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Leak Check® User`s Guide - Dynamic

1. Dynamic Leak Check Summary Critical errors 4 Boundary Overflows 1 Bytes leaked 3020 Blocks leaked 5 Unique stacks for leaks 5 Bytes potentially leaked 2000 Blocks potentially leaked 1 Unique potential leak stacks 1 Bytes suppressed 34411 Blocks suppressed 27 Unique suppressed stacks 22 Bytes in use 39463 Blocks in use 34 Peak bytes in use 43276 Critical errors 1 are memory errors that could cause a program to crash These include free without malloc freeing a pointer to the middle of a block and multiple free The total count of critical errors is provided here Boundary overflows 2 indicates the number blocks where the program has written beyond the boundaries of allocated memory If the program writes before the start of a block or beyond the end of a block the value is incremented by one If the program writes before and beyond the block the value is incremented by two Bytes leaked Blocks leaked and Unique stacks for leaks 3 indicate the total number of bytes and the number of allocations of heap memory leaked during program execution Additionally the number of unique stacks provides the user with an indication as to how many distinct leaks are in the executable program For example if the only leak in a program is in a loop that is executed 10 times there are 10 blocks leaked but the number of unique stacks is one Debug your operation Dynamic Memory
2. www dynamic memory com 15 Dynamic Memory Solutions To re enable the writing of banner information and results summary to standard output after it has been disabled execute this statement unset DYNQUIET The following options are supported DYNROOT directory The DYNROOT variable must be set in the users environment It contains the Leak Check installation directory DYNLICENSEFILE path and file name This variable overrides the default path to the license file If the license file is not located in the default directory then this option designates its location including full path and file name Default value is DYNROOT license license dat DYNPATH path This option designates an alternate path that Leak Check uses to locate the application source files Access to the source files allows Leak Check to provide more complete information about the memory errors within a program Multiple paths can be specified by delimiting their values with a colon within the value of DYNPATH For example DYNPATH myproduct libs libsrcdir myproduct src programsrcdir If this variable is not specified the path included by the compiler in the debug information within the object file will be used Default value is not set Debug your operation Dynamic Memory Solutions DYNOUTPUT directory The DYNOUTPUT variable specifies the directory where Leak Check writes the output f
3. Dynamic Leak Analyzepby Dynamic Memory Solutions www dynamic memory com 43 Dynamic Memory Solutions Detail Results The Detail Results tab contains four sub tabs that each display a different class of detailed results for the currently loaded Leak Check binary file These sub tabs are located at the bottom of the detail table The four sub tabs are Critical Errors Boundary Errors Memory Leaks and Potential Leaks Dynamic Leak Analyzer by Dynamic Memory Solutions E m Free w o Malloc 0x00924371 reportFreeWithoutMalloc example function2 64 example c tmp start exanple free example _start example main 100 example c ftnp reportMultipleFree example main 104 example c tmp Free w o Malloc Oxffbef6bO reportFreeWithoutMalloc example main 110 example c tmp Critical Errors 4 Each sub tab shows the number of errors reported for that class of detailed results After a Leak Check binary file is opened the first sub tab with errors of that class is automatically selected Each sub tab displays a table showing the details for that class of errors The columns for each table are specific to the class of errors Table columns may be resized by dragging the column separator on the table header Table rows may be expanded by clicking the right facing arrow at the left of the row Rows may be collapsed by clicking the downward facing arrow at the left of the row All rows in the table may also be expanded and c
4. DYNROOT env Exclusion files in the two directories are joined to create a complete list of functions and libraries to exclude from the reports The files in DYNROOT env are typically used to list standard C and C libraries or other 3 party libraries linked into the application and the files in the HOME directory are used by individual developers Libraries and functions to be excluded must be added to the exclusion file prior to running Leak Check www dynamic memory com 21 Dynamic Memory Solutions Understanding the results 22 When run Leak Check generates two or three output files The summary output file is always generated and is named program name PID dlcsum program name is the name of the user s executable and PID is the Process ID of this execution of the program If there are reportable errors a detail output file is generated and is named program name PID dicdet As with the summary output file the program name is the name of the user s executable and PID is the Process ID of this execution of the program The third file is named program name PID dlcbin This file is used by the graphical user interface Leak Analyzer Summary output file The summary output file contains an overview of the results from Leak Check Only the total number of each error type and associated number of bytes are provided in this file This following is an example of a summary output file
5. Dynamic Memory Solutions Leak Check Version 2 1 for Linux User s Guide Including Leak Analyzer For x86 Servers Document Number DLC20 L 021 1 Copyright 2003 2009 Dynamic Memory Solutions LLC www dynamic memory com Notices Trademarks Comments Copyright Dynamic Memory Solutions Information in this document is subject to change without notice Dynamic Memory Solutions Dynamic Leak Check Leak Check and Leak Analyzer are trademarks of Dynamic Memory Solutions LLC Linux is a registered trademark of Linus Torvalds in several countries All other trademarks are the property of their respective owners Comments about this document may be sent to Dynamic Memory Solutions LLC Publications Department 271 Kings Highway North Haven CT 06473 Voice Fax 1 877 293 4144 Email sales dynamic memory com Web www dynamic memory com Copyright 2003 2009 Dynamic Memory Solutions LLC All Rights Reserved Note to U S Government Users Documentation related to restricted rights Debug your operation Dynamic Memory Solutions Contents nr I distri ed ne de eine nr Net te eee 2 Trademarks ER ne ee SR men ci rm ser E ee le ere mener 2 COMMONS 522 se de On 2 COPIA sae RS hah RS TN te tn nd nl Re 2 jUUn M 3 j M
6. 6 Dynamic Memory Solutions ss 6 nog RE H 6 Leak Check Functional Overview eee esee tentata stata stas tn sss s tts tn sonans on sens en sens sn satus 7 IGI nalcr qe rr qm ses0 8 Installation yeguirements e D twa rege vg ehanteieud dec PUR RS EET PRENNE Ran EIAS eleg uuu duc 8 Obtaining the Leak Check sofiware renien e eieiei a entiers 8 Installation procedure ues data gi c etg E A e Wie hg a Du eR y eu dude 8 Before you install aee reta sons ee iaa i a a Had cated E A les E ras E else 9 First install 2 Hanna MARNE a a sete ca EENE E ARNEE 9 Additional product install 2 2 trn eite eren ieii a aia aea E ER etu ep ebore EEEE E 10 User configuration ox o scd eO DURO RUNDEN EEEE AN OLTRE baa eRe 10 OLTEAN E I m M 12 jn 13 Allocated memory use error detection eee tette 13 Memory leak detection iei tr ERE PORT be Ee bte e ut eia rapi ab d MERE a AAEE TEE 13 Potential memory leak detection essere 13 Freed memory access checking ie desee tese M Lena ena p eR Ra Le Exo AREE eap LER ein e ELEME R ead oca gd 13 Retention Of freed M moriser ORO EH RUPEM UI be HO Hb atediim ns 13 Allocated block boundary checking eese ener nnne 14 Multiple reporting options es suites teret ade leap ok x Thee Vaan duth dad
7. Limitations ot Fc qaid cc 47 4 Debug your operation Dynamic Memory Solutions www dynamic memory com 5 Dynamic Memory Solutions Preface Dynamic Memory Solutions From Day One we have focused our efforts on providing you with the highest quality software development tools to enable you to maximize your productivity and the quality and stability of your code We backup our products with the level of technical support that you would expect from experienced software professionals that have been developers themselves Our goal is to help you use our products in the most effective way possible and we welcome your opinions and suggestions You can contact DMS via Our Website www dynamic memory com Email Sales sales dynamic memory com Support support dynamic memory com Telephone Voice 1 877 293 4144 8am 5pm EST Fax 1 877 293 4144 Support DMS is fully committed to supporting our products With each sale DMS establishes a support agreement where technical support is provided via one or more of the following e Website Please visit our website at www dynamic memory com for answers to the most frequently asked questions regarding installation and use A recent version of the frequently asked questions is also included in this manual e Email support dynamic memory com We attempt to answer email questions within three business days though most will be answered by
8. the pid is 1234 ps ef grep example tester 1234 1000 0 02 59 pts 7 00 04 04 dynleak example 3 In the second window start gdb with the attach option specifying the pid of the running process gdb example 1234 The running process is attached and you may use the debugger as normal Be aware that you may see Leak Check internal functions in the call stacks These Leak Check internal functions do not impact your debugging session You may run a memory leak check at any time from within the debugger Usually you will set a breakpoint in your program and allow the process to run until the breakpoint is hit When your program has stopped at the desired point in gdb you may run print DYNleakCheck Debug your operation Dynamic Memory Solutions to execute the memory leak and heap corruption check Stopping at a point in your program is very important if the process is currently running in a Leak Check internal function then running DYNleakCheck may deadlock the process The Leak Check output is written to the directory specified by SDYNOUTPUT or to tmp if DYNOUTPUT is not set Only leaks not previously reported will be written www dynamic memory com 37 Dynamic Memory Solutions Leak Analyzer Introduction Setup Leak Analyzer is an X Windows based graphical user interface for displaying and analyzing the results from Leak Check version 2 0 and newer Leak Analyzer allows t
9. Solutions Bytes potentially leaked Blocks potentially leaked and Unique potential leak stacks 4 indicate the total number of bytes and the number of allocations of heap memory where the program has not maintained a pointer to the start of the allocation throughout program execution However for each there is a pointer to a location within the block so the user could potentially return it This pointer may provide access to a data structure within the block but should be examined for correctness The definition for Unique potential leak stacks is the same as for Unique stacks for leaks It is an indication as to the number of distinct potential leaks in the code Bytes suppressed Blocks suppressed and Unique suppressed stacks 5 indicate the total number of bytes and the number of allocations of heap memory leaked or potentially leaked during program execution but not reported because the user has chosen to suppress reporting A user may choose to suppress reporting of known leaks that occur in library functions or other system or application functions that cannot be fixed to streamline reporting via the exclusion files The number of unique stacks is reported to provide an indication as to how many distinct leaks or potential leaks are in the code but are suppressed Bytes in use and Blocks in use 6 indicate the total number of bytes and the number of allocations of heap memory still in use by the executable and not ret
10. and line numbers The following allocated memory error types are reportable e free within block www dynamic memory com 23 24 Dynamic Memory Solutions free without malloc reallocate without malloc double free free then reallocate BAD FREE Identified a bad pointer 0X1234 sent to free reportFreeWithoutMalloc 0x120 at example free 0x234 at example main at line 98 in tmp example c _start 0x5c at example The first line of a critical error contains the address of the allocated memory block of a pointer in hexadecimal format and the error type The following lines provide the call stack leading up to the error In this example the error is detected by Leak Check when the the application calls the function free The next line of the call stack shows that free is called from line 98 of function main The final line of the call stack is unimportant but shows where the application example is passed control during application startup Errors such as double free where free is called more than once for the same block include additional information as shown below DOUBLE FREE Identified a block 0X924D18 sent to free more than once The allocation call stack main at line 100 in tmp example c _start 0x5c at example The first free call stack was not recorded Set the DYNRECORDFREESTACKS environment variable and run the program again to get both call stacks The second free call stack reportMultipleFr
11. and report results based on elapsed time This option is particularly useful for long running applications Setting this variable allows the user to monitor the program execution for leaks and errors and to establish trends based on elapsed time or associated with processing loads and data sets Note the report is not updated when the timer expires until the program performs a memory allocation or deallocation Set this variable to the number of seconds of wall time between results update If not set results are generated only at program exit Warning Do not set the value too low or program thrashing will occur Default value is not set DYNNOPOTENTIALLEAK The No Potential Leak option allows the user to suppress reporting of potential memory leaks This may result in a smaller report file when the user is not interested in potential memory leaks Set this variable to prevent potential memory leak reporting If this variable is not set Leak Check includes potential memory leaks in the report Default value is not set DYNNOFORK The No Fork option allows the user to control leak checking of child processes This may result in a smaller report file and faster execution when the user is not interested in processes forked by the main program Set this variable to prevent child processes from being checked If this variable is not set Leak Check will check child processes for memory leaks Default value is not set www dynamic me
12. capability of Leak Check Selecting Refresh causes the current file to be reloaded thus displaying updated results if available The Execution Info tab contains the time when Leak Check last updated the results When Refresh is selected the data and formating on the Summary Results Detail Results and Leak Analysis tabs is reset If Refresh is not active no file is currently loaded that can be reloaded Expand All Expand All causes all items in the table on the current window to be expanded If Expand All is not active no expandable table is currently being displayed Collapse All Collapse All causes all items in the table on the current window to be collapsed If Collapse All is not active no collapsible table is currently being displayed Help These menu items assist the user in operating and understanding Leak Analyzer Help Contents Help Contents opens a new window and displays this help information Multiple help windows may be open at the same time In this window the user can scroll back and forth to browse the help information or click on a link to go directly to a specific subject Clicking the Contents button takes the user to the Table of Contents Clicking the ndex button takes the user to the Help Index The Back and Forward buttons moves the user back and forth through the links that have been selected Back and Forward does not scroll through the contents The scroll bar should be used to do this To close th
13. describes how to use the basic features of Leak Check on a program To use Leak Check 1 Compile and link your program as you normally do It is not necessary to compile with the debug flag but Leak Check can provide more information if the application is compiled with the debug flag enabled Ensure that the DYNROOT environment variable is set and that the DYNROOT bin directory is in your PATH Set the DYNOUTPUT environment variable to the directory where you want Leak Check to write the results Execute dynleak program name program options where program name is the name of your executable program and program options are the command line parameters you use for your program When your program has completed view the report files in the DYNOUTPUT directory If you did not set SDYNOUTPUT or you do not have write permissions to that directory the output files will be created in the tmp directory The report files contain the call stack for any allocations leaked by your program Three files may be created e programname pid dlcsum A textfile containing a summary of the memory allocations and deallocations during the program execution Included is a summary of memory leaks and boundary errors e programname pid dicdet A textfile containing detailed locations of errors including allocations leaked freed but not allocated and boundary errors This file is only created when memory errors are
14. found e programname pid dlcbin A binary file that is used by the graphical user interface program Leak Analyzer Debug your operation Dynamic Memory Solutions Feature Descriptions Allocated memory use error detection Leak Check monitors the allocation and deallocation of memory blocks and detects when the application attempts to free blocks that have already been freed or when the application passes an invalid pointer to free The erroneous free is detected prevented and reported Leak Check also reports the first and successful free if the DYNRECORDFREESTACKS environment variable is set prior to running the application Memory leak detection This feature provides fundamental memory leak information Leak Check monitors all memory allocations and reports any outstanding heap allocation without a reference as a leak The Leak Check report includes the call stack and line number where the program allocated the leaked memory If a source line leaks multiple times Leak Check reports the total number of leaked allocations and the total number of bytes leaked Potential memory leak detection When the only reference to a heap allocation is a reference to a memory address other than the beginning of the block Leak Check reports this block as a potential leak In order for the program to deallocate the block or free the memory the program must know the initial address of the allocation so it is likely that the potentially leaked
15. inNbrToMalloc 35 36 Initialize a minimun number to malloc 37 int nbrToMalloc 2 38 char myCharArray 39 int myIntArray 40 41 if nbrToMalloc inNbrToMalloc 42 43 If the input number is larger than the minimum 44 use the input number 45 nbrToMalloc inNbrToMalloc 46 47 48 Allocate an array of chars 49 myCharArray char malloc nbrToMalloc sizeof char 50 51 Advance the pointer to an address within the allocation but not at the start 52 myCharArray 53 54 inti 0 55 Debug your operation Dynamic Memory Solutions 56 Write past the end of the allocated array 51 for i 0 i lt nbrToMalloc i 58 59 myCharArray i A 60 61 myCharArray i 0 62 63 free the pointer which no longer references the beginning of the allocation 64 free myCharArray 65 66 Call another function that will allocate memory and leak the returned memory 67 myIntArray functionl inNbrToMalloc 68 69 return 0 70 Jl 72 get rid of any stray pointers on the stack 73 In complex programs this is not needed 74 void clearStack 75 76 char bigArray 10000 77 78 memset bigArray 0 10000 79 80 81 82 int myIntPtr 83 int main int argc char argv 84 85 int rc 0 86 char myWildPtr char 0x1234 87 char myDoubleFreePtr 88 char myBuffer 100 89 char myBufferPtr 90 char myGoodBuffer 91 92 93 myIntPtr functionl 500 94 95 rc funct
16. indicates that the application attempted to free a memory block at address 0X924371 that has not been allocated or has been allocated but already freed and returned The next lines of the error show the program call stack from the point at which the error is detected in a Dynamic Memory Solutions library back to the program invocation Working from the bottom up we see where the program example is passed control from the operating system The program executes the main function until it reached line 95 where control is passed to function2 function2 executes and at line 64 calls free dynleak intercepts the call to free and determines that the memory has not been allocated This particular error is caused by line 52 of example c where the pointer to the memory allocation is altered and no longer points to the beginning of the allocation A Leak Check v2 0 enhancement is illustrated by the DOUBLE FREE critical error identified by 2 DOUBLE FREE Identified a block 0X924D18 sent to free more than once The allocation call stack main at line 100 in tmp example c _start 0x5c at example The first free call stack was not recorded Set the DYNRECORDFREESTACKS environment variable and run the program again to get both call stacks The second free call stack reportMultipleFree 0x130 at example free 0x100 at example main at line 104 in tmp example c _start 0x5c at example When an application attempts to free the same memory
17. reports ss 21 Understanding the results terisini ee iare egeo tt ses ae ans soap RR apu diner leie teste cine tent e 22 Summary output file RAR eme Eu ette he oem ek cuta 22 Detar output thle c 23 Critical rond disease cy san veces eed sels dene secede hes 23 Boundary errors ccc Sic ud cee OO ERE ee EU RR eee ee eles 24 Memory leak onii E E ER cei RE HERE UTERE ERE NER Ra 25 Potential memory leak ise cis Rc etude Lad chip toe peers dean ral Sues 26 Ipcuio eee 27 Example files OTRO NBN ERR ceeds ad RES IHRER OR HR CEU E DEI URS 27 Compiling the example a e E tete is Rete ete PARRA rd re aap EMT E sine entente 27 SOUICE CODE EE RE RU 27 Summary output file te der Ue Scat ade dise Casta ou ve och ap van Xa se inerte niet ne els 30 Detail output file ess Ra RERO HR GAS GI UN ne note REER 3l Debugging with Leak Ch tk ce 36 IER UeNrhy m 38 Introductions etUm I D E REG 38 T Ee 38 Invoking Leak Analyser stet ede Ge e b EH e ede deu berto Dee et de tei e den 38 gU M 38 Using Leak Analyzer cda ROBORE RHENO ORO ERUNT PUE EN GRE Toate 39 Menu Baf ss sn in ne An E rentree enr maiden etit ra neresee ewe 39 NI nain M 41 Display Function Tabs i ie cei RR E edi e EH ted eine e MR ed 42
18. the location of the application depending on how the user application is created Memory leak Memory leaks are reported when the application program no longer has a pointer to the beginning of an allocated memory block Unlike potential memory leaks there does not appear to be a pointer to a location within the block that might be used to access the block Each error includes information on the size of the leak the address of the block and the allocation call stack LEAK Identified a block of size 500 bytes at address 0X886760 The allocation call stack functionl at line 20 in tmp example c main at line 93 in tmp example c _start 0x5c at example The first line of a memory leak error provides the size of the leak in bytes and the address of the allocated memory block in hexadecimal format The remaining lines provide the call stack leading up to the allocation of the memory block In this example the memory is www dynamic memory com 25 26 Dynamic Memory Solutions allocated at line 20 of function function1 function1 in turn is called from line 93 of main The final line of the call stack is unimportant but shows where the application example is passed control during application startup In your detail output file the function names shown may not actually be used directly by your application but result from explicit or implicit application calls to library functions Line numbers are only available if debugg
19. the next business day e Telephone Telephone support is obtained by calling 1 877 293 4144 during our regular business hours 8am 5pm EST Your support agreement may include telephone support Otherwise it is provided at additional cost e On site support DMS will travel to your site or connect to your server via an externally accessible network Our consultants will help diagnose and resolve difficult problems found while using our tools On site support is negotiated on a case by case basis Please call our Telephone Support line for more information on this service e Training DMS will arrange training seminars via electronic delivery or in person at your facility Please contact us for additional information 6 Debug your operation Dynamic Memory Solutions Leak Check Functional Overview Leak Check is an advanced memory leak detection tool It checks all code within a process including shared libraries and third party code for a variety of memory management errors As with all products in the Dynamic Suite Leak Check requires no modification of the application to insert compile time or link time instrumentation The major features of Leak Check include C and C support All features work with either programming language Memory leak detection All memory allocations are carefully tracked If the program loses all references to a particular allocation and therefore leaks Leak Check reports the problem
20. the start of the allocated block and overflow writing after the end of the allocated block This problem often occurs when an array index goes beyond the defined bounds of the array Boundary checking is performed when the user s program exits The user can also use the DYNBOUNDARYCHECKCOUNT option to perform boundary checking every time the configured number of allocations have been made Multiple reporting options Leak Check results are generated when your program exits Results can also be updated while the user s program is is running The DYNLEAKTIMER option allows the user to request periodic updating of results The user may also signal Leak Check at any time to cause an update 14 Debug your operation Dynamic Memory Solutions Using Leak Check Setup Before using Leak Check it must be installed on your server with a valid license key Please see the product installation section for more information In order to use Leak Check the DYNROOT environment variable must be set to the directory chosen for the product at installation Additionally you will need to add the DYNROOT bin directory to your PATH environment variable The setting of these variables is independent of the location of your application program and may be included in your profile for increased ease of use Output from Leak Check is directed to the directory specified by the DYNOUTPUT environment variable In a development environment it may be most co
21. the user s program has a signal handler for one or both of these signals then the signal cannot be used to trigger the results update Usually programs do not use the SIGUSR1 and SIGUSR2 signals Debug your operation Dynamic Memory Solutions Excluding known leaks from reports By default Leak Check reports memory leak information for all libraries source files and functions in or used by the program including the standard C and C libraries There may be known memory leaks in these functions and libraries that cannot be corrected and appear in the reports Leak Check provides the ability to exclude certain functions or entire libraries from the leak check reports Functions to be excluded are entered in the file dynleak function excl dynleak function excl is a simple text file with one function name per line A function exclusion file looks like this myFunction strcpy Libraries to be excluded are entered in the file dynleak library excl Excluding libraries can speed up Leak Check initialization Since debug information in excluded libraries is not read any defects reported in these libraries do not contain line or file information dynleak library excl is a simple text file with one shared library name per line Library paths are not required A library exclusion file looks like this mySharedLibrary so libncurses so 5 These files can be placed in either the users HOME directory or in the directory
22. well as test and development environments www dynamic memory com 7 Dynamic Memory Solutions Installing Leak Check Installation requirements Minimum system requirements for Leak Check ALinux distribution with kernel version 2 4 20 and greater or 2 6 4 and greater on an i586 platform Please contact us for current availability on other kernels and platforms Linux libelf package installed version 0 8 4 recommended This package in included in most Linux distributions and may also be downloaded from the Internet The graphical user interface Leak Analyzer requires a working X11 installation However Leak Analyzer does not have to be run on the same server that is used for running Leak Check Atleast 50 MB of available disk space Obtaining the Leak Check software The first step is to read and accept the Leak Check software license If you do not accept our license you should not download our software and should remove any existing copies immediately Please contact us to obtain a copy of Leak Check We prefer electronic distribution via our website or email but special arrangements can be made for delivery on Compact Disc Call us at 1 877 293 4144 or email us at sales dynamic memory com When you contact us we will request information from you regarding the system you will use to host our software This information permits us to generate a license key to permit our software to run on that server or workstation Y
23. Multiple de allocation Calling delete or free more than once for the same allocated block is a serious error that often causes a program to crash Leak Check blocks additional deletes or frees and reports the error Memory block over underwrite bounds checking Heap allocated blocks are subject to being written beyond the beginning or ending boundary under a variety of conditions This can cause memory corruption that causes the program to behave erratically or crash Leak Check detects and pinpoints the over underwriting in most cases and reports the error Other memory errors A variety of other errors are also identified including Free without Malloc Realloc without Malloc Free then Realloc and more Forked program checking Leak checking includes reporting of leaks in forked child programs 32 64 bit and multithread support All features work in both 32 and 64 bit memory models and multi threaded applications Periodic results updating User can configure leak check reporting to occur at an interval of their choice This is particularly useful for long running applications Graphical User Interface Results can be viewed and manipulated using the Leak Analyzer GUI for easier understanding Requires X11 support The capabilities of Leak Check enable your organization to locate and correct program problems quickly and easily Since no instrumentation is required the tool is perfect for use in production environments as
24. allocation is actually leaked Freed memory access checking The Freed Memory Access feature can help detect program errors when the program attempts to access previously deallocated memory Using freed memory is a serious error To help catch such errors Leak Check can fill each block with zeros when free or delete is called Clearing memory often causes a program to crash when freed memory is accessed rather than allowing the program to continue with the invalid data The core file can then be used to determine the location where the program accessed the invalid memory Retention of freed memory Memory corruption errors may cause a program to crash Since Leak Check shares heap space with the application a program with bugs may crash unexpectedly even when Leak Check is being used The No Free option prevents the return of memory to the system when free or delete is called In this fashion each block of memory is only used once Setting this option may keep a program with memory corruption errors from crashing and allow the program to be debugged When this feature is used the memory usage of a program will continually increase The program must end before exhausting available heap space www dynamic memory com 13 Dynamic Memory Solutions Allocated block boundary checking Writing beyond the boundaries of an allocation is a serious memory corruption error By default Leak Check validates each block for underflow writing before
25. ample If the view contains a table table columns may be resized by dragging the column separator on the table header Table rows may be expanded by clicking the right facing arrow at the left of the row Rows may be collapsed by clicking the downward facing arrow at the left of the row All rows in the table may also be expanded and collapsed by using the Expand All and Collapse All commands under the View menu Table contents may be sorted by clicking on the header of the desired sort column Clicking the header a second time will reverse the sort order of the column Only parent i e non collapsible rows are sorted Opening a different Leak Check binary file or using Refresh to update the results resets the view chosen by the user Debug your operation Dynamic Memory Solutions Limitations of Leak Check Leak Check can be used to locate memory leaks and other memory errors without recompiling or relinking the application The information available to Leak Check when reporting errors is limited to the source code information that is included in the executable program and shared libraries Known Limitations 1 Leak Check only reports line and system information when objects and or debug information is available Source code compiled without the debug option g will not include source line debugging information Leak Check will detect memory errors and the function allocating the leaked blocks but will be unable to report the exact
26. ation call stack The following boundary error types may be reported e Boundary Overflow e Boundary Underflow BOUNDARY OVERFLOW discovered after block starting at address 0X924370 The block was allocated at time 1186160768 The error was reported at time 1186160769 The allocation call stack function2 at line 49 in tmp example c main at line 95 in tmp example c _start 0x5c at example The first line of a boundary error contains the address of the allocated memory block in hexadecimal format and indicates whether it is an overflow or underflow BOUNDARY OVERFLOW indicates that data has been written past the end or highest address of the buffer BOUNDARY UNDERFLOW indicates that data has been written before the beginning or lowest address of the buffer The remaining lines provide the call stack leading up to the allocation of the memory block In this example the memory is allocated at line 49 of function function2 function2 in turn is called from line 95 of main The final line of the call stack is unimportant but shows where the application example is passed control during application startup In your detail output file the function names shown may not actually be used directly by your application but result from explicit or implicit application calls to library functions Line numbers are only available if debugging information is included in the application and library object files Pathnames are absolute or relative to
27. block multiple times Leak Check identifies the location of the initial allocation and the location of the second deallocation of the block Additionally if the DYNRECORDFREESTACKS environment variable is set Leak Check reports the location of the first and successful deallocation of that memory block In this specific example of DOUBLE FREE the memory block at address 0x924D18 is allocated in main at line 100 in example c The next part of the error entry indicates that the first deallocation location is not recorded because DYNRECORDFREESTACKS is not set The final part of the error entry indicates that the second deallocation of the memory www dynamic memory com 33 34 Dynamic Memory Solutions block occurs in main at line 104 of the program If the first deallocation is recorded it is shown to occur in main at line 102 A BOUNDARY OVERFLOW error 3 is reported in a manner similar to a BAD FREE as illustrated by the following part of the detail file BOUNDARY OVERFLOW discovered after block starting at address 0X924370 The block was allocated at time 1186160768 The error was reported at time 1186160769 The allocation call stack function2 at line 49 in tmp example c main at line 95 in tmp example c _start 0x5c at example The first line of the BOUNDARY OVERFLOW error indicates if the overflow is before or after the memory allocation and the address of the allocation An overflow after the block indicates that th
28. ck main at line 100 in tmp example c _start 0x5c at example The Set run The tMultipl first free call stack was not recorded the DYNRECORDFREESTACKS environment variable and the program again to get both call stacks Second free call stack repor eFree 0x130 at example free 0x100 at example main at line 104 in tmp example c _star BAD FREE Iden repor t 0x5c a tified a t example bad pointer free 0x234 at example main at line 110 in tmp example c _star t 0x5c a t example OXFFBEF6BO tFreeWithoutMalloc 0x120 at example sent to free more than once sent to free BOUNDARY OVERFLOW discovered after block starting at address 0X924370 The bloc The error was repor The alloca B POTENTIAL A word was The alloca function2 at functionl at te tion call s tart 0x5c a LEAK Identi found poin tion call s k was allocated at time 1186160768 d at time 1186160769 tack t example tack main at line 93 in tmp example c S tart 0x5c a t example line 49 in tmp example main at line 95 in tmp example c line 23 in tmp example c fied a single block of size 2000 bytes at address 0X923B88 ting at 4 bytes after the beginning of the block c LEAK Identified a block of size 1600 bytes at address 0X9246C0 The alloca tion call s tack functionl at line 23 in tmp example c function2 at line 67 in tmp example main at line 95
29. ck has a requirement that the SUN SUNWIibC package is installed Please have this package installed and try the tool again e Is Leak Check thread safe Yes Leak Check is thread safe on all platforms and word sizes www dynamic memory com 49 F Dynamic Memory Solutions You re gonna need stronger debugging software Document Number DLC20 L 021 1 Copyright 2003 2009 Dynamic Memory Solutions LLC www dynamic memory com 50 Debug your operation
30. cution This memory is recovered by the operating system during program termination Peak bytes in use 7 indicates the greatest number of bytes allocated during program execution at any point in time It identifies the minimum amount of dynamically allocated memory required by the program under the specific execution conditions and input dataset Detail output file The detail output file contains information about each memory error or memory leak detected by Leak Check during program execution Critical errors are reported first followed by memory overflows and memory leaks Memory leaks are sorted so the largest and most frequent leaks appear first in the report Multiple leaks from the same execution stack are combined into a single report item indicating the total number of leaked blocks and the associated number of bytes This is the text of the detail output file for the example 1 Bap FREE Identified a bad pointer 0X924371 sent to free reportFreeWithoutMalloc 0x120 at example free 0x234 at example function2 at line 64 in tmp example c main at line 95 in tmp example c _start 0x5c at example BAD FREE Identified a bad pointer 0X1234 sent to free reportFreeWithoutMalloc 0x120 at example free 0x234 at example www dynamic memory com 31 32 Dynamic Memory Solutions main at line 98 in tmp example c _start 0x5c at example DOUBLE FREE Identified a block 0X924D18 The allocation call sta
31. e Fee eee eue nests etd cad ge Ea daa dada 14 Using Leak 15 DT m 15 Invoking Leak Check id oe e rb p eb RO DRE ER GER IN PdpS Mp Pe EIS 15 www dynamic memory com 3 Dynamic Memory Solutions go MM 15 DYNROOT directory Rs tete Era t Hae ne ere ends tee RR Oe aste RRE 16 DYNLICENSEFILE path and file name 16 DYNPA THS path E M 16 DYNOUTPUT directory eterne rre epe tte re repe neto rera aceite TEE Tn 17 DYINOUIET ceno EUN Ue iude net CEU 17 DYNRECORDFREESTACKG sssssssssessssescssescssescssescesescessecensscesscenscessssescaaescnereceseesesaseaeesesseeseons 17 DYNFREEMEMORY CLEAR cccccssesesseseseeseseseseeseseecseeseseeseneesesecaeeeeseeeesesecaeseeseeseaeeseseeaeaeeseneeaceesaees 17 DYNNOPBRDBE iet gail teen REIR anni aoa nn 17 DYNNOBOUNDARYCHEGCK ote ba cite erm Mt an Gaines 18 DYNBOUNDARYCHECKCOUNT count ire 18 DYNEBAKTIMER seconds nec rete ehm tene ee aed nt anni nadia 19 DYNNOEPORK 5 2 5 ERREUR FORO RUN NONE eni ES eee ee ex ebd nine 19 Pg m HEN 20 Updating results periodically sen 20 Updating results on demand 4 eio eim ee tee n ant 20 Excluding known leaks from
32. e Help Contents window select the File menu from the window and then Quit About About opens a new window containing information about the Leak Analyzer program and how to contact Dynamic Memory Solutions for help with sales and support Only one instance of the About window may be opened at anytime and it must be closed before the user can continue to use Leak Analyzer To close the About window press the Close button What s This What s This provides a simple description of any field and answers the question what s this Debug your operation Dynamic Memory Solutions After selecting this menu item or using the shortcut Shift F7 the user can click on a field on the screen and receive a short description of the function or purpose of the field For additional information the user can consult this detailed help via the Help Contents menu item or the Leak Check User Manual Status Bar Status information regarding program operation is displayed in the status bar at the bottom of the Leak Analyzer window Normally this field displays the status Ready Ready status indicates that the program is accepting commands Other status frequently seen is Error loading filename and Try again file locked by dynleak filename The status Error loading indicates that the file opened by the user is not in the correct format This is usually caused when a file other than a dlcbin file is opened It may also occur if a dlcbin f
33. e example To compile the example using the gcc compiler execute this command gcc g example c o exampl Source code The source file example c contains a main function and two supporting functions Each of these functions contain memory errors The errors include memory leaks potential memory leaks array boundary errors free without malloc multiple frees of a memory block and free called with a pointer to the middle of an allocated block www dynamic memory com 27 28 Dynamic Memory Solutions This is the text of the source file example c 1 include lt stdlib h gt 2 include lt stdio h gt 3 include lt string h gt 4 5 int functionl const int inNbrToMalloc 6 7 Initialize a minimun number to malloc 8 int nbrToMalloc 2 9 char myCharArray 10 int myIntArray 1 12 if inNbrToMalloc nbrToMalloc 13 14 If the input number is larger than the minimum 15 use the input number 16 nbrToMalloc inNbrToMalloc 17 18 19 Allocate an array of chars 20 myCharArray char malloc nbrToMalloc sizeof char 21 22 Allocate an array of ints 23 myIntArray int malloc nbrToMalloc sizeof int 24 25 Advance the pointer to an address within the allocation but not at the start 26 myIntArray 1 27 28 Return the pointer to the middle of the array of ints 29 The array of chars is leaked 30 return myIntArray 31 32 33 34 int function2 const int
34. e pointer it is possible that the block is still in use and that it has not been leaked The next lines of the error show the program call stack for the memory block allocation Working from the bottom up we see where the program example is passed control from the operating system The program executes the main function until it reached line 93 where control is passed to function function executes and at line 23 it allocates 2000 bytes of memory via malloc Debug your operation Dynamic Memory Solutions Examining the source code starting at the memory allocation shows that the pointer to this block is altered at line 26 of example c LEAK reporting is similar as is shown by examining a leak 5 reported in the detail output file LEAK Identified a block of size 500 bytes at address 0X886760 The allocation call stack functionl at line 20 in tmp example c main at line 93 in tmp example c _start 0x5c at example The first line of the error indicates that it is a leak of 500 bytes at address 0X886760 This indicates that the memory has been allocated and not freed prior to program exit Additionally no pointer to this allocation is found so it is impossible for the application to free it and therefore it is leaked The next lines of the error show the program call stack for the allocation Again working from the bottom up we see where the program example is passed control from the operating system The program execut
35. e program has written to a memory address higher than the allocation For this error the program writes beyond the end of the memory block located at address 0X924370 The next lines of the error show when the error is detected The time of each memory allocation in Unix seconds since epoch is recorded during allocation of the block Additionally the time when the BOUNDARY OVERFLOW is first detected is also provided Finally the call stack for the memory block allocation is shown Working from the bottom up we see where the program example is passed control from the operating system The program executes the main function until it reached line 95 where control is passed to function2 function2 executes and at line 49 it allocates the memory block at address 0X924370 POTENTIAL LEAK reporting is illustrated by examining the potential leak 4 in the detail output file POTENTIAL LEAK Identified a single block of size 2000 bytes at address 0X923B88 A word was found pointing at 4 bytes after the beginning of the block The allocation call stack functionl at line 23 in tmp example c main at line 93 in tmp example c _start 0x5c at example The first line of the error indicates that it is a potential leak of 2000 bytes at address 0X923B88 This memory has been allocated and not freed prior to program exit However unlike a leak a pointer was found pointing 4 bytes after the start of the block If the program purposely alters th
36. ee 0x130 at example free 0x100 at example main at line 104 in tmp example c _start 0x5c at example When an application attempts to free the same memory block multiple times Leak Check identifies the location of the initial allocation and the location of the second deallocation of the block Additionally if the DYNRECORDFREESTACKS environment variable is set Leak Check reports the location of the first and successful deallocation of that memory block The call stack information provided is the same as for other errors In your detail output file the function names shown may not actually be used directly by your application but result from explicit or implicit application calls to library functions Line numbers are only available if debugging information is included in the application and library object files Pathnames are absolute or relative to the location of the application depending on how the user application is created Boundary errors Entries for boundary errors provide details for each memory block overflow write past highest memory address allocated or underflow write before lowest memory address allocated detected by Leak Check When memory is allocated a guard band is added to Debug your operation Dynamic Memory Solutions the beginning and end of the block An error is detected when either of these areas are written Each error includes information on the boundary error type address of block and the alloc
37. es the main function until it reached line 93 where control is passed to function function executes and at line 20 it allocates 500 bytes of memory via malloc Examining the source code starting at the memory allocation shows that a pointer to this memory is neither saved nor returned to the calling function main Since the pointer is lost when function returns the memory is leaked www dynamic memory com 35 Dynamic Memory Solutions Debugging with Leak Check 36 Leak Check can be used while you are debugging your program While in your debugger you can execute a leak check at any breakpoint This feature aids you in determining which sections of your code are not properly managing memory resources A debugger such as gdb can be used on a process running under Leak Check All modern Unix debuggers support an attach option The attach option allows a debugger to take control of a running process By starting a process under Leak Check and then attaching your debugger you can combine memory leak checking with source level debugging The following steps describe how to attach to a process running under Leak Check 1 Start your process under Leak Check as usual Environment variables should be set to direct output and control features export DYNOUTPUT my output directory dynleak example 2 Open another terminal window and determine the pid of the process you are debugging with the ps command In this example
38. he user to select and load binary formated output files created by Leak Check with an extension of dlcbin Once loaded the user may view information about the user s program that led to the creation of the dlcbin file Execution Info the summary results containing the number of each type of error found Summary Results the detailed results Detail Results and can examine the results in a variety of ways Leak Analysis Each of these activities appears on a different tab at the top of the window Leak Analyzer is included with Leak Check No further installation or setup is required However it is X11 Windows based and therefore you must be able to run X Windows applications Please ensure that you have the necessary environment variables set and that you can run simple X applications such as xterm prior to running Leak Analyzer Invoking Leak Analyzer Options 38 After you have executed your application program using Leak Check you can view the results with Leak Analyzer dynanalyzer options dlcbin file where dlcbin file is the name of your executable program and options are the command line parameters for Leak Analyzer as described next Leak Analyzer has only a few options These options are passed on the command line when invoking the program and the options can be displayed by passing the h option with no other parameters Usage dynanalyzer h v display displayname lt filena
39. ile becomes corrupted through editing or transfer or if the dlcbin file was generated by a different version of Leak Check Try again indicates that the dlcbin file is marked as busy When Leak Check is in the process of writing to the file it is marked busy In addition to at program exit the file is written during periodic updates by Leak Check if enabled Once the dlcbin file update is complete opening or reloading the file should result in success www dynamic memory com 41 Dynamic Memory Solutions Display Function Tabs The graphical interface provides access to four types of information Execution Information Summary Results Detail Results and Leak Analysis via a tabbed interface Execution Information The Execution Infotab provides information about currently loaded Leak Check binary file This information includes the filename currently loaded the command line used when Leak Check was invoked the date and time when the user s program began executing and the date and time of the most recent Leak Check results update Dynamic Leak Analyzer by Dynamic Memory Solutions n x tmp example 4933 dlcbin tmp example 08 03 07 13 06 08 08 03 07 13 06 10 42 Debug your operation Dynamic Memory Solutions Summary Results The Summary Results tab displays all high level or summary results for the currently loaded Leak Check binary file This includes critical errors boundary errors leaks and potential leaks
40. iles If the DYNOUTPUT option is not specified or designates a directory where the user does not have write permission then the output files are written to the tmp directory Default value is not set DYNQUIET Leak Check writes banner information and the results summary to standard output Setting the DYNQUIET environment variable prevents this writing to standard output stdout This is useful in a variety of situations including program I O from the stdin stdout piping program output to another program or running the target program in the background Set this variable to prevent banner information from being written to standard output If this variable is not set banner information is written Default value is not set DYNRECORDFREESTACKS Set the DYNRECORDFREESTACKS option to cause Leak Check to report successful memory deallocations when they are followed by erroneous deallocations of the same memory block If this option is not set Leak Check reports details of the erroneous deallocation Default value is not set DYNFREEMEMORYCLEAR Set the DYNFREEMEMORYCLEAR option to cause Leak Check to file the allocated blocks with zeros when they are deleted or freed If this option is not set Leak Check does not clear blocks when they are deallocated Default value is not set DYNNOFREE The DYNNOFREE option prevents Leak Check from returning memory to the system when it is freed or deleted This may prevent application crashes u
41. in tmp example c S tart 0x5c a t example LEAK Identified a block of size 500 bytes at The alloca functionl at line 20 in tmp example tion call s tack main at line 93 in tmp example c S tart 0x5c a t example LEAK Identified a block of size 400 bytes at The alloca function2 at line 49 in tmp example tion call s tack main at line 95 in tmp example c S tart 0x5c a t example LEAK Identified a block of size 400 bytes at The alloca functionl at line 20 in tmp example function2 at line 67 in tmp example tion call s tack main at line 95 in tmp example c S tart 0x5c a t example c address 0X886760 c address 0X924370 c address 0X924518 Debug your operation Dynamic Memory Solutions The first error reported in the detail output file 1 is a critical error All critical errors are reported in a similar manner and we will examine the reporting of this error in detail BAD FREE Identified a bad pointer 0X924371 sent to free reportFreeWithoutMalloc 0x120 at example free 0x234 at example function2 at line 64 in tmp example c main at line 95 in tmp example c _start 0x5c at example The first line of each error is the error type In this case 1 the error is a BAD FREE or free without malloc Additionally the first line contains specific information including address and size as applicable to the error For this error it
42. ing information is included in the application and library object files Pathnames are absolute or relative to the location of the application depending on how the user application is created Potential memory leak Potential memory leaks are reported when the application program no longer has a pointer to the beginning of the allocated memory block While it is likely that this is actually a memory leak the application program may still be using the block and might be able to compute the address of the beginning of the block to return it Each error includes information on the size of the leak the address of the block and the allocation call stack POTENTIAL LEAK Identified a single block of size 2000 bytes at address 0X923B88 A word was found pointing at 4 bytes after the beginning of the block The allocation call stack functionl at line 23 in tmp example c main at line 93 in tmp example c _start 0x5c at example The first line of a potential memory leak error provides the size of the potential leak in bytes and the address of the allocated memory block in hexadecimal format The second line indicates the offset of the potential pointer The remaining lines provide the call stack leading up to the allocation of the memory block In this example the memory is allocated at line 23 of function function1 function1 in turn is called from line 93 of main The final line of the call stack is unimportant but shows where the applica
43. ion2 400 96 97 free a pointer which does not reference a block allocated by malloc 98 free myWildPtr 99 100 myDoubleFreePtr char malloc 50 101 102 free myDoubleFreePtr 103 f r the pointer a second time to cause a multiple free error 104 free myDoubleFreePtr 105 106 Assign a pointer to an allocation on the stack 107 myBufferPtr amp myBuffer 0 108 109 free a pointer to an allocation on the stack 110 free myBufferPtr 111 www dynamic memory com 29 Dynamic Memory Solutions 112 Allocate a buffer that will be properly freed 113 myGoodBuffer char malloc 120 114 strcpy myGoodBuffer Example is complete Wn 115 116 printf myGoodBuffer 117 clearStack 118 119 exit rc 120 121 Summary output file 30 The summary file contains an overview of the results of Leak Check The text of the summary file for the example program is Dynamic Leak Check Summary Critical errors 4 Boundary Overflows 1 Bytes leaked 2900 Blocks leaked 4 Unique stacks for leaks 4 Bytes potentially leaked 2000 Blocks potentially leaked 1 Unique potential leak stacks 1 Bytes suppressed 0 Blocks suppressed 0 Unique suppressed stacks 0 Bytes in use 5020 Blocks in use 6 Peak bytes in use 5020 Critical errors 1 are memory errors that can cause a program to crash These include free without malloc calling free with a p
44. ive as much information as is available How can use Leak Check with a script that starts my application The easiest way is to just leak check every process that is started by the script by exporting the LD PRELOAD variable into the environment An example can be seen in the DYNROOT env leak32 env file If this file is sourced then any 32 bit processes started from that terminal will be checked for leaks The output will appear in the DYNOUTPUT directory or in tmp As an alternative the master script can be modified to kick off Leak Check on the target application The DYNROOT bin dynleak file is a script and a useful example My application crashes when use Leak Check what should do Try the DYNNOFREE option Sometimes a bug in the application will cause the program to crash By using each block of memory only once the program may avoid the crash If you are still having problems please contact our technical support staff at support dynamc memory com We will work with you to determine the problem Debug your operation Dynamic Memory Solutions e am having problems with my Solaris 64 bit program compiled with gcc It works fine when I do not use the Leak Check but get an ELF class error when running with the DLC What can do Include usr local lib sparcv9 in your LD_LIBRARY_PATH before usr local lib e Whenl run my Solaris application with Leak Check am told that libdemangle so 1 is missing Why Leak Che
45. l without needing to modify environment variables including DYNROOT PATH and LD LIBRARY PATH when switching between products When installing a new release of a DMS product the name of the top level directory in the archive is different in order to support multiple installed releases For example if you have already installed Leak Check release 1 0 in the apps directory the product is in directory apps dms 1 0 When you install Leak Check release 2 0 it is installed in directory apps dms 2 0 You can use either version by setting your DYNROOT environment variable to the corresponding directory User configuration 10 Before running Leak Check you must configure the environment by setting a few variables The DYNROOT environment variable must be set to the directory containing the release e g apps dms 2 0 Once this is set you run a script we provide dms 2 0 env dyn env to set the other variables PATH and LD LIBRARY PATH export DYNROOT install directory SDYNROOT env dyn env The above commands may be added to a user s shell profile For example add these Debug your operation Dynamic Memory Solutions lines to the kshrc file to configure the variables and Leak Check is available by simply typing its name www dynamic memory com 11 Dynamic Memory Solutions Quick Start 12 Leak Check is easy to use and comes with default settings appropriate for most C and C applications This section
46. line where the allocation occurred The DYNPATH option can be used to locate the missing object files if more detailed information is necessary 2 Leak Check cannot check programs that statically link malloc or free 3 Heap allocations in main are reported as leaked if main does not call exit www dynamic memory com 47 FAQ Dynamic Memory Solutions This section answers many commonly asked questions about Leak Check Do have to recompile or re link my application to use Leak Check No recompilation or re link is not required The application must be compiled with the debug flag g to get full information If the executable is fully stripped little information will be available If a shared library is stripped function level information will still be available If an application is a mix of stripped and not stripped libraries Leak Check will provide as much information as is available Which platforms does Leak Check run on e Solaris 6 7 8 9 10 UltraSparc 32 bit 64 bit e Solaris 10 x86 32 bit 64 bit e Linux x86 32 bit 64 bit including AMD Opteron e Linux Itanium 64 bit e HP UX 11i Itanium 64 bit The output does not contain line number information for some functions what should do To get line number information the application must contain debug g information and must not be stripped Some parts of the application can be stripped while other parts contain debug information Leak Check will always g
47. llow the following steps Obtain the software directly from Dynamic Memory Solutions Obtain either an evaluation or full license key To provide this key we require information about the system on which our software will be running The information we require is purely hardware related and requires no disclosure of software or data on your server To obtain the required information issue the three commands hostname ifconfig and uname a as either root or user and record the values Additionally please provide the processor brand and model and the total number of CPU cores For example the following commands will capture the information to a file that can be sent to us for key generation hostname gt tmp descriptive name gt dmshost ifconfig gt gt tmp descriptive name gt dmshost uname a gt gt tmp lt descriptive name gt dmshost Then either email this information or this file to sales dynamic memory com or print it and fax it to us at 1 877 293 4144 Please use a descriptive name that identifies the system to you and we will reference this name when we send you the license key When you request multiple license keys this allows you to match the key to the corresponding system First install If you are installing your first DMS product follow these steps to install the Leak Check software Decide where you will install Leak Check and create the directory if it does not exist For example directo
48. me gt display display X server to use default is SDISPLAY h print a summary of the options v print the version number lt filename gt optionally load dynbin file on startup The h option prints the dynanalyzer usage information at the command line When it is used all other parameters are ignored Debug your operation Dynamic Memory Solutions The v option prints the dynanalyzer version at the command line After printing the version the program exits The display displayname option allows the user to override the default X server and to explicitly specify the address and screen number to be used As an example the user can specify display 111 122 133 144 0 to display dynanalyzer on the X server running at IP address 111 122 133 144 with screen number O If this parameter is not specified dynanalyzer is displayed on the default X server or as specified by the user s DISPLAY environment variable The filename parameter allows the user to pass the dlcbin file they want to examine Leak Analyzer will load this file on startup if it exists Otherwise the user can load a file using the program s File menu Using Leak Analyzer Leak Analyzer provides a typical look and feel to other windowed programs It includes a Menu Bar at the top and a Status Bar at the bottom Between these two components a set of tabs allows the user to focus on the specific information they want Menu Bar Top level menu i
49. mory com 19 Results 20 Dynamic Memory Solutions Leak Check reports results when the user s application exits Additionally the user can configure results to be generated periodically during program execution or at any time via a signal Result files are written to the DYNOUTPUT directory If the DYNOUTPUT environment variable is not set or you do not have write permission for that directory the output files are created in the tmp directory Three files may be created e programname pid dlcsum A text file containing a summary of the memory allocations and deallocations during the program execution This file provides a summary of memory leaks and boundary errors e programname pid dicdet A text file containing detailed locations of errors including allocations leaked freed but not allocated and boundary errors This file is only created when memory errors are found e programname pid dicbin A binary file used by the graphical user interface program Leak Analyzer Updating results periodically The DYNLEAKTIMER environment variable is used to cause Leak Check to update and report results based on elapsed time Please refer to the DYNLEAKTIMER description in the Options section for complete details Updating results on demand Leak Check monitors two operating system signals and the user may trigger a results update by sending one of these signals to the application process These signals are SIGUSR1 and SIGUSR2 If
50. ntil the problem is corrected www dynamic memory com 17 18 Dynamic Memory Solutions Warning When this option is used the memory usage of a program continually increases The program must end before running out of memory Setting this variable prevents freed memory from being retumed to the heap If this variable is not set Leak Check allows the normal return of allocated memory Default value is not set DYNNOBOUNDARYCHECK The No Boundary Check option controls allocated memory block boundary checking Set this variable to prevent memory block boundary checking If this variable is not set Leak Check performs boundary checking Default value is not set DYNBOUNDARYCHECKCOUNT count The Boundary Check Count option is set to cause Leak Check to perform boundary over underrun checking every time the specified number count of memory allocations take place Using this option and monitoring the output files may provide the user with a better idea of where in the application memory block over underruns are occurring Set this variable to the number of memory allocations to occur before performing boundary error checking again If not set boundary error checking occurs only at program exit Warning Do not set the value too low or program thrashing will occur Default value is not set Debug your operation Dynamic Memory Solutions DYNLEAKTIMER seconds The Leak Timer option is set to cause Leak Check to update
51. nvenient to set this to the directory used to compile and link the executable In a test environment where the executable is already built and resides in a shared read only directory DYNOUTPUT may be set to a directory owned by the tester with write access If DYNOUTPUT is not set or is set to a directory to which the user does not have write access output will be directed to the frmp directory Invoking Leak Check Options The application program is compiled and linked in your normal manner It is not necessary to compile the application with the debug flag but Leak Check can provide more information with the debug flag enabled Set any additional Leak Check options required for your test Options are identified in the following section and are set using environment variables After performing these steps invoke Leak Check as follows dynleak program name program options where program name is the name of your executable program and program options are the command line parameters you would normally use for your program Leak Check supports a number of options These options are enabled by setting the environment variable indicated by the option name to the desired value They are disabled by unsetting the environment variable For example to prevent the writing of banner information and results summary to standard output execute the statement found on the top of the next page export DYNQUIET 1
52. o a user s data structure within the block but should be examined for correctness The definition for Unique potential leak stacks is the same as for Unique stacks for leaks It is an indication as to the number of distinct potential leaks in the code In this example 2000 bytes in one block are potentially leaked by the example program from a single location stack Bytes and Blocks suppressed 5 indicate the total number of bytes and the number of allocations of heap memory leaked or potentially leaked during program execution but not reported because the user has chosen to suppress reporting A user may choose to suppress reporting of known leaks that occur in library functions or other system or application functions that cannot be fixed to streamline reporting The number of unique stacks is reported to provide an indication as to how many distinct leaks or potential leaks are in the code In this example with a default suppression file there is no suppression of leak reporting Bytes and Blocks in use 6 indicate the total number of bytes and the number of allocations of heap memory still in use by the program and not returned at the time it terminates While these blocks may no longer be needed the program has maintained references so they are not considered leaks even though they are not returned The example program has 5020 bytes in 6 blocks in use at exit These may include allocations created by the compiler to support program exe
53. ointer to the middle of a block or multiple frees of the same block In this example there are four critical errors Boundary overflows 2 indicates the number of blocks where the program has written beyond the boundaries of allocated memory If the program writes before the start of a block or beyond the end of a block the count is incremented by one If the program writes before and beyond the block the count is incremented by two In the example there is one boundary overflow Bytes and Blocks leaked 3 indicate the total number of bytes and the number of allocations of heap memory leaked during the program execution Additionally the summary file includes the number of unique stacks where leaks occur This gives the user an indication as to how many distinct leaks are in the code If the only leak in a program is in a loop that is executed 10 times there are 10 blocks leaked but the number of unique stacks is one The example program leaks 2900 bytes in four memory block allocations from four different locations stacks Debug your operation Dynamic Memory Solutions Bytes and Blocks potentially leaked 4 indicate the total number of bytes and the number of allocations of heap memory where the program does not maintain a pointer to the start of the allocation throughout program execution However there is a pointer to somewhere within the block so the user can potentially access it and return it This pointer may provide access t
54. ollapsed by using the Expand All and Collapse All commands under the View menu Table contents may be sorted by clicking on the header of the desired sort column Clicking the header a second time will reverse the sort order of the column Only parent i e non collapsible rows are sorted Debug your operation Dynamic Memory Solutions Opening a different Leak Check binary file or using Refresh to update the results resets any table formatting changes made by the user www dynamic memory com 45 46 Dynamic Memory Solutions Leak Analysis The Leak Analysis tab provides a variety of ways to view Leak Check results These new ways of looking at the results are intended to assist the user in understanding how and where memory allocation errors are being introduced into their applications Leak Analysis is expandable and additional capabilities and views are expected to be added with each release Initially the Leak Analysis tab is a blank canvas ready to be populated with tables graphs and other forms of information display A specific view is selected via the drop down list just below the upper window tabs When a view is selected data from the currently loaded Leak Check binary file is processed and displayed in the selected view format Dynamic Leak Analyzeihoy Dynamic Memory Solutions Error Summary by Sourcefile Function gt A0 2 lt ALL gt example c Amp JUEZ TUR tnp 1 TE peat reportHultipleFree ex
55. our license key options are t Evaluation license An evaluation license key enables full program operation for a short time to allow evaluation of Leak Check There is no charge for this type of license e Ww Full license A full license key enables you to use Leak Check on the designated server or workstation and entitles you to minor program updates Normally this entitles you to use the software for an unlimited period of time as long as you abide by the license Installation procedure Dynamic Memory Solutions offers a number of products to maximize your productivity and software quality Normally you will want to install these products in the same directory Installation of the Leak Check software does not modify any system files and while installation as root is suggested it is not required but facilitates use by multiple users Our products can be installed on a shared file system but you will still require a license key for each client machine 8 Debug your operation Dynamic Memory Solutions Leak Check is distributed as a compressed tar file tar gz with a top level directory named dms 2 0 The complete directory structure is dms 2 0 bin executable binaries Nib supporting libraries lenv environment setup scripts license product license files docs product documentation examples example program and results extras optional or supporting files Before you install In preparation for installation please fo
56. ry apps Ensure that users of the product will have read access to this directory You may also install the product to a shared file system e g NFS www dynamic memory com 9 Dynamic Memory Solutions Change to the directory chosen for the install e g apps Uncompress and install the product with the following commands cd install directory cp full path product filename tar xvzf product filename This results in the creation of the dms 2 0 directory and subdirectories containing the product code For example if you installed in the apps directory directory apps dms 2 0 is created This is your DYNROOT directory and you set the environment variable DYNROOT to it C Copy the Leak Check license file if sent separately to a directory where users have read permission The default location for the license file is DYNROOT license License keys may be kept on a shared file system if that is where you installed the software If you choose a license key file directory and name other than the default DYNROOT license license dat the DYNLICENSEFILE environment variable must be set to the full path and name of the file before you run the software Additional product install If you have other Dynamic Memory Solutions products installed it is highly recommended that you install Leak Check in the same location This allows users to access any of the products at the same release leve
57. tems File View and Help appear in the menu bar at the top of the Leak Analyzer window File These menu items allow the user to select and load Leak Check binary output files and to close the program Open Open causes the open file dialog to be displayed This dialog allows the user to browse the filesystem and select a Leak Check binary output file When the user has located the desired file it should be selected highlighted and the dialog s Open button pressed to load the file If the user decides not to load a file the dialog s Cancel button will close the window and return to the main Leak Analyzer window with the prior contents Recent Recent displays up to 8 of the previously loaded Leak Check binary files in most recently loaded order A file must have been successfully loaded for it to appear in this list Older filenames are automatically removed when newer files are loaded Files that have been deleted by the user may still appear in the Recent file list until they are replaced by newly loaded files Quit Quit causes Leak Analyzer to immediately exit View These menu items allow the user to affect the way the information is displayed www dynamic memory com 39 Dynamic Memory Solutions Refresh Refresh causes Leak Analyzer to reload or refresh the currently loaded Leak Check binary output file This menu item is particularly useful when the user has a long running program and is using the periodic reporting
58. tion example is passed control during application startup In your detail output file there may be function names shown that are not actually used directly by your application but result from explicit or implicit application calls to library functions Line numbers are only available if debugging information is included in the application and library object files Pathnames are absolute or relative to the location of the application depending on how the user application is created Debug your operation Dynamic Memory Solutions Example Included with the installation of Leak Check is an example program you can use to verify your installation The example includes the most common types of memory management programming errors and the sample output files show the error messages that Leak Check reports when each error is encountered Example files The example consists of 4 files example c The source code for the example program example 1234 dlcsum A text file containing a summary of the memory allocations and deallocations during the program execution This file provides a summary of memory leaks and boundary errors example 1234 dlcdet A text file containing detailed locations of errors including allocations leaked freed but not allocated and boundary errors This file is only created when memory errors are found example 1234 dlcbin A binary file used by the graphical user interface program Leak Analyzer Compiling th
59. urned at program termination While these blocks may no longer be needed the program has maintained references so they are not considered leaks even though they are not returned These values may include allocations created by the compiler to support program execution This memory is recovered by the operating system during program termination Peak bytes in use 7 indicates the greatest number of bytes allocated during this program execution at any point in time It identifies the minimum amount of dynamically allocated memory require by the program under these specific execution conditions and this input dataset Detail output file The detail output file contains information about each reportable memory management error or memory leak detected by Leak Check during program execution There are four classes of errors critical errors boundary errors memory leaks and potential memory leaks Critical errors are reported first followed by boundary errors and then memory leaks including potential leaks Leaks are sorted so the largest and most frequent leaks appear first in the report Multiple leaks from the same execution stack are combined into a single report item indicating the total number of leaked blocks and the associated number of bytes Critical errors Entries for critical errors provide details for each dynamically allocated memory error detected by Leak Check Each error includes information on type address calling functions

Leak Check® User`s Guide - Dynamic

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Leak Check&reg; User`s Guide - Dynamic

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Leak Check® User`s Guide - Dynamic