
339. ing a ni1 value for the POA Manager argument to the create_Poa operation In fact this is the only portable means of creating POA Managers In this text we ll refer to POA Managers created in this way as anonymous POA Managers One limitation of anonymous POA Managers in Orbacus is that their endpoints cannot be configured externally via properties therefore anonymous POA Managers always use the default endpoint configuration Specifically each anonymous POA Manager will create a single IIOP endpoint on a port chosen by the operating system Consequently object references created by POAs managed by an anonymous POA Manager are inherently transient 2 Applications which require configurable POA Managers in addition to the Root POA Manager can use the proprietary POA Manager factory described in the next section 1 IONA has proposed adding support for POA Manager identity For details see http cgi omg org issues orb_revision html Issue4297 2 Unless of course an indirect persistence mechanism such as the Implementation Repository is in use 79 CHAPTER 4 ORB and Object Adapter Initialization The POA Manager Factory 80 To allow an application to easily configure POA Managers Orbacus provides the standard CORBA 3 0 factory interface for creating named POA Managers Wie Won module PortableServer local interface POAManagerFactory typedef sequence lt POAManager gt POAManagerSeq exception ManagerAl
340. ing initial services Orbacus Events also provides proprietary factory interfaces which allow construction and administration of multiple event channels in a single service The object keys and corresponding interface types of the factories are shown in Table 3 Table 3 Object Keys and Interface Types for Event Channel Factories Object Key Interface Type Event Channel DefaultEventChannelFactory OBEventChannelFactory Factory EventChannelFactory Typed Event DefaultTypedEventChannelFactory OBTypedEventChannelFactory Channel TypedEvent ChannelFactory Factory For a description of the factory interfaces please refer to the documented IDL files event idl OBEventChannelFactory idl and event idl1 OBTypedEventChannelFactory idl 243 CHAPTER 12 Orbacus Events Using the Event Service with the IMR The Event Service may be used with the Implementation Repository IMR However if used with the IMR it is important to note that the corbaloc URL style object reference described in the previous section cannot be used If the IMR is used then the object reference for the untyped Event Service must be created using one of the following methods where EventServer refers to the server name configured with the IMR e Start the Event Service with the options ORBServerld EventServer ior causing the Event Service to print its reference to standard output e Use the mkref utility mkref EventServer DefaultEv
341. ing the C ORB In C the ORB is initialized with CORBA oRB_init For example Hf CAF alge wisilie adie elatcle ehar argv CORBA ORB_var orb CORBA ORB_init argc argv i o isa The CORBA ORB_init Call interprets arguments starting with oRB and oa All of these arguments passed through the argc and argv parameters are automatically removed from the argument list 54 Initializing the Java ORB Initializing the Java ORB The ORB implementation included in JDK 1 3 and newer can be considered a minimal ORB suitable primarily for use in basic client oriented tasks In order to use the Orbacus ORB instead of the JDK s default ORB you must start your application with the following properties java Dorg omg CORBA ORBClass com ooc CORBA ORB Dorg omg CORBA ORBSingletonClass com ooc CORBA ORBSingleton MyApp An alternative is to set these properties in your program before initializing the ORB For example Java import org omg CORBA public static void main String args java util Properties props System getProperties props put org omg CORBA ORBClass com ooc CORBA ORB props put org omg CORBA ORBSingletonClass com ooc CORBA ORBSingleton ORB orb ORB init args props The ors init call interprets arguments starting with ors and oa Unlike the C version these arguments are not removed see Advanced Property Usage on page
342. int JTC_NORM_PRIORITY A constant for the default priority of a thread 627 CHAPTER A Class Reference Related Functions 628 JTC_MAX_PRIORITY const int JTC_MAX_PRIORITY A constant for the maximum priority a thread can have operator lt lt ostream amp operator lt lt ostream amp os const JTCThread amp thr Print the thread id to the output stream os The output format of the thread id field is platform specific Parameters os Output stream in which to insert the thread id thr Reference to the thread Returns The output stream os JTCRunnable Overview This class is provided as an alternative method of providing functionality in a thread In order to use this class you must write a subclass and provide a definition for the run method An instance of this class should then be provided as an argument to the stcThread constructor When the thread is started the run method of that instance will be invoked Member Functions run virtual void run Called when the start method is called on the associated thread object 629 CHAPTER A Class Reference JTCThreadGroup Overview Constructors Member Functions 630 This class represents a collection of threads and other thread groups The thread groups form a tree rooted at the system thread group New threads by default belong to the thread group of their parent thread A thread group can optionally be a daemon thread group which autom
343. ion with get_response Or poll_response However the main advantage of a reactive client becomes apparent if it is used together with a reactive server in mixed client server applications A mixed client server application is a program that is both a client and server at the same time Without the reactive concurrency model it is not possible to use nested method calls in single threaded applications which are absolutely necessary for most kinds of callbacks Consider two programs A and B both mixed client server applications First A tries to call a method f on B Before this method returns B calls back A by invoking method g This scenario is quite common and for example is used in the popular Model View Controller pattern 1 Using the reactive concurrency model for the client A can dispatch incoming requests while waiting for B s reply for This is shown in Figure 10 gt Tal dispatch go dispatch lt p ai e lt a Client Server Client Server Figure 10 Reactive Client Server The reactive concurrency models are also very fast There is no overhead for thread creation or context switching Only an additional call to an operation like select is needed before operations such as send recv Or accept Can be used by the ORB 2 1 For more information on send_deferred get_response and poll_response see the chapter The Dynamic Invocation Interface in 4
344. ions become and today s applications are complex the more you will learn to appreciate having a high level abstraction of your applications key interfaces captured in CORBA IDL 1 Note that after the startup of the server program you have to copy the stringified object reference i e the file Hello ref to the machine where the client program is to be run Where To Go From Here Where To Go From Here Further Reading To understand the remaining chapters of this manual you must have read the CORBA specifications in 4 5 and 6 You will not be able to understand the chapters that follow without a good understanding of CORBA in general CORBA IDL and the IDL to C or IDL to Java mappings 31 CHAPTER 2 Getting Started 32 In this chapter CHAPTER 3 Generating Code with Orbacus This chapter describes the Orbacus translators This chapter contains the following sections Orbacus Translators page 34 Translating IDL to C page 35 Translating IDL to Java page 39 Translating IDL to HTML page 41 Translating IDL to RTF page 42 The IDL to C Translator and the Interface Repository page 45 Include Statements page 46 Documenting IDL Files page 47 Using javadoc page 49 33 CHAPTER 3 Generating Code with Orbacus Orbacus Translators Overview Orbacus includes the following code generators or translators idl Translates IDL to C jidl Tran
345. ions using AMI polling model Application development considerations 344 The following is a sample configuration file that specifies the endpoint for the application along with three routers that can be used for routing request replies Persistent handlers require a persistent port ooc orb oa endpoint iiop port 20000 List of routers to use for routing requests ooc ami router 1 relfile routerl ref ooc ami router 2 relfile router2 ref ooc ami router 3 corbaloc localhost 30000 AMIRouter This configuration file defines three routers for routing request replies to an application using the file with router 3 given first preference then router 2 and finally router 1 Applications using the AMI polling model should start a single persistent AMI request router instead of the usual list of routers This can be done through the configuration property coc ami persistent_router and is placed in the configuration for the application making the polling requests The value for this property is again a string that represents an object reference or location to be used for contacting the router These object references or locations can be specified using one of the four methods listed for the coc ami router configuration property For example AMI Persistent Router ooc ami persistent_router relfile p_router ref Applications that can potentially receive requests or in the case of applications using the AMI callb
346. irst line 161 CHAPTER 7 The Implementation Repository POAs 162 However if a batch file or shell script is used then it should accept the ORBServerId option since it is automatically appended to the args attribute by the IMR In the case of Java servers a batch file or shell script should be created to start the server An alternative is to set the exec attribute to the Java interpreter and to use the args attribute to specify the class implementing the server The IMR allows implicit registration of POAs when the server is started This can be enabled or disabled for each server using the activate_poas Server attribute If implicit registration is enabled then the user does not have to register any of the POAs instead the server transparently notifies the IMR whenever a Call to create_Poa is made by the application code If the user disables implicit registration then the user must register all persistent POAs i e POAs with the PERSISTENT life span policy POAs are registered using the name of its server and the name of the POA Note that any transient POAs POAs with the TRANSIENT life span policy created by the server are not registered with the IMR The IMR also maintains the status for each POA which indicates the state of its POA Manager The valid values are inactive active holding and discarding IMR Security IMR Security It is very important that only the IMR s public endpoint also referred
347. ist of transport plug in identifiers which determine the preferred order in which the ORB should attempt to establish connections Only those profiles which match an entry in the list will be used If no profile from the object reference matches a transport in the list or the ORB was unable to establish a connection then a TRANSIENT exception is raised OB RequestTimeoutPolicy If an object has this policy and no response is available for a request after value milliseconds a CORBA NO_RESPONSE exception is raised Table 4 Supported Policies Orbacus policies Policy Description OB RetryPolicy This policy is used to specify retry behavior after communication failures Namely e the types of failures for which retries are allowed e the time between successive retries and e the maximum number of retries OB TimeoutPolicy If an object has this policy and a connection cannot be established or no response is available for a request after value milliseconds a CORBA NO_RESPONSE exception is raised If an object has OB ConnectTimeoutPolicy or OB RequestTimeoutPolicy set those policies have precedence OBPortableServer InterceptorCall Policy This policy determines whether server side interceptors will be called for requests on a POA Server side interceptors are enabled by default To disable server side interceptors for a POA create the POA using this policy with a value
348. istered with the LoadUpdater object The implementation provided by the service calculates the load based on the number of active requests The LoadUpdater object is used to manage load updates sent to the Balancer At regular intervals the LoadUpdater object gets the load from the LoadCalculator object and pushes it to the load balanced group of each registered member Utilities Utility Object Configuration Properties ooc balancer util create_alert ooc balancer util create_calculat or ooc balancer util create_updater ooc balancer trace alert_expire ooc balancer trace load_update The Orbacus Balancer utility objects support the following properties Value true false If set to true then the LoadAlert object will be created and will be available as an initial service The default value is true Value true false If set to true then the LoadCalculator object will be created and will be available as an initial service The default value is true Value true false If set to true then the LoadUpdater object will be created and will be available as an initial service The default value is true If the LoadCalculator object is also created then this object does not have to be set in the LoadUpdater object Value timeout gt O Specifies the expiry time for a load alert in milliseconds The default is 1000 1 second A value of O means that load alerts never expire Value frequency gt
349. ith the options ior ORBServerId NamingServer causing the Naming Service to print its reference to standard output e Use the mkref utility mkref NamingServer NameService RootContextPOA When using the Naming Service with the IMR the service must be started with the option ORBServerId NamingServer where NamingServer refers to the server name configured with the IMR When the IMR is configured to start the Naming Service this option is automatically added to the service s arguments However when the Naming Service is started manually the option must be present For further information on configuring a service with the IMR refer to Getting Started with the Implementation Repository on page 173 196 Bindings Bindings Object references registered with the Naming Service are maintained in a hierarchical structure similar to a filesystem A file in a filesystem is analogous to an object binding in the Naming Service The equivalent for a folder in a filesystem is a naming context in Naming Service terms The pieces of information stored in a Naming Service are called bindings A binding consists of an object s name and its type as defined in the CosNaming module Jif mo typedef string Istring struct NameComponent Tstring id Estring kind typedef sequence lt NameComponent gt Name enum BindingType nobject ncontext Struct Binding Name binding_name BindingType binding_type As you can see
350. itional features are provided when used with Orbacus Names This chapter contains the following sections Usage page 212 Naming Service Lookup page 213 The Menus page 214 The Toolbar page 222 The Popup Menu page 223 CHAPTER 10 Orbacus Names Console Usage com ooc CosNamingConsole Main f file FILE i ior n no updates look CLASS windows motif mac h help v version f FILE Read the Naming Service IOR from FILE file FILE i Print the stringified IOR of the Naming Service to ior standard output no updates Disables automatic updates i e callbacks that notify interested clients of changes to the naming service look CLASS Use the specified Look amp Feel class windows Use the Windows Look amp Feel if available motif Use the Motif Look amp Feel if available mac Use the Macintosh Look amp Feel if available H help Display the command line options supported by the program CLASSPATH Requirements 212 The Orbacus Names Console requires the classes in 0B jar OBNaming jar and OBUtil jar Naming Service Lookup Naming Service Lookup In order to locate a Naming Service the application takes the following steps on start up e First it checks whether a Naming Service reference was given with the f option e If this is not the case
351. ividual properties are defined as sub keys of the base For example the property ooc orb trace connections 5 is stored in the registry as the following key containing a value named connections with a REG_SZ data member equal to 5 Software O0C Properties ooc orb trace The Orbacus distribution includes a utility called RegUpdate The tool first removes all sub keys defined under the specified registry key Next all values defined in an Orbacus configuration file are transferred to the registry RegUpdate HKEY_LOCAL MACHINE HKEY_CURRENT_USER config file RegUpdate HKEY_LOCAL_MACHINE ob conf This command reads the properties defined in the file ob conf and writes the values under the following registry key HKEY_LOCAL_MACHINE Software O00C Properties 1 Use caution when defining Orbacus properties in the registry as they become global properties that will be used in every Orbacus for C application For example subtle errors can occur if the coc iiop port property is defined on a global basis 71 CHAPTER 4 ORB and Object Adapter Initialization Defining Properties Properties in Java 72 3 4 3 4 Java applications can use the standard Java mechanism for defining system properties because Orbacus will also search the system properties during ORB initialization For example 1 Java 2 java util Properties props System getProperties 3 props put ooc orb oa conc_model thread_poo
352. ject in a server program The server responds by printing Hello World on its standard output Defining the Example in IDL Defining the Example in IDL CORBA based program How do we write a CORBA based Hello World program The first step is to create a file containing our IDL definitions Since our example application isn t a complicated one the IDL code needed for this example is simple Save the IDL code shown below to a file called Hello idl ff WD interface Hello void say_hello OO PWN BP hi An interface with the name Hello is defined An IDL interface is conceptually equivalent to a pure abstract class in C or to an interface in Java The only operation defined is say_hello which neither takes any parameters nor returns any result CHAPTER 2 Getting Started Implementing the Example in C Generating C from IDL The next step is to translate the IDL code to C using the IDL to C translator Translate the code in Hello id1 to C using the following command idl Hello idl This command will create the files Hello h Hello cpp Hello_skel h Hello_skel cpp Now we will implement the server and client In this section This section discusses the following topics Implementing the Server page 11 Writing the Server Program page 13 Implementing the Client page 17 Compiling and Linking page 19 Running the Application page 20 10 Implementing the E
353. k typedef long Mask An event handler s mask The mask determines which events the event handler is interested in TypeMask typedef long TypeMask An event handler s type mask The type mask determines which category the event handler belongs to A value of zero means no specific category EventRead const Mask EventRead 1 The mask for read events EventWrite const Mask EventWrite 2 The mask for write events TypeClient const TypeMask TypeClient 1 The type mask for client event handlers TypeServer const TypeMask TypeServer 2 The type mask for server event handlers EventHandler native EventHandler An event handler is a native type Module OB Interface OB Reactor Operations local interface Reactor A generic Reactor interface register_handler void register_handler in EventHandler handler in Mask handler_mask in TypeMask type_mask in Handle h Register an event handler with the Reactor or change the registration of an already registered event handler Parameters handler The event handler to register mask The type of events the event handler is interested in type_mask The category the event handler belongs to h The event handler s handle unregister_handler void unregister_handler in EventHandler handler Remove an event handler from the Reactor Parameters handler The event handler to remove dispatch boolean dispatch in TypeMask
354. l 4 props put ooc orb oa thread_pool 20 5 org omg CORBA ORB orb org omg CORBA ORB init args null Obtain the system properties Define Orbacus properties Initialize the ORB Java virtual machines typically allow you to define system properties on the command line For example using Sun s JVM you can do the following java Dooc orb oa thread_pool 20 MyServer You can also use the java util Properties object that is passed to the ORB init method to provide Orbacus property definitions Java java util Properties props new java util Properties props put ooc orb oa conc_model thread_pool props put ooc orb oa thread_pool 20 org omg CORBA ORB orb orb omg CORBA ORB init args props or gS Gay RS Create a java util Properties object to hold our properties Define Orbacus properties Initialize the ORB using the java util Properties object Properties in C 2 3 Configuring the ORB and Object Adapter In C the Orbacus specific class oB Properties can be used to define properties i Cet class Properties iil joule Properties Properties Properties_ptr p Properties static Properties_ptr _duplicate Properties_ptr p static Properties_ptr _nil static Properties_ptr getDefaultProperties void setProperty const char key const char value const char getProperty const char key const For example to add the threaded conc
355. lAdmin Reference 830 If found a reference to the proxy consumer is returned Otherwise a ProxyNotFound exception is raised obtain_notification_pull_consumer ProxyConsumer obtain_notification_pull_consumer in ClientType ctype out ProxyID proxy_id raises AdminLimitExceeded Creates a new proxy pull consumer Parameters ctype Specifies the client type The returned proxy can be narrowed to a type suitable for the given client type proxy_id Returns the ID assigned to the newly created proxy Returns A reference to a newly created proxy consumer is returned This reference should be narrowed to the appropriate type before use The AdminLimitExceeded exception is raised if creating a new proxy would exceed the limit for the target admin obtain_notification_push_consumer ProxyConsumer obtain_notification_push_consumer in ClientType ctype out ProxyID proxy_id raises AdminLimitExceeded Creates a new proxy push consumer Parameters ctype Specifies the client type The returned proxy can be narrowed to a type suitable for the given client type proxy_id Returns the ID assigned to the newly created proxy Returns A reference to a newly created proxy consumer is returned This reference should be narrowed to the appropriate type before use The AdminLimitExceeded exception is raised if creating a new proxy would exceed the limit for the target admin destroy void destroy Destroys the targe
356. lass Product_impl extends ProductPOA public void destroy byte id _default_POA servant_to_id this _default_POA deactivate_object id St OO sd CR Cri aise G Pe 2 Servant class Product_imp1 is defined as an implementation of the Product interface 6 7 The destroy operation deactivates the servant with the POA As long as no other references to the servant are held in the server the object will be eligible for garbage collection Here s our implementation of the factory o vena 2 public class Factory_impl extends FactoryPOA Saat 4 public Product createProduct 5 6 Product _ impl result new Product impl orb_ 7 org omg PortableServer POA poa Get servant s POA 8 byte id Assign an ID 9 poa activate_object_with_id id result 10 return result _this orb_ LI 2 Servant class Factory_imp1 s defined as an implementation of the Factory interface 4 11 The createProduct operation instantiates a new Product servant activates it with the POA and returns an object reference to the client 118 Caveats Factory Objects In these simple examples the factory objects do not maintain any references to the Product servants they create it is the responsibility of the client to ensure that it destroys a Product object when it is no longer needed This design has a significant potential for resource leaks in the server as it is quite possible that a client will not destroy its
357. leServer ServantBase_var servant helloImpl 26 PortableServer ObjectId_var oid 27 PortableServer string_to_ObjectId hello 28 helloPOA gt activate_object_with_id oid servant 29 Hello_var hello helloImpl gt _this 30 Sil CORBA String_var s orb gt object_to_string hello 32 ofstream out Hello ref 33 out lt lt s lt lt endl 34 out close 35 36 manager gt activate 7 orbi run 38 39 return 0 14 22 Create a new POA using PERSISTENT life span policy and the uSER_rD object identification policy 24 25 Create the Hello servant Programming Example 26 27 Using the string hello create an object id 28 Activate the servant with the new POA The remainder of the code is unchanged 179 CHAPTER 7 The Implementation Repository 180 In this chapter CHAPTER 8 The Implementation Repository Console The Orbacus Implementation Repository IMR includes a graphical client for administering the service called the Orbacus IMR Console The Orbacus IMR Console provides complete control over the IMR OADs and servers in a domain This chapter contains the following sections Usage page 182 The Menus page 183 181 CHAPTER 8 The Implementation Repository Console Usage com ooc IMRConsole Main look CLASS windows motif mac h help look CLASS Use the specified Look amp Feel cl
358. lidConstraint Add a list of filter constraints to the target filter object This operation is incremental in that new constraints are appended to the existing list of constraints Parameters constraint_list The list of constraints to be added to the target filter object Returns The target filter object assigns an ID to each constraint This list of constraint ID pairs is returned If any of the constraints violate the constraint grammar an Invalidconst raint exception is raised modify_constraints void modify_constraints in ConstraintIDSeq del_list in ConstraintInfoSeq modify_list raises InvalidConstraint ConstraintNotFound Modifies the list of constraints associated with the target filter object If one or more of the IDs in either of the two lists are not found the Const raintNotFound exception is raised Parameters 858 Module CosNotifyFilter del_list A list of constraint IDs representing constraints to remove from the target filter object modify_list A list of constraint IDs and constraint expressions Constraints which exist in the target filter object are modified to those in the list with the same constraint ID If a constraint in this list does not conform to the constraint grammar for the target filter object an Invalidconstraint exception is raised get_constraints ConstraintInfoSeq get_constraints in ConstraintIDSeq id_list raises ConstraintNotFound Retrieves a set of constrain
359. lients to create Acceptors and Connectors Acceptors are created infrequently usually only when POA Managers are created Connectors however need to be created by clients whenever a new connection to a server has to be established The only component of the OCI that is configurable by applications is the Acceptor When creating a new Acceptor an Acceptor Factory takes a sequence of protocol specific parameters which are used to configure the Acceptor Each plug in implementation should document these configuration parameters The configuration parameters for the plug ins included with Orbacus are described later in this chapter The ORB provides Acceptor and Connector Factory Registries These registries allow the plugging in of new protocols Transport Connector Connector Factory Acceptor Factory and Acceptor must be written by the Interface Summary plug in implementers The Connector Factory must then be registered with the ORB s Connector Factory Registry and the Acceptor Factory must be registered with the ORB s Acceptor Factory Registry The Info Objects Info objects provide information on Transports Acceptors and Connectors A Transport Info provides information on a Transport an Acceptor Info on an Acceptor and a Connector Info on a Connector To get information for a concrete protocol these info objects must be narrow d to an info object for this protocol for example in the case of an IIOP plug in a OCI Transp
360. list_members Enumerate the members destroy void destroy Destroy the load balanced group 503 CHAPTER F Orbacus Balancer Reference Interface LoadBalancing GroupFactory Operations 504 interface GroupFactory Used to create destroy and retrieve load balanced groups create Group create in GroupId group_id raises GroupExists Create a new load balanced group with the given id get Group get in GroupId group_id raises GroupNotFound Get the load balanced group with the given id list GroupIdSeq list List the set of existing load balanced groups shutdown void shutdown Shutdown the Balancer Module LoadBalancing Util Module LoadBalancing Util The definitions in this module provide the interface for the Orbacus Balancer utility objects that are provided by the Balancer These utility objects can be used to implement the features required by load balanced servers that use adaptive load balancing 505 CHAPTER F Orbacus Balancer Reference Interface LoadBalancing Util LoadAlert Operations 506 local interface LoadAlert Interface to manage load alerts sent by the Balancer alert void alert Forward the next request to the Balancer get_alert_expire unsigned long get_alert_expire Retrieve the alert expire time set_alert_expire void set_alert_expire in unsigned long millis Set the alert expire time Module LoadBalancing
361. lize object was destroyed 1 Construction and destruction of static monitors which is out of the control of the application programmer is not using of monitors in this context 598 Static Monitors Note that the only JThreads C classes that can be used as a static member are the JTCMutex JTCRecursiveMutex and JTCMonitor Classes All other classes must not be used as static members 599 CHAPTER 3 Working With Threads The Wait Notify and NotifyAll Methods Inter thread communication Like in Java JThreads C offers the wait notify and notifyAll methods for inter thread communication As an example let s return to our previous example involving the characterBuffer Class This time we want the writeBuffer operation to behave in a slightly different way writeBuffer should only print the buffer s contents if there are at least 80 characters in the buffer Using Wait Notify with Java Let s start with rewriting the writeBuffer method in Java using wait 1 synchronized void writeBuffer 2 3 while len_ lt 80 4 5 EEN 6 y wait 8 9 catch InterruptedException ex 10 ALL 12 T3 System out write data_ 0 len_ 14 System out flush j T5 len_ 0 le J 1 The writeBuffer method must be declared synchronized This makes sure that the monitor lock is acquired on entry to the method 3 The while loop is executed until there are at least 80 characters available 7 wait is called This releas
362. ll result in a dangling pointer because any will free its own value which is s on assignment Invalid union discriminator type used This message appears if the discriminator type argument to CORBA ORB create_union_tc denotes a type invalid for union discriminators Valid types have a CORBA TCKind that is one of CORBA tk_short CORBA tk_ushort CORBA tk_long CORBA tk_ulong CORBA tk_char CORBA tk_boolean Or CORBA tk_enum Union discriminator mismatch This message either indicates an attempt to set a union discriminator to an invalid value with the _a modifier function or the use of a wrong accessor function i e an accessor function that does not correspond to the type of the union s actual value Uninitialized union used If this message appears an uninitialized union i e a union that was created with the default constructor and that was not set to any legal value was used 421 CHAPTER 20 Exceptions and Error Messages 422 Message Description CORBA Any operator lt lt Exception cannot be used with no type codes This message indicates that CORBA Any operator lt lt Exception was invoked for an exception for which no TypeCode is available That is the IDL defining the exception was compiled with the no typecodes option An operation on an unembedded recursive TypeCode was invoked If this message appears an operation was invok
363. load of a member may cause bad load balancing decisions 3 Yet another problem with load balancing is that in most cases it is difficult to estimate the load that a new client connection will impose on a member This becomes a bigger problem on a heavily loaded system since a load balancing decision may cause a members load to increase well past the critical level Errors of this type can be alleviated by using load re balancing However load re balancing will introduce other sources of errors as discussed in the next section Load re balancing is the transfer of a client connection from the replica of one member to the replica of another This is achieved by getting a member to forward the next client request back to the service Load re balancing is useful when the loads of the members become imbalanced Through load re balancing these imbalances can be corrected resulting in a higher average throughput Several factors may contribute to a load imbalance e Clients not generating a consistent load while connected e Clients not connected for the same amount of time e Heterogeneous hosts e Non dedicated hosts e Member selection errors For effective load re balancing we must be able track client connections and the load generated by each connection However the concept of a connection is hidden from the CORBA developer so in general all that is Choosing a Load Balancing Strategy Load Balancing Strategies availabl
364. lock has not been acquired by the calling thread 661 CHAPTER A Class Reference JTCillegalArgumentException Overview This exception is thrown when an illegal argument is passed to a JThreads C method The methods stcMonitor wait with a timeout argument JTCThread setPriority and JTCThread sleep can throw this exception 662 JTCSystemCallException Overview This exception indicates a failed system call Most JThreads C methods can generate this exception The JTCException getError method returns the error value Under UNIX this is the value of errno under WIN32 this is the value of getLastError There is no application method of determining which operation caused the error However the exception message contains a description of the operation and all arguments to assist in debugging 663 CHAPTER A Class Reference JTCUnknownThreadException Overview This exception is generated from the JTCThread current Thread method when the current thread is not known 664 JTCOutOfMemoryError Overview This exception is generated from the uTcThread constructors on an out of memory condition 665 CHAPTER A Class Reference JTCinitializeError Overview This exception is generated from the uTcInitialize int amp char constructor when an invalid option or option argument is specified 666 JThreads Bibliography 1 Scott Oaks amp Henry Wong Java Threads O Reilly
365. locking Raises COMM_FAILURE In case of an error send_detect boolean send_detect in Buffer buf in boolean block Similar to sena but it signals a connection loss by returning FALSE instead of raising COMM FAILURE Parameters buf The buffer to fill block If set to TRUE the operation blocks until the entire buffer has been sent If set to FALSE the operation sends as much of the buffer s data as possible without blocking Returns FALSE if a connection loss is detected TRUE otherwise Raises COMM_FAILURE In case of an error send_timeout void send_timeout in Buffer buf in unsigned long timeout Similar to sena but it is possible to specify a timeout On return the caller can test whether there was a timeout by checking if the buffer has been sent completely Parameters buf The buffer to send timeout The timeout value in milliseconds A zero timeout is equivalent to calling send buf FALSE Raises COMM_FAILURE In case of an error send_timeout_detect boolean send_timeout_detect in Buffer buf in unsigned long timeout Module OCI Similar to send_timeout but it signals a connection loss by returning FALSE instead of raising COMM_FATLURE Parameters buf The buffer to fill timeout The timeout value in milliseconds A zero timeout is equivalent to calling send buf FALSE Returns FALSE if a connection loss is detected TRUE otherwise R
366. lso Interface OCI AccFactory Attributes id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag Operations describe string describe Returns a human readable description of the transport Returns The description 484 Module OCI Interface OCI AccFactoryRegistry Synopsis Operations local interface AccFactoryRegistry A registry for Acceptor factories See Also Interface OCI Acceptor Interface OCI AccFactory add_factory void add_factory in AccFactory factory raises FactoryAlreadyExists Adds an Acceptor factory to the registry Parameters factory The Acceptor factory to add Raises FactoryAlreadyExists If a factory already exists with the same plugin id as the given factory get_factory AccFactory get_factory in PluginId id raises NoSuchFactory Returns the factory with the given plugin id Parameters id The plugin id Returns The Acceptor factory Raises NoSuchFactory If no factory was found with a matching plugin id get_factories AccFactorySeq get_factories Returns all registered factories Returns The Acceptor factories 485 CHAPTER E Open Communications Interface Reference Interface OCI Current Synopsis Operations 486 local interface Current inherits from CORBA Current Interface to access Transport and Acceptor information o
367. lt lt remoteAddr 2 lt lt lt lt remoteAddr 3 6 lt lt lt lt remotePort lt lt endl wi 4 6 Get the OCI connector info and narrow to an IIOP connector info 8 The if block is only executed if this really was an IIOP connector info 10 16 The address and port are obtained and displayed on standard output 373 CHAPTER 19 The Open Communications Interface The Java version looks as follows 1 Java 2 org omg CORBA Object obj Get an object reference somehow org omg CORBA portable ObjectImpl objImpl org omg CORBA portable ObjectImp1 obj com ooc CORBA Delegate ob jDelegate com ooc CORBA Delegate objImpl _get_delegate KOM CO Gy Or Co com ooc OCI ConnectorInfo info objDelegate get_oci_connector_info com ooc OCI IIOP ConnectorInfo iiopiInfo com ooc OCI IIOP ConnectorInfoHelper narrow info if iiopInfo null int remoteAddr Converter addr iiopInfo remote_addr int remotePort Converter port iiopInfo remote_port OG TS ON ae a BO e oO System out PEINE INON E connection st remoteAddr 0 remoteAddr 1 remoteAddr 2 remoteAddr 3 NNN a a E N w remotePort 24 4 7 We need to retrieve the Orbacus specific Delegate object so that we can get the connector info 9 12 Get the OCI connector info and narrow to an IIOP connector info 14 The if block is only entered if this really was an IIOP connector info 16 23 T
368. lt OL gt lt P gt lt TABLE gt lt TD gt lt TR gt lt U gt lt UL gt Using javadoc Adding IDL Comments Example Using javadoc If not explicitly suppressed with the no comments option the Orbacus IDL to Java translator jia1 adds IDL comments starting with to the generated Java files so that javadoc can be used to generate documentation as long as the comments are in a format compatible with javadoc Here is an example that shows how to include documentation in an IDL interface description file Let s assume we have an interface z in a module m ji Woy module M This is a comment related to interface I author Uwe Seimet version 1 0 FF F OF interface I This comment describes exception E xk exception E 49 CHAPTER 3 Generating Code with Orbacus The description for operation S param arg A dummy argument return A dummy string exception E Raised under certain circumstances Lae Je oP ct i a ca am string S in long arg raises E When running jid1 on this file the comments are automatically added to the generated Java files M I java and M IPackage E java For I java the generated code looks as follows Java package M Hy ETDE NAT LO mA This is a comment related to interface I author Uwe Seimet version 1 0 4 OF 50 Using javadoc public int
369. lterM Filter Filter2 Proxy 3 FilterN Figure 13 Admin and Proxy Filtering RFinal i Reinert Reiner2 t R Fiteran Reinert RFilter2 Reinern where RFinal is the boolean result of applying all filters for the admin and proxy Rejtterm M 1 M_ is the boolean result of applying admin filter m Reiltern N 1 N is the boolean result of applying proxy filter n If the OR interfilter group operator is specified during creation of the admin object then the resulting expression is R Final Reinert Rritter2 tae Reiter Reiter Reiner2 Han Rrittern 705 CHAPTER 3 Notification Service Concepts Filters can be applied at the supplier and consumer ends of a channel and at the admin and proxy levels Also note that a single filter can be associated with multiple admins or proxies This practice is not recommended since it can lead to a service which is difficult to manage 706 Mapping Filters Overview IDL interface The OMG Notification Service Mapping filters allow consumers to affect the priority and lifetime settings of an event The application of a mapping filter does not actually change any event settings instead it influences how the consumer perceives the event The structure of the mapping filter is shown in Figure 14 on page 708 The IDL interface for mapping filters MappingFilter is defined in the CosNotifyFilter module Note the similarities between mapping filte
370. luate to true If a filter contains multiple constraints OR semantics are applied between the constraints That is the boolean result of applying a filter can be expressed as Reiner Cyt Cat Cy where RFilter is the boolean result of applying a filter Ch n 1 N is the boolean result of applying constraint n within the filter A given proxy or admin may have multiple filters associated with it Again OR semantics are applied between filter results That is the boolean result of applying multiple filters is Rauriners Reinert Reiter2 Fan Rrittern where RaiFilters is the boolean result of applying all filters for an admin or proxy Reitterns N 1 N is the boolean result of applying filter n Perhaps the most complicated scenario is when a proxy and its parent admin both have multiple filters associated with them The filters associated with the admin are applied as described above using OR semantics Likewise the filters associated with the proxy are applied again using OR semantics Next the results of these two operations are combined The semantics AND or OR of this final operation are specified at the time the The OMG Notification Service admin object was created and is known as the interfilter group operator So for the configuration depicted in Figure 13 the following expression applies Filter Admin Filter2 AND interfilter group operator Fi
371. lude the plug in s modules Shown below is the technique used by the sample programs in the bidir demo subdirectory Note that the code below is enclosed in guard macros that are only activated when statically linking These macros are appropriate for both Unix and Windows First extra include files are necessary if defined HAVE_SHARED amp amp defined OB_DLL include lt OB OCI_init h gt include lt OB OCI_BiDir_init h gt endif Next the plug in must be registered prior to calling oRB_init if defined HAVE_SHARED amp amp defined OB_DLL Cif When linking statically we need to explicitly register f the plug in prior to ORB initialization OCN regu stermo lu gain uomcanall OCE EDTA endif 397 CHAPTER 19 The Open Communications Interface URL Support 398 The bi directional plug in supports corbaloc URLs with the following protocol syntax corbaloc bidir_ID peer object key corbaloc bidir_ID peer options object key The first form indicates a callback endpoint whereas the second form indicates an endpoint using an underlying plug in The components of the URL are as follows bidir ID This selects the bi directional plug in using the underlying plug in identified by ID peer The peer ID options Options specific to the underlying plug in object key A stringified object key For example corbaloc bidir_iiop Client Foo corbaloc bidir_iiop Server theho
372. m Chapter 2 all have memory leaks since the thread objects are created with new but never deleted with delete However you would be wrong Why The magic comes in the form of reference counting Every gTCThread object and also utcThreadGroup and JTCRunnable objects has a reference counter When a new thread object is created this counter is set to 1 When the thread terminates i e the run method returns the counter is decremented by 1 Whenever the counter s value drops to O the thread object is deleted with delete Since in our Hello World example the reference count is never incremented the reference count drops to O as soon as run returns meaning that the thread object is deleted upon thread termination so there is no memory leak One drawback of using reference counting is that it is not possible to allocate reference counted objects on the stack It s only possible to allocate them with new on the heap since they will be deleted with delete as soon as the reference count becomes 0 Introducing Handles Introducing Handles Smart pointers You might think that reference counting is pretty complicated because you now have to remember when to increment or to decrement the counter of a reference counted object However this is not the case JThreads C provides handle classes sometimes also called smart pointers that take care of incrementing and decrementing the refer
373. ment Group Object Management Group 1999 Naming Service Specification ftp ftp omg org pub docs ptc 99 12 03 pdf Framingham MA Object Management Group 509 CHAPTER G 510 11 12 13 14 IONA Technologies Inc 2001 JThreads C http www orbacus com jtc Waltham MA IONA Technologies Inc IONA Technologies Inc 2001 JThreads C User s Manual Waltham MA IONA Technologies Inc IONA Technologies Inc 2001 Orbacus http www orbacus com ob Waltham MA IONA Technologies Inc Schmidt D C 1995 Reactor An Object Behavioral Pattern for Concurrent Event Demultiplexing and Event Handler Dispatching In Pattern Languages of Program Design ed James O Coplien and Douglas C Schmidt Reading MA Addison Wesley Part Il FreeSSL In this part This part contains the following chapters Using FreeSSL for Orbacus page 513 Extending the Hello World Application page 529 FSSL Definitions page 559 Toolkits Supported by FSSL page 561 FSSL Reference page 563 FSSL Bibliography page 573 In this chapter CHAPTER 1 Using FreeSsSL for Orbacus This chapter describes the FreeSSL plug in which enables secure communications using the Orbacus ORB in both Java and C This chapter contains the following sections What is SSL page 514 Installation page 517 Endpoint Configuration page 519 Command Line Options page 520
374. min StructuredProxyPushConsumer Operations interface StructuredProxyPushConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm StructuredPushConsumer The structuredProxyPushConsumer interface supports connections by suppliers who wish to push structured events on the channel connect_structured_push_supplier void connect_structured_push_supplier in CosNotifyComm StructuredPushSupplier push_supplier raises CosEventChannelAdmin AlreadyConnected Connects a supplier to the channel If a supplier is already connected the AlreadyConnected exception is raised Parameters push_supplier A reference to the supplier object A nil reference is permitted 815 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin SequenceProxyPushConsumer Operations 816 interface SequenceProxyPushConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm SequencePushConsumer The SequenceProxyPushConsumer interface supports connections by suppliers who wish to supply sequences of structured events to the channel connect_sequence_push_supplier void connect_sequence_push_supplier in CosNotifyComm SequencePushSupplier push_supplier raises CosEventChannelAdmin AlreadyConnected Connects a supplier to the channel If a supplier is already connected the AlreadyConnected exception is raised Parameters push_supplier A reference to the supplier
375. model property and set it to threaded if its value is not valid Initialize the ORB Using POA Managers Using POA Managers In this section The CORBA specification states that a POA Manager is used to control the flow of requests to one or more POAs In Orbacus each POA Manager also encapsulates a set of network endpoints on which a server listens for new connections This design provides applications with a great deal of flexibility e endpoints can be activated and deactivated on demand e a group of endpoints can be controlled using a single POA Manager and serviced by one or more POAS This section contains the following sections The Root POA Manager page 78 Anonymous POA Managers page 79 The POA Manager Factory page 80 Creating a POA Manager page 81 POA Manager Policies page 83 Endpoints page 84 Command line Options and Endpoints page 85 Dispatching Requests page 86 Callbacks page 87 77 CHAPTER 4 ORB and Object Adapter Initialization The Root POA Manager As its name suggests the Root POA Manager is the POA Manager of the Root POA When the Root POA is first resolved using resolve_initial_references the Root POA Manager is automatically created to manage the Root POA For administrative purposes the name of the Root POA Manager is RootPOAManager 78 Using POA Managers Anonymous POA Managers An application can implicitly create POA Managers by supply
376. mpiling Java Clients Ensure that the cLASSPATH environment variable includes the following e Orbacus Notify Java classes that is the oBNotify jar file e Orbacus for Java classes that is the oB jar file Note The Orbacus Notify Java classes are available for download with the Orbacus Notify Console distribution If using the Unix Bourne shell or a compatible shell this is accomplished with the following commands CLASSPATH notify_directory lib OBNotify jar orbacus_directory lib OB jar SCLASSPATH export CLASSPATH Replace notify directory with the name of the directory where Orbacus Notify is installed and replace orbacus_directory with the name of the directory where Orbacus is installed If running Orbacus on a Windows based system use the following command within the Windows command interpreter set CLASSPATH notify_directory lib OBNotify jar orbacus_directory lib OB jar SCLASSPATH Note that for Windows the delimiter is and not 751 CHAPTER 4 Programming Example 752 CHAPTER 5 Orbacus Notify Console This chapter describes how to use the Orbacus Notify graphical interface In this chapter This chapter contains the following sections Overview page 754 The Orbacus Notify Console Menus page 757 Creation Wizards page 759 Managing Notification Channels page 760 Managing Admins page 763 Managing Proxies page 766 Managing Filters page 769 Managing F
377. mple does not destroy the filter Rather its IOR is published and used to locate the filter object on subsequent executions of the FilteredConsumer example Disconnecting from a Notification Channel Disconnecting from a Notification Channel When a supplier or consumer wishes to disconnect from an event channel it simply disconnects its proxy object The example structured supplier implementation disconnects as follows C CosNotifyChannelAdmin_StructuredProxyPushConsumer_var structuredProxyPushConsumer structuredProxyPushConsumer gt disconnect_structured_push_consumer And in Java Java StructuredProxyPushConsumer structuredProxyPushConsumer structuredProxyPushConsumer disconnect_structured_push_consumer Likewise for the structured push consumer Hy Cae CosNotifyChannelAdmin_StructuredProxyPushSupplier_var structuredProxyPushSupplier structuredProxyPushSupplier gt disconnect_structured_push_supplier 749 CHAPTER 4 Programming Example And in Java Java StructuredProxyPushSupplier structuredProxyPushSupplier structuredProxyPushSupplier disconnect_structured_push_supplier Note that disconnecting a proxy effectively destroys the target proxy object Note The cosNotifyChannelAdmin EventChannel CosNotifyChannelAdmin SupplierAdmin and CosNotifyChannelAdmin ConsumerAdmin all support the destroy operation Care should be taken when invoking t
378. mponents of a structured event are the event header and event body The event header is further sub divided into a fixed header and variable header The fixed header categorizes the event while the variable header consists of zero or more name value pairs which specify per event QoS information See 1 for complete event header details The event body holds the interesting event data in name value pairs comprising the filterable fields and other event data in the opaque remaining body field Sequence Events In some instances it is inefficient to transfer events one at a time To address this the Notification Service includes support for sequences of structured events on the supplier and consumer side Suppliers may transfer multiple events to a channel in a single CORBA method invocation likewise consumers may receive multiple structured events in a single CORBA method call 701 CHAPTER 3 Notification Service Concepts Event Translation The Notification Service does not impose the restriction that peer entities suppliers and consumers must deal with the same event type For example a structured consumer can receive events from an unstructured supplier Rules exist see 1 that define how events are translated into a format suitable for various consumers Event translation supports configurations like that in Figure 11 Direction of Event Flow SequencePushConsumer AnyPushConsumer StructuredPullConsumer
379. n AlreadyConnected CosEventChannelAdmin TypeError Connects a supplier to the channel If a supplier is already connected the AlreadyConnected exception is raised Parameters pull_supplier A reference to the supplier object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pulling events from the connected supplier If the connection is already suspended the Connect ionAlreadyInactive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target to resume pulling events from the connected supplier If the connection is not suspended the Connect ionAlreadyActive exception is raised If the target object is not connected to a supplier the NotCconnected exception is raised 821 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin SequenceProxyPullConsumer Operations 822 interface SequenceProxyPullConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm SequencePul1lConsumer The SequenceProxyPullConsumer interface manages connections from suppliers who wish to have sequences of structured events pulled from them by the channel connect_sequence_pull_suppl
380. n void setDaemon bool daemon Sets the daemon flag for this thread group If the daemon flag is true the thread group is destroyed once all threads are terminated and sub groups are empty Parameters daemon The new value for the daemon flag uncaughtException virtual void uncaughtException JTCThreadHandle t const JTCException amp e This method is called if a JTCThread run exits because of an uncaught JTCException By default if the thread group has a parent this method invokes the parent s uncaughtException method otherwise it displays the exception to stderr Parameters t The thread that threw the JTcException e The uncaught exception 631 CHAPTER A Class Reference 632 uncaughtException virtual void uncaughtException JTCThreadHandle t This method is called if a JTCThread run exits because of an uncaught exception By default if the thread group has a parent this method invokes the parent s uncaughtException method otherwise it displays the text uncaught exception to stderr Parameters t The thread that threw the gTcException getMaxPriority int getMaxPriority const Returns the maximum priority permitted for threads in this thread group Returns The maximum priority of this thread group isDestroyed bool isDestroyed const Determines if the thread group has been destroyed A thread group is destroyed once all threads have terminated in the thread group and all
381. n Orbacus replaces the deprecated Basic Object Adapter BOA The BOA was deprecated by the OMG because it had a number of serious deficiencies and was under specified The POA is a far more flexible and powerful object adapter than the BOA The POA not only allows you to write code that is portable among ORBs from different vendors it also provides a number of features that are essential for building high performance and scalable servers 93 CHAPTER 5 CORBA Objects Implementing Servants 94 2 5 7 10 12 15 In this section we will implement servant classes or implementation classes for the IDL interfaces defined below il 2 3 4 5 6 7 8 9 10 ILE ile 1S 14 lS A I interface A ri ri r void op_a interface B NOHO DMO Ry interface I A B NOHIGl mn hy An interface a is defined with the operation op_a An interface B is defined with the operation op_b Interface 1 is defined which is derived from a and B It also defines a new operation op_i Implementing Servants Implementing Servants using Inheritance Overview Inheritance using C 2 6 Orbacus for C and Orbacus for Java both support the use of inheritance for interface implementation To implement an interface using inheritance you write a servant class that inherits from a skeleton class generated by the IDL translator By convention the name of the servant class should be the name of
382. n UnsupportedAdmin PropertyErrorSeq admin_err This exception is raised when a channel or proxy does not support the requested aministrative property settings Members admin_err Contains a list of the rejected administrative settings along with reason for rejection and suitable property values if applicable QoSError_code enum QoSError_code UNSUPPORTED_PROPERTY UNAVAILABLE_PROPERTY UNSUPPORTED_VALUE UNAVAILABLE_VALUE BAD_PROPERTY BAD_TYPE BAD_VALUE Error codes used to indicate an invalid property assignment 801 CHAPTER C CosNotification Reference 802 Members UNSUPPORTED_PRO the target object UNAVAILAB LE_PRO PERTY Property not supported by this implementation of PERTY Property cannot be set within the current context of other property settings UNSUPPORT implement UNAVAILAB ED_VAL LE_VAL UE The property value is not supported by this ation of the target object UE The property value is not supported within the current context of other property settings BAD_PROPE RTY Unrecognized property name BAD_TYPE Incorrect value type for this property BAD_VALUE Illegal value for this property Module CosNotification Interface CosNotification QoSAdmin Synopsis Operations interface QoSAdmin Supports the management of QoS property settings get_qos QoSProperties get_qos Retrieves the current lis
383. n a CORBA Any Consumers must first extract the event before deciding whether to process or discard it The OMG Notification Service The OMG Notification Service Much of the previous discussion on the OMG Event Service applies equally to the OMG Notification Service The Notification Service was designed to be backward compatible with the Event Service and it reuses and or derives from equivalent Event Service IDL interfaces In this section This section contains the following topics Delivery Models page 698 Object Management Hierarchy page 699 Event Delivery page 700 Event Translation page 702 Filtering page 703 Mapping Filters page 707 Quality of Service page 709 Proprietary QoS Properties page 713 Administrative Properties page 715 Subscription Sharing page 716 697 CHAPTER 3 Notification Service Concepts Delivery Models The Notification Service supports the same delivery models as the Event Service described in The OMG Event Service on page 690 698 The OMG Notification Service Object Management Hierarchy The relationship between Notification Service objects is illustrated in Figure 9 EventChannelFactory L EventChannel ConsumerAdmin 1 ProxyPushSupplier m StructuredProxyPushSupplier t SequenceProxyPushSupplier ProxyPullSupplier m StructuredProxyPullSupplier SequenceProxyPullSupplier SupplierAdmin ProxyPushConsumer
384. n empty string was provided as part of a NameComponent 205 CHAPTER 9 Orbacus Names Exceptions This code fragment deals with exceptions that may be thrown by the Naming Service operations Lh Wi eRe 2 catch NotFound ex 3 4 System err print Got a NotFound exception 5 switch ex why value 6 7 case NotFoundReason _missing_node 8 System err print missing node g break 0 1 case NotFoundReason _not_context 2 System err print not context 3 break 4 5 case NotFoundReason _not_object 6 System err print not object 7 break 8 9 20 System err printin 20 ex printStackTrace 22 throw new SystemException 23 24 catch CannotProceed ex 25 26 System err println Got a CannotProceed exception 27 ex printStackTrace 28 throw new SystemException 29 30 catch InvalidName ex Sil 22 System err println Got an InvalidName exception 23 ex printStackTrace 34 throw new SystemException 206 5 36 Bi 38 3g 40 41 Programming Example catch AlreadyBound ex System err println Got an AlreadyBound exception ex printStackTrace throw new SystemException 2 41 Catch exceptions Don t ever forget to do this It can be useful to call printStackTrace on the exception object in order to get detailed information about the program flow causing the exception 207 CHAPTER 9 Orbacus Names Th
385. n the ORB s property set java util Properties props com ooc CORBA ORB orb properties Resolve the FSSL Context Manager ae com ooc FSSL Manager fsslManager com ooc FSSL ManagerHelper narrow orb resolve_initial_references FSSLContextManager 543 CHAPTER 2 Extending the Hello World Application Next the client s certificate chain must be constructed Li Cie Hil Create the clients certificate chain FSSL Certificate_var clientCert fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file client der FSSL Certificate_var caCert fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file ca der FSSL CertificateSeq chain chain length 2 chain 0 clientCert chain 1 caCert Java Create the client certificate chain iy com ooc FSSL Certificate clientCert fsslManager create_certificate com ooc FSSL FSSL load_file client der com ooc FSSL Certificate caCert fsslManager create_certificate com ooc FSSL FSSL load_file ca der com ooc FSSL Certificate chain new com ooc FSSL Certificate 2 chain 0 clientCert chain 1 caCert 544 Complete Example Once that has been done a context must be created For this demo all RSA ciphers can be used The implementation of the TrustDecider will come a little later Lie Cost Create the client context
386. nage thread specific storage which is an extremely useful method of managing data that is associated with each thread while avoiding the overhead of a mutex Using thread specific storage each thread associates data with a key Because each thread has its own data there is no contention for the data among multiple threads allocate static JTCThreadKey allocate Creates a new thread specific storage key Returns A new thread specific storage key Throws JTCSystemCallException Indicates a failed system call allocate static JTCThreadKey allocate void void Creates a new thread specific storage key with an associated cleanup function Upon thread termination the registered cleanup function is called with an argument that contains the value associated with the thread specific storage key Returns A new thread specific storage key Throws JTCSystemCallException Indicates a failed system call release static void release JTCThreadKey key Releases a thread specific storage key The developer is responsible for freeing any associated storage before releasing the key Any associated cleanup function is not called Parameters key The thread specific storage key to release Throws JTCSystemCallException Indicates a failed system call get static void get JTCThreadKey key Gets the data associated with a thread specific storage key Parameters key The thread specific storage key Returns
387. nally The threaded concurrency model is still fast No calls to operations like select are required Time consuming thread creation is only necessary when a new client is connecting but not for each request However thread context switching makes this approach slower than the reactive concurrency model at least on a single processor computer 355 CHAPTER 18 Concurrency Models Thread per Client Server The thread per client server concurrency model is very similar to the threaded server concurrency model except that the ORB allows one active thread per client in the user code This is shown in Figure 12 f0 hO DX lt a I Client A Thread per Client Client B Server Figure 12 Thread per Client Server A s call to and B s call to g are carried out simultaneously each in its own thread However if A tries to call another operation n for example by sending requests from different threads in a multi threaded client or by using the DII operation send_deferred in a single threaded client as long as f has not finished yet the execution of n is delayed until returns The thread per client model is still efficient Like with the threaded concurrency model no threads need to be created except when new connections are accepted 356 Multi Threaded Concurrency Models Thread per Request Server If the thread per request server con
388. nd Register a load balanced group member unregister_member void unregister_member in MemberId member_id in GroupId group_id Unregister a load balanced group member Orbacus Bibliography 5 6 8 9 10 Buschman F et al 1996 Pattern Oriented Software Architecture A System of Patterns New York Wiley Gamma E et al 1994 Design Patterns Reading MA Addison Wesley Henning M and S Vinoski 1999 Advanced CORBA Programming with C Reading MA Addison Wesley Object Management Group 1999 The Common Object Request Broker Architecture and Specification Revision 2 3 1 ftp www omg org pub docs formal 99 10 07 pdf Framingham MA Object Management Group Object Management Group 1999 C Language Mapping ftp www omg org pub docs formal 99 07 45 pdf Framingham MA Object Management Group Object Management Group 1999 DL Java Language Mapping ftp www omg org pub docs formal 99 07 53 pdf Framingham MA Object Management Group Object Management Group 1999 Portable Interceptors ftp ftp omg org pub docs orbos 99 12 02 pdf Framingham MA Object Management Group Object Management Group 1998 CORBA Messaging ftp ftp omg org pub docs orbos 98 05 06 pdf Framingham MA Object Management Group Object Management Group 1998 CORBAservices Common Object Services Specification ftp www omg org pub docs formal 98 12 09 pdf Framingham MA Object Manage
389. nd a connection cannot be established after value milliseconds a CORBA NO_RESPONSE exception is raised 309 CHAPTER 16 Using Policies 310 Table 4 Orbacus policies Policy Description OB InterceptorPolicy This policy determines whether client side interceptors will be called Client side interceptors are enabled by default To disable client side interceptors this policy can be set on an ORB or object reference with a value of false OB LocateRequestPolicy This policy determines whether the ORB sends GIOP LocateRequest messages This policy exists to avoid an interoperability issue regarding the formatting of GIOP 1 2 LocateReply messages Orbacus uses the correct formatting as of version 4 1 Unfortunately all versions of Orbacus 4 0 x use the incorrect formatting as do some other ORB implementations As a result the default value of this policy is false which means the ORB will not send LocateRequest messages and therefore will not receive improperly formatted replies OB LocationTransparencyPolicy This policy determines how strictly the ORB will enforce location transparency The default behavior is relaxed An application may wish to sacrifice performances to have strict CORBA compliance for local invocations OB ProtocolPolicy This policy allows an application to influence how the ORB orders and filters the profiles of an object reference The value of the policy is a l
390. nd the Interface Repository Include Statements Documenting IDL Files Using javadoc Chapter 4 ORB and Object Adapter Initialization Initializing the C ORB Initializing the Java ORB Object Adapter Initialization Configuring the ORB and Object Adapter ORB Properties OA Properties Command line Options Using a Configuration File Using the Windows NT Registry Defining Properties Precedence of Properties Advanced Property Usage Using POA Managers The Root POA Manager Anonymous POA Managers The POA Manager Factory Creating a POA Manager POA Manager Policies Endpoints Command line Options and Endpoints Dispatching Requests Callbacks ORB Destruction Server Event Loop Chapter 5 CORBA Objects Overview Implementing Servants Implementing Servants using Inheritance Implementing Servants using Delegation Creating Servants Creating Servants using C Creating Servants using Java Activating Servants Implicit Activation of Servants using C Implicit Activation of Servants using Java Explicit Activation of Servants using C Explicit Activation of Servants using Java Deactivating Servants Factory Objects Factory Objects using C Factory Objects using Java Caveats Obtaining the POA for a Servant Getting the POA for a Currently Executing Request Chapter 6 Locating Objects Obtaining Object References Lifetime of Object References Hostname Port Number Object Key Stringified Object References Using a F
391. nding from the internal table Parameters oid The object id to remove Raises NotFound Thrown if no binding found 424 Interface OB BootManager set_locator void set_locator in BootLocator locator Set the BootLocator The BootLocator is called when a binding for an object id does not exist in the internal table Parameters locator The BootLocator reference See Also Interface OB BootLocator 425 CHAPTER A Boot Manager Reference Interface OB BootLocator local interface BootLocator Interface used by BootManager to assist in locating objects See Also Interface OB BootManager Operations locate void locate in PortableServer ObjectId oid out Object obj out boolean add raises BootManager NotFound Locate the object corresponding to the given object id Parameters oid The object id obj The object reference to associate with the id add Whether the binding should be added to the internal table Raises NotFound Raised if no binding found 426 In this appendix APPENDIX B Orbacus Policy Reference This appendix describes the Orbacus Policy interfaces This appendix contains the following sections Module OB page 428 Module OBPortableServer page 439 BiDirPolicy page 441 427 CHAPTER B Orbacus Policy Reference Module OB Constants 428 CONNECTION_REUSE POLICY_ID const CORBA PolicyType CON
392. ned otherwise disconnect_sequence_pull_supplier void disconnect_sequence_pull_supplier Terminates communication between the target supplier and its consumer Also frees resources at the supplier 851 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm SequencePushSupplier Operations 852 interface SequencePushSupplier inherits from CosNotifyComm NotifySubscribe The SequencePushSupplier interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel Clients do not need to implement this interface to simply push events disconnect_sequence_push_supplier void disconnect_sequence_push_supplier Terminates communication between the target supplier and its consumer Also frees resources allocated by the supplier APPENDIX F CosNotifyFilter Reference This appendix describes the CosNotifyFilter module In this appendix This appendix contains the following section Module CosNotifyFilter page 854 853 CHAPTER F CosNotifyFilter Reference Module CosNotifyFilter Aliases 854 This module provides interfaces which support all aspects of filter and mapping filter management ConstraintID typedef long ConstraintID Alias for a constraint ID ConstraintIDSeq typedef sequence lt ConstraintID gt Constraint IDSeq Alias for a sequence of constraint IDs ConstraintExpSeq t
393. nent bName new NameComponent 2 ST bName 0 new NameComponent 58 bName 0 id ncl 59 bName 0 kind 60 bName 1 new NameComponent 61 bName 1 id b 62 bName 1 kind 63 nc bind bName b 64 65 NameComponent cName new NameComponent 3 66 cName 0 new NameComponent 67 cName 0 id ncl 68 cName 0 kind 69 cName 1 new NameComponent 70 cName 1 id nc2 71 cName 1 kind 72 cName 2 new NameComponent WS cName 2 id c 74 cName 2 kind 75 nc bind cName c 76 Several sample objects are created that will later be bound to our Naming Service These objects implement an interface called Named In this example the details of this interface are not important Namea might even be an interface without any operations defined in it 17 75 Programming Example Create and bind some new contexts and bind the sample objects to these contexts Each binding name consists of several NameComponents that are similar to the path components of a file located somewhere in a filesystem Objects are bound with the Naming Service s bind operation for contexts the corresponding operation bind_context is used In addition to the object s IOR both operations expect a unique binding name If a name already exists an AlreadyBound exception is thrown There are also other exceptions you might encounter at this stage e g IllegalName if a
394. nfigured with the IMR When the IMR is configured to start the Property Service this option is automatically added to the service s arguments However when the Property Service is started manually the option must be present For further information on configuring a service with the IMR refer to Getting Started with the Implementation Repository on page 173 228 Creating Properties Creating Properties A property handled by the CORBA Property Service consists of two components the property s name and its value The name is a CORBA string and the associated value is represented by a CORBA Any fo DoT typedef string PropertyName struct Property PropertyName property_name any property_value New properties are created using a factory object implementing the PropertySet interface A new property is created using the define_property Operation IDL void define_property in PropertyName in any property_value raises InvalidPropertyName ConflictingProperty UnsupportedTypeCode UnsupportedProperty ReadOnlyProperty As a property consists of a name value pair both the name and the value are the parameters to this operation 229 CHAPTER 11 Orbacus Properties Querying for Properties As soon as a property is defined the PropertySet can be queried for the property s value with the get_property_value operation IDL any get_property_value in PropertyName property_name raises PropertyNo
395. ng The remaining property represents a short value If for some reason a property cannot be created an exception is thrown Now we try to get a list of all the properties that were previously defined With get_all_properties the PropertySetDef returns its properties As we have set the how_many parameter to O we have to use the PropertiesIterator for each item An application would normally provide a positive integer for how_many The iterator has fulfilled its duty and can now be destroyed 235 CHAPTER 11 Orbacus Properties 236 In this chapter CHAPTER 12 Orbacus Events Some applications need to exchange information without explicitly knowing about each other Often a server isn t even aware of the nature and number of clients that are interested in the data the server has to offer A special mechanism is required that provides decoupled data transfer between servers and clients This requirement is addressed by the CORBA Event Service Orbacus Events is compliant with 9 This chapter does not provide a complete description of the service It only provides an overview suitable to get you started For more information please refer to the specification This chapter contains the following sections Usage page 238 Connecting to the Service page 243 Using the Event Service with the IMR page 244 Event Service Concepts page 245 Programming Example page 253 237 CHAPTER 12 Orbacus Events
396. ng Policies And now the same example in Java Java org omg CORBA Object obj orb resolve_initial_references RootPOA org omg PortableServer POA rootPOA org omg PortableServer POAHelper narrow ob 4 org omg PortableServer POAManager manager rootPOA the_POAManager woMWAtaw Fb WN FE org omg CORBA Any any orb create_any 0 org omg CORBA Policy policies new org omg CORBA Policy 1 org omg BiDirPolicy BidirectionalPolicyValueHelper insert any org omg BiDirPolicy BOTH value policies 0 orb create_policy org omg BiDirPolicy BIDIRECTIONAL_POLICY_TYPE value any org omg PortableServer POA myPOA CO ao OF se 0 ho rootPOA create_POA MyPOA manager policies This is equivalent to the C version BidirectionalPolicy Client This example shows how to create an object reference with the Implementation BidirectionalPolicy enabled to signal connection reuse is allowed over connections established with this object reference The C example is presented first followed by the Java version Di Che CORBA Object_var obj orb gt string_to_object relfile Hello ref CORBA PolicyList policies 1 policies length 1 CORBA Any any any lt lt BibirPolicy BOTH policies 0 orb gt create_policy 10 BiDirPolicy BIDIRECTIONAL POLICY_TYPE TF any 12 13 obj obj gt _set_policy_overrides 14 policies CORBA ADD_OVERRIDE 15 16 Hello_var
397. ng a well known name libname so UNIX libname si HP UX or name a11 Windows where name is the module name The ORB then invokes the initialization function init_module_name in that shared library The initialization function takes no arguments and returns void A module initialization function will typically register an ORBInitializer which allows interceptors and initial references to be installed This property is only supported in C In Java the standard mechanism for installing an ORBInitializer should be used See 7 for more information on ORBInitializers Value string Specifies the name of a module s shared library or DLL In most cases this property is not necessary because the ORB attempts to locate the library using a well known name as described above for the ooc orb modules property The value of this property can be a simple filename in which case the ORB will attempt to load the library using the search path or it can be an absolute pathname Value string Specifies the native character code set for the ORB The default is ISO 8859 1 Value string Specifies the native wide character code set for the ORB The default is UTF 16 ooc orb policy connect_timeout ooc orb policy connection_reuse ooc orb policy interceptor ooc orb policy locate_request ooc orb policy location_transpare ncy ooc orb policy protocol ooc orb policy rebind ooc orb policy request_timeout Configuring the
398. ng double array MinorReadLongDoubleArrayOverflow Overflow while reading longdouble array MinorReadInvTypeCodeIndirection Invalid type code indirection MinorWriteObjectLocal Attempt to marshal a locality constrained object MinorLongDoubleNot Supported Long double is not supported 411 CHAPTER 20 Exceptions and Error Messages NO_IMPLEMENT Minor Exception Code 412 MinorMissingLocalValueImplementation Missing local value implementation MinorIncompatibleValueImplementationVersion Incompatible value implementation version MinorNot SupportedByLocalObject Operation not supported by local object MinorDIINot SupportedByLocalOb ject DII operation not supported by local object CORBA System Exceptions NO RESOURCES Minor Exception Code MinorInvalidBinding Portable Interceptor operation not supported in binding 413 CHAPTER 20 Exceptions and Error Messages BAD_INV_ORDER Minor Exception Code 414 MinorDependencyPreventsDestruction Dependency exists in Interface Repository prevents destruction of object MinorIndestructibleObject Attempt to destroy indestructible object in Interface Repository MinorDest royWouldBlock Operation would deadlock MinorShutdownCalled ORB has shutdown inorDuplicateSend Request has already been sent MinorServantManagerAlreadySet Servant m
399. ng is a brief description of the Orbacus specific policies that are currently supported For a detailed description please refer to Appendix B For standard policies please refer to 4 Table 4 Orbacus policies Policy Description BiDirPolicy BidirectionalPolicy This policy is used to enable CORBA 3 compliant BiDir GIOP functionality on both the Object and POA levels Enabling this policy with a value of BiDirPolicy BOTH on both levels will result in connection reuse when the server is required to make requests to the client The default value is BiDirPolicy NORMAL disabled BiDir functionality Both the client object and server POA needs this policy set to BOTH for BiDir communication to take place OB ACMTimeoutPolicy This policy determines whether the ORB performs active connection management ACM on the connection associated with an object reference The policy specifies a time after which idle connections are shutdown A value of O means no timeout The default for this policy is the value of the ooc orb client_timeout property see ooc orb client_timeout on page 59 OB ConnectionReusePolicy This policy determines whether the ORB is permitted to reuse a communications channel between peers If this policy is false then each object will have a new communications channel to its peer The default for this policy is true OB ConnectTimeoutPolicy If an object has this policy a
400. ng pu11 the consumer polls the event channel for new events The event channel acts as a pull supplier in this case The pull operation blocks until a new event is available The consumer expects a string wrapped in a CORBA Any The string value is extracted and displayed If an exception is raised the Any contained some other data type which is simply ignored In all of these examples the event channel acts either as a consumer if the clients are suppliers or a supplier if the clients are consumers of events Actually each client is not directly connected to the event channel but to a proxy that receives or sends events on behalf of the channel For more information on the Event Service and for the complete definitions of the IDL interfaces please refer to the official Event Service specification In this chapter CHAPTER 13 The Interface Repository A CORBA Interface Repository IFR is essential for applications using the dynamic features of CORBA such as the Dynamic Invocation Interface and DynAny The IFR holds IDL type definitions and can be queried and traversed by applications The Orbacus Interface Repository is compliant with 4 This chapter does not provide a complete description of the IFR For more information please refer to the specification This chapter contains the following sections Usage page 258 Connecting to the Interface Repository page 262 Configuration Issues page 263 Int
401. nnel eventChannel eventChannelFactory create_channel initialQoS initialAdmin channelTIqd cs 2 eee e S 2 3 Create empty property sequences for QoS and Channel Administration To specify properties other than the default add the appropriate name value pairs to these sequences For this example the default properties are sufficient 4 The unique channel ID assigned by Orbacus Notify is passed back in the channellId parameter 5 8 Use the event channel factory to create a new channel Alternatively a channel may be obtained from an IOR In C fd Cts CORBA Object_var obj Get reference to the channel CosNotifyChannelAdmin EventChannel_var eventChannel CosNotifyChannelAdmin EventChannel _narrow obj And in Java Java org omg CORBA Object obj Get reference to the channel EventChannel eventChannel EventChannelHelper narrow obj 1 For this simple example the IOR is published in a file See the C or Java demos for details 724 Connecting to a Notification Channel The code presented so far applies equally to supplier and consumer applications using either the push or pull model Connecting the supplier and consumer is discussed next 725 CHAPTER 4 Programming Example Connecting a Supplier This section describes how to connect an event supplier to an event channel Figure 17 illustrates the steps Supplier Obtain Supplier Admin y Obtain Proxy Consumer e Delive
402. nnelIDSeq get_all_channels Obtains a list of all channels known to the factory Returns A sequence of IDs representing all channels currently managed by the target object get_event_channel EventChannel get_event_channel in ChannellD id raises ChannelNotFound Module CosNotifyChannelAdmin Obtains a channel reference from a channel ID Parameters ia The id of channel for which a reference is required Returns A reference to a channel with the corresponding ID If no channel could be found with the given ID a Channe1NotFouna exception is raised 835 CHAPTER D CosNotifyChannelAdmin Reference 836 APPENDIX E CosNotifyComm Reference This appendix describes the CosNotifyComm module In this appendix This appendix contains the following section Module CosNotifyComm page 838 837 CHAPTER E CosNotifyComm Reference Module CosNotifyComm Exceptions InvalidEventType exception InvalidEventType CosNotification EventType type Raised to indicate an event type name which contains syntax errors 838 Module CosNotifyComm Interface CosNotifyComm NotifyPublish Operations interface NotifyPublish The NotifyPublish interface provides a method which suppliers can use to inform consumers of changes in the set of events offered offer_change void offer_change in CosNotification EventTypeSeq added in CosNotification EventTypeSeq removed raises Invalid
403. no match is found the ORB appends a slash character and the service identifier to the specified URL and invokes string_to_object to obtain the initial reference Value string Specifies the default wide character code set for the ORB Note that the CORBA specification states that a default wide character code set does not exist Therefore this option should only be used when communicating with a broken ORB that expects a particular wide character code set and does not correctly support the negotiation of wide character code sets Value true false Enables transfers of wide characters IDL types wchar and wstring with IIOP 1 0 using Unicode as the code set This proprietary extension is required in order to exchange wide characters with Orbix E which only supports IIOP 1 0 The default is false Value max gt 0 59 CHAPTER 4 ORB and Object Adapter Initialization ooc orb id ooc orb modules ooc orb module name ooc orb native_cs ooc orb native_wcs 60 Specifies the maximum GIOP message size in bytes If set to O no maximum message size will be used If a message is sent or received that exceeds the maximum size the ORB will raise the IMP_LIMIT system exception Value id Specifies the identifier of the ORB to be used by the application Value string Specifies a comma separated list of modules to be loaded dynamically by the ORB The ORB locates the shared library for a module usi
404. nonical Push Model The OMG Event Service The mode of event delivery in the Event Service is selected by suppliers and consumers at connection time The models supported by the event service are discussed next In this model the supplier pushes events to an event channel which in turn pushes events to the consumer see Figure 3 Direction of Event Flow gt Push Push Push Supplier Event Channel Push Consumer Canonical Pull Model Figure 3 Canonical Push Model The push supplier is termed active since it initiates event delivery with the channel Conversely the push consumer is passive since the channel initiates event delivery In this model the channel pulls events from the supplier while the consumer pulls events from the channel see Figure 4 Direction of Event Flow gt Pull Pull Pull Supplier Event Channel Pull Consumer Figure 4 Canonical Pull Model A pull supplier is passive since the channel initiates event delivery A pull consumer initiates event delivery with a channel and is termed active 691 CHAPTER 3 Notification Service Concepts Hybrid Push Pull Model In the Hybrid Push Pull model a push supplier pushes events to an event channel while a pull consumer pulls event from the channel see Figure 5 Direction of Event Flow gt Push Pull Push Supplier Event Channel Pull Consumer Figure 5 Hybrid Push Pull Model Both the suppl
405. ns the ID you assigned to the object 110 Activating Servants Explicit Activation of Servants using Java Servant activation in Java also uses activate_object for sySTEM_ID and activate_object_with_id for USER_ID With SYSTEM_ID the code looks as follows 1 I_impl impl new I_impl 2 orb omg PortableServer POA poa impl _default_POA 3 poa activate_object imp1 For USER_ID you must provide the Object ID 1 TI_impl impl new I_impl 2 org omg PortableServer POA poa impl _default_POA 3 byte id MyObjectName getBytes 4 poa activate_object_with_id id impl 111 CHAPTER 5 CORBA Objects Deactivating Servants Deactivation of Servants using C Deactivation of Servants using Java Transient and Persistent Objects 112 A servant can be deactivated Deactivating a servant breaks the association between the CORBA object and the servant requests that arrive from clients thereafter result in an OBJECT_NOT_EXIST exception or a TRANSIENT exception if the server is down at the time a request is made To deactivate a servant call the deactivate_object member function on the servant s POA i Cee PortableServer POA_var poa impl _default_POA PortableServer ObjectId_var id poa gt servant_to_id amp impl1 amp m WDNR poa gt deactivate_object id The code obtains a reference to the servant s POA by calling _default_Poa This assumes that _default_pPoa is cor
406. nt context For new object bindings an IOR can be specified Use Delete to remove the selected items from a naming context Deleting Naming Service entries removes all selected bindings from their parent context The objects belonging to these bindings are not affected Destroying Naming Service information only affects the actual Naming Service data not the objects themselves Use Link to create a new binding for an existing naming context where the naming context is specified by an IOR The operation Unlink unbinds the selected items For objects Unlink is equivalent to Delete but for contexts Unlink differs in that the context is not destroyed Since a context is not destroyed using Unlink it should only be used when there are multiple bindings to a context in order to avoid orphaned contexts The Menus The console supports a clipboard that you can use to move bindings between different contexts Data is transferred to the clipboard using the Cut or Copy commands Cut moves the currently selected items to the clipboard and deletes the original entries whereas Copy simply creates a copy in the clipboard but keeps the source entry unchanged When new data is transferred to the clipboard the old clipboard contents are replaced Using Paste you can add the clipboard data into a naming context The clipboard contents are not changed by this operation i e you can Paste the same items several times Note that if naming contexts are trans
407. nt the PushConsumer interface which ensures that the event channel actively forwards events to them using the push operation Ji moii interface PushConsumer void push in any data raises Disconnected void disconnect_push_consumer Push consumers are passive that is are servers Conversely pull consumers are active that is are clients Pull consumers poll an event channel for new events As events may arrive at a greater rate than they are polled for by a pull consumer or accepted and processed by a push consumer some events might get lost A buffering policy implemented by the event channel determines whether events are buffered and what happens in case of an event queue overflow Like consumers suppliers can also use push or pull behavior Push suppliers are the more common type in which the supplier directly forwards data to the event channel and thus plays the client role in the link to the channel Pull suppliers on the other hand are polled by the event channel and supply an event in response if a new event is available Polling is done by the try_pu11 operation if it is to be non blocking or by the blocking pull call 247 CHAPTER 12 Orbacus Events 248 Event Service Concepts Event Channel Policies The untyped event channel implementation included in the Orbacus distribution features a simple event queue policy Events are buffered in the form of a queue i e a certain number of eve
408. nt for the servant A_imp1 is decremented which leads to the destruction of the servant geta returns an object reference to the A_imp1 servant implicitly creating and activating the CORBA object if necessary 127 CHAPTER 6 Locating Objects 128 2 4 6 21 11 15 17 20 In Java the interfaces can be implemented like this Java public class A_impl extends APOA public class B_impl extends BPOA org omg CORBA ORB orb_ Deimp likan ooN 0n fF WN PE public B_impl org omg CORBA ORB orb orb_ orb a_ new A_impl A getA return a_ _this orb_ Kt RO eh I ie 1 I he N The servant class A_imp1 is defined which inherits from the skeleton class APOA The servant class B_imp1 is defined which inherits from the skeleton class BPOA B_impl s constructor stores a reference to the orb and creates a new A impl servant geta returns an object reference to the a _imp1 servant implicitly creating and activating the CORBA object if necessary A client written in C could use code like the following to get references to A Mi CAFF B_var b Get a B object reference somehow A var a b gt getA And in Java Java Bbe Get a B object reference somehow Aa b getA Obtaining Object References In this example once your application has a reference to a B object it can obtain a reference to an a object using geta The question that arises however is H
409. nt is assigned to a ServantBase_var which decrements the servant s reference count when it goes out of scope Activates the servant and returns an object reference to the client It is important to understand how the servant is eventually destroyed The RefCount ServantBase Class from which the servant inherits implements a reference count When the servant is instantiated the RefCount ServantBase constructor sets this reference count to 1 When the servant is activated with the POA the POA increases the reference count by at least 1 When the ServantBase_var we assigned the servant to goes out of scope the reference count is decremented by 1 This means that when createProduct returns only the POA is holding a reference to the servant Later when the servant is deactivated in destroy the POA decrements the reference count by exactly the same number it used to increment the reference count upon activation This causes the reference count to drop to zero in which case the servant will be implicitly deleted Note that whenever the ORB starts to dispatch a request on the servant the reference count is incremented After request dispatching is finished the count is decremented by the same amount This ensures that a reference counted servant cannot be deleted while a request is executing 117 CHAPTER 5 CORBA Objects Factory Objects using Java Here is our Java implementation of the Product interface Java public c
410. nterface CosNotification AdminPropertiesAdmin Module CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Interface CosNotifyChannelAdmin Module CosNotifyComm Appendix D CosNotifyChannelAdmin Reference ProxyConsumer ProxySupplier ProxyPushConsumer StructuredProxyPushConsumer SequenceProxyPushConsumer ProxyPullSupplier StructuredProxyPullSupplier SequenceProxyPullSupplier ProxyPullConsumer StructuredProxyPullConsumer SequenceProxyPullConsumer ProxyPushSupplier StructuredProxyPushSupplier SequenceProxyPushSupplier ConsumerAdmin SupplierAdmin EventChannel EventChannelFactory Appendix E CosNotifyComm Reference Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm Interface CosNotifyComm
411. nteventservice i This adds the orbacus Event Service entry to the Services dialog in the Control Panel To start the event service select the orbacus Event Service entry and press start If the service is to be started automatically when the machine is booted select the orbacus Event Service entry then click Startup Next select Startup Type Automatic and press ox Alternatively the service could have been installed using the s option which configures the service for automatic start up nteventservice s If you want to remove the service run 239 CHAPTER 12 Orbacus Events nteventservice u Note If the executable for the Event Service is moved it must be uninstalled and re installed Any trace information provided by the service is be placed in the Windows NT Event Viewer with the title EventService To enable tracing information add the desired trace configuration property i e one of the ooc event trace properties or one of the ooc orb trace properties to the HKEY_LOCAL_MACHINE NT registry key with a REG_sz value of at least 1 240 Configuration Properties In addition to the standard configuration properties described in Chapter 4 Orbacus Events also supports the following properties OOC ooc 00C O0C ooc ooc ooc O00C event event event event event event event event inactivity_timeout SEC max_events N max_retries N endpoint ENDPOINT x p
412. ntly needed operations is normally present below the menu If you don t have a need for this toolbar or if you just want to save space on the screen you can switch it off with the Toolbar toggle button The same applies to the status bar where information about the currently selected item is displayed The status bar displays an object s repository ID the host where this object is located and the port it is bound to If an item with a nil object reference is selected or if multiple items are selected the status bar is empty If an error occurs while editing bindings the console automatically displays a new window with information about what went wrong Usually this information consists of exception data The visibility of this window can be explicitly controlled with the Error Window toggle button If the console is connected to Orbacus Names as described in Chapter 9 the console can display timestamp information for each binding by making use of proprietary features of Orbacus Names This information is shown in the binding table if the Details display mode instead of the Simple List mode is active Usually the console sorts the items in the binding table in ascending alphabetical order with naming contexts being listed at the top You can change this order with the options available in the Sort menu Bindings can be sorted by their ID or Kind fields If the extended attributes are displayed items can also be sorted by date and time Yo
413. nts are stored and in case of a buffer overflow the oldest events are discarded 249 CHAPTER 12 Orbacus Events Event Channel Factories 250 The standard CORBA Event Service provides no support for managing the lifecycle of event channels as a result applications requiring multiple channels are often forced to run a separate instance of the Event Service for each channel To remedy this situation Orbacus Events provides optional proprietary interfaces for event channel administration The oBEventChannelFactory EventChannelFactory interface describes the factory for untyped event channels a module OBEventChannelFactory typedef string Channelld typedef sequence lt ChannellId gt ChannellIdSeq exception ChannelAlreadyExists exception ChannelNotAvailable interface EventChannelFactory CosEventChannelAdmin EventChannel create_channel in ChannellId id raises ChannelAlreadyExists CosEventChannelAdmin EventChannel get_channel_by_id in ChannelId id raises ChannelNotAvailable ChannelIdSeq get_channels void shutdown he he Event Service Concepts The OBTypedEventChannelFactory TypedEventChannelFactory interface describes the factory for typed event channels IDL module OBTypedEventChannelFactory interface TypedEventChannelFactory CosTypedEventChannelAdmin TypedEventChannel create_channel in OBEventChannelFactory ChannelId id raises OBEventChannel
414. o adaptive strategies e Adaptive strategies will produce a more balanced system when the assumptions for the non adaptive strategies are not satisfied Under certain conditions load re balancing will be error prone In such a case adaptive strategies which take an aggressive approach to re balancing may result in many load re balancing errors Furthermore load re balancing can be an expensive operation making these errors even more severe On the other hand if the system is such that load re balancing errors seldom occur and the expense of re balancing is minimal then adaptive strategies that take an aggressive approach to load re balancing should result in a higher average throughput due to a more balanced system 271 CHAPTER 14 Orbacus Balancer Service Security 272 It is very important that only Orbacus Balancer s public port also referred to as its forward port be accessible outside of the network firewall Otherwise anyone can mimic the members of a load balanced group causing a denial of service For additional security many of the operations on the service are only allowed when the service is running in administrative mode That is e creating and destroying load balanced groups e setting the load balancing strategy and e adding or removing members are only possible when the service is running in administrative mode An attempt to perform these operations when it is not running in administration mod
415. o a JThreads C application as follows include lt JTC JTC h gt i 2 3 class HelloWorld public JTCRunnable a S aalies 6 virtual void run I 8 cout lt lt Hello World lt lt endl 9 hi NE ienlin aisle EuECe ENars a EGM JTCInitialize initialize JTCThread t new JTCThread new HelloWorld E gt eeen aE return 0 00 J Oy On E GOON A 3 As in the Java example the class HelloWorld inherits from the JThreads C class sTcRunnable 16 Create a new thread using a new instance of the Helloworla class as the required JTCRunnable parameter 17 Start the new thread which invokes the run method 586 In this chapter CHAPTER 3 Working With Threads This chapter describes how JThreads C implements Java Monitors used in multithreading This chapter contains the following sections Synchronization page 588 Block Synchronization page 594 Static Monitors page 597 The Wait Notify and NotifyAll Methods page 600 The Stop and Suspend Methods page 604 The Join and IsAlive Methods page 608 587 CHAPTER 3 Working With Threads Synchronization Example Let s write a plain C class which can be used for the buffering of characters This class defines the methods addchar and writeBuffer addChar adds a character to an internal character buffer and writeBuffer prints the buffer contents on standard output DO ao ET a Ol OE a
416. o implementation class il ff JIVA 2 package hello 8 4 public class Hello_impl extends HelloPOA S i 6 public void say_hello 7 8 System out println Hello World 9 iLO F 4 The implementation class Hello_imp1 must inherit from the generated class HelloPOA 6 8 As with the C implementation the say_hello method simply prints Hello World on standard output 22 Implementing the Example in Java Server class main method Create a file Server java in the directory hello and enter the following Server Class code which holds the server s main and run methods 6S 00 J oy OT iS Go SD a Sana amp WO ME Oo PP BPW WWW WWW WWWNnNNDNNYNN NN DNDN DN H E OO SO OS NO i BS OD hy i Sa Ns oS KS Java package hello public class Server public static void main String args java util Properties props System getProperties props put org omg CORBA ORBClass com ooc OBServer ORB props put org omg CORBA ORBSingletonClass com ooc CORBA ORBSingleton im stetus 0 org omg CORBA ORB orb null Ery orb org omg CORBATORB imi tlargs props status run orb catch Exception ex ex printStackTrace status 1 if orb null try orb destroy catch Exception ex ex printStackTrace status 1 System exit status 23 CHAPTER 2 Getting Started 24 20 22 26 28 39 41 These properties are necessary to
417. oadAlertImp1 S7 LoadBalancing LoadAlert_var loadAlert 58 loadAlertImpl gt _this 59 60 manager gt activate 61 62 LoadBalancing Group_var group factory gt get Hello 63 group gt set_load_alert memberId loadAlert 64 65 updater gt register_member memberId Hello 66 67 Oude gt one 68 69 return EXIT SUCCESS TO Get the GroupFactory and the LoadUpdater and LoadAlert utility objects Create the member POA Create the LoadAlert servant and activate it on the root POA Set the member s LoadAlert object Note that this should be done after activating the POA manager since it may result in a request to this server Register the member with the LoadUpdater The remainder of the run function is the same as in section Non adaptive Load Balancing on page 289 297 CHAPTER 14 Orbacus Balancer Running the Load Balanced Servers In this section we present the step required to set up the Orbacus Balancer for the Hello World load balanced servers We will assume that Orbacus has been installed in the directory usr local Orbacus and the executables balancer lbadmin and lbmkref all exist in a directory that is in the search path The steps are as follows 1 Create a configuration file for Orbacus Balancer containing the following balancer conf ooc balancer admin_endpoint iiop port 10000 ooc balancer forward_endpoint iiop port 10001 ooc balancer dbdir usr local
418. object has a Request TimeoutPolicy set and no response to a request is available after value milliseconds a CORBA NO_RESPONSE exception is raised The default value is 1 which means no timeout 436 Module OB Interface OB RetryPolicy Attributes local interface RetryPolicy inherits from CORBA Policy The retry policy This policy is used to specify retry behavior after communication failures i e CORBA TRANSIENT and CORBA COMM_FAILURE exceptions retry_interval readonly attribute unsigned long retry_interval retry_max readonly attribute unsigned long retry_max retry_mode readonly attribute short retry_mode For retry_mode RETRY_NEVER indicates that requests should never be retried and the exception is re thrown to the application RETRY_STRICT will retry once if the exception completion status is COMPLETED_NO in order to guarantee at most once semantics RETRY_ALWAYS will retry once regardless of the exception completion status The default value is RETRY_STRICT retry_interval is the time in milliseconds between retries The default is O retry_max is the maximum number of retries The default is 1 retry_remote determines whether or not to retry on exceptions received over the wire The default is false only retry on locally generated exceptions Note Many TCP IP stacks do not provide a reliable indication of communication failure when sending smaller requests therefore the failure may not be detec
419. of the mutex to release it The mutex must be locked and the calling thread must be the one that last locked the mutex If these conditions are not met undefined behavior will result Returns This method always returns true trylock bool trylock const This method is identical to lock except that if the mutex is already locked then false is returned Returns true if the mutex was locked false otherwise get_owner JTCThreadId get_owner const 1 Under Windows NT JTCMutex allows recursive locking while a pthreads implementation i e UNIX does not Return the thread id of the owning thread Returns The thread id of the owning thread 645 CHAPTER A Class Reference JTCRWMutex Overview Member Functions 646 This class can be used to create read write locks This class has no direct equivalent in Java It is provided for performance reasons only Like JTCMutex this class not does guarantee recursive locking semantics If the mutex is locked more than once by the same thread a deadlock may result read_lock void read_lock const Lock the mutex for reading If the mutex is locked for writing or writers are waiting for a write lock the calling thread blocks until the mutex is unlocked If the current owner of the mutex attempts to re lock the mutex a deadlock may result write_lock void write_lock const Lock the mutex for writing If the mutex is locked for reading or writing the calling t
420. om the CORBA Object object reference Although _narrow for CORBA objects works similar to dynamic_cast lt gt for plain C objects dynamic_cast lt gt must not be used for CORBA object references That s because in contrast to dynamic_cast lt gt narrow might have to query the server for type information The say_hello operation on the hello object reference is invoked causing the server to print Hello World Implementing the Example in C Compiling and Linking Overview Dependencies For more details Compiling Hello cpp results in an object file with the following name e UNIX Hello o e Windows Hello obj You must link both the client and the server with the file for your platform The compiled Hello_skel cpp and Hello_impl cpp are only needed by the server Compiling and linking is to a large degree compiler and platform dependent Many compilers require unique options to generate correct code To build Orbacus programs you must at least link with the Orbacus library for your platform e UNIX 1iboB a Windows ob lib Additional libraries are required on some systems such aS libsocket a and libns1l a for Solaris or wsock32 1ib for Windows The Orbacus distribution includes various README files for different platforms which give hints on the options needed for compiling and the libraries necessary for linking Please consult these README files for details 19 CHAPTER 2 Gettin
421. onst POAManagerFactory ManagerAlreadyExists amp ex do something And now the same example in Java 323 CHAPTER 16 Using Policies 324 oma numb WN FE oO 20 21 BO 23 24 25 Java org omg CORBA Object obj orb resolve_initial_references RootPOA org omg PortableServer POA rootPOA org omg PortableServer POAHelper narrow obj org omg PortableServer POAManagerFactory factory rootPOA the_the_POAManagerFactory com ooc OBPortableServer POAManagerFactory pmFactory com ooc OBPortableServer POAManagerFactoryHelper narrow facto ry org omg PortableServer POAManager myPOAManager null org omg CORBA Policy pl new Policy 1 Seine Come Wiga Anosic ilerilinosie joome iOS amel localhost pl 0 pmFactory create_endpoint_configuration policy config try myPOAManager pmFactory create_POAManager MyPOAManager pl catch org omg PortableServer POAManagerFactoryPackage Manager AlreadyExists ex do something catch org omg CORBA PolicyError ex do something GlOPVersionPolicy Programming Examples This example shows how to create a new POA Manager with a specific GIOP vesion to be used in object references generated by that POA Manager This option is useful for backward compatibility with older ORBs that reject object references using a newer version of the protocol In the example below the GIOP version is set to 1 2 The C version is pres
422. ontains the following topics AMI Router page 333 Router Usage page 334 Router Administration Properties page 335 AMI Reply Handler Implementation page 337 AMI Poller Implementation page 341 Configuring Clients and Servers page 343 AMI Router AMI Router The AMI Router allows users to configure their systems so that servers that have the potential to go offline on a regular basis can have an associated set of AMI Routers specified as an alternative fallback destination for their requests Rather than encumbering the client application with retry logic the AMI Router allows the client application to send a message as though the server were available and continue processing The message will actually be delivered to a router that can then worry about delivering the message to the server when it becomes available The client application can then handle the expected response from the asynchronous invocation when necessary 333 CHAPTER 17 Asynchronous Method Invocation Router Usage The AMI Router is currently implemented using Orbacus for C but can be used with C and Java clients and servers Command line usage is as follows amirouter h help v version i ior p persistent w workers WORKERS Options h Display the command line options supported by the help router v Display the version of the router version i Prints the stringified IOR of t
423. oot POA Hi CORBA Object_var poaObj orb gt resolve_initial_references RootPOA PortableServer POA_var rootPOA PortableServer POA _narrow poa0b Java dy Create the POA Manager org omg PortableServer POAManager poaManager com ooc FSSL FSSL create_poa_manager RootPOAManager orb fsslManager id props Resolve Root POA Hf org omg PortableServer POA root org omg PortableServer POAHelper narrow orb resolve_initial_references RootPOA 555 CHAPTER 2 Extending the Hello World Application After this has been done the remainder of run will be the same as the original demo Are Create implementation object Hello_imp1l helloImpl new Hello_impl PortableServer ServantBase_var servant helloImp1 Hello_var hello helloImpl gt _this he Save reference Ve CORBA String_var s orb gt object_to_string hello const char refFile Hello ref ofstream out refFile EOE E G Carr lt lt NO lt lt eo weeimitc Gan lt lt oaa lt lt Wie W lt lt strerror errno lt lt endl return EXIT_FAILURE gut lt lt 3 lt lt end out close Run implementation cout lt lt Server is ready lt lt endl poaManager gt activate SLD gt EUS return EXIT_SUCCESS 556 Complete Example Java Ui Create implementation object Ki Hello_impl helloIm
424. operties 715 Subscription Sharing 716 Chapter 4 Programming Example 719 Introduction 720 Connecting to a Notification Channel 721 Connecting a Consumer 731 XV CONTENTS Connecting to a Proxy 735 Supplying Events 739 Consuming Events 741 Filtering 742 Disconnecting from a Notification Channel 749 Building Orbacus Notify Clients 751 Chapter 5 Orbacus Notify Console 753 Overview 754 The Orbacus Notify Console Menus 757 Creation Wizards 759 Managing Notification Channels 760 Managing Admins 763 Managing Proxies 766 Managing Filters 769 Managing Filter Constraints 770 Managing Mapping Filters 772 Managing Mapping Filter Constraint Value Pairs 773 Appendix A CosEventChannelAdmin Reference 777 Module CosEventChannelAdmin 778 Interface CosEventChannelAdmin ProxyPushConsumer 779 Interface CosEventChannelAdmin ProxyPullSupplier 780 Interface CosEventChannelAdmin ProxyPullConsumer 781 Interface CosEventChannelAdmin ProxyPushSupplier 782 Interface CosEventChannelAdmin ConsumerAdmin 783 Interface CosEventChannelAdmin SupplierAdmin 784 Interface CosEventChannelAdmin EventChannel 785 Appendix B CosEventComm Reference 787 Module CosEventComm 788 Interface CosEventComm PushConsumer 789 Interface CosEventComm PushSupplier 790 Interface CosEventComm PullSupplier 791 Interface CosEventComm PullConsumer 792 Appendix C CosNotification Reference 793 Module CosNotification 794 xvi Interface CosNotification QoSAdmin I
425. operty name value name value ORBreactive ooc orb conc_model reactive ORBrepository or ooc orb service InterfaceRepository or ORBServerlId string ooc orb server_name Sstring 68 Configuring the ORB and Object Adapter Option Property ORBservice name ior ooc orb service name ior ORBthreaded ooc orb conc_model threaded ORBt race_connections level ooc orb trace connections evel ORBt race_retry level ooc orb trace retry level A few additional command line options are supported that do not have equivalent properties These options are described in the following table Option Description ORBconfig filename Causes the ORB to load the configuration file specified by filename ORBversion Causes the ORB to print its version to standard output 69 CHAPTER 4 ORB and Object Adapter Initialization Using a Configuration File 70 A convenient way to define a group of properties is to use a configuration file A sample configuration file is shown below Concurrency models ooc orb conc_model threaded ooc orb oa conc_model thread_pool ooc orb oa thread_pool 5 Initial services ooc orb service NameService corbaloc myhost 7000 NameService ooc orb service EventService corbaloc myhost 7001 DefaultEventC hannel ooc orb service TradingService corbaloc myhost 7002 TradingServ ice Note that trailing blanks are no
426. opertyError struct PropertyError PropertyName name PropertyErrorCode code hi A load balancing strategy configuration property error MemberData struct MemberData MemberId member_id LoadAlert alert The member data MemberPolicyValue struct MemberPolicyValue GroupId group_id MemberId member_id The member policy value Module LoadBalancing MemberExists exception MemberExists A MemberExists exception indicates that a member with the specified id is already exists in the load balanced group MemberNotFound exception MemberNotFound A MemberNotFound exception indicates that the specified member does not exist in the load balanced group GroupExists exception GroupExists 497 CHAPTER F Orbacus Balancer Reference 498 A GroupExists exception indicates that a load balanced group with the specified id already exists GroupNotFound exception GroupNotFound A GroupNotFound exception indicates that the specified load balanced group does not exist StrategyNotFound exception StrategyNotFound A StrategyNotFound exception indicates that the specified strategy is not supported by the Balancer StrategyNotAdaptive exception StrategyNotAdaptive A StrategyNotAdaptive exception indicates that the strategy is not an adaptive strategy and does not require load updates InvalidProperties exception InvalidProperties
427. ort Returns Module OCI The description add_close_cb void add_close_cb in CloseCB cb Add a callback that is called before a connection is closed If the callback has already been registered this method has no effect Parameters cb The callback to add remove_close_cb void remove_close_cb in CloseCB cb Remove a close callback If the callback was not registered this method has no effect Parameters cb The callback to remove 465 CHAPTER E Open Communications Interface Reference Interface OCI CloseCB Synopsis local interface CloseCB An interface for a close callback object See Also Interface OCI TransportInfo Operations close_cb void close_cb in TransportInfo transport_info Called before a connection is closed Parameters transport_info The TransportInfo for the new closeion 466 Module OCI Interface OCI Connector Synopsis Attributes Operations local interface Connector An interface for Connector objects A Connector is used by CORBA clients to initiate a connection to a server It also provides operations for the management of IOR profiles See Also Interface OCI ConFactory Interface OCI Transport id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag connect Transport connect Used by CORBA clients to establish a connection to a CORBA server It
428. ort N Specifies the port number on which to bind the socket If no port is specified the operating system selects an unused port automatically 519 CHAPTER 1 Using FreeSSL for Orbacus 520 Command Line Options The FreeSSL plug in defines the following command line options for both the C and the Java version of the plug in FSSLbacklog N Equivalent to the backlog endpoint option FSSLbind ADDR Equivalent to the bind endpoint option FSSLhost ADDR ADDR Equivalent to the host endpoint option FSSLnumeric Equivalent to the numeric endpoint option FSSLport N Equivalent to the port endpoint option Static Linking Static Linking When statically linking a C application an explicit reference must be made to the FSSL plug in in order to include the plug in s modules Shown below is the technique used by the sample programs in the fssl demo subdirectory Note that the code below is enclosed in guard macros that are only activated when statically linking These macros are appropriate for both Unix and Windows First extra include files are necessary if defined HAVE_SHARED amp amp defined FSSL_DLL include lt OB OCI_init h gt include lt FSSL OCI_FSSLIOP_init h gt endif Next the plug in must be registered prior to calling ORB_init if defined HAVE_SHARED amp amp defined FSSL_DLL it When linking statically we need to explicitly
429. ortInfo must be narrow d to OCI IIOP TransportInfo 365 CHAPTER 19 The Open Communications Interface Class Diagram 366 Figure 15 shows the classes and interfaces of the OCI except for the Buffer and Info interfaces Sa 1 ORB OA 1 Connector Acceptor Factory Factory Registry Registry if Connector Acceptor Factory Connector Transport Acceptor Factory creates creates lt creates lt creates n Protocol Protocol Protocol f Specific Specific Specific pecitic Connector Acceptor Factory Connector Transport Acceptor Factory Figure 15 OC Class Diagram Orbacus provides abstract base classes for the interfaces Connector Factory Connector Transport Acceptor Factory and Acceptor The protocol plug in must inherit from these classes in order to provide concrete implementations for a specific protocol Orbacus also provides concrete classes for the interfaces Buffer Connector Factory Registry and Acceptor Factory Registry Instances of Connector Factory Registry and Acceptor Factory Registry can be obtained via the ORB operation resolve_initial_references using the identifiers OCIConFactoryRegistry and OCIAccFactoryRegistry respectively Concrete implementations of Connector Factory must be registered with the Connector F
430. oryHelper narrow facto ry org omg PortableServer POAManager myPOAManager null org omg CORBA Policy pl new Policy 1 pl 0 pmFactory create_communications_concurrency_policy com ooc OBPortableServer COMMUNICATIONS_CONCURRENCY_POLICY_TH READED value try myPOAManager pmFactory create_POAManager MyPOAManager pl catch org omg PortableServer POAManagerFactoryPackage Manager AlreadyExists ex do something catch org omg CORBA PolicyError ex do something Programming Examples EndpointConfigurationPolicy This example shows how to create a new POA Manager with a list of endpoints for the Root POA Manager The C version is presented first followed by the Java version Noe Ww hme H ao N js gt o o e 9 20 21 22 AU Cia CORBA Object_var poaObj orb gt resolve_initial_references RootPOA OBPortableServer POA var rootPOA OBPortableServer POA _narrow poa0bj POAManagerFactory_var factory rootPOA gt the_POAManagerFactory OBPortableServer POAManagerFactory_var pmFactory OBPortableServer POAManagerFactory _narrow factory POAManager_var myPOAManager Polievyirst pl String_var config CORBA rstring cup atop host localhost port 5555 pind localhosi pl length 1 pl 0 pmFactory gt create_endpoint_configuration_policy config in try myPOAManager create_POAManager MyPOAManager pl catch c
431. ow do obtain a reference to a B object This chapter answers that question by describing a number of ways an application can bootstrap its first object reference 129 CHAPTER 6 Locating Objects Lifetime of Object References All of the strategies described in this chapter involve the publication of an object reference in some form A common source of problems for newcomers to CORBA is the lifetime and validity of object references Using IIOP an object reference can be thought of as encapsulating several pieces of information e hostname e port number e object key If any of these items were to change any published object references containing the old information would likely become invalid and its use might result in a TRANSIENT Of OBJECT_NOT_EXIST exception The sections that follow discuss each of these components and describe the steps you can take to ensure that a published object reference remains valid 130 Hostname Lifetime of Object References By default the hostname in an object reference is the canonical hostname of the host on which the server is running Therefore running the server on a new host invalidates any previously published object references for the old host Orbacus provides the 110Phost option to allow you to override the hostname in any object references published by the server This option can be especially helpful when used in conjunction with the Domain Name System DNS in whic
432. oxyPushSupplier interface manages connections from consumers who wish to have structured events pushed on them by the channel connect_structured_push_consumer void connect_structured_push_consumer in CosNotifyComm StructuredPushConsumer push_consumer raises CosEventChannelAdmin AlreadyConnected CosEventChannelAdmin TypeError Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters push_consumer A reference to the consumer object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pushing events to the connected consumer If the connection is already suspended the Connect ionAlreadyInactive exception is raised If the target object is not connected to a supplier the NotCconnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target object to resume pushing events to the connected consumer If the connection is not suspended the Connect ionAlreadyActive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised Interface Module CosNotifyChannelAdmin CosNotifyChannelAdmin SequenceProxyPushSupplier Operations interface SequenceProxyPushSupplier inherits from Co
433. p Of JTCRunnable As long as you follow these basic rules memory management in JThreads C is virtually automatic The nice thing about reference counting and handle classes is that it makes JThreads C even more Java like Reference counting emulates the Java garbage collector and handles emulate Java references APPENDIX A Class Reference This chapter provides a reference to the classes in the JThreads C library CHAPTER A Class Reference JTCinitialize Overview JTCOptions Constructors 618 An instance of this class must be instantiated before JThreads C is used If no instance of this class is created the JThreads C library will not work properly JTCInitialize can be instantiated multiple times However only the first instantiation has any effect When the last uTcInitialize instance is destroyed the destructor will wait for all running threads to terminate JTCInitialize interprets arguments starting with utc All of these arguments passed through the argc and argv parameters are automatically removed from the argument list The following JThreads C options can be used JTCversion Shows the JThreads C version number JTCss stack size This option sets the thread stack size to stack size kilobytes JTClnitialize JTCIinitialize Initializes the JThreads C library Throws JTCSystemCallException Indicates a failed system call JTCInitialize JTCInitialize int amp
434. per consumer supplier or per channel basis Interfaces which support QoS properties derive from the cosNotification QoSAdmin IDL interface Perhaps one of the most important QoS properties added by the Notification Service is persistence as it applies to event and connection reliability QoS parameters Connection Persistence Persistent connection reliability refers to Orbacus Notify s ability to restore all object connections after a service restart That is when Orbacus Notify starts it restores all channels admins proxies and filters to their state at shutdown In addition Orbacus Notify also attempts to re establish communication with any clients that were connected at shutdown Orbacus Notify can also restore connections to restarted clients These clients must supply a persistent non nil object reference when connecting to the proxy Note Orbacus Notify does not permit admin and proxy objects to set a connection reliability different than that set on the parent event channel Event Persistence With connection persistence enabled Orbacus Notify also supports event persistence That is all consumers connected at the time an event is delivered to the channel are guaranteed to receive that event within event expiry limits 709 CHAPTER 3 Notification Service Concepts The following briefly describes the The following QoS properties are set on a per event basis available properties Event QoS Properties Table 3
435. perty ooc orb conc_model threaded 12 13 CORBA ORB_var orb OBCORBA ORB_init argc argv props Create an oB Properties object that is based on the default properties Initialize the properties for the ORB After invoking 0B ParseArgs props contains the ORB properties and argv no longer contains any ORB or OA command line arguments The oB ParseArgs operation takes an optional Logger object which ParseArgs will use to display any warning or error messages In this example a custom Logger object is not used so the code passes a nil value 75 CHAPTER 4 ORB and Object Adapter Initialization 76 8 12 13 4 8 Retrieve the ooc orb conc_model property and set it to threaded if its value is not valid Initialize the ORB ooun ebe WN Ee Java java util Properties props System getProperties args com coc CORBA ORB ParseArgs args props null String orbModel props get ooc orb conc_model if orbModel equals threaded props put ooc orb conc_model threaded org omg CORBA ORB orb org omg CORBA ORB init arg props Create a java util Properties object Initialize the properties for the ORB After invoking com ooc CORBA ORB ParseArgs props contains the ORB properties The return value of ParseArgs is a string array with all oRB and oa arguments removed As in the C example a Logger object is not used Retrieve the ooc orb conc_
436. phed luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr Sophed luke software Pee Leow Ce omen Figure 6 The Ping Window This is very similar to the Windows or Unix ping command for an IP address or a host name If there is a time out while trying to contact an object this information is displayed in the Ping Window and the console continues with the next object The Menus If you want objects that cannot be contacted for example because of a server breakdown to be unbound from the current context Clean up does the job Clean up non recursively tries to connect to the selected objects If there is a communication failure or the _non_existent operation returns true for a particular object the corresponding binding is automatically removed Clean up should be used with care 221 CHAPTER 10 Orbacus Names Console The Toolbar 222 In addition to the operations offered by the menu bar some frequently needed functions are available by icons located in the toolbar as shown in Figure 7 Jee re ee x Figure 7 A closer look at the too bar The icon on the toolbar s left is the Upwards icon which changes the naming context to the parent of the context currently being displayed The
437. pl 8 Named a impl A _this orb 9 Named al implAl _this orb 0 Named a2 implA2 _this orb 1 Named a3 imp1lA3 _this orb 2 Named b imp1B _this orb 3 Named c implC _this orb 4 5 EEY 6 i NameComponent nclName new NameComponent 1 8 nclName 0 new NameComponent 9 nclName 0 id ncl 20 nclName 0 kind 21 NamingContext ncl nc bind_new_context nclName 22 29 NameComponent nc2Name new NameComponent 2 24 nc2Name 0 new NameComponent 25 nc2Name 0 id ncl 26 nc2Name 0 kind oe nc2Name 1 new NameComponent 28 nc2Name 1 id nc2 2S nc2Name 1 kind 30 NamingContext nc2 nc bind_new_context nc2Name Sil 32 NameComponent aName new NameComponent 1 33 aName 0 new NameComponent 34 aName 0 id a 35 aName 0 kind 36 nc bind aName a 203 CHAPTER 9 Orbacus Names 204 37 38 NameComponent alName new NameComponent 1 39 alName 0 new NameComponent 40 alName 0 id al 41 alName 0 kind 42 nc bind alName al 43 44 NameComponent a2Name new NameComponent 1 45 a2Name 0 new NameComponent 46 a2Name 0 id a2 47 a2Name 0 kind 48 nc bind a2Name a2 49 50 NameComponent a3Name new NameComponent 1 SE a3Name 0 new NameComponent 52 a3Name 0 id a3 53 a3Name 0 kind 54 nc bind a3Name a3 55 56 NameCompo
438. pl new Hello_impl Hello hello helloImpl _this orb ve Save reference if Ery String ref orb object_to_string hello String refFile Hello ref java io FileOutputStream file new java io FileOutputStream refFile java io PrintWriter out new java io PrintWriter file out printin ref ble 5 1 IlnSsin 2 file close catch java io IOException ex System err printin hello Server can t write to ex getMessage return 1 if Run implementation vy System out println Server is ready poaManager activate Oros romii return 0 557 CHAPTER 2 Extending the Hello World Application Trust Decider The trust decider for the server is slightly different in that the distinguished name of the client is not validated since the server accepts connections from any client validated by the CA Hi Ca if chain length 2 amp amp chain 1 gt is_signed_by ca_ CORBA_String_var dnl chain 1 gt subject_DN CORBA String van dn2 ca gt subject_DN if strcmp dn1 dn2 0 return true return false Java if chain length 2 amp amp chain 1 is_signed_by ca_ String dnl chain 1 subject_DN String dn2 ca_ subject_DN if dnl equals dn2 return true return false 558 APPENDIX A FSSL Definitions ADH The anonymous Diffie Hellman public key algorithm see 9 ASN 1
439. plemented and registered connected by clients who wish to have structured events pulled from them by the channel pull_structured_event CosNotification StructuredEvent pull_structured_event raises CosEventComm Disconnected This method blocks the calling thread until the supplier has data available or an exception is raised Returns A structured event try_pull_structured_event CosNotification StructuredEvent try_pull_structured_event out boolean has_event raises CosEventComm Disconnected This method does not block and can be used to poll a pull supplier for events Parameters has_event Set to TRUE if there is an event available FALSE otherwise Returns A structured event if has_event is TRUE undefined otherwise disconnect_structured_pull_supplier void disconnect_structured_pull_supplier Terminates communication between the target supplier and its consumer Also frees resources allocated by the supplier 847 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm StructuredPushSupplier Operations 848 interface StructuredPushSupplier inherits from CosNotifyComm NotifySubscribe The structuredPushSupplier interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel Clients do not need to implement this interface to simply push events disconnect_structured_push_
440. port 1234 Now let s consider a more complicated example Suppose that we have an existing endpoint configuration property defined and we also use command line options The existing endpoint configuration is ooc orb oa endpoint iiop port 5555 And the command line options are IIOPport 5556 After the command line options are processed by the IIOP plug in the endpoint configuration property will be ooc orb oa endpoint iiop port 5555 iiop port 5556 Note that there are now two endpoints the command line options resulted in an additional endpoint being appended to the existing property value 85 CHAPTER 4 ORB and Object Adapter Initialization Dispatching Requests As explained in 4 a POA Manager is initially in the holding state where incoming requests on the POA Manager s endpoints are queued To dispatch requests the POA Manager must be activated using the activate operation 86 Callbacks Using POA Managers In mixed client server applications in which callbacks occur it is important to remember that callbacks will not be dispatched until the POA Manager has been activated If the POA Manager has not been activated the application will likely hang In general applications should activate the POA Manager prior to making any request that might result in a callback 87 CHAPTER 4 ORB and Object Adapter Initialization ORB Destruction 88 Applications must destroy the ORB before returning
441. pply an implementation for clone impl Generates example servant implementation classes For IDL interface types a class is generated in the same package as the interface classes having the same name as the interface with the suffix _imp1 The generated class extends the POA class of the interface For IDL valuetypes a class is generated in the same package as the valuetype with the suffix valueFactory_imp1l You must not use no skeletons in combination with this option impl tie Similar to imp1 but implementation classes for interfaces implement the Operations interface to facilitate the use of TIE classes You must not use no skeletons in combination with this option with interceptor args Generate code with support for arguments result and exception list values for interceptors Note that use of this option will generate proprietary stubs and skeletons which are not compatible with ORBs from other vendors 1 Prefix refers to the value of the pragma prefix statement in an IDL file For example the statement pragma prefix ooc com defines ooc comas the prefix The prefix is included in the Interface Repository identifiers for all types defined in the IDL file 40 Translating IDL to HTML Translating IDL to HTML Synopsis Description Options for hidl hidl options idl files Creates HTML files from IDL files An HTML file is generated for each module and interface defined in an IDL f
442. pportedQos exception is raised Parameters Module CosNotifyChannelAdmin required_qos The QoS properties of interest to the caller are passed in this parameter available_gos If the properties in required_qos are supported other optional QoS properties which are also supported are returned in this parameter 811 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin ProxySupplier Attributes Operations 812 interface ProxySupplier inherits from CosNotification QoSAdmin CosNotifyFilter FilterAdmin The ProxySupplier interface supports operations common to all proxy suppliers MyType readonly attribute ProxyType MyType The type delivery model and event type of the proxy MyAdmin readonly attribute ConsumerAdmin MyAdmin Reference to the parent consumer admin object priority_filter attribute CosNotifyFilter MappingFilter priority_filter Reference to an optional priority mapping filter lifetime_filter attribute CosNotifyFilter MappingFilter lifetime_filter Reference to an optional lifetime mapping filter obtain_offered_types CosNotification EventTypeSeq obtain_offered_types in ObtainInfoMode mode Obtains an aggregate list of all event types currently offered on the channel Parameters mode Determines how offered event types are returned Returns A sequence of event types representing all events currently offered on the channel validate_event_
443. property i e the ooc naming trace_level property or one of the coc orb trace properties to the HKEY_LOCAL_MACHINE NT registry key with a rEc_sz value of at least l Configuration Properties In addition to the standard configuration properties described in Chapter 4 Orbacus Names also supports the following properties Configuration Properties ooc naming callback_timeout SECS Equivalent to the c command line option ooc naming database FILE Equivalent to the a command line option ooc naming no_updates Equivalent to the n command line option ooc naming endpoint ENDPOINT Specifies the endpoint configuration for the service Note that this property is only used if the coc orb oa endpoint property is not set ooc naming timeout MINS Equivalent to the t command line option ooc naming trace_level LEVEL Defines the output level for diagnostic messages printed by Orbacus Names The default level is O which produces no output A level of 1 or higher produces messages related to database operations a level of 2 or higher produces messages related to adding and removing listeners and a level of 3 or higher produces messages related to binding operations 193 CHAPTER 9 Orbacus Names Persistence 194 Orbacus Names can optionally be used in a persistent mode in which all data managed by the service is saved in a file If you do not run the service in its persistent mode all of the data will b
444. pty repository id The default value is true Note that there is one rare case where the cache may not work as expected if an application requires the received TypeCode to be equal to the one that was transmitted where equal implies a successful result from the TypeCode equal operation Although TypeCodes with the same repository id are always equivalent they are not always equal because of TypeCode compaction However if the cache is enabled two TypeCode objects received over the wire with the same repository id will always be equal For more information on the semantics of the equal and equivalent TypeCode operations see 3 Value for 63 CHAPTER 4 ORB and Object Adapter Initialization ooc orb trace connections ooc orb trace retry 64 Adds an initial service to the ORB s internal list This list is consulted when the application invokes the ORB operation resolve_initial_references name is the key that is associated with an IOR or URL For example the property coc orb service NameService adds NameService to the list of initial services See The BootManager on page 144 for more information Value evel gt O Defines the output level for diagnostic messages printed by Orbacus that are related to connection establishment and closure A level of 1 or higher produces information about connection events and a level of 2 or higher produces code set exchange information The default level i
445. qos void validate_event_gos in CosNotification QoSProperties required_qos out CosNotification NamedPropertyRangeSeq available_qos Module CosNotifyChannelAdmin raises CosNotification UnsupportedQoS Checks for a conflict between per event QoS and the QoS settings of the target proxy If the target proxy cannot honor any of QoS properties in required_gos an UnsupportedQos exception is raised Parameters required_gos The QoS properties of interest to the caller are passed in this parameter available_gos If the properties in required_qos are supported other optional QoS properties which are also supported are returned in this parameter 813 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin ProxyPushConsumer Operations 814 interface ProxyPushConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm PushConsumer The ProxyPushConsumer interface supports connections by suppliers who wish to push unstructured CORBA Any events connect_any_push_supplier void connect_any_push_supplier in CosEventComm PushSupplier push_supplier raises CosEventChannelAdmin AlreadyConnected Connects a supplier to the channel If a supplier is already connected the AlreadyConnected exception is raised Parameters push_supplier A reference to the supplier object A nil reference is permitted Interface Module CosNotifyChannelAdmin CosNotifyChannelAd
446. quests without compile time knowledge of interface types and operation signatures e Implementation Repository start servers on demand and migrate servers to different hosts without adversely affecting clients e interface Repository build IDL to anything translators easily e Support for Local Interfaces standard way to implement locality constrained objects For platform availability please refer to the Orbacus home page at http www orbacus com support new_site platforms jsp This manual is except for the Getting Started chapter no replacement for a good CORBA book This manual also does not contain the precise specifications of the CORBA standard which are freely available on line A good grasp of the CORBA specifications in 4 5 and 6 is absolutely CHAPTER 1 Introduction to Orbacus necessary to effectively use this manual In particular the chapters in 4 covering CORBA IDL and the IDL to C mapping should be studied thoroughly For C users we also highly recommend 3 This book contains by far the best treatment of CORBA programming with C to date What this manual does contain however is information on how Orbacus implements the CORBA standard A shortcoming of the current CORBA specification is that it leaves a high degree of freedom to the CORBA implementation For example the precise semantics of a oneway call are not specified by the standard To make it easier to get started wit
447. r admin object assigns an ID to each proxy it creates Returns If found a reference to the proxy supplier is returned Otherwise a ProxyNotFound exception is raised obtain_notification_pull_supplier ProxySupplier obtain_notification_pull_supplier in ClientType ctype out ProxyID proxy_id raises AdminLimitExceeded Creates a new proxy pull supplier Parameters ctype Specifies the client type The returned proxy can be narrowed to a type suitable for the given client type proxy_id Returns the ID assigned to the newly created proxy Returns A reference to a newly created proxy supplier is returned This reference should be narrowed to the appropriate type before use The AdminLimitExceeded exception is raised if creating a new proxy would exceed the limit for the target admin obtain_notification_push_supplier ProxySupplier obtain_notification_push_supplier in ClientType ctype out ProxyID proxy_id raises AdminLimitExceeded Creates a new proxy push supplier Parameters ctype Specifies the client type The returned proxy can be narrowed to a type suitable for the given client type proxy_id Returns the ID assigned to the newly created proxy Returns 827 CHAPTER D CosNotifyChannelAdmin Reference 828 A reference to a newly created proxy supplier is returned This reference should be narrowed to the appropriate type before use The AdminLimitExceeded exception is raised if creating a new prox
448. r concurrency models are only available in Orbacus for C See Chapter 18 for more information on concurrency models If this property is set to thread_pool then the property ooc orb oa thread_pool determines how many threads are in the pool If this property is set to leader_follower then the property ooc orb oa leader_follower_pool determines how many threads are to be used 65 CHAPTER 4 ORB and Object Adapter Initialization ooc orb oa endpoint ooc orb oa leader_follower_pool ooc orb oa thread_pool 00c orb oa version 66 This property is also used to determine the default value of the communications concurrency model for POA Managers see ooc orb poamanager Manager conc_model below The following table summarises how the setting of this property determines the POA Manager defaults Table 1 POA Managers Communications Concurrency Model Value of ooc orb oa conc_model ooc orb poamanager lt manager gt conc_model default reactive reactive leader_follower leader_follower threaded threaded thread_per_client threaded thread_per_request threaded thread_pool threaded Value string Specifies a comma separated list of endpoints for the Root POA Manager The default value is iiop See Endpoints on page 84 for more information Value n gt O Determines the number of threads in the pool used by the leader_follower concurrency model The default
449. r selection does not use load information from the members Hence non adaptive member selection will only correctly balance connections under a certain set of conditions These conditions are as follows Dedicated hosts e Homogeneous hosts e Clients generate the same load and are connected for the same amount of time or clients are connected for short periods of time While adaptive member selection can be used in more situations than non adaptive member selection it is not without problems The problems with adaptive member selection are highlighted below 1 Using a polling technique to retrieve member loads does not scale Hence it is decided that loads will be reported to the load balanced group at regular intervals by each member However this implies that 269 CHAPTER 14 Orbacus Balancer Load Re balancing 270 when making a load balancing decision loads do not necessarily represent the current loads of the members but instead past loads This is a source of error These errors will be large when many clients connect in a short period of time This is because the actual load of members will increase dramatically before the loads can be updated Increasing the frequency of load updates will decrease the error but then the overhead of load balancing is increased due the extra network traffic Hence an optimum value must be discovered for each installation 2 Another source of error is that spikes in the
450. r_ with the identifier of the underlying plug in e g bidir_iiop bidir_ID callback options The only option supported by the bi directional plug in is callback which creates a callback endpoint If this option is specified it must be the only option If callback is not the first and only option all additional options are passed to the underlying plug in for processing For example a server would typically use a configuration such as ooc orb oa endpoint bidir_iiop port 7000 This creates a bi directional IIOP endpoint on the static port 7000 On the other hand a bi directional client would use the following configuration ooc orb oa endpoint bidir_iiop callback This creates a callback endpoint which can only receive requests when an existing outgoing bi directional IIOP connection has been established from this client to the server that wishes to make a callback The Bi directional OCI Plug in Command line Options No command line options are supported 395 CHAPTER 19 The Open Communications Interface Configuration Properties The bi directional plug in supports a single configuration property ooc bidir peer Specifies the peer ID If not specified a unique peer ID is used 396 Static Linking The Bi directional OCI Plug in When statically a C application an explicit reference must be made to the bi directional plug in as well as to the underlying plug in in order to inc
451. rations interface ConsumerAdmin An event consumer uses this interface to create the appropriate proxy supplier obtain_push_supplier ProxyPushSupplier obtain_push_supplier Creates a new ProxyPushSupplier object Returns An object reference to the new proxy is returned obtain_pull_supplier ProxyPullSupplier obtain_pull_supplier Creates a new ProxyPullSupplier object Returns An object reference to the new proxy is returned 783 CHAPTER A CosEventChannelAdmin Reference Interface CosEventChannelAdmin SupplierAdmin Synopsis Operations 784 interface SupplierAdmin An event supplier uses this interface to create the appropriate proxy consumer obtain_push_consumer ProxyPushConsumer obtain_push_consumer Creates a new ProxyPushConsumer object Returns An object reference to the new proxy is returned obtain_pull_consumer ProxyPullConsumer obtain_pull_consumer Creates a new ProxyPullConsumer object Returns An object reference to the new proxy is returned Module CosEventChannelAdmin Interface CosEventChannelAdmin EventChannel Synopsis Operations interface EventChannel Event suppliers and consumers use the EventChannel interface to obtain the admin objects required for proxy creation for_consumers ConsumerAdmin for_consumers Creates a new ConsumerAdmin object Returns An object reference to the new admin is returned for_suppliers SupplierAdmin for
452. rations info void info in string msg Log an informational message Parameters msg The message error void error in string msg Log an error message Parameters msg The error message warning void warning in string msg Log a warning message Parameters msg The warning message trace void trace in string category in string msg Log a trace message Parameters category The trace category msg The trace message 448 Interface OB WLogger Interface OB WLogger Operations local interface WLogger Logger The Orbacus message logger interface with support for wide strings winfo void winfo in wstring msg Log an informational message Parameters msg The message werror void error in wstring msg Log an error message Parameters msg The error message wwarning void warning in wstring msg Log a warning message Parameters msg The warning message wtrace void trace in wstring category in wstring msg Log a trace message Parameters category The trace category msg The trace message 449 CHAPTER D Logger Reference 450 In this appendix APPENDIX E Open Communications Interface Reference This appendix describes the interfaces for the Open Communication Interface This appendix contains the following sections Module OCI page 452 Module OCI IIOP page 487 CHAPTER E Open Comm
453. rbacus lib OBNotify jar Note that the console application also requires OB jar OBEvent jar and OBUtil jar from Orbacus for Java distribution Assuming these files are in the same directory aS OBNotify jar the console can be started as follows Unix CLASSPATH usr local 1lib OB jar usr local lib OBEvent jar usr 1 ocal lib OBUtil jar usr local lib OBNotify jar CLASSPATH export CLASSPATH java com ooc CosNotifyConsole Main ORBconfig tmp ob conf Windows set CLASSPATH C Orbacus lib OB jar C Orbacus lib OBEvent jar C Orbacus lib OBUtil jar C Orbacus lib OBNotify jar CLASSPATH java com ooc CosNotifyConsole Main ORBconfig C temp ob conf 685 CHAPTER 2 Configuration and Startup Figure 1 shows a screenshot of the console right after startup Fs ORBacus Notify Console Event Channel Factory 0 Filter Factory 0 Figure 1 Starting the Orbacus Notify Console 686 In this chapter CHAPTER 3 Notification service Concepts This chapter describes the Orbacus Event and Notification Services This chapter contains the following sections Overview page 688 The OMG Event Service page 690 The OMG Notification Service page 697 687 CHAPTER 3 Notification Service Concepts Overview In general CORBA communications are synchronous A client obtains a reference to a target object invokes a request on that object and blocks while waiting for a reply
454. rce code compatible with Java we recommend that you provide your own termination method for your thread classes As an example let s visit our CharacterBuf fer class once more We now want to have a separate thread which waits for 80 characters to become available It then prints these 80 characters on standard output resets the buffer s contents and starts over again The thread should only stop if a terminate method is called on the CharacterBuffer Class We can write this class as follows 1 class CharacterBuffer public JTCMonitor public JTCThread 2 3 char data_ 4 int max 5 int len_ 6 bool done_ 7 G jowloilsies S 0 CharacterBuffer i data_ 0 len_ 0 max_ 0 done_ false 2 3 4 5 CharacterBuffer 6 7 delete data_ 8 g 605 CHAPTER 3 Working With Threads 606 20 Zil BE BS 24 25 26 27 28 BY 30 Shik 32 33 34 35 36 3y 38 39 40 fs fy PS TE ES a PS COO MOANA UU PWN FE O x o BO S o e O O Or OT YH WH UW PI a ORO 00 SP Oy OF a D w 64 void addChar char c JTCSynchronized synchronized this if len_ gt max_ char newData new char len_ 128 memcpy newData data_ len_ delete data_ data_ newData max_ 128 Gletica _ eio_srr ep if len_ gt 80 DOLEC virtual void run JTCSynchronized synchronized senis while true while done_ amp amp len_ lt 80 Ery wait catch
455. re now thread safe Instead of declaring the operations as synchronized as is done in Java the functions first create an instance of JTCSynchronized with the CharacterBuffer sS monitor object as argument So all that has to be done to translate a thread safe i e synchronized Java class to a thread safe JThreads C class is to Derive the class from gtcMonitor Replace synchronized methods by methods which contain JTCSynchronized synchronized this as the first statement in the function body That s quite easy isn t it 593 CHAPTER 3 Working With Threads Block Synchronization Code blocks Java not only supports synchronized methods but also synchronized code blocks For example let s assume that we want to write a thread class whose run method puts a string into a CharacterBuffer object using addchar In Java this could be written as follows 1 class Writer extends Thread 2 i 2 private CharacterBuffer buffer_ 4 private String stri 5 6 public Writer CharacterBuffer buffer String str 7 8 buffer_ buffer 3 str stry 0 T 2 public void run 3 4 monone a OQ gp a lt Siew lamoen pg wars 5 buffer_ addChar str_ characterAt i 6 Ute 1 A writer Class is defined which inherits from Thread 6 10 The constructor initializes the buffer_ and str_ data members 12 16 The thread s run method puts the string str_ into the buffer character by character using the buffers add
456. reads The Join and IsAlive Methods Waiting for threads to terminate In some applications it is necessary to explicitly wait for threads to terminate For instance if a set of threads is performing a complex parallel calculation the application may have to wait for the calculation to be completed before continuing As an example let s assume that we want the main function of our Hello World program from Chapter 2 to wait for the Hel1loWorld thread to terminate One way this can be done is as follows i aloe A mera Slide aae Cloieie o Sul 4 JICInitialize initialize 5 JTCThreadHandle t new HelloWorld 6 i S SEENE y while t gt isAlive 8 9 return 0 iLO F 5 It is absolutely necessary to use JTCThreadHandle instead of JTcThread here See Introducing Handles on page 613 for more information For now let s just think of a JTcThreadHandle as if it would be a typedef for JTCThread 7 8 The isAlive method is used to wait for the thread to terminate isAlive returns true if the thread is alive that is if it was started and not yet terminated or false otherwise 608 The Join and IsAlive Methods The code above has the obvious problem of busy looping which should be avoided at all costs Fortunately there is alternative approach join can be used for this purpose This method waits for the thread to terminate and then returns aLigte maim ING BUCS ehars aaco J ICInitialize
457. readyExists POAManager create_POAManager in string id in CORBA Policylist policies raises ManagerAlreadyExists CORBA PolicyError POAManagerSeq list POAManager find in string id local interface POA readonly attribute POAManagerFactory the_POAManagerFactory Using POA Managers Creating a POA Manager 2 6 7 16 The example below illustrates how to create a new POA Manager using the POA Manager Factory For this example an empty policy list is used Here is an example in C LO Oo lo OO Be WH NM H N oO MOHAN HA UB A S E OO Hl Cae CORBA Object_var poaObj orb gt resolve_initial_references RootPOA OBPortableServer POA_var rootPOA OBPortableServer POA _narrow poaOb POAManagerFactory_var factory rootPOA gt the_POAManagerFactory OBPortableServer POAManagerFactory_var pmFactory OBPortableServer POAManagerFactory _narrow factory POAManager_var myPOAManager Pol veya ac ply Ery myPOAManager pmFactory gt create_POAManager MyPOAManager pl catch const POAManagerFactory ManagerAlreadyExists amp ex do something Resolve the POA Manager Factory Create a new POA Manager with the name MyPOAManager 81 CHAPTER 4 ORB and Object Adapter Initialization 82 2 9 10 17 And in Java 1 Java 2 org omg CORBA Object obj 2 orb resolve_initial_references RootPOA 4 org omg PortableServer POA rootPOA
458. reate_channel TelemetryData 251 CHAPTER 12 Orbacus Events 252 Here is the same example in Java Java org omg CORBA Object obj orb string_to_object corbaloc myhost 2098 DefaultEventChannelFactory com ooc OBEventChannelFactory EventChannelFactory factory com ooc OBEventChannelFactory EventChannelFactoryHelper narrow obj org omg CosEventChannelAdmin EventChannel channel factory create_channel TelemetryData Programming Example Programming Example In the Event Service example that comes with Orbacus two supplier and two consumer clients demonstrate how to use an untyped event channel to propagate information The pieces of information transferred by this example are strings containing the current date and time After starting the Event Service server you can start these clients in any order The demo applications obtain the initial Event Service reference as already demonstrated i e by calling resolve_initial_references When started each supplier provides information about the current date and time and each client displays the event data in its console window This is the push supplier s main loop 1 Java 2 while consumer_ null 3 4 java util Date date new java util Date 5 String s PushSupplier says date toString 6 7 Any any orb_ create_any 8 any insert_string s s 0 EEY il 2 consumer_ push any 3 4 catch Disconnected ex 5 6
459. receiver threads are not shown fO g0 h gt _ gt EX AS i a at al IO 4 Client Thread Pool Server Figure 14 Thread Pool Server The first three operation calls g and h can be carried out immediately since there are three threads in the pool However the fourth request i is delayed until at least one of the other requests returns Since there is no time consuming thread creation the thread pool concurrency model performs better than the thread per request model The thread pool is a good trade off if on the one hand frequent thread creation and destruction result in unacceptable performance but on the other hand delaying the execution of concurrent method calls is also not desired Leader_Follower Multi Threaded Concurrency Models In the Leader Follower concurrency model each thread from the thread pool will transition between the following states e leader e processing e follower The leader thread of which there can only be one at any given time waits for incoming requests When a request is received the leader thread will promote a new leader while it goes into the processing state to handle the received requests Once processing is complete the thread is absorbed back into the pool where it waits to be promoted again While in the waiting state the thread is said to be a follower In this model it is possible to have multiple threads
460. rectly overridden to return the appropriate POA if the servant is not activated with the Root POA The call to servant_to_id on the servant s POA returns the object ID with which the servant is activated The call to deactivate_object breaks the association between the CORBA object and the servant Note that deactivate_object returns immediately even though the servant may still be executing requests possibly in a number of different threads Deactivation of a servant in Java is analogous to C Java org omg PortableServer POA poa impl _default_POA byte id poa servant_to_id impl poa deactivate_object id BUNE A POA has either the TRANSIENT or the PERSISTENT policy value A transient POA generates transient object references A transient object reference remains functional only for as long as its POA remains in existence Once the POA for a transient reference is destroyed the reference becomes Deactivating Servants permanently non functional and client requests on such a reference raise either OBJECT_NOT_EXIST Of TRANSIENT depending on whether or not the server is running at the time the request is sent Transient references remain non functional even if you restart the server and re create a transient POA with the same name as was used previously Transient POAs almost always use the sySTEM_tD policy as a matter of convenience although the combination of TRANSIENT and USER_ID is legal Object refe
461. rences created on a persistent POA continue to be valid beyond the POA s life time That is if you create a persistent reference on a POA destroy the POA and then recreate that POA again with the same POA name the original reference continues to denote the same CORBA object even if the server was shut down and restarted Persistent references require the same POA name and object ID to be used to denote the same object This means that persistent references rely on the combination of PERSISTENT and USER_ID USER_ID must be used in conjunction with NO_IMPLICIT_ACTIVATION SO servants for persistent references are always activated explicitly 113 CHAPTER 5 CORBA Objects Factory Objects 114 It is quite common to use the Factory 2 design pattern in CORBA applications In short a factory object provides access to one or more additional objects In CORBA applications a factory object can represent a focal point for clients In other words the object reference of the factory object can be published in a well known location and clients know that they only need to obtain this object reference in order to gain access to other objects in the system thereby minimizing the number of object references that need to be published The Factory pattern can be applied in a wide variety of situations including the following e Security A client is required to provide security information before the factory object will allow the clien
462. rent current 5 com ooc OCI CurrentHelper narrow baseCurrent 6 vi com ooc OCI TransportiInfo info current get_oci_transport_info 8 com ooc OCI IIOP TransportInfo iiopInfo S com ooc OCI IIOP TransportInfoHelper narrow baseInfo 0 Ll ff iiopinto null 2 3 int remoteAddr Converter addr iiopInfo remote_addr 4 int remotePort Converter port iiopInfo remote_port 5 6 Sacrat ate eae DIAC nn E a Wl remoteAddr 0 8 remoteAddr 1 remoteAddr 2 20 remoteAddr 3 remotePort Zi 2 11 This code is equivalent to the C version 13 14 Again the port number must be converted from short to int 16 20 This is also equivalent to the C version 372 OCI Reference Determining a Server s IP Address To determine the server s IP address and port that an object will attempt to connect to the following code can be used i ff CF 2 CORBA Object_var obj Get an object reference somehow 2 4 OCI ConnectorInfo_var info obj gt get_oci_connector_info 5 OCi IIOP ConnectorInfo_var iiopInfo 6 OCI TIOR IC onneceormin Orr miiciersew duato i 7 8 if CORBA is_nil iiopInfo OY Ff 0 OCI IIOP InetAddr_var remoteAddr iiopInfo gt remoteAdar i CORBA UShort remotePort iiopInfo gt remote_port 2 3 cowe lt lt Will connect to 4 lt lt ieesnitoceyNelohe 0 lt lt lt lt remotetddriz2 lt lt 5
463. ress and port The no loopback option for multicast communication is to be specified on the client side for Unix systems and on the server side for Windows systems The UDP plug in supports the following command line options UDPbind ADDR Equivalent to the bind endpoint option UDPhost ADDR ADDR Equivalent to the host endpoint option The UDP OCI Plug in UDPmulticast Equivalent to the multicast endpoint option UDPnumeric Equivalent to the numeric endpoint option UDPport N Equivalent to the port endpoint option See Command line Options and Endpoints on page 85 for more information on the behavior of command line options 385 CHAPTER 19 The Open Communications Interface Static Linking 386 When statically a C application an explicit reference must be made to the UDP plug in in order to include the plug in s modules Shown below is the technique used by the sample programs in the udp demo subdirectory Note that the code below is enclosed in guard macros that are only activated when statically linking These macros are appropriate for both Unix and Windows First extra include files are necessary if defined HAVE_SHARED amp amp defined OB_DLL include lt OB OCI_init h gt include lt OB OCI_UDP_init h gt endif Next the plug in must be registered prior to calling oRB_init if defined HAVE_SHARED amp amp defin
464. rface for converting object references to and from strings IDL module CORBA interface ORB string object_to_string in Object obj Object string_to_object in string ref Using stringified object references is the simplest way of bootstrapping your first object reference In short the server must create a stringified object reference for an object and make the string available to clients A client obtains the string and converts it back into an object reference and can then invoke on the object The examples discussed in the sections below are based on the IDL definitions presented at the beginning of this chapter 134 Using a File 3 5 Stringified Object References One way to publish a stringified object reference is for the server to create the string using object_to_string and then write it to a well known file Subsequently the client can read the string from the file and use it as the argument to string_to_object This method is shown in the following C and Java examples First we ll look at the relevant server code dil Cae CORBA ORB_var orb Get a reference to the ORB somehow B_imp1 bImlp new B_impl PortableServer ServantBase_var servant bImpl BEvari by OIM E RSO CORBA String_var s orb gt object_to_string b ofstream out object ref out lt lt s lt lt endl out close SO lt OF On wa G ho E A servant for the interface B is cr
465. rithms BAD_CIPHER const Cipher BAD_CIPHER 0 Identifies an invalid cipher CONTEXT_POLICY const CORBA PolicyType CONTEXT_POLICY 100 Identifies the ContextPolicy DHE_DSS_EXPORT_WITH_DES40_CBC_SHA const Cipher DHE_DSS_EXPORT_WITH_DES40_CBC_SHA 14 Key Exchange Algorithm DHE_DSS Symmetric Encryption Algorithm DES 40 MAC Encoding SHA DHE_DSS_ WITH_3DES EDE_CBC_SHA const Cipher DHE_DSS_WITH_3DES_EDE_CBC_SHA 16 565 CHAPTER C FSSL Reference 566 Key Exchange Algorithm DHE_DSS Symmetric Encryption Algorithm DES 168 MAC Encoding SHA DHE_DSS_WITH_DES CBC_SHA const Cipher DHE_DSS_WITH_DES_CBC_SHA 15 Key Exchange Algorithm DHE_DSS Symmetric Encryption Algorithm DES 56 MAC Encoding SHA DHE_RSA_EXPORT_WITH_DES40_CBC_SHA const Cipher DHE_RSA_EXPORT_WITH_DES40_CBC_SHA 11 Key Exchange Algorithm DHE_RSA MAC Encoding SHA DHE_RSA_WITH_3DES_EDE_CBC_SHA const Cipher DHE_RSA_WITH_3DES_EDE_CBC_SHA 13 Key Exchange Algorithm DHE_RSA Symmetric Encryption Algorithm DES 168 MAC Encoding SHA DHE_RSA_WITH_DES_CBC_SHA const Cipher DHE_RSA_WITH_DES _CBC_SHA 12 Key Exchange Algorithm DHE_RSA Symmetric Encryption Algorithm DES 56 MAC Encoding SHA DH_anon_EXPORT_WITH_DES40 CBC_SHA const Cipher DH_anon_EXPORT_WITH_DES40_CBC_SHA 19 Key Exchange Algorithm DH Symmetric Encryption Algorithm DES 40 MAC Encoding SHA DH_anon_EXPORT_WITH_RC4_40 MD5 const Cipher DH_anon_EXPORT_WITH_
466. roperties PropertySeq get_properties Get the property set of the strategy push_load void push_load in MemberId member_id in unsigned long load raises MemberNotFound StrategyNotAdaptive Update the load of a member 501 CHAPTER F Orbacus Balancer Reference Interface LoadBalancing Group Operations 502 interface Group Represents a load balanced group get_id GroupId get_id Get the id of the load balanced group get_ior Object get_ior in string repository_id in ObjectId oid Get an IOR for use by a client of this load balanced group get_strategy proxy StrategyProxy get_strategy_proxy Get the strategy proxy of the load balanced group set_strategy void set_strategy in string name in PropertySeq properties raises StrategyNotFound InvalidProperties Use the specified built in load balancing strategy set_custom_strategy void set_custom_strategy in Strategy the_strategy Use the given custom load balancing strategy add_member void add_member in MemberId member_id raises MemberExists Add a member to the load balanced group remove_member void remove_member in MemberId member_id raises MemberNotFound Remove a member of the load balanced group set_load_alert void set_load_alert in MemberId member_id Module LoadBalancing in LoadAlert alert raises MemberNotFound Set the LoadAlert object for a member list_members MemberIdSeq
467. rror_code code PropertyName name PropertyRange available_range Structure to indicate a property error for the name property and if applicable a suitable range of values FixedEventHeader struct FixedEventHeader EventType event_type string event_name Structured event fixed header Members event_type Categorizes the event event_name A name given to this event instance to differentiate it from other events of the same type EventHeader struct EventHeader FixedEventHeader fixed_header OptionalHeaderFields variable_header Structured event header Members fixed_header Categorizes and names the event variable_header Optional header information This may contain any name value pair that the user chooses Standard values are related to per event QoS settings StructuredEvent struct StructuredEvent EventHeader header Exceptions Enums Module CosNotification FilterableEventBody filterable_data any remainder_of_body The StructuredEvent Type Events transmitted in this form are subject to filtering UnsupportedQoS exception UnsupportedQoS PropertyErrorSeq gos_err This exception is raised when a channel or channel component cannot satisfy a client s QoS request Members qos_err Contains a list of the rejected QoS settings along with reason for rejection and suitable property values if applicable UnsupportedAdmin exceptio
468. rs init_server void init_server in ParamSeq params Initialize the server side of the plug in Parameters params Plug in specific parameters Module OCI Interface OCI Transport Synopsis Attributes Operations local interface Transport The interface for a Transport object which provides operations for sending and receiving octet streams In addition it is possible to register callbacks with the Transport object which are invoked whenever data can be sent or received without blocking See Also Interface OCI Connector Interface OCI Acceptor id readonly attribute PluginId id The plugin id tag readonly attribute ProfilelId tag The profile id tag mode readonly attribute SendReceiveMode mode The send receive capabilities of this Transport handle readonly attribute Handle handle The handle for this Transport The handle may only be used to determine whether the Transport object is ready to send or to receive data e g with select on Unix based operating systems All other uses e g calls to read write close are strictly non compliant A handle value of 1 indicates that the protocol plug in does not support selectable Transports close void close Closes the Transport After calling close no operations on this Transport object and its associated TransportInfo object may be called To ensure that no messages get lost when close is calle
469. rs and regular filters both have a list of constraints e within each constraint there is a constraint expression and list of event types When a mapping filter is applied to an event each constraint is checked until a match is found or there are no more constraints If there is a match then the value stored in the Va ue field of the matching constraint is returned to the proxy This value is used instead of the actual value for the event property If there is no match then the property value contained in the event is used unless the event does not specify this property in which case the mapping filter Default Value is used For this reason mapping filters can only be added to proxy suppliers and consumer admin objects 707 CHAPTER 3 Notification Service Concepts 708 Mapping Filter Default Value Constraint Value Event Types domain name type name domain name type name Constraint Expression Constraint Value Event Types domain name type name domain name type name Constraint Expression Figure 14 Mapping Filter Composition Quality of Service Overview Persistence The OMG Notification Service The Notification Service defines standard interfaces for controlling the QoS characteristics of event delivery QoS is specified on a per event
470. rted on the same host and port and that the object keys in the object references will continue to be valid The same is true of peer IDs If you want a bi directional IIOP object reference to remain valid across process restarts you must use the same peer ID host port and object key Conversely if an object reference is transient then the peer ID can vary along with the host port and object key 391 CHAPTER 19 The Open Communications Interface Client Installation 392 The client side bi directional plug in is installed as shown below ooc oci client ID options bidir protocol ID The following options are supported protocol ID Specifies the identifier of the underlying plug in This parameter is required Because the bi directional plug in is layered on another plug in the underlying plug in must be installed first For example to install bi directional IIOP the IIOP plug in is installed first and then the bi directional plug in is installed ooc oci client iiop bidir protocol iiop Note that a bi directional application generally needs to install both the client and server side plug ins Server Installation The Bi directional OCI Plug in The server side bi directional plug in is installed as shown below ooc oci server ID options bidir protocol ID The following options are supported protocol ID Specifies the identifier of the underlying plug in This par
471. rver for the first time using this database you must also use the s command line option 189 CHAPTER 9 Orbacus Names 1 COUNT limit COUNT Limits the number of bindings returned in the binding list by a call to list to COUNT bindings Using this option can reduce the memory requirements of the server t MINS timeout MINS Specifies the timeout in minutes after which a persistent server automatically compacts its database The default timeout is five minutes cC SECS callback timeout SECS Specifies the timeout in seconds to be used for the Orbacus timeout policy oB TimeoutPolicy The default timeout is five seconds See Chapter 16 for more information CLASSPATH Requirements 190 Orbacus Names for Java requires the classes in oB jar and OBNaming jar Windows NT Native Service Windows NT Native Service The C version of Orbacus Names is also available as a native Windows NT service ntnameservice h help i install s start install u uninstall d debug h Display the command line options supported by help the server i Install the service The service must be started asin manually s Install the service The service will be started start insta automatically u Uninstall the service uninstall d Run the service in debug mode debug In order to use the Naming Service as a native
472. ry Model e Push e Pull e Client Type Any e Structured e Sequence Push Pull Callback on Disconnect Yes Implement Supplier y gt Connect to Proxy Consumer Figure 17 Connecting a Supplier to a Notification Channel 726 Connecting to a Notification Channe Supplier Admin The first step in connecting a supplier is to obtain a supplier admin object All event channels come with two read only attributes default_supplier_admin and default_consumer_admin fae In interface EventChannel readonly attribute ConsumerAdmin default_consumer_admin readonly attribute SupplierAdmin default_supplier_admin This example uses the default admin objects ii Ce CosNotifyChannelAdmin SupplierAdmin_var supplierAdmin eventChannel gt default_supplier_admin Java SupplierAdmin supplierAdmin eventChannel default_supplier_admin Supplier applications may also create a new supplier admin using the following ve IDL EventChannel SupplierAdmin new_for_suppliers in InterFilterGroupOperator op out AdminID id 727 CHAPTER 4 Programming Example Proxy Consumer 728 or use an admin with a given Adminip Note that Admintp is a unique ID assigned by Orbacus Notify jf IDG EventChannel SupplierAdmin get_supplieradmin in AdminID id raises AdminNotFound hi The next step in connecting to an event channel is to ob
473. s Java org omg PortableServer POAManager poaManager com ooc FSSL FSSL create_poa_manager RootPOAManager orb fsslManager id props Determining Peer Identity The FSSL Current interface can be used if the server needs to determine the identity of the peer that invoked the current operation First a reference to the FSSL Current object must be retrieved Hl Chest FSSL Current_var fsslCurrent FSSL Current _narrow CORBA Object_var orb gt resolve_initial_references FSSLCurrent Java com ooc FSSL Current fsslCurrent com ooc FSSL CurrentHelper narrow orb resolve_initial_references FSSLCurrent Now the FSSL Current get_peer_certificate_chain can be used to determine the identity of the caller Ht Case FSSL CertificateSeq_var chain fsslCurrent gt get_peer_certificate_chain Java com ooc FSSL X509Certificate chain fsslCurrent getPeerCertificateChain 532 Server Side Usage The negotiated cipher can also be determined using the FSSL current object Ue Crt FSSL Cipher cipher fsslCurrent gt get_peer_cipher Java com ooc FSSL Cipher cipher fsslCurrent get_peer_cipher If this method is called outside of the context of a server method invocation a FSSL Current NoContext exception is raised If the current connection is not an SSL connection then a FssL Current NoPeer exception is raised 533 CHAPTER 2 Extending the
474. s Client Side Usage Therefore to associate a context policy with every object reference created by the ORB the policy should be set on the ORB Policy Manager Ii Cast CORBAR TROIE ELS ERPIN II pl length 1 pl 0 contextPolicy policyManger gt add policy_overrides pl Java org omg CORBA Policy pl new org omg CORBA Policy 1 pl 0 contextPolicy policyManager add_policy_overrides pl Once object references have been created it is possible to create a new object reference with a different set of associated policies by calling set_policy_overrides on the object reference In Java set_policy_overrides is not actually called on the object but on a delegate created from the object Uy Crt CORBA PolicyList pl 1 pl length 1 pl 0 contextPolicy CORBA Object_var obj myObj gt _set_policy_overrides pl CORBA ADD_OVERRIDE Java org omg CORBA Policy pl new org omg CORBA Policy 1 pl 0 contextPolicy com ooc CORBA Delegate delegate com ooc CORBA Delegate org omg CORBA portable Object Impl myObj _get_delegate org omg CORBA Object obj delegate set_policy_overrides pl org omg CORBA SetOverrideType ADD_OVERRIDE Once set_policy_overrides has been called the returned object reference will have a new set of associated policies Note that the original object reference is not affected A thread of execution in the application may have an associated set
475. s IOR dialog window as shown in Figure 5 The IOR can be entered directly Enter IOR x TargetlOR From File Browse Figure 5 Entering an IOR or can be read from a file If an IOR is entered manually you usually either use the URL style notation as described in Chapter or you copy a stringified object reference into the dialog box using Cut amp Paste After selecting Browse a file containing an IOR can be selected Sometimes it is not desirable to completely replace the currently visible root context by another root context For example you may need to copy bindings from one context to another If this is the case simply open an additional window for the new root context using New Window You can then switch the root context in only one window without affecting the information displayed in the other one Using two windows you can easily transfer bindings from one context to another using Cut amp Paste Complete naming contexts can be loaded from a special file with naming context information Such a file which was previously created with Save Context As is loaded with Load Context The bindings saved to this file are added to the current naming context When saving a naming context the console checks each context for accessibility If a context cannot be accessed i e if its contents cannot be saved a message is displayed in the error window You also get an error message if the console det
476. s MappingConstraintInfoSeq get_mapping_constraints in ConstraintIDSeq id_list raises ConstraintNotFound Retrieves a set of constraint value pairs from the target filter object Parameters id_list A list of constraint IDs representing the constraint value pairs to be retrieved Returns The constraint value pairs associated with the target filter object with the given IDs If one or more of the IDs are not found the const raintNotFound exception is raised 863 CHAPTER F CosNotifyFilter Reference 864 get_all_mapping_ constraints MappingConstraintInfoSeq get_all_mapping_constraints Retrieve all constraint value pairs associated with the target filter object Returns All constraint value pairs associated with the target filter object remove_all_mapping_constraints void remove_all_mapping_constraints Remove all constraint value pairs associated with the target filter object destroy void destroy Destroys the target filter object match boolean match in any filterable_data out any result_to_set raises UnsupportedFilterableData Compare the filter constraints from the target filter object with the supplied event Parameters filterable_data The event to be evaluated in the form of a CORBA Any result_to_set If the match is successful that is the return result is TRUE this parameter is set to the value paired with the matching constraint Otherwise if the match fails that is
477. s O which produces no output Value evel gt O Defines the output level for diagnostic messages printed by Orbacus that are related to transparent re sending of failed messages A level of 1 or higher produces information about re sending of messages and a level of 2 or higher also produces information about use of individual IOR profiles The default level is O which produces no output OA Properties Overview ooc orb oa conc_model Configuring the ORB and Object Adapter Configuring an object adapter is achieved by setting properties on POA Managers These properties are grouped into two categories global properties and properties specific to a particular POA Manager Global properties have the prefix ooc orb oa while properties specific to a particular POA Manager have the prefix ooc orb poamanager name where name is the name of the POA Manager see Using POA Managers on page 77 Unless otherwise noted a POA Manager will search for configuration properties using the following algorithm e First use properties defined specifically for that POA Manager e Next use global properties e Finally use default settings See Using POA Managers on page 77 for more information on POA Managers Value reactive threaded thread_per_client thread_per_request thread_pool leader_follower Selects the server side concurrency model The default value is thread_per_client The reactive and leader_followe
478. s executed until there are at least 80 characters available 8 wait is called just in the same way as in the Java example This releases the monitor lock which was acquired with the synchronization through the JTCSynchronize Class and waits for notification 602 The Wait Notify and NotifyAll Methods 5 9 The equivalent to java lang InterruptedException is the JThreads C exception JTCcInterruptedException 1 void addChar char c Zee 3 JTCSynchronized synchronized this 4 if len_ gt max_ 5 6 char newData new char len_ 128 fi memcpy newData data_ len_ 8 delete data_ S data_ newData 10 max_ 128 1i 12 data_ len_ c 13 if len_ gt 80 14 AEE AS Y 3 addChar is made synchronized 12 13 notify s called if 80 characters are available waking a waiting thread As you can see the semantics of wait notify and notifyAll in JThreads C are exactly the same as in Java 603 CHAPTER 3 Working With Threads The Stop and Suspend Methods Terminating and suspending execution of a thread Control Points Implementing a Thread Termination Method 604 We have already introduced the start method of the JTCThreaa class The opposite of start is stop which terminates the execution of a thread Besides stop there is also a suspend method which suspends the execution of a thread until resume is called stop and suspend do not terminate or suspend a thread immedia
479. s related to communications with the OADs The default level is O which produces no output ooc imr trace process_control level gt 0 Defines the output level for IMR diagnostic messages related to the forking and death of server processes The default level is O which produces no output ooc imr trace server_status level gt 0 Defines the output level for IMR diagnostic messages related to the status of servers and POAs The default level is O which produces no output 168 Connecting to the Service Connecting to the Service Servers that use the IMR must be configured with the IMR initial reference The object key of the IMR is mmr hence a URL style object reference of the IMR service running on host imrhost at port 10000 would be corbaloc imrhost 10000 IMR Using this object reference a server can configure the IMR initial reference with the property ooc orb service IMR corbaloc imrhost 10000 IMR An alternative to using the above property is to use the oRBInitRef command line option Refer to Chapter 6 for more information on URLs and configuring initial services 169 CHAPTER 7 The Implementation Repository Utilities Implementation Repository Administration 170 The imradmin utility provides complete control over the IMR OADs and servers in a domain Its command interface is shown below h help Display this information add oad host Register an OAD for
480. s to simply let the ORB block while sending and receiving messages Another model is to let the ORB do some work while sending and receiving messages for example to receive user input through a keyboard or a GUI or to simply transfer buffered messages Multi threaded concurrency models describe how the ORB makes use of multiple threads for example to send and receive messages in the background Multi threaded concurrency models also describe how several threads can be active in the user code and the strategy the ORB employs to create these threads There is no one size fits all approach with respect to concurrency models Each concurrency model provides a unique set of properties each having advantages and disadvantages For example applications using callbacks must have a concurrency model that allows nested method invocations to avoid deadlocks Other applications must be optimized for speed in which case a concurrency model with the least overhead will be chosen Some ORBs are highly specialized providing only the most frequently used concurrency models for a specific domain Orbacus takes a different approach by supporting several concurrency models Orbacus allows different concurrency models to be established for the client and server activities of an application The client side concurrency models are Reactive and Threaded The server side concurrency models are Reactive Threaded Thread per Client Thread per Reque
481. s using the imradmin utility imradmin ORBInitRef IMR corbaloc master 10000 IMR add server Serverl usr local bin serverl slavel imradmin ORBInitRef IMR corbaloc master 10000 IMR add server Server2 usr local bin server2 slave2 Next we set the server arguments imradmin ORBInitRef IMR corbaloc master 10000 IMR set server Serverl args ORBInitRef IMR corbaloc master 10000 IMR imradmin ORBInitRef IMR corbaloc master 10000 IMR set server Server2 args ORBInitRef IMR corbaloc master 10000 IMR A C server can automatically register itself with the IMR using the ORBregister command line option For example to registered Server1 run the following on slavel usr local bin serverl ORBregister Serverl ORBInitRef IMR corbaloc master 10000 IMR If the server requires command line options then these options must be added using the imradmin utility Add each POA to the IMR In this example the servers are registered without setting the activate_poas attribute so the attribute defaults to true Hence all Getting Started with the Implementation Repository persistent POAs will be registered automatically If this were not the case the POAs would have to be registered manually 7 Configure your servers to use the IMR There are three ways to configure a server to use the IMR i Use the orBregister command line option only available for C servers This option is us
482. sEventChannelAdmin SupplierAdmin while consumers will want a CosEventChannelAdmin ConsumerAdmin e Obtain the appropriate proxy from the admin as summarized in Table 2 Table 2 Proxy Selection Event Service Client Type Required Proxy Type push supplier CosEventChannelAdmin ProxyPushConsumer pull supplier CosEventChannelAdmin ProxyPullConsumer 1 This diagram is for an untyped event channel A similar structure exists for typed event channels The OMG Event Service Table 2 Proxy Selection Event Service Required Proxy Type Client Type push consumer CosEventChannelAdmin ProxyPushSupplier pull consumer CosEventChannelAdmin ProxyPullSupplier e Connect to the proxy Note Alternatively Event Service clients may obtain an object reference from a naming service for example to any of the Event Service objects and then obtain and connect to the proxy The proxy depending on its type has methods which support the push and pull of events by suppliers and consumers 695 CHAPTER 3 Notification Service Concepts Event Delivery 696 Untyped event delivery in the event service is via a CORBA Any That is the event data is unknown to the channel The proxy interfaces require suppliers to insert event data into a CoRBA Any before the event is pushed on or pulled by the channel Similarly for consumers all pulled and pushed events are contained withi
483. sNotifyChannelAdmin ProxySupplier CosNotifyComm SequencePushSupplier The SequenceProxyPushSupplier interface manages connections from consumers who wish to have sequences of structured events pushed on them by the channel connect_sequence_push_consumer void connect_sequence_push_consumer in CosNotifyComm SequencePushConsumer push_consumer raises CosEventChannelAdmin AlreadyConnected CosEventChannelAdmin TypeError Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters push_consumer A reference to the consumer object A nil reference is not permitted suspend_connection void suspend_connection raises ConnectionAlreadyInactive NotConnected This operation causes the target object to stop pushing events to the connected consumer If the connection is already suspended the Connect ionAlreadyInactive exception is raised If the target object is not connected to a supplier the NotConnected exception is raised resume_connection void resume_connection raises ConnectionAlreadyActive NotConnected This operation causes the target object to resume pushing events to the connected consumer If the connection is not suspended the Connect ionAlreadyActive exception is raised If the target object is not connected to a supplier the NotCconnected exception is raised 825 CHAPTER D CosNotifyChannelAdmin Reference Interface Cos
484. sNotifyFilter Raised during the addition or modification of constraints if the new constraint does not conform to the specified grammar for the target filter object DuplicateConstraintID exception DuplicateConstraintID ConstraintID id Not used ConstraintNotFound exception ConstraintNotFound ConstraintID id Raised when an operation cannot find a constraint with the given ID CallbackNotFound exception CallbackNotFound Raised when an operation cannot find a callback with the given ID InvalidValue exception InvalidValue ConstraintExp constr any value Raised if the datatype of a value in an input constraint value pair does not match the value_type for the target mapping filter object FilterNotFound exception FilterNotFound Indicates that a reference for a specified filter was not found 857 CHAPTER F CosNotifyFilter Reference Interface CosNotifyFilter Filter interface Filter The Filter interface manages groups of filter constraint expressions and has operations which evaluate events against these constraints Attributes constraint_grammar readonly attribute string constraint_grammar The constraint grammar specified during creation of the filter All constraints for the target filter object must be expressed in this grammar Operations add_constraints ConstraintInfoSeq add_constraints in ConstraintExpSeq constraint_list raises Inva
485. sPhrase foobar myTrustDecider com ooc FSSL FSSL get_RSA_ciphers This example defines the certificate chain for the server The server s X 509 certificate will be obtained from the file server der This certificate is authenticated by the certificate in the file CAcert der The private key of the server s certificate is contained in the file serverkey der and is decrypted using the passphrase foobar In a real application it wouldn t be prudent to store the certificate s passphrase in plain text Typically the pass phrase should be requested from the user Once a context has been created the next step is to call FSSL create_poa_manager to initialize the server side of the FreeSSL connection You can configure the RootPOA s POAManager simply by creating a POAManager name RootPOAManager Keep in mind that this step must be done prior to resolving the RootPOA initial reference otherwise the RootPOAManager will have already been created with the default configuration The third and fourth arguments to FSSL create_poa_manager are the reference to the FSSL Manager and a 531 CHAPTER 2 Extending the Hello World Application ContextID which should be associated with the POAManager to be created The associated ContextID identifies the SSL identity the server will use when establishing connections A Cre PortableServer POAManager_var poaManager FSSL create_poa_manager RootPOAManager orb fsslManager id prop
486. sed and the thread waits for notification by another thread via a call to either notify or notifyAl11 or until timeout milliseconds have passed The thread then waits until it can regain ownership of the monitor s lock and then resumes execution Parameters timeout The maximum number of milliseconds to wait for notification Throws JTCIllegalMonitorStateException If the monitor is not locked by the calling thread JTCSystemCallException Indicates a failed system call 640 notify void notify Wakes a single thread waiting on the monitor The calling thread must own the monitor s lock notifyAll void notifyAll Wakes all threads waiting on the monitor The calling thread must own the monitor s lock 641 CHAPTER A Class Reference JTCRecursiveMutex Overview Member Functions 642 This class can be used to establish a critical section This class has no direct equivalent in Java and is provided for performance reasons only An instance of JTCRecursiveMutex can be locked multiple times by the same thread and therefore may not be as efficient as the JTCMutex class The developer is responsible for ensuring that each mutex lock has a corresponding unlock lock bool lock const Lock the mutex If the mutex is already locked the calling thread blocks until the mutex is unlocked If the current owner of the mutex attempts to re lock the mutex a deadlock will not result Returns true if the m
487. ses in oB jar and OBProperty jar 226 Connecting to the Service Connecting to the Service The object key of the Property Service is PropertyService which identifies an object of type cosPropertyService PropertySetDefFactory The object key can be used when composing URL style object references For example the following URL identifies the Property Service running on host prophost at port 10000 corbaloc prophost 10000 PropertyService Refer to Chapter 6 for more information on URLs and configuring initial services 227 CHAPTER 11 Orbacus Properties Using the Property Service with the IMR The Property Service may be used with the Implementation Repository IMR However if used with the IMR it is important to note that the corbaloc URL style object reference described in the previous section cannot be used If the IMR is used then the object reference for the Property Service must be created using one of the following methods where PropertyServer refers to the server name configured with the IMR e Start the Property Service with the options ior ORBServerId PropertyServer causing the Property Service to print its reference to standard output e Use the mkref utility mkref PropertyServer PropertyService PropertyServicePOA When using the Property Service with the IMR the service must be started with the option ORBServerlId PropertyServer where PropertyServer refers to the server name co
488. short value raises CORBA PolicyError GlIOPVersionPolicy create_giop_version_policy in short value raises CORBA PolicyError These policies map to the POA Manager specific configuration properties coc orb poamanager Manager endpoint conc_model and version see OA Properties on page 65 For examples of how to use these policies refer to Using Policies on page 307 83 CHAPTER 4 ORB and Object Adapter Initialization Endpoints 84 Orbacus supports a flexible mechanism for configuring a POA Manager s endpoints via properties A single property is used to configure the endpoints for a particular POA Manager The property value consists of a comma separated list of endpoints with the following syntax plugin id options plugin id options For example ooc orb oa endpoint iiop port 9998 iiop port 9999 ooc orb poamanager MyManager endpoint iiop This configuration creates two IIOP endpoints for the Root POA Manager on specific ports and one IIOP endpoint for the POA Manager named MyManager on an arbitrary port Technically the second property isn t necessary because this is the default configuration if no endpoints are specified for a POA Manager It is important to note that only those transport plug ins which were installed via the ooc oci server property can be used in endpoint configuration When experimenting with various endpoint configurations it can be very
489. sing the Edit Destroy menu operation A confirmation is displayed before the admin is removed Note that destroying an admin also destroys all proxies associated with it Any filters created from the selected admin are not destroyed Rather the destroyed admin is removed from the filter s subscriber list 765 CHAPTER 5 Orbacus Notify Console Managing Proxies Creating a New Proxy Supplier and consumer proxies are created from an admin object Supplier admins control the creation of consumer proxies while consumer admins provide methods for the creation of supplier proxies In either case to create a proxy from the console choose the appropriate admin and select Edit Create The Filter Proxy Creation Wizard then steps through the creation of the proxy Proxy Properties QoS Properties Proxy QoS properties are configured in the Proxy Properties dialog displayed in Figure 29 E Any Pull Supplier 0 Properties QoS Properties Order Policy Priority Order v Discard Policy Any Order v Max Events per Consumer 0 Timeout msec 0 0 Priority 0 Request Timeout msec 5000 0 Figure 29 Proxy QoS Properties Choose a proxy from the Service Structure tree and select Edit Properties to display this dialog 766 Managing Proxies Mapping Filters Priority and lifetime mapping filters may be assigned to or removed from supplier proxy objects in the Mapping Filters tab of the Proxy Properties dialog
490. slates IDL to Java hidl Translates IDL to HTML ridl Translates IDL to RTF irgen Generates C from an Interface Repository 34 Translating IDL to C Translating IDL to C Synopsis idl options idl files Description Translates IDL files into C files For each IDL file four C files are generated For example idl MyFile idl produces the following files MyFile h Header file containing MyFile idi s translated data types and interface stubs MyFile cpp Source file containing Myrile ial s translated data types and interface stubs MyFile_skel h Header file containing skeletons for MyFile idi s interfaces MyFile_skel cpp Source file containing skeletons for MyFile idl s interfaces Options h help Show a short help message v version Show the Orbacus version number d debug Print diagnostic messages This option is for Orbacus internal debugging purposes only DNAME Defines name as 1 This option is directly passed to the preprocessor DNAME DEF Defines name as DEF This option is directly passed to the preprocessor UNAME Removes any definition for name This option is directly passed to the preprocessor IDIR 35 CHAPTER 3 Generating Code with Orbacus Adds the directory pir to the include file search path This option is directly passed to the preprocessor Runs the source files through the preprocessor without generating code
491. st 9999 Foo The first example is a URL for a bi directional IIOP callback endpoint The second example is a URL for a bi directional IIOP endpoint on host thehost and port 9999 CHAPTER 20 Exceptions and Error Messages CHAPTER 20 Exceptions and Error Messages CORBA System Exceptions The CORBA specification defines the standard system exceptions shown in the following table UNKNOWN Unknown exception type BAD_PARAM An invalid parameter was passed NO_MEMORY Failure to allocate dynamic memory IMP_LIMIT Implementation limit was violated COMM_FATLURE Communication failure INV_OBJREF Invalid object reference NO_PERMISSION The attempted operation was not permitted INTERNAL Internal error in ORB MARSHAL Error marshalling a parameter or result INITIALIZE Failure when initializing ORB NO_IMPLEMENT Operation implementation unavailable BAD_TYPECODE Bad typecode BAD_OPERATION Invalid operation NO_RESOURCES Insufficient resources for a request NO_RESPONSE Response to a request is not yet available PERSIST_STORE Persistent storage failure BAD_INV_ORDER Routine invocation out of order TRANSIENT Transient failure request can be reissued FREE_MEM Cannot free memory INV_IDENT Invalid identifier syntax INV_FLAG Invalid flag was specified 400 In this section CO
492. st and Thread Pool Selecting Concurrency Models Concurrency Models Concurrency models can be selected either by properties or command line parameters see Chapter 4 The default concurrency models are shown in Table 5 Table 5 Default Concurrency Models Client Server Java Threaded Threaded C Threaded Reactive 349 CHAPTER 18 Concurrency Models Single Threaded Concurrency Model Orbacus supports one single threaded concurrency model reactive Reactive servers use calls to operations like select in order to simultaneously accept incoming connection requests to receive requests from multiple clients and to send back replies This is shown in Figure 9 connect aie a l accept ae gt al dispatch g g connect accept C f dispatch 1 lt disconnect a B close lwq disconnect close fy Ss L_ Client A Server Client B Figure 9 Reactive Server Reactive clients also use operations like select to avoid blocking This means that while a request to a server is sent or a reply from that server is received the client can simultaneously send buffered requests to other 350 Single Threaded Concurrency Model servers or receive and buffer replies This is very useful for oneway operations or the Dynamic Invocation Interface DII operation send_deferred in combinat
493. supplier void disconnect_structured_push_supplier Terminates communication between the target supplier and its consumer Also frees resources allocated by the supplier Module CosNotifyComm Interface CosNotifyComm SequencePushConsumer Operations interface SequencePushConsumer inherits from CosNotifyComm NotifyPublish The SequencePushConsumer interface is implemented and registered connected by clients who wish to have sequences of structured events pushed on them by the channel push_structured_events void push_structured_events in CosNotification EventBatch notifications raises CosEventComm Disconnected Suppliers invoke this operation to pass sequences of structured events to consumers If communication is disconnected the Disconnected exception is raised Parameters notifications The structured events being pushed to the consumer disconnect_sequence_push_consumer void disconnect_sequence_push_consumer Terminates communication between the target consumer and its supplier Also frees resources allocated by the consumer 849 CHAPTER E CosNotifyComm Reference Interface CosNotifyComm SequencePullConsumer Operations 850 interface SequencePullConsumer inherits from CosNotifyComm NotifyPublish The SequencePullconsumer interface is implemented and registered connected by clients who wish to participate in subscription sharing and be notified when disconnected by the channel
494. suppliers The IDL for the structured pull supplier is given below a interface StructuredPullSupplier NotifySubscribe CosNotification StructuredEvent pull_structured_event raises CosEventComm Disconnected CosNotification StructuredEvent try_pull_structured_event out boolean has_event raises CosEventComm Disconnected void disconnect_structured_pull_supplier The blocking pull_structured_event and non blocking try_pull_structured_event are the methods which retrieve events from the supplier 740 Consuming Events Consuming Events Overview Push Consumer Pull Consumer Like supplying events receiving events varies with the selected delivery model The Orbacus Notify C and Java demos implement push and pull consumers for any structured and sequence events The push consumer is passive and has events pushed on it by Orbacus Notify As such it needs to implement the appropriate servant As with the suppliers there are separate IDL interfaces for the different push consumers any structured sequence Below is the IDL for the structured push consumer if Woy interface StructuredPushConsumer NotifyPublish void push_structured_event in CosNotification StructuredEvent notification raises CosEventComm Disconnected void disconnect_structured_push_consumer It is in the servant s implementation of push_structured_event that events are receive
495. system specific identifier generated by the operating system when a new thread is created Application developers are encouraged to use the uTcThreadId class to refer to thread ids getName const char getName const Returns the name of the thread object Returns start The thread object name void start Starts execution of the thread If the thread was created with a target object i e with an object of a class derived from gtcRunnable the run method of the target object is invoked If there is no target object the run method of the thread object itself is invoked In this case a class derived from sTcThread with an overridden run method should be used Throws run JTCSystemCallException Indicates a failed system call JTCIllegalStateException Thrown if the thread has already been started virtual void run This method is called when start is invoked If the thread object has been constructed with an associated target sTcRunnable object the 623 CHAPTER A Class Reference 624 target s run method is invoked Otherwise the run method should be overridden in a class derived from JTCThread If run terminates due to an uncaught exception then the thread s thread group method uncaughtException is called isAlive bool isAlive const This method determines whether the thread is alive Returns true if the thread is alive false otherwise join void join Waits for the thread to termin
496. t ooc orb server_timeout ooc orb use_type_code_cache ooc orb service name Configuring the ORB and Object Adapter Specifies the name of the server as registered with the Implementation Repository IMR Note that you should not put this property in a configuration file that is shared by several IMR enabled servers Furthermore this property should not be specified for servers that are not registered with the IMR Value timeout gt O If the server is not able to gracefully disconnect from the client in timeout seconds a connection shutdown is forced If this property is set to zero then the server will not force a connection shutdown If the property is not set a default timeout value of two seconds is used Value timeout gt O The server actively closes a connection that has been idle for timeout seconds once that connection has no more outstanding replies Note that the application must use one of the threaded server side concurrency model if connection timeouts are desired If this property is set to zero or not set at all then the server does not close idle connections Value true false Determines whether the ORB caches TypeCodes When the TypeCode cache is disabled the ORB creates a new TypeCode object for each TypeCode received over the wire including those associated with Any values When the TypeCode cache is enabled only one TypeCode object is instantiated for each TypeCode with a unique non em
497. t determine precisely the number of threads is that threads can be added and removed from the thread group at the same time as they are enumerated Parameters list The array into which the set of active threads should be copied len The length of the array list recurse If set to true active threads from subgroups are also enumerated Returns The number of active threads copied to the array 633 CHAPTER A Class Reference Related Functions 634 enumerate int enumerate JTCThreadGroupHandle list int len bool recurse true const Copies handles for every active subgroup of this thread group into the array list activeGroupCount can be used to determine how big the array must be If more than 1en active subgroups are present the remaining subgroups are silently ignored Parameters list The array in which to copy the thread group handles len The length of the array recurse If set to true child subgroups are also enumerated Returns The number of handles copied to list list void list Outputs to the stream cout the set of threads and subgroups list void list ostream amp os int indent Outputs to the stream os the set of threads and subgroups Use indent spaces for indentation operator lt lt ostream amp operator lt lt ostream amp os const JTCThreadGroup g Prints a string representation of the thread group to the output stream os This calls g list os 4 Parameters os O
498. t admin object and all proxies it is managing Module CosNotifyChannelAdmin Interface CosNotifyChannelAdmin EventChannel Attributes Operations interface EventChannel inherits from CosNotification QoSAdmin CosNotification AdminPropertiesAdmin CosEventChannelAdmin EventChannel The EventChannel interface has operations which support the management of supplier and consumer admin objects MyFactory readonly attribute EventChannelFactory MyFactory A reference to the event channel factory which created the target object default_consumer_admin readonly attribute ConsumerAdmin default_consumer_admin A reference to a default consumer admin which is created automatically when the channel is created default_supplier_admin readonly attribute SupplierAdmin default_supplier_admin A reference to a default supplier admin which is created automatically when the channel is created default_filter_factory readonly attribute CosNotifyFilter FilterFactory default_filter_factory A reference to the default filter factory new_for_consumers ConsumerAdmin new_for_consumers in InterFilterGroupOperator op out AdminID id Creates a new consumer admin Parameters op The InterFilterGroupOperator to apply between filter results from the target object and subsequently created proxy objects id The id assigned to the new consumer admin by the event channel Returns 831 CHAPTER D CosNotifyChannelAdmin
499. t are not implemented in JThreads C These are The security API This is because some parts of the API simply can t be implemented in C In general this issue is not as important as in Java since C is not used for Internet applications applets in the same way as Java The thread control primitives java lang Thread stop java lang Thread suspend and java lang Thread resume Cannot be implemented with the same semantics as the Java thread model in a portable fashion The WIN32 thread API supports primitives for these operations but the POSIX thread API does not In general it is not a Overview good idea to use these API primitives as they exist in the Java thread model for they can easily lead to deadlock situations These primitives are deprecated in JDK 1 2 4 and therefore won t be supported in upcoming versions of Java About this Document This manual is not a substitute for a good thread programming book This manual only describes how Java thread constructs translate to JThreads C There are excellent books available on Java thread programming for example 2 and 3 We highly recommend use of these books while learning JThreads C programming With the help of this manual it s easy to translate the examples provided there to JThreads C programs 1 In fact the WIN32 programmers guide recommends against using TerminateThread the API call to stop a thread s execution since it can easily le
500. t assigns an ID to each constraint value pair The input list is returned along with the ID assigned to each constraint value pair If any of the constraints violate the constraint grammar an InvalidConstraint exception is raised If any of the values in the list of constraint value pairs are not of the same type as the value_type for the target filter object an InvalidValue exception is raised modify_mapping_constraints void modify_mapping_constraints in ConstraintIDSeq del_list in MappingConstraintInfoSeq modify_list raises InvalidConstraint InvalidValue ConstraintNotFound Modifies the list of constraint value pairs associated with the target filter object If one or more of the IDs in either of the two lists are not found the Const raintNotFound exception is raised Parameters del_list A list of constraint IDs representing constraint value pairs to remove from the target filter object modify_list A list of constraint IDs and constraint value pairs Constraints which exist in the target filter object are modified to those in the list with the same constraint ID Both the constraint and value types may be modified If a constraint in this list does not conform to the constraint grammar for the target filter object an InvalidConstraint exception is raised Likewise if a value in this list is not of the same type as the value_type for the target filter object an InvalidVvalue exception is raised get_mapping_constraint
501. t blocking Returns Module OCI FALSE if a connection loss is detected TRUE otherwise Raises COMM_FAILURE In case of an error receive_timeout void receive_timeout in Buffer buf in unsigned long timeout Similar to receive but it is possible to specify a timeout On return the caller can test whether there was a timeout by checking if the buffer has been filled completely Parameters buf The buffer to fill timeout The timeout value in milliseconds A zero timeout is equivalent to calling receive buf FALSE Raises COMM_FAILURE In case of an error receive_timeout_detect boolean receive_timeout_detect in Buffer buf in unsigned long timeout Similar to receive_timeout but it signals a connection loss by returning FALSE instead of raising COMM_FATLURE Parameters buf The buffer to fill timeout The timeout value in milliseconds A zero timeout is equivalent to calling receive buf FALSE Returns FALSE if a connection loss is detected TRUE otherwise Raises COMM_FAILURE In case of an error send void send in Buffer buf in boolean block Sends a buffer s contents Parameters buf The buffer to send 461 CHAPTER E Open Communications Interface Reference 462 block If set to TRUE the operation blocks until the buffer has completely been sent If set to FaLsE the operation sends as much of the buffer s data as possible without b
502. t filter object Returns A list of IDs representing all callbacks currently registered 861 CHAPTER F CosNotifyFilter Reference Interface CosNotifyFilter MappingFilter interface MappingFilter The MappingFilter interface manages groups of mapping filter constraint value pairs and has operations which evaluate events against these constraints Attributes constraint_grammar readonly attribute string constraint_grammar The constraint grammar specified during creation of the filter All constraints for a filter object must be expressed in this grammar value_type readonly attribute TypeCode value_type Identifies the datatype of the property value which the mapping filter affects default_value readonly attribute any default_value This parameter is returned as the result of a match operation for which the given event satisfied none of the constraints associated with the target mapping filter object Operations add_mapping_constraints MappingConstraintInfoSeq add_mapping_constraints in MappingConstraintPairSeq pair_list raises InvalidConstraint InvalidValue Add a list of mapping filter constraints to the target mapping filter object This operation is incremental in that new constraints are appended to the existing list of constraints Parameters pair_list The list of constraint value pairs to be added to the target filter object Returns 862 Module CosNotifyFilter The target filter objec
503. t ignored but are a part of the property You can define the name of the configuration file using a command line option an environment variable C or a system property Java e Command line option ORBconfig filename Environment variable ORBACUS_CONFIG filename e Java system property ooc config filename When an ORB is initialized it first checks for the presence of the environment variable or system property If present the ORB loads the configuration file Next the ORB loads the configuration file specified by the ORBconfig option Therefore the properties loaded from the file specified by oRBconfig will override any existing properties including those loaded by a configuration file specified in the environment variable or system property See Precedence of Properties on page 74 for more information Configuration files are only loaded during ORB initialization Changes made to a configuration file after an ORB has been initialized have no effect on that ORB 1 Orbacus for Java also accepts a URL specification as the filename Configuring the ORB and Object Adapter Using the Windows NT Registry RegUpdate Synopsis Example Another convenient mechanism for use with C applications under Windows NT is to use the system registryt Properties can be stored in the registry under the following registry keys HKEY_LOCAL_MACHINE Software OOC Properties HKEY_CURRENT_USER Software 00C Properties Ind
504. t is 10 678 Table 1 Orbacus Notify Configuration Properties Property Value Description ooc notification endpoint Value string Specifies the endpoint configuration for the service Note that this property is only used if the ooc orb oa endpoint configuration property see ooc orb oa endpoint on page 66 is not set ooc notification events_per_transact events gt O Determines the maximum number of events ion selected per database transaction for transmission to a push consumer This property reduces total transaction overhead for persistent events The default value is 100 ooc notification eventqueue true false If true a central event queue is used The default value is false that is the central event queue is not used The central event queue helps isolate suppliers from consumers at the expense of an increased number of transactions For configurations with few suppliers and consumers it is recommended to set this to false ooc notification trace events level gt 0 Controls the level of diagnostic output related to event lifecycles Set this value to 1 or greater to enable event lifecycle tracing The default is O which produces no output ooc notification trace lifecycle level gt 0 Controls the level of diagnostic output related to service object channel admin proxy lifecycles Set this value to 1 or greater to enable service objec
505. t lifecycle tracing The default is O which produces no output ooc notification trace queue Value eve gt 0 Controls the level of diagnostic output related to proxy event queue operations Set this value to 1 or greater to enable proxy event queue tracing The default is O which produces no output ooc notification trace retry level gt 0 Controls the level of diagnostic output related to retried event transmissions Set this value to 1 or greater to enable event retry tracing The default is O which produces no output 679 CHAPTER 2 Configuration and Startup Table 1 Configuration Properties Property Value Description ooc notification trace subscriptio level gt 0 Controls the level of diagnostic output related to subscription sharing Set this value to 1 or greater to enable subscription sharing tracing The default is O which produces no output ooc filter trace lifecycle Value eve gt 0 Controls the level of diagnostic output related to filter object forwarding filter mapping filter filter factory lifecycles Set this value to 1 or greater to enable service object lifecycle tracing The default is O which produces no output OOC database trace transactions level gt 0 Controls the level of diagnostic output from the transaction subsystem Set this value to 1 or greater to enable database transaction tra
506. t of QoS properties for the target object Returns A sequence of QoS property name value pairs set_qos void set_qos in QoSProperties qos raises UnsupportedQoS Incrementally applies QoS settings to the target object New elements are appended to the list of QoS properties already associated with the target object If the property already exists for the target object its value is changed to the new setting Parameters qos A list of QoS properties validate_qos void validate_gos in QoSProperties required_qos out NamedPropertyRangeSeq available_qos raises UnsupportedQoS Checks to see if a list of QoS properties are supported by the target object without changing the list of properties already associated with the object If any of the properties in required_qos are not supported the Unsupportedgos exception is raised Parameters required_qos The QoS properties of interest to the caller are passed in this parameter available_gos If the properties in required_qos are supported other optional QoS properties which are also supported are returned in this parameter 803 CHAPTER C CosNotification Reference Interface CosNotification AdminPropertiesAdmin Synopsis interface AdminPropertiesAdmin Supports the management of administrative properties Operations get_admin AdminProperties get_admin Retrieves the list of administrative properties associated with the target object Returns A
507. t to have access to another object Load balancing The factory object manages a pool of objects often representing some limited resource and assigns them to clients based on some utilization algorithm e Polymorphism A factory object enables the use of polymorphism by returning object references to different implementations depending on the criteria specified by a client These are only a few examples of the potential applications of the Factory pattern The examples listed above can also be used in any combination depending on the requirements of the system being designed Note that the factory pattern applies equally to persistent and transient objects A simple application of the Factory pattern in which a new object is created for each client is illustrated below The implementation uses the following interface definitions IDL interface Product void destroy interface Factory Product createProduct Se RS OO E IC N a 2 5 7 10 Factory Objects The Product interface is defined The destroy operation allows a client to destroy the object when it is no longer needed The Factory interface is defined The createProduct operation returns the object reference of a new Product 115 CHAPTER 5 CORBA Objects Factory Objects using C 116 2 4 First we ll implement the Product interface i ff aes 2 class Product wol 3 public virtual POA_Product 4 public virtual Port
508. tExceeded Forced connection shutdown because of timeout 415 CHAPTER 20 Exceptions and Error Messages INTF_REPOS Minor Exception Code 416 MinorNoInt fRepos Interface Repository is not available MinorLookupAmbiguous Search name for lookup is ambiguous MinorIllegalRecursion Illegal Recursion MinorNoEntry IFR is not populated with a required definition CORBA System Exceptions OBJECT NOT EXIST Minor Exception Code MinorUnregisteredValue Attempt to pass unactivated unregistered value as an object reference MinorCannotDispatch Unable to dispatch servant or POA not found 417 CHAPTER 20 Exceptions and Error Messages INV_POLICY Minor Exception Code 418 MinorCannotReconcilePolicy Cannot reconcile IOR policy with effective policy override MinorInvalidPolicyType Invalid PolicyType MinorNoPolicyFactory No PolicyFactory for the PolicyType has been registered Non Compliant Application Asserts Non Compliant Application Asserts If the Orbacus library was compiled without the preprocessor definition DNDEBUG defined Orbacus tries to detect common programming mistakes that lead to non compliant CORBA applications If such a mistake is found an error messages like this will appear Non compliant application error detected Application used wrong memory allocation function After detecting such an
509. tFound InvalidPropertyName For a particular property name this call either returns the any associated with that name or throws an exception if a property with the name does not exist You can not only query for a particular property value but also for a list of all the properties defined within a PropertySet The get_all_properties operation serves this purpose jf IDE void get_all_properties in unsigned long how_many out Properties nproperties out PropertiesIterator rest This operation works similar to the 1ist call offered by the Naming Service In both cases the maximum number of items to be returned at once is specified An iterator implementing the PropertiesIterator interface gives access to the remaining items if any if IDE interface PropertiesIterator void reset boolean next_one out Property aproperty boolean next_n in unsigned long how_many out Properties nproperties void destroy he 230 Querying for Properties If you are only interested in a list of property names you can get this list by calling get_all_property_names Ji Toi void get_all_property_names in unsigned long how_many out PropertyNames property_names out PropertyNamesIterator rest As with get_all_properties a list of names as well as an iterator is returned This iterator implements the PropertyNamesIterator interface IDL interface PropertyNamesIterator void reset boolean next_one out Prop
510. t_var pmObj g orb gt resolve_initial_references ORBPolicyManager 10 CORBA PolicyManager_var pm 0o 3 a a e G a e 1 CORBA PolicyManager _narrow pmObj 12 pm gt set_policy_overrides policies CORBA ADD_OVERRIDE Create an any and insert the value O false Create a sequence containing one policy object 313 CHAPTER 16 Using Policies 6 7 Ask the ORB to create a connection reuse policy Pass the any that contains the value for this policy 8 10 Obtain the ORB level policy manager object 12 Add the policies to the ORB level policy manager And here is the same example in Java 1 Java 2 org omg CORBA Any boolAny orb create_any 3 boolAny insert_boolean false 4 org omg CORBA Policy policies new org omg CORBA Policy 1 5 policies 0 orb create_policy 6 com ooc OB CONNECTION_REUSE_POLICY_ID value boolAny 7 org omg CORBA PolicyManager pm 8 org omg CORBA PolicyManagerHelper narrow 9 orb resolve_initial_references ORBPolicyManager 10 pm set_policy_overrides policies SetOverrideType ADD_OVERRIDE 1 10 This is equivalent to the C version Connection Reuse Policy atObject And now the same example but at the object level C first Level ff Cime 2 CORBA Any boolAny 3 boolAny lt lt CORBA Any from_boolean 0 4 CORBA PolicyList policies 1 5 policies length 1 6 policies 0 orb gt create_policy 7 OB CONNECTION_REUSE_PO
511. tain the proper proxy consumer from the supplier admin This is the point at which the application specifies the delivery model and type of events it will supply This example uses the push delivery model and structured events The C code looks like Wie CosNotifyChannelAdmin ProxyID proxylId CosNotifyChannelAdmin ProxyConsumer_var proxyConsumer supplierAdmin gt obtain_notification_push_consumer CosNotifyChannelAdmin STRUCTURED_EVENT proxyId CosNotifyChannelAdmin StructuredProxyPushConsumer_var structuredProxyPushConsumer CosNotifyChannelAdmin StructuredProxyPushConsumer _narrow proxyConsumer Connecting to a Proxy Connecting to a Notification Channel And in Java 1 Java 2 org omg CORBA IntHolder proxyId new org omg CORBA IntHolder ProxyConsumer proxyConsumer supplierAdmin obtain_notification_push_consumer ClientType STRUCTURED_EVENT proxyId StructuredProxyPushConsumer structuredProxyPushConsumer StructuredProxyPushConsumerHelper narrow proxyConsumer E OO OT Oy OF a i Variable to hold the ID later assigned to the proxy by Orbacus Notify Obtain a push consumer specifying the type This example wants a structured event push consumer Valid types are ANY_EVENT STRUCTURED_EVENT SEQUENCE_EVENT Narrow the proxy consumer to the appropriate type specified in the previous call Equivalent objects and methods exist for pull model suppliers The final s
512. tall the service The service must be started manually s start install Install the service and start it u uninstall Uninstall the service qd debug Run the service in debug mode In order to use the IFR as a native Windows NT service it is first necessary to add the ooc ifr endpoint configuration property to the HKEY_LOCAL_MACHINE NT registry key see Using the Windows NT Registry on page 71 for more details Next the service should be installed with ntirservice i This adds the orbacus Interface Repository Service entry to the Services dialog in the Control Panel To start the naming service select the Orbacus Interface Repository Service entry and press start If the service is to be started automatically when the machine is booted select the Orbacus Interface Repository Service entry then click Startup Next select Startup Type Automatic and press ox Alternatively the service could have been installed using the s option which configures the service for automatic start up ntirservice s If you want to remove the service run 259 CHAPTER 13 The Interface Repository 260 ntirservice u Note If the executable for the Interface Repository is moved it must be uninstalled and re installed Any trace information provided by the service is placed in the Windows NT Event Viewer with the title 1RService To enable tracing information add the desired
513. tatic Linking 386 CONTENTS URL Support 387 Narrowing UDP Object References 388 The Bi directional OCI Plug in 389 How Does it Work 390 Peers 391 Client Installation 392 Server Installation 393 Endpoint Configuration 394 Command line Options 395 Configuration Properties 396 Static Linking 397 URL Support 398 Chapter 20 Exceptions and Error Messages 399 CORBA System Exceptions 400 INITIALIZE Minor Exception Code 403 UNKNOWN Minor Exception Code 404 BAD_PARAM Minor Exception Code 405 NO_MEMORY Minor Exception Code 407 IMP_LIMIT Minor Exception Code 408 COMM_FAILURE Minor Exception Code 409 MARSHAL Minor Exception Code 410 NO_IMPLEMENT Minor Exception Code 412 NO_RESOURCES Minor Exception Code 413 BAD_INV_ORDER Minor Exception Code 414 TRANSIENT Minor Exception Code 415 INTF_REPOS Minor Exception Code 416 OBJECT _NOT_EXIST Minor Exception Code 417 INV_POLICY Minor Exception Code 418 Non Compliant Application Asserts 419 Appendix A Boot Manager Reference 423 Interface OB BootManager 424 Interface OB BootLocator 426 Appendix B Orbacus Policy Reference 427 Module OB 428 Interface OB ConnectTimeoutPolicy 430 Interface OB Interface OB ConnectionReusePolicy Interface OB Interface OB Interface OB Interface OB Interface OB Interface OB InterceptorPolicy LocateRequestPolicy LocationTransparencyPolicy ProtocolPolicy RequestTimeoutPolicy RetryPolicy TimeoutPolicy Module OBPortableServer Interfa
514. ted until the ORB attempts to read the reply In this case the ORB must assume that the remote end has received the request in order to guarantee at most once semantics for the request The implication is that when using the default setting of RETRY_STRICT Most communication failures will not cause a retry This behavior can be relaxed using RETRY_ALWAYS retry_remote readonly attribute boolean retry_remote 437 CHAPTER B Orbacus Policy Reference Interface OB TimeoutPolicy Attributes 438 local interface TimeoutPolicy inherits from CORBA Policy The timeout policy This policy can be used to specify the default timeout for connection establishment and requests If an object also has Connect ionTimeoutPolicy Of RequestTimeoutPolicy set those values have precedence See Also Interface OB ConnectTimeoutPolicy Interface OB RequestTimeoutPolicy value readonly attribute unsigned long value If an object has a TimeoutPolicy set and a connection cannot be established or no response to a request is available after value milliseconds a CORBA NO_RESPONSE exception is raised The default value is 1 which means no timeout Module OBPortableServer Module OBPortableServer Constants INTERCEPTOR_CALL_POLICY_ID const CORBA PolicyType INTERCEPTOR_CALL_POLICY_ID 1330577667 This policy type identifies the interceptor call policy 439 CHAPTER B Orbacus Policy Reference Interface OBPort
515. tely because this is not supported by every underlying low level thread API e g POSIX threads Instead the JThreads C library uses the concept of control points to implement the suspend and stop methods This is similar to the cancellation points concept used in the POSIX threads library If suspend OF stop is called from outside the thread that is to be suspended or stopped the thread is marked as contro pending When this thread calls a method which is a contro point the thread is stopped or suspended respectively Once a thread has been suspended execution for that thread is halted until it is resumed If a thread has been stopped the exception sTcThreadDeath is raised If this exception is caught by user code it must be re thrown to ensure the proper termination of the thread The control points in the JThreads C library are e JTCThread suspend e JTCThread join e JTCThread sleep e JTCThread yield e JTCSynchronized JTCSyncronized e JTCSynchronized JTCSyncronized e JTCMonitor wait The Java versions of stop resume and suspend are deprecated 4 The reason is that under very rare circumstances these methods can lead to a deadlock of the Java Virtual Machine The Stop and Suspend Methods The JThreads C implementation of stop resume and suspend is completely portable and does not suffer from the same shortcomings as the Java counterpart However in order to keep your sou
516. tep in connecting a supplier to an event channel is to connect to the proxy Each of the various proxy types implement their own connect method A proxy of type CosNotifyChannelAdmin StructuredProxyPushConsumer is used in this example if WI interface StructuredProxyPushConsumer ProxyConsumer CosNotifyComm StructuredPushConsumer void connect_structured_push_supplier in CosNotifyComm StructuredPushSupplier push_supplier raises CosEventChannelAdmin AlreadyConnected A supplier registers itself with a proxy when it invokes the appropriate connect method If the supplier wants notification of either of the following e when it is about to be disconnected 729 CHAPTER 4 Programming Example 730 e when there is a change in the set of events to which consumers are currently subcribed it must implement the appropriate CORBA servant and pass it as an argument in the connect call In this case the supplier must also assume the role of CORBA server The example supplier is not interested in these notifications so it passes a nil argument during the connect call Hil Case structuredProxyPushConsumer gt connect_structured_push_supplier CosNotifyComm StructuredPushSupplier _nil Java structuredProxyPushConsumer connect_structured_push_supplier null Connecting to a Notification Channel Connecting a Consumer This section describes how to connect to an event channel so that an appl
517. ter contains the following sections Server Side Usage page 530 Client Side Usage page 534 Complete Example page 540 529 CHAPTER 2 Extending the Hello World Application Server Side Usage Setting Identity A server application must provide its identity using a context Wy Cites Wf Load the certificate chain Hi FSSL CertificateSeq myCerts 2 myCerts length 2 myCerts 0 fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file server der myCerts 1 fsslManager gt create_certificate FSSL OctetSeq_var FSSL load_file CAcert der Create a new context with this certificate chain Le FSSL ContextID id fsslManager gt create_context myCerts FSSL OctetSeq_var FSSL loadFile Sserverkey der FSSL PassPhrase_var FSSL string_to_PassPhrase foobar myTrustDecider FSSL CipherSeq_var FSSL get_RSA_ciphers 530 Server Side Usage Java Load the certificate chain He com ooc FSSL Certificate myCerts new com ooc FSSL Certificate 2 myCerts 0 fsslManager create_certificate com ooc FSSL FSSL load_file server der myCerts 1 fsslManager create_certificate com ooc FSSL FSSL load_file ca der ti Create the server context Hy int id fsslManager create_context myCerts com ooc FSSL FSSL load_file serverkey der com ooc FSSL FSSL string_to_Pas
518. terface ConnectCB An interface for a connect callback object See Also Interface OCI Connector nfo Operations connect_cb void connect_cb in TransportInfo transport_info Called after a new connection has been established If the application wishes to reject the connection CORBA NO_PERMISSION may be raised Parameters transport_info The TransportInfo for the new connection 471 CHAPTER E Open Communications Interface Reference Interface OCI ConFactory Synopsis Attributes Operations 472 local interface ConFactory A factory for Connector objects See Also Interface OCI Connector Interface OCI ConFactoryRegistry id readonly attribute PluginId id The plugin id tag readonly attribute Profileld tag The profile id tag describe_profile string describe_profile in IOP TaggedProfile prof Returns a description of the given tagged profile Parameters prof The tagged profile Returns The profile description create_connectors ConnectorSeq create_connectors in IOR ref in CORBA PolicyList policies Returns a sequence of Connectors for a given IOR and a list of policies The sequence includes one or more Connectors for each IOR profile that matches this Connector factory and satisfies the list of policies Parameters ref The IOR for which Connectors are returned policies The policies that must be satisfied Returns Module OCI
519. ters rhs The handle from which to retrieve the object operator JTCHandle lt T gt amp operator const JTCHandleT lt T gt amp rhs Creates a handle that refers to the object referenced by rhs Parameters 635 CHAPTER A Class Reference 636 rhs The handle from which to retrieve the object Returns A reference to the handle operator bool operator const JTCHandleT lt T gt amp rhs const Returns true if rhs references the same object as this object Parameters rhs The handle to compare with Returns true if the objects are equivalent false otherwise operator bool operator const JTCHandleT lt T gt amp rhs const Returns true if rhs references a different object as this Parameters rhs The handle to compare with Returns true if the objects are not equivalent false otherwise operator bool operator const Determines if the object referenced by the handle is not valid i e that it is nil Returns true if the object is not valid false otherwise operator bool operator bool const Determines if the object referenced by the handle is valid i e that it is not nil Returns true if the object is valid false otherwise operator gt T operator gt const Invokes a method on the referenced object Returns A pointer to the referenced object get T get const Gets a pointer to the referenced object Returns A pointer to the referenced o
520. th checkpoint_kbyte Set this value to O to disable checkpointing The default is 300 seconds 00c database checkpoint_kbyte kbyte gt 0 The minimum amount of database log data in kilobytes that must be present before a checkpoint occurs Set this value to O to create a checkpoint every checkpoint_interval seconds The default is 64 kilobytes ooc database sync_transactions true false Determines whether transactions are truly synchronous If set to false event throughput will be higher but there is a risk of events being lost if the service crashes The default is true 00c database max_locks locks gt O Configures the maximum number of database locks that may be acquired at any time The default value is 16384 If it is expected that the database will contain a large number of events at any one time then this value should be increased ooc database max_transactions transactions gt 0 Configures the maximum number of concurrent transactions that may be active at any one time This value should be set proportional to the number of persistent proxies Otherwise if there are many persistent proxies and not enough concurrent transactions are permitted performance will decrease The default is 20 681 CHAPTER 2 Configuration and Startup Connecting to the Service 682 The object key of Orbacus Notify is DefaultEventChannelFactory which id
521. the interface with the suffix _imp1 e g for an interface 1 the implementation class is named T_imp1 In C I_imp1 must inherit from the skeleton class poa_r that was generated by the IDL to C translator If 1 inherits from other interfaces for example from the interfaces a and B then 1_imp1 must also inherit from the corresponding implementation classes A_imp1 and B_impl i ff Ci 2 class A_impl virtual public POA A 3 4 public 5 virtual void op_a throw CORBA SystemException 6 T 8 class Blimp wirtual public FEOANE 9 0 joUlollaies ai virtual void op_b throw CORBA SystemException 2 3 Iie lass rimpi rual pub AiCi EOANT 5 virtual public A_impl 6 virtual public B imp Uy 8 public S virtual void op_i throw CORBA SystemException 20 The servant class A_imp1 is defined inheriting from the skeleton class poa_A If op_a had any parameters these parameters would be mapped according to the standard IDL to C mapping rules 4 This is the servant class for B_imp1 1 These naming rules are not mandatory they are just a recommendation 95 CHAPTER 5 CORBA Objects Inheritance using Java 96 14 20 5 7 The servant class for 1_imp1 is not only derived from Poa_i but also from the servant classes A_imp1 and B_impl Note that virtual public inheritance must be used The only situation in which the keyword virtual is not necessary is for an interface 1 w
522. the javadoc tool to produce documentation from the generated Java files See Using javadoc on page 49 for additional information h help v version d debug DNAME DNAME DEF UNAME IDIR E no skeletons locality constrained all tie file list FILE no local copy case sensitive with async These options are the same as for the idl command no comments The default behavior of jial is to add any comments from the IDL file starting with to the generated Java files Specify this option if you don t want these comments added to your Java files package PKG Specifies a package name for the generated Java classes Each class will be generated relative to this package 39 CHAPTER 3 Generating Code with Orbacus prefix package PRE PKG Specifies a package name for a particular prefix Each class with this prefix will be generated relative to the specified package auto package Derives the package names for generated Java classes from the IDL prefixes The prefix ooc com for example results in the package com OOc output dir DIR Specifies a directory where jid1 will place the generated Java files Without this option the current directory is used clone Generates a clone method for struct union enum exception valuetype and abstract interface types For valuetypes only an abstract method is generated The valuetype implementer must su
523. the private key the data must have been sent by the true party Each peer is authenticated using an X 509 certificate 4 Generally a certificate will contain the user s name and public key and is signed by a trustworthy entity the so called Certificate Authority CA Usually a chain of X 509 certificates are presented The certificate at the head of the chain is the peer s certificate Each certificate is signed by the next certificate in the chain The certificate at the end of the chain is self signed and is generally the certificate of the Certificate Authority itself A certificate has an associated private key and passphrase Without the private key is it not possible to use a certificate to prove identity The passphrase protects the private key and is used to decrypt the private key at runtime What is SSL Given a certificate there must be some logic to determine whether this certificate is trusted This is typically done against some certificate authority A certificate authority is an organization that is responsible for issuing certificates to individuals The choice of trusted certificate authorities is something that is best left up to the application For instance a company may issue certificates to all of their employees and only trust one certificate authority certificate The generation and signing of certificates is beyond the scope of this document For the C plug in please see 5 for the Java plug in using iSa
524. the return result is FALSE this parameter is set to the default_value for the target filter object Returns Returns TRUE if the event satistifes at least one constraint FALSE otherwise If the filterable data of the input event contains data that the match operation cannot handle an UnsupportedFilterableData exception is raised match_structured boolean match_structured in CosNotification StructuredEvent filterable_data out any result_to_set raises UnsupportedFilterableData Compare the filter constraints from the target filter object with the supplied event Parameters Module CosNotifyFilter filterable_data The event to be evaluated in the form of a structured event result_to_set If the match is successful that is the return result is TRUE this parameter is set to the value paired with the matching constraint Otherwise if the match fails that is the return result is FALSE this parameter is set to the default_value for the target filter object Returns Returns TRUE if the event satistifes at least one constraint FaLsE otherwise If the filterable data of the input event contains data that the match operation cannot handle an UnsupportedFilterableData exception is raised match_typed boolean match_typed in CosNotification PropertySeq filterable_data out any result_to_set raises UnsupportedFilterableData Not Implemented 865 CHAPTER F CosNotifyFilter Reference Interface CosNot
525. the selected server Reset Reset the state of the selected server The Create menu item creates a child object under the selected object OADs are created under the IMR Domain root object servers are created under OADs and POAs are created under servers The Modify menu item applies to all objects However servers are currently the only objects that have attributes that can be modified To delete an object the Delete menu item is used This operation recursively deletes all children under the selected item 183 CHAPTER 8 The Implementation Repository Console The View Menu The Toolbar and the Popup Menu 184 The Cut and Paste menu items only apply to servers and are used to move servers to different hosts Note that OAD for the desired host must be selected when using Paste In very rare circumstances it s possible for the IMR and OAD to become confused as to the state of a server In this case it might be necessary to manually reset the state of the server using the Reset menu item It also necessary to use this item if the server continually crashes on startup and has reached the maximum number of retries specified by its max_spawns attribute This prevents the OAD from continually starting the same broken server The View menu contains the Refresh menu item The Refresh menu item is used to update the console when the contents of the IMR have been changed from outside the console Note that clicking or
526. the string_to_object operation The corbaname URL extends the capabilities of the corbaloc URL to allow the object key to identify a binding in a Naming Service For example consider this URL corbaname ns1 5001 NameService ctx MyObject When the ORB interprets this URL it attempts to resolve a naming context object located at host ns1 on port 5001 and having the object key NameService Once the naming context has been resolved the ORB attempts to lookup the binding named myobject in the naming context ctx If successful the result of string_to_object is the object reference associated with the binding 141 CHAPTER 6 Locating Objects file URLs 142 A file URL provides a convenient way to obtain object references using an IOR or URL reference that is in a file The format of a file URL is file lt absolute file name gt Using the file URL and given that the file object ref is located in the tmp directory the client side example of on page 135 may be simplified as follows Hi Cat CORBA ORB_var orb Get a reference to the ORB somehow CORBA Object_var obj orb gt string_to_object file tmp object ref Bivar b B _narrow ob Java org omg CORBA ORB orb Get a reference to the ORB somehow org omg CORBA Object obj orb string_to_object file tmp object ref B b BHelper narrow obj Object Reference URLs relfile URLs Orbacus also provides the proprietary relfile UR
527. then the initial Naming Service is used as provided to the ORB with options like ORBservice or ORBconfig If both of the above steps fail an error window is displayed and the Names console exits 213 CHAPTER 10 Orbacus Names Console The Menus The File Menu 214 The menus provide access to all of the features of the application In addition the most common actions are also available in the toolbar as well as in a popup menu that is displayed when pressing the right mouse button over an item in the binding table or context tree This menu contains operations that create bindings and define the current root context New Window Opens an additional control window Switch Root Context Selects a new root naming context Load Context Recursively loads a naming context from a file Save Context As Recursively saves the selected naming context to a file Save IOR to File Saves the stringified IOR of the currently selected item to a file Close Window Closes the current window Exit Quits the Orbacus Names Console After starting the application the current root context is the naming context corresponding to the IOR specified on the command line or the initial Naming Service as provided to the ORB with options like ORBservice or ORBconfigby You can make another naming context the root context using Switch Root Context The new root context s IOR is specified in the Enter The Menu
528. thread for receiving requests from clients but sends replies in the dispatch thread Additionally there is a separate thread dedicated to accepting incoming connection requests so that a threaded server can serve more than one client at a time Orbacus s threaded server concurrency model allows only one active thread in the user code This means that even though many requests can be received simultaneously the execution of these requests is serialized This is shown in Figure 11 For simplicity the dispatch arrows and the corresponding return arrows are omitted in this and all following diagrams f Q p gl a ox lt a I Client A Threaded Server Client B Figure 11 Threaded Server In the example the threaded server has two clients connected to it and thus two receiver threads First A calls on the server If before returns B tries to call another operation g this request is delayed until returns The same is true for A s call to n which must wait until g returns Multi Threaded Concurrency Models Allowing only one active thread in user code has the advantage of the user code not having to take care of any kind of thread synchronization This means that the user code can be written as if for a single threaded system but without losing the advantage of the ORB optimizing its operation by using multiple threads inter
529. tion PropertyValue value Contains a property name value pair representing a limit on the number of proxies that may connected to an admin object Exceptions Module CosNotifyChannelAdmin ConnectionAlreadyActive exception ConnectionAlreadyActive Raised on an attempt to resume an already active connection ConnectionAlreadyInactive exception ConnectionAlreadyInactive Raised on an attempt to suspend an already inactive connection NotConnected exception NotConnected Raised on an attempt to suspend or a resume a disconnected proxy AdminNotFound exception AdminNotFound Raised when an admin identified by an Adminip cannot be found ProxyNotFound exception ProxyNotFound Raised when a proxy identified by a Proxy1p cannot be found AdminLimitExceeded exception AdminLimitExceeded AdminLimit admin_property_err Raised on an attempt to connect a proxy which would exceed the maximum number allowed for the target admin object ChannelNotFound exception ChannelNotFound 807 CHAPTER D CosNotifyChannelAdmin Reference Enums 808 Indicates that a channel with a given channel ID was not found ProxyType enum ProxyType PUSH_ANY PULL_ANY PUSH_STRUCTURED PULL_STRUCTURED PUSH_SEQUENCE PULL_SEQUENCE Supplier and consumer proxy types Members PUSH_ANY Push delivery model any events PULL_ANY Pull deliver
530. tory and invoke the Edit Create menu operation The Filter Creation Wizard then steps through the creation of the filter Note that all mapping filters are property of the FilterFactory and have associations with zero one or many admins and or proxies There are no editable properties associated with a mapping filter When a filter is selected in the Service Structure Tree the right hand panel displays the read only list of subscribers and the default value associated with the mapping filter A selected mapping filter is destroyed by choosing the Edit Destroy menu operation A confirmation is displayed before the mapping filter is removed 1 If the filter is created from a consumer admin then the Filter Proxy Creation Wizard is used Managing Mapping Filter Constraint Value Pairs Managing Mapping Filter Constraint Value Pairs Creating a New Constraint Value A constraint value pair is created from a mapping filter object To create a Pair constraint value pair from the console choose the appropriate mapping filter and select Edit Create The Constraint Creation Wizard then steps through the creation of the constraint value pair Constraint Value Pair Properties The Edit Properties menu operation for a selected mapping filter constraint value pair displays a tabbed property dialog in which various constraint properties may be edited All the properties in this dialog are set initially when the constraint value pair is
531. trace configuration property i e one of the ooc orb trace properties to the HKEY_LOCAL_MACHINE NT registry key with a REG_sz value of at least 1 Configuration Properties Usage In addition to the standard configuration properties described in Chapter 4 the Orbacus Interface Repository also supports the following properties ooc ifr options OPTS Allows command line options to be passed to the Windows NT Native service at start up Note that absolute pathnames should be used when specifying include directives IDL files etc ooc ifr endpoint ENDPOINT Specifies the endpoint configuration for the service Note that this property is only used if the ooc orb oa endpoint property is not set 261 CHAPTER 13 The Interface Repository Connecting to the Interface Repository The object key of the IFR is DefaultRepository which identifies an object of type CORBA Repository The object key can be used when composing URL style object references For example the following URL identifies the IFR running on host ifrhost at port 10000 corbaloc ifrhost 10000 DefaultRepository Refer to Chapter 6 for more information on URLs and configuring initial services 262 Configuration Issues Configuration Issues Although applications can interact with the IFR as with any other CORBA server it does have special status within the ORB Specifically use of the standard operation object get_interface requir
532. ts MD5 515 CHAPTER 1 Using FreeSSL for Orbacus 516 Table 1 Supported Cipher Suites Name Key Alg Symmetric Alg MAC Calc FSSL_RSA_WITH_RC4_128 SHA RSA RC4 128 bits SHA FSSL_RSA_EXPORT_WITH_RC2_CBC_40 MD5 RSA RC2 40 bits MD5 FSSL_RSA_WITH_IDEA_CBC_SHA RSA IDEA 128 bits SHA FSSL_RSA_EXPORT_WITH_DES40_CBC_SHA RSA DES 40 bits SHA FSSL_RSA_WITH_DES_CBC_SHA RSA DES 56 bits SHA FSSL_RSA_WITH_3DES_EDE_CBC_SHA RSA DES 168 bits SHA FSSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA RSA DES 40 bits SHA FSSL_DHE_RSA_WITH_DES CBC_SHA RSA DES 56 bits SHA FSSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA RSA DES 168 bits SHA FSSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA DSS DES 40 bits SHA FSSL_DHE_DSS_WITH_DES CBC_SHA DSS DES 56 bits SHA FSSL_DHE_DSS_WITH_3DES EDE_CBC_SHA DSS DES 168 bits SHA FSSL_DH_anon_EXPORT_WITH_RC4_40 MD5 ADH RC4 40 bits MD5 FSSL_DH_anon_WITH_RC4_128 MD5 ADH RC4 128 bits MD5 FSSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA ADH DES 40 bits SHA FSSL_DH_anon_WITH_DES CBC_SHA ADH DES 56 bits SHA FSSL_DH_anon_WITH_3DES EDE_CBC_SHA ADH DES 168 bits SHA Note Not all algorithms are supported in JSSE Installation Plug in Installation Client Installation Installation The FSSL plug in is an implementation of the Orbacus Open Communi
533. ts and servers can specify any routers they want to use for the routing of requests and replies to them via the configuration file property ooc ami router where is a unique integer that differentiates the router from other routers in the list When the list of router property keys is sorted in increasing order which is done automatically by the client or server routers that appear later in the list are given preference when routing request replies over routers that appear earlier in the list The value for the coc ami router property is a string that represents an object reference or location to be used for contacting the router These can be specified in one of the following four formats 1 An object reference file for example router1 ref ooc ami router 1 relfile routerl ref 2 Astringified IOR object reference ooc ami router 2 I0R 013074b70d00000049444c3a4563686f3a3 3 Acorbaloc address ooc ami router 3 corbaloc localhost 20000 AMIRouter The Orbacus AMI router uses the stringified object key AMIRouter 4 A host port combination in the format lt host gt lt port gt ooc ami router 4 localhost 20000 Note Using corbalocs or host port combinations limits the functionality of the router administration as these methods provide incomplete object references that prevent the router administration from doing proper object comparisons 343 CHAPTER 17 Asynchronous Method Invocation Sample configuration file Applicat
534. ts from the target filter object Parameters id_list A list of constraint IDs representing the constraints to be retrieved Returns The constraints associated with the target filter object with the given IDs If one or more of the IDs are not found the const raintNotFound exception is raised get_all_constraints ConstraintInfoSeq get_all_constraints Retrieve all constraints associated with the target filter object Returns All constraints associated with the target filter object remove_all_constraints void remove_all_constraints Remove all constraints associated with the target filter object destroy void destroy Destroys the target filter object match boolean match in any filterable_data raises UnsupportedFilterableData Compare the filter constraints from the target filter object with the supplied event Parameters 859 CHAPTER F CosNotifyFilter Reference 860 filterable_data The event to be evaluated in the form of a CORBA Any Returns Returns TRUE if the event satistifes at least one constraint FALSE otherwise If the filterable data of the input event contains data that the match operation cannot handle an UnsupportedFilterableData exception is raised match_structured boolean match_structured in CosNotification StructuredEvent filterable_data raises UnsupportedFilterableData Compare the filter constraints from the target filter object with the supplied ev
535. ty property value StartTime const string StartTime StartTime Gives an absolute time e g 12 12 99 at 23 59 after which the channel may deliver the event The value for this property is of type TimeBase UtcT StopTime const string StopTime StopTime Gives an absolute time e g 12 12 99 at 23 59 at which the channel should discard the event The value for this property is of type TimeBase UtcT Timeout const string Timeout Timeout Gives a relative time e g 10 minutes from time received after which the channel should discard the event The value O indicates there is no timeout The value for this property is of type TimeBase TimeT OrderPolicy const string OrderPolicy OrderPolicy This QoS property sets the policy used by a given proxy to order the events it has buffered for delivery either to another proxy or a consumer Constant values to represent the permitted settings are defined AnyOrder const short AnyOrder 0 OrderPolicy property value indicating any ordering policy is permitted FifoOrder const short FifoOrder 1 OrderPolicy property value indicating events should be delivered in the order of their arrival Module CosNotification PriorityOrder const short PriorityOrder 2 OrderPolicy property value indicating events should be buffered in priority order such that higher priority events will be delivered before lower priority events DeadlineOrder const short Deadl
536. u can reverse the sort order by 218 The Menus selecting the current sorting mode a second time in the View menu or by clicking on the table header cells In this case the display switches from ascending to descending order and vice versa If the contents of a naming context have been changed by a third party and you want to update the information displayed in the console window selecting Refresh updates the display If the console is connected to Orbacus Names a refresh is done automatically each time a change occurs 219 CHAPTER 10 Orbacus Names Console The Tools Menu 220 The operations available in this menu are meant as tools for your everyday work Ping Checks the accessibility of the selected items Clean up Unbinds inaccessible objects from the current context Sometimes it is useful to check if an object bound to a name still exists or if the object reference associated with it has become invalid for example because of a server crash To perform such a check select all the objects you want to check and start the Ping operation The console tries to contact each of the selected objects and displays the time it took to get a connection to them in a separate window ORBacus Names Ping Window olx Sophed luke software Sophed demosophe esr Sophed i luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr Sophed luke software Sophed demosophe esr So
537. u supply is output file then irgen will produce output file cpp output file h output file_skel cpp and output file_skel h Note that irgen will generate code for a of the type definitions contained in the Interface Repository server See Chapter 13 for more information on the Interface Repository 44 The IDL to C Translator and the Interface Repository The IDL to C Translator and the Interface Repository Private Versus Global Interface Repositories Steps Example The Orbacus IDL to C and IDL to Java translators internally use the Interface Repository for generating code That is these programs have their own private Interface Repository that is fed with the specified IDL files All code is generated from that private Interface Repository However it is also possible to generate C code from a global Interface Repository To generate C code from a global Interface Repository 1 Start the Interface Repository using the command irserv 2 Feed the Interface Repository the IDL code using the command irfeed 3 Finally use the irgen command to generate the C code For example irserv ior gt IntRep ref amp irfeed ORBrepository cat IntRep ref file idl irgen ORBrepository cat IntRep ref file By comparison the IDL to C translator ia1 performs all these steps at once in a single process using a private Interface Repository Thus you only have to run a single command idl
538. ule OCI IIOP Interface OCI IIOP ConnectorInfo Synopsis Attributes local interface ConnectorInfo inherits from OCI ConnectorInfo Information on an IIOP OCI Connector object See Also Interface OCI Connector Interface OCI Connector nfo remote_addr readonly attribute InetAddr remote_addr The remote IP address to which this connector connects remote_port readonly attribute unsigned short remote_port The remote port to which this connector connects 489 CHAPTER E Open Communications Interface Reference Interface OCI IIOP ConFactoryInfo Synopsis 490 local interface ConFactoryInfo inherits from OCI ConFactoryInfo Information on an IIOP OCI Connector Factory object See Also Interface OCI ConFactory Interface OCI ConFactoryInfo Module OCI IIOP Interface OCI IIOP AcceptorInfo Synopsis Attributes local interface AcceptorInfo inherits from OCI AcceptorInfo Information on an IIOP OCI Acceptor object See Also Interface OCI Acceptor Interface OCI AcceptorInfo hosts readonly attribute CORBA StringSeq hosts Hostnames used for creation of IIOP object references addr readonly attribute InetAddr addr The local IP address on which this acceptor accepts port readonly attribute unsigned short port The local port on which this acceptor accepts 491 CHAPTER E Open Communications Interface Reference Interfac
539. ull_consumer A reference to the consumer object A nil reference is permitted Interface Module CosNotifyChannelAdmin CosNotifyChannelAdmin SequenceProxyPullSupplier Operations interface SequenceProxyPullSupplier inherits from CosNotifyChannelAdmin ProxySupplier CosNotifyComm SequencePullSupplier The SequenceProxyPullSupplier interface supports connections from consumers who wish to pull sequences of structured events from the channel connect_sequence_pull_consumer void connect_sequence_pull_consumer in CosNotifyComm SequencePullConsumer pull_consumer raises CosEventChannelAdmin AlreadyConnected Connects a consumer to the channel If a consumer is already connected the AlreadyConnected exception is raised Parameters pull_consumer A reference to the consumer object A nil reference is permitted 819 CHAPTER D CosNotifyChannelAdmin Reference Interface CosNotifyChannelAdmin ProxyPullConsumer Operations 820 interface ProxyPullConsumer inherits from CosNotifyChannelAdmin ProxyConsumer CosNotifyComm PullConsumer The ProxyPullConsumer interface manages connections from suppliers who wish to have unstructured events pull from them by the channel connect_any_pull_supplier void connect_any_pull_supplier in CosEventComm PullSupplier pull_supplier raises CosEventChannelAdmin AlreadyConnected CosEventChannelAdmin TypeError Connects a supplier to the channel If
540. ull_interval MSEC reap_frequency SEC retry_timeout MSEC retry_multiplier N ooc event request_timeout MSEC Usage Proxies that are inactive for the specified number of seconds will be reaped The default value is four hours The maximum number of events in each event queue If this limit is reached and another event is received the oldest event is discarded The default value is 10 The maximum number of times to retry before giving up and disconnecting the proxy The default value is 10 Specifies the endpoint configuration for the service Note that this property is only used if the ooc orb oa endpoint property is not set This specifies the number of milliseconds between successive calls to pull on PullSupplier Default value is 0 This specifies the frequency in seconds in which inactive proxies will be reaped The default value is thirty minutes Setting this property to O disables the reaping of proxies Specifies the initial amount of time in milliseconds that the service waits between successive retries The default value is 1000 A double that defines the factor by which the retry_timeout property should be multiplied for each successive retry The amount of time permitted for a blocking request on a client to return before a timeout The default value is 5 seconds 241 CHAPTER 12 Orbacus Events ooc event trace events LEVEL Defines the output level for event diagnostic messages printed by Orb
541. unications Interface Reference Module OCI Aliases 452 BufferSeq typedef sequence lt Buffer gt BufferSeq Alias for a sequence of buffers IOR typedef IOP IOR IOR Alias for an IOR Profileld typedef IOP ProfileId Profileld Alias for a profile id ProfileldSeq typedef sequence lt ProfileId gt ProfileIdSeq Alias for a sequence of profile ids Pluginld typedef string PluginlId Alias for a plugin id PluginIdSeq typedef sequence lt PluginId gt PluginIdSeq Alias for a sequence of plugin ids ObjectKey typedef CORBA OctetSeq ObjectKey Alias for an object key which is a sequence of octets TaggedComponentSeq typedef IOP TaggedComponentSeq TaggedComponentSeq Alias for a sequence of tagged components Handle typedef long Handle Alias for a system specific handle type Constants Module OCI ProfilelnfoSeq typedef sequence lt ProfileInfo gt ProfileInfoSeq Alias for a sequence of basic information about profiles ParamSeq typedef sequence lt string gt ParamSeq Alias for a sequence of parameters CloseCBSeq typedef sequence lt CloseCB gt CloseCBSeq Alias for a sequence of close callback objects ConnectorSeq typedef sequence lt Connector gt ConnectorSeq Alias for a sequence of Connectors ConnectCBSeq typedef sequence lt ConnectCB gt ConnectCBSeq Alias for a sequence of connect callback objects ConFactorySeq typedef sequence lt ConFactory gt ConFactorySeq
542. until timeout milliseconds have passed The thread then waits until it can regain ownership of the monitor s lock and then resumes execution Parameters timeout The maximum number of milliseconds to wait for notification Throws JTCIllegalMonitorStateException If the monitor is not locked by the calling thread JTCSystemCallException Indicates a failed system call notify void notify Wakes a single thread waiting on the monitor The calling thread must own the monitor s lock notifyAll void notifyAll Wakes all threads waiting on the monitor The calling thread must own the monitor s lock 639 CHAPTER A Class Reference JTCMonitorT Overview This is a template class that allows creation of synchronized classes without altering the implementation Member Functions wait void wait Waits for notification by another thread The calling thread must own the monitor s lock The monitor s lock is released and the thread waits for notification by another thread via a call to either notify or notifyAll The thread then waits until it can regain ownership of the monitor s lock and then resumes execution Throws JTCIllegalMonitorStateException If the monitor is not locked by the calling thread JTCSystemCallException Indicates a failed system call wait wait long timeout Waits for notification by another thread The calling thread must own the monitor s lock The monitor s lock is relea
543. ur new persistent POA This class must be created by the user and derived from the generated AMI_EchoHandlerPoa Sample code for an AsyncEchoHandler can be found in the AsyncEchoHandler java file located in the ob demo AMI echo_reply_router demo folder Create the Echo object based on the IOR in the Echo ref file Make the deferred call passing the handler as the first parameter AMI Poller Implementation AMI Poller Implementation Overview C In the poller implementation the user is returned a poller object from the deferred AMI request or sendp_ call The user can then query this poller object to find out when a request has completed This is shown in the C and Java code examples that follow For complete code please see the EchoClient cpp file in the ob demo AMI echo_poll_router directory of the Orbacus for C distribution il CORBA Object_var obj orb gt string_to_object relfile Echo ref g Echo_var echo Echo _narrow obj 3 AMI_EchoPoller_var poller echo gt sendp_echo_message L Hello 4 CORBA WString_var reply 5 CORBA ULong max_timeout CORBA ULong 1 6 poller gt echo_message max_timeout reply Create the Echo object based on the IOR in the Echo ref file Make the deferred call which returns an AMI_EchoPoller object based on the generated class Note that the user does not have to override this class as must be done for the Reply Handler implementation
544. urrency model to a property set that is used to initialize the ORB i ff Ci 2 OB Properties_var dflt OB Properties getDefaultProperties 3 OB Properties_var props new OB Properties dflt props gt setProperty ooc orb conc_model threaded CORBA ORB_var orb OBCORBA ORB_init argc argv props aw Create an oB Properties object that is based on the default properties This is important because unlike org omg CORBA ORB init OBCORBA ORB_init does not read the default properties if the property parameter is not null Define Orbacus property Initialize the ORB using the Orbacus specific oBcoRBA ORB_init operation 73 CHAPTER 4 ORB and Object Adapter Initialization Precedence of Properties 74 Given that properties can be defined in several ways it s important to establish the order of precedence used by Orbacus when collecting and processing the property definitions The order of precedence is listed below from highest to lowest Properties defined at a higher precedence override the same properties defined at a lower precedence 1 2 3 4 al Command line options Configuration file specified at the command line User supplied properties Configuration file specified by the oRBacus_conF IG environment variable C or the ooc config system property Java System properties Java only HKEY_CURRENT_USER Software 00C Properties Windows NT C only HKEY_LOCAL_MACHIN
545. use access to a long value in Java is not atomic It is not possible to inherit from JTCMonitor if static member functions need to be synchronized since the stcSynchronized class requires this as the argument to its constructor which is not available within static member functions To solve this problem a static data member of type JTcMonitor is used to synchronize static member functions 597 CHAPTER 3 Working With Threads This is the Java example converted to C 1 class Stat icCounter Ba 3 Static long counter 4 statie JICMonitor mon y 5 G jouloliees 7 8 static void increment 9 0 JTCSynchronized sync mon_ Al FE COmn team 2 3 4 static void decrement 5 6 JTCSynchronized syne mon Fi COn CSE Ff 8 9 20 static long value 2m 22 JTCSynchronized sync mon_ 23 return counter 24 BS We 26 2 long StaticCounter tcounter_ 0 28 JI Monitor StaticCounter mon_ 4 A static JTCMonitor instance variable is declared This allows the class to be synchronized 10 16 22 The methods are synchronized Instead of using this the static variable mon_ is used Note that there are certain restrictions on the use of static monitors It is not correct to use a static monitor before an instance of stcInitialize has been created Any use before initialization of JThreads C will result in undefined behavior Additionally the monitor class must not be used after the final instance of the JTCInitia
546. use the Orbacus ORB instead of the JDK s ORB The ORB must be initialized using orB init The ORB class resides in the package org omg CORBA You must either import this package or as shown in this example you must use org omg CORBA explicitly The run helper function is called This code catches and prints all CORBA exceptions raised by orB init or run If the ORB was successfully created it is destroyed This releases the resources used by the ORB If destroy raises a CORBA exception this exception is caught and printed The exit status is returned If there was no error o is returned or 1 otherwise Server class run method 15 28 30 31 Implementing the Example in Java Add the run method to Server java woMmAt nao amp FWDN EF OoarANnNO PWN FE CO wo 20 21 22 23 24 25 26 27 28 29 30 Sil 32 33 34 Java Stetic int run org omg CORBA ORe ofp throws org omg CORBA UserException org omg PortableServer POA rootPOA org omg PortableServer POAHelper narrow orb resolve_initial_references RootPOA org omg PortableServer POAManager manager rootPOA the_POAManager Hello_impl helloImpl new Hello_impl Hello hello helloImpl _this orb Ery String ref orb object_to_string hello String refFile Hello ref java io PrintWriter out new java io PrintWriter new java io FileOutputStream refFile out printin ref out close
547. used in Java and 5 in C bind ADDR Specifies the hostname or dotted decimal address of the network interface on which to bind the socket If not specified the socket will be bound to all available interfaces This option is useful in situations where a host has several network interfaces but the server should only listen for connections on a particular interface host ADDR ADDR Specifies a list of one or more hostnames and or dotted decimal addresses representing the addresses that should be advertised in IORs Using IIOP 1 0 or 1 1 multiple addresses are represented as multiple tagged profiles Using IIOP 1 2 multiple addresses can be represented as either multiple tagged profiles or as a single tagged profile with a tagged component for each additional address The multi profile option determines how multiple addresses are represented in IIOP 1 2 If host is not specified the canonical hostname is used multi profile If set multiple addresses in the host option are represented as multiple tagged profiles in an IOR By default multiple addresses are represented as a single tagged profile using the first address in the host list as the primary address with all additional addresses represented as alternate addresses in tagged components If IIOP 1 0 or 1 1 is in use multiple addresses are always represented as multiple tagged profiles no keepalive Disable the use of TCP keepaliv
548. used to acquire and release a write lock To create a synchronized method an instance of this class should be created with the JTCRWMutex as the constructor argument The constructor acquires the lock and the destructor releases the lock Constructor JTCWriteLock JTCWriteLock const JTCRWMutex amp mon Acquires the mutex s lock for writing The destructor releases the mutex s lock Throws JTCSystemCallException Indicates a failed system call 651 CHAPTER A Class Reference JTCThreadlid Member Functions 652 This class represents a thread id The only operations that should be used are equality and inequality Two thread objects may be considered to be equal if their thread ids are equivalent A user should not directly construct instances of this class operator bool operator const JTCThreadId amp rhs Compares for equality Parameters rhs The thread id with which to compare Returns true if the thread ids are equivalent false otherwise operator bool operator const JTCThreadId amp rhs const Compares for inequality Parameters rhs The thread id with which to compare Returns true if the thread ids are not equivalent false otherwise JTCThreadKey Overview This type represents a thread specific storage key JTCThreadKey should be used as an opaque type 653 CHAPTER A Class Reference JTCTSS Overview Member Functions 654 This class is used to ma
549. utex is locked for the first time false otherwise unlock bool unlock const This method is called by the owner of the mutex to release it The mutex must be locked and the calling thread must be the one that last locked the mutex If these conditions are not met undefined behavior will result Returns true if the mutex is available for locking by some other thread false otherwise trylock bool trylock const This method is identical to lock except that if the mutex is already locked then false is returned Returns true if the mutex was locked false otherwise get_owner JTCThreadId get_owner const Return the thread id of the owning thread Returns The thread id of the owning thread 643 CHAPTER A Class Reference JTCMutex Overview Member Functions 644 This class can be used to establish a critical section This class has no direct equivalent in Java It is provided for performance reasons only Unlike JTCMonitor Of JTCRecursiveMutex this class not does guarantee recursive locking semantics If the mutex is locked more than once by the same thread a deadlock may result 1 lock bool lock const Lock the mutex If the mutex is already locked the calling thread blocks until the mutex is unlocked If the current owner of the mutex attempts to re lock the mutex a deadlock may result Returns This method always returns true unlock bool unlock const This method is called by the owner
550. utput stream in which to insert the thread id g Reference to the thread group Returns The output stream os JTCHandleT Overview Constructors Member Functions The JThreads C library cannot know when to delete instances of JTCThread JTCRunnable and JTCThreadGroup One solution to this dilemma is to force application developers to delete instances of these classes when they are sure the instances are no longer useful However this is error prone Fortunately there is a well known solution to this problem reference counting see 5 p 782 This isn t necessary in Java since it provides garbage collection The basic idea is to count the number of references to the object and delete the object when the reference count drops to zero To ease the counting of references a handle class is used that increments the reference count when constructed and decrements the reference count when destructed The gTcHandleT is a smart pointer to a reference counted object A regular pointer to instances of these classes should never be stored The classes JTCThreadGroupHandle JTCThreadHandle and JTCRunnableHandle are all convenience typedefs of this template class JTCHandleT JTCHandleT T tg 0 Creates a handle that refers to the object tg Parameters tg The object to reference JTCHandleT JTCHandleT const JTCHandleT lt T gt amp rhs Creates a handle that refers to the object referred to by rhs Parame
551. value is 10 This property is only effective when the ooc orb oa conc_model property has the value leader_follower Value n gt O Determines the number of threads to reserve for servicing incoming requests The default value is 10 This property is only effective when the ooc orb oa conc_model property has the value thread_pool Value 1 0 1 1 or 1 2 ooc orb poamanager manager co nc_model ooc orb poamanager manager en dpoint ooc orb poamanager manager lea der_follower_pool 00c orb poamanager manager ver sion Configuring the ORB and Object Adapter Specifies the GIOP version to be used in object references The default value is 1 2 This option is useful for backward compatibility with older ORBs that reject object references using a newer version of the protocol Value reactive threaded Specifies the communications concurrency model used by the POA Manager with name manager The default value is determined by ooc orb oa conc_model See Chapter 18 for more information on concurrency models Value string Specifies a comma separated list of endpoints for the POA Manager with name manager The default value is iiop See Endpoints on page 84 for more information Value n gt O Determines the number of threads in the pool used by the leader_follower concurrency model The default value is 10 This property is only effective when the ooc orb poamanager manager conc_model property has the valu
552. values 3 displays the call stack 4 displays object id adapter id effective profile The tracing levels are cumulative i e the higher levels include the output generated by the lower levels In order to make request parameters results and exceptions available for tracing the option with interceptor args has to be specified to the IDL compiler 302 Installing Watson in C Installing Watson in C 2 4 10 16 If Orbacus was built with shared libraries or DLLs Orbacus Watson can be installed dynamically by defining the following configuration properties ooc orb modules watson ooc orb module watson lt library name gt Please refer to Chapter 4 for more information on these properties If Orbacus was built statically the module initialization function has to be called directly from the application code io ff CMe 2 if defined HAVE_SHARED amp amp defined OB_DLL 3 include lt OB watson h gt 4 endif 5 6 int main int argc char argv 7 8 CORBA ORB_var orb state 0O if defined HAVE_SHARED amp amp defined OB_DLL 1 he 2 When linking statically we need to explicitly initialize 3 Watson 4 iy 5 init_module_watson 6 endif Il 8 orb CORBA ORB_init argc argv 9 20 Include oB watson h only when building statically Explicitly install the Watson module prior to initializing the ORB Specifying the configuration property coc orb modules watson
553. vants using C If NO_IMPLICIT_ACTIVATION and sysTEM_ID are in effect for a servant s POA you activate the servant by calling activate_object i owe ayes 2 PortableServer POA_var poa impl _default_POA 3 poa gt activate_object amp imp1 1 The code instantiates a servant 2 To activate a servant we need the servant s POA activate_object creates a unique ID for the servant Once a servant is activated calls to this on the servant return an object reference that contains the ORB assigned ID for the object If NO_IMPLICIT_ACTIVATION and USER_ID are in effect for servant s POA you activate the servant by supplying the ID value as an octet sequence to activate_object_with_id Tmall angels PortableServer POA_var poa impl _default_POA PortableServer ObjectId_var oid PortableServer string_to_ObjectId MyObjectName poa gt activate_object_with_id oid amp impl Gr iss Gay ss a 3 4 The string_to_Objectid helper function converts a string into an octet sequence 5 activate_object_with_id uses the octet sequence as the object ID for the servant You can use any suitable key value as an object ID Typically the key will be part of the object s state such as a social security number However you can also use keys that are not directly related to object state such as database record identifiers Once the servant is activated calls to_this on the servant return an object reference that contai
554. ve the template poa_i_tie is generated and must be instantiated with a class that implements all operations of 1 By convention the name of this class should be the name of the interface with _imp1_tie appended 1 Note that tie classes are rarely necessary Not only is the inheritance implementation less complex but it also avoids a number of problems that arise with the life cycle of objects particularly in threaded servers We suggest that you use the tie approach only if you have no other option 2 Again you are free to choose whatever name you like This is just a recommendation 98 Implementing Servants In contrast to the inheritance based approach it is not necessary for the class implementing 1 s operations i e I_imp1_tie to be derived from a skeleton class Instead an instance of poa_t_tie delegates all operation calls to I_imp1_tie as shown in Figure 3 POALI d POA tie Vaelegates to _impl_tie Figure 3 Class Hierarchy for Delegation Implementation in C Here is our definition of I_impl_tie fil C class I_impl_tie PUDITE virtual void op_a throw CORBA SystemException virtual void op_b throw CORBA SystemException virtual void op_i throw CORBA SystemException OA A a F amp F WDN FE I_impl_tie is defined and not derived from any other class I_impl_tie must implement all of 1 s operations including inherited operations
555. vice initial reference myclient ORBInitRef NameService corbaloc nshost 10000 NameService The oRBconfig option is an alternative method for defining a list of initial services and is often preferable when a number of services must be defined See Configuring the ORB and Object Adapter on page 57 for more information on these command line options Also refer to the INS specification 10 for detailed information on the standard options ORBInitRef and ORBDefaultInitRef In addition to using command line parameters a program can add to the list of initial services using the ORB operation register_initial_reference if Wily module CORBA interface ORB void register_initial_reference in ObjectId id in Object obj raises InvalidName For example in C iY Cire 2 CORBA Object_var obj Get a name service reference somehow 3 orb gt register_initial_reference NameService obj 1 This will become part of the ORB interface when the Portable Interceptor specification is adopted 151 CHAPTER 6 Locating Objects 152 Get a reference to the naming service for example by reading a stringified object reference and converting it with string_to_object or by any other means Add the reference to the ORB s list of initial references Or in Java Y EE 2 org omg CORBA Object obj Get a name service reference somehow 3 orb register_initial_reference NameService obj
556. vice is be placed in the Windows NT Event Viewer with the title Balancer To enable tracing information add the desired trace configuration property i e one of the ooc balancer trace properties or one of the coc orb trace properties to the HKEY_LOCAL_MACHINE NT registry key with a REG_sz value of at least 1 275 CHAPTER 14 Orbacus Balancer Configuration Properties ooc balancer administrative ooc balancer dbdir ooc balancer admin_endpoint ooc balancer forward_endpoint ooc balancer trace database ooc balancer trace lifecycle ooc balancer trace load_balance 276 In addition to the standard configuration properties described in Chapter Orbacus Balancer also supports the following properties Value true false If set to true then run the service in administrative mode For details refer to the a command line option Value directory Equivalent to the a command line option Value info Equivalent to the a command line option Value info Equivalent to the command line option Value jeve l gt O Defines the output level for database diagnostic messages printed by the service The default level is O which produces no output A level of 1 or higher produces database information e g loading adding and removing group records in the database Value evel gt O Defines the output level for lifecycle diagnostic messages printed by the service The default level
557. view Supported Policies Programming Examples Connection Reuse Policy Retry Policy Timeout Policy Interceptor Call Policy CommunicationsConcurrencyPolicy EndpointConfigurationPolicy GlOPVersionPolicy Bidirectional Policy Chapter 17 Asynchronous Method Invocation viii 272 273 274 276 278 281 282 283 284 285 286 287 288 289 294 298 301 302 303 304 305 306 307 308 309 312 313 316 318 319 321 323 325 327 331 CONTENTS Introduction 332 AMI Router 333 Router Usage 334 Router Administration Properties 335 AMI Reply Handler Implementation 337 AMI Poller Implementation 341 Configuring Clients and Servers 343 Chapter 18 Concurrency Models 347 Concurrency Models 348 Single Threaded Concurrency Model 350 Multi Threaded Concurrency Models 353 Threaded Clients and Servers 354 Thread per Client Server 356 Thread per Request Server 357 Thread Pool Server 358 Leader_Follower 359 The Reactor 360 The X11 Reactor 361 The Windows Reactor 362 Chapter 19 The Open Communications Interface 363 Interface Summary 364 Class Diagram 366 OCI Reference 367 A Converter Class for Java 368 Getting Hostnames and Port Numbers 369 Determining a Client s IP Address 371 Determining a Server s IP Address 373 The IIOP OCI Plug in 375 Endpoint Configuration 376 Command line Options 378 Static Linking 379 The UDP OCI Plug in 380 Client Installation 381 Server Installation 382 Endpoint Configuration 383 S
558. virtual PortableServer POA_ptr _default_POA 7 he Private member to store the servant s default POA A constructor must be defined to allow the assignment of the servant s default POA Declaration of the _default_poa method Programming Example The remainder of the class declaration is unchanged The definition of the constructor and _default_Poa method follow 0 a ee gt OO eo 3 Sy e a Jil Cite Hello_impl Hello_impl PortableServer POA_ptr poa poa_ PortableServer POA _duplicate poa PortableServer POA_ptr Hello_imp1 _default_POA return PortableServer POA _duplicate poa_ 177 CHAPTER 7 The Implementation Repository 178 The modified portion of the server program is shown below oof Car 2 Saline 4 run CORBA ORB_ptr orb int argc a i 6 CORBA Object_var poaObj F orb gt resolve_initial_references RootPOA 8 PortableServer POA var rootPoa 9 PortableServer POA _narrow poa0bj 0 iL PortableServer POAManager_var manager 2 rootPoa gt the_POAManager 3 4 CORBA PolicyList pl 2 5 pl length 2 6 pl 0 rootPOA gt create_lifespan_policy 7 PortableServer PERSISTENT 8 pl 1 rootPOA gt create_id_assignment_policy 9 PortableServer USER_ID 20 eal PortableServer POA_var helloPOA 22 rootPOA gt create_POA hello manager pl 20 24 Hello _impl helloImpl new Hello_imp1 helloPOA 25 Portab
559. void this problem we will use a helper class which converts port numbers and IP addresses to Java int types This helper class looks as follows 1 Java 2 final class Converter 3 y 4 Mesieae dar joerc Slavoveie S 5 6 tits lt 0 wi return ORAM t intis ils 8 else 9 return int s 0 dL 2 static int addr byte bArray 3 4 int iArray new int 4 3 f rlint at 9 al 4 6 Gist 6 if bArray i lt 0 i iArray i Oxff int bArray i 1 8 else 9 iArray i int bArray i 20 2u return iArray 22 2S We 4 10 Converts short port numbers to int 12 22 Converts byte IP addresses to int The converter class is used throughout the examples in the sections below 368 OCI Reference Getting Hostnames and Port Numbers 10 12 16 The following code fragments show how it is possible to find out on what hostnames and port numbers a server is listening First the C version Jl CBRE OCI AcceptorSeq_var acceptors poaManager gt et_acceptors OCI AcceptoriInfo_var info acceptors i gt get_info OCI IIOP AcceptorInfo_var iiopInfo T 2 gi 3 4 for CORBA ULong i 0 i lt acceptors gt length i 5 6 Tl 8 OCI IIOP AcceptorInfo _narrow info S 0 te CORBAN To EME pN EO 1 2 CORBA StringSeq_var hosts iiopInfo gt hosts 3 CORBA UShort port iiopInfo gt port 4 5 cout lt lt host lt lt
560. w i Cart const int numChars 26 forint L O 7 1 lt nuMeharrsie TFI courti Pus Mno eend CosNotification_StructuredEvent_var event CreateNewEvent i structuredProxyPushConsumer gt push_structured_event event And in Java Java final int numChars 26 Om nie OM i lt punChars y tha System out printin Pushing StructuredEvent event createNewEvent orb i structuredProxyPushConsumer push_structured_event event 1 A servant is required if the supplier is interested in knowing when it is disconnected or when the channel subscription information changes 739 CHAPTER 4 Programming Example The different types of push suppliers have similar but distinct IDL interfaces The IDL for the structured push supplier is ff Dy interface StructuredPushSupplier NotifySubscribe void disconnect_structured_push_supplier hi Our example does not implement this interface for reasons stated earlier Pull Supplier Unlike the push supplier the pull supplier assumes a passive role in event delivery The push supplier is active in that it initiates event delivery on the channel Conversely the pull supplier is passive and has events pulled from it by the channel For this reason the pull supplier must implement a servant which incarnates a CORBA object capable of accepting requests from Orbacus Notify Separate but similar IDL interfaces exist for the any structured and sequence pull
561. xample in C Implementing the Server Overview Hello_impl definition To implement the server we need to define an implementation class for the Hello interface To do this we create a class Hello_imp1 that is derived from the skeleton class POA_Hello defined in the file Hello_skel h Create a file Hello_impl h and enter the class definition of Hello_imp1 shown below Lif Cats include lt Hello_skel h gt class Hello_impl public POA_Hello public PortableServer RefCountServantBase puple 0o I D O e w o e Koj virtual void say_hello 10 throw CORBA SystemException dle Since our implementation class derives from the skeleton class POA_Hello we must include the file Hello_skel h Here we define Hello_imp1 as a class derived from PoA_Hello and RefCount ServantBase RefCount ServantBase is part of the PortableServer namespace and provides reference counting Our implementation class must implement all operations from the IDL interface In this case this is just the operation say_hello 11 CHAPTER 2 Getting Started Hello_impl implementation Create a file Hel1lo_imp1 cpp and enter the class implementation of Hello_imp1 shown below i ff Came 2 include lt iostream h gt 3 include lt OB CORBA h gt 4 include lt Hello_impl h gt 5 6 void Hello_impl say_hello throw CORBA SystemException qr 8 cout lt lt Hello World lt lt endl oO F 3 We must inclu
562. y Bibliography 1 2 Object Management Group 2000 Notification Service Specification ftp ftp omg org pub docs formal OO 06 20 pdf Framingham MA Object Management Group Object Management Group 2001 Event Service Specification ftp ftp omg org pub docs formal O1 03 01 pdf Framingham MA Object Management Group 873 CHAPTER H 874 Index A amirouter 334 B Basic Object Adapter 93 Bindings 197 BOA 93 C Callbacks 87 Command line Options 68 Concurrency Models Threaded 354 Thread per Client 356 Thread per Request 357 Thread Pool 358 Configuration File 70 Currently Executing Request 122 D Documenting IDL Files 47 E Event Channel 246 Event Consumers 247 Event Loop 89 Event Service 237 Event Suppliers 247 Exceptions 399 H Hello World example application 8 Hostname 131 369 HTML 47 IFR 257 Implementation Repository 157 159 Implementation Repository Administration 170 IMR 157 159 IMR Console 181 included IDL files 46 Initial Services 144 154 Configuring 151 Resolving 149 Interface Repository 257 IP Address 371 373 irdel 264 irfeed 264 J javadoc 49 M message URL http java sun com products jdk 1 2 docs guide misc threadPrimitiveDeprecation html 667 N Names Console 211 Name Service Configuration 193 Initialization 201 Persistence 194 0 OAD 159 Object Activation Daemon 159 Object Adapter Configuration 65 Initialization 56 Obje
563. y the plug in splits a single request into multiple packets of the specified size and reassembles them on the server Note that there are hard operating system limits on the size of a datagram The default size is 1472 which is the largest portable size no loopback Specifies that loopback mode of the socket shall be disabled for multicast communication This prevents sending multicast packets back to the local socket For Java this functionality is only available from JDK 1 4 0 on ttl N Specifies the time to live value 0 255 of multicast packets sent System defaults apply if not specified trace N Sets the level of diagnostic output The default value is O Note The no loopback option for multicast communication is to be specified on the client side for Unix systems and on the server side for Windows systems 381 CHAPTER 19 The Open Communications Interface Server Installation The server side UDP plug in is installed as shown below ooc oci server udp trace N The following options are supported trace N Sets the level of diagnostic output The default value is O 382 The UDP OCI Plug in Endpoint Configuration The configuration options for a UDP endpoint are shown below udp bind ADDR buffer size N host ADDR ADDR message timeout SEC multicast no loopback tt1 N numeric port N transport timeout SEC bind
564. y Reference page 427 Reactor Reference page 443 Logger Reference page 447 Open Communications Interface Reference page 451 Orbacus Balancer Reference page 493 Orbacus Bibliography page 509 CHAPTER 1 Introduction to Orbacus This chapter gives a short overview of Orbacus In this chapter This chapter contains the following section Overview page 4 CHAPTER 1 Introduction to Orbacus Overview What is Orbacus Orbacus is an Object Request Broker ORB that is compliant with the Common Object Request Broker Architecture CORBA specification as defined in The Common Object Request Broker Architecture and Specification 4 C Language Mapping 5 IDL Java Language Mapping 6 and Portable Interceptors 7 The following sections highlight some of the features of Orbacus Ease of Use e Configuration and bootstrapping is simple Daemon less servers e Servers started automatically by the Implementation Repository URL style object references e Watson diagnostics and analysis method tracing within the ORB e Extensible Logging facility output to multiple devices e Documentation Tools Translators see Orbacus Translators on page 34 IDL to Hypertext Markup Language HTML IDL to Rich Text Format RTF e JThreads C Java like threading for C See JThreads on page 575 Qualities of Service e Load Balancing balance client requests across a s
565. y calling _this Note that implicit activation as shown requires the RETAIN IMPLICIT_ACTIVATION and SYSTEM_ID policies on the servant s POA The servant is activated with the POA that is returned by the servant s _default_PoA member function The default implementation of _default_poa returns the Root POA if you want servants activated on a different POA you must override _default_poa in the implementation class to return the POA you want to use 108 Activating Servants Implicit Activation of Servants using Java This is how Java servants are implicitly activated 1 Java 2 org omg CORBA ORB orb Get a reference to the ORB somehow 3 I_impl impl new I_impl 4 I Iref impl _this orb To activate a servant we need the ORB A new servant imp1 is created 4 The new servant is activated using the POA returned by the servant s _default_Poa operation As shown above a servant in Java must be associated with an ORB and cannot be associated with multiple ORBs The first call to _this must supply the ORB reference subsequent calls to _this for the same servant can omit the ORB reference An alternative way to associate a servant with an ORB is to call the set_delegate method defined in org omg CORBA_2_3 ORB Java org omg CORBA ORB orb Get a reference to the ORB somehow org omg CORBA_2_3 ORB orb set_delegate impl 109 CHAPTER 5 CORBA Objects Explicit Activation of Ser
566. y model any events PUSH_STRUCTURED Push delivery model structured events PULL_STRUCTURED Pull delivery model structured events PUSH_SEQUENCE Push delivery model sequence of structured events PULL_SEQUENCE Pull delivery model sequence of structured events ObtainInfoMode enum ObtainInfoMode ALL NOW_UPDATES_OFF ALL NOW_UPDATES_ON NONE_NOW_UPDATES_OFF NONE_NOW_UPDATES_ON Configures the mode by which event types are communicated during subscription sharing Members ALL_NOW_UPDATES_OFF Operation should return all types known by the target object and disable automatic updates ALL_NOW_UPDATES_ON Operation should return all types known by the target object and enable automatic updates NONE_NOW_UPDATES_OFF Operation should disable automatic updates and return no event types Module CosNotifyChannelAdmin NONE_NOW_UPDATES_ON Operation should enable aautomatic updates and return no event types ClientType enum ClientType ANY_EVENT STRUCTURED_EVENT SEQUENCE_EVENT Notification Service client types based on supported event type Members ANY_EVENT Supports unstructured event delivery STRUCTURED_EVENT Supports structured event delivery SEQUENCE_EVENT Supports sequences of structured events InterFilterGroupOperator enum InterFilterGroupOperator AND_OP OR_OP The InterFilterGroupOperator determines how filter results from an admin object an
567. y would exceed the limit for the target admin destroy void destroy Destroys the target admin object and all proxies it is managing Module CosNotifyChannelAdmin Interface CosNotifyChannelAdmin SupplierAdmin Attributes Operations interface SupplierAdmin inherits from CosNotification QoSAdmin CosNotifyComm NotifyPublish CosNotifyFilter FilterAdmin CosEventChannelAdmin SupplierAdmin The SupplierAdmin interface supports the creation of proxy consumers MyID readonly attribute AdminID MyID The ID assigned to the target admin object by the channel MyChannel readonly attribute EventChannel MyChannel A reference to the parent channel MyOperator readonly attribute InterFilterGroupOperator MyOperator The InterFilterGroupOperator to be used when combining filter results from the target admin object a its child proxies pull_consumers readonly attribute ProxyIDSeq pull_consumers A list of pull consumers managed by the target admin object push_consumers readonly attribute ProxyIDSeq push_consumers A list of push consumers managed by the target admin object get_proxy_consumer ProxyConsumer get_proxy_consumer in ProxyID proxy_id raises ProxyNotFound Obtains a reference to a proxy consumer with the given proxy ID Parameters proxy_id The ID of the proxy to locate A supplier admin object assigns an ID to each proxy it creates Returns 829 CHAPTER D CosNotifyChanne
568. ypedef sequence lt ConstraintExp gt ConstraintExpSeq Alias for a sequence of filter constraints ConstraintInfoSeq typedef sequence lt ConstraintInfo gt Constraint InfoSeq Alias for a sequence of constraint ID pairs MappingConstraintPairSeq typedef sequence lt MappingConstraintPair gt MappingConstraintPairSeq Alias for a sequence of mapping constraint pairs MappingConstraintInfoSeq typedef sequence lt MappingConstraintInfo gt MappingConstraint InfoSeq Alias for a sequence of constraint value pairs CallbackID typedef long CallbackID Alias for a callback ID CallbackIDSeq typedef sequence lt CallbackID gt CallbackIDSeq Alias for a sequence of callback IDs FilterID typedef long FilterID Structs Module CosNotifyFilter Alias for a filter ID FilterIDSeq typedef sequence lt FilterID gt FilterIDSeq Alias for a sequence of filter IDs ConstraintExp struct ConstraintExp CosNotification EventTypeSeq event_types string constraint_expr A single filter constraint Members event_types A sequence of event types which are matched against the event type information in the structured event header constraint_expr A constraint expression which conforms to some constraint grammar ConstraintInfo struct ConstraintInfo ConstraintExp constraint_expression ConstraintID constraint_id Used to maintain an association between filter constraints and constraint IDs Memb

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