topic Not even close - A Feature Request in Analyzers

Not even close

namsaray — Fri, 15 Jun 2012 14:32:39 GMT

Hi,
I downloaded a trial version, and it sucks.
C++, 64 bit.
I commented out a delete statement as the simple test, and
VS 2010 compiler points to memory leaks, and this expensive tool is way off - points me to some DLLs and
handles that are actually properly disposed of.
I did not change any parameters, just ran "Memory error analysis/detect leaks".
What gives?
Am I doing something wrong?

Please advise,

Thank you

Not even close

Holly_W_Intel — Mon, 18 Jun 2012 19:02:16 GMT

Would it be possible for you to attach the results or give a code sample so thatwe could get a better idea of why you might be seeing this?

Thanks,

Not even close

Mark_D_Intel — Tue, 19 Jun 2012 21:12:06 GMT

One possible issue is IXE only reports unreachable leaks. If there exists some pointer to the allocated memory at program exit, it will not be reported.

You could also try a different analysis type ("Detect Memory Problems" or "Locate Memory Problems"). These use a slightly different instrumentation approach than "Detect Leaks", and may give different results.

Not even close

SergeyKostrov — Wed, 20 Jun 2012 01:53:04 GMT

Quoting Mark Dewing (Intel)

One possible issue is IXE only reports unreachable leaks.If there exists some pointer to the allocated memory at program exit, it will not be reported...

Mark,

I didn't hear anything about Unreachable Leaks. Could you provide aC or C++ test case, please?

Best regards,
Sergey

Not even close

Mark_D_Intel — Wed, 20 Jun 2012 16:45:01 GMT

#include
#include

int *make_unreachable_leak()
{
// Will be reported by Inspector XE
int *tmp = (int *)malloc(sizeof(int));
return NULL;
}

int *make_reachable_leak()
{
// Still accessible through global pointer
// Will not be reported by Inspector XE
int *tmp = (int *)malloc(sizeof(int));
return tmp;
}

int *ptr;

int main(int argc, char **argv)
{

make_unreachable_leak();
ptr = make_reachable_leak();

return 0;
}

Not even close

SergeyKostrov — Thu, 21 Jun 2012 00:55:57 GMT

Thank you, Mark!

Best regards,
Sergey

Not even close - Unreachable & Reachable Memory Leaks

SergeyKostrov — Tue, 26 Jun 2012 00:51:04 GMT

Hi Mark,

I'll try to do a follow up onyour Test-Case tomorrow.

Best regards,
Sergey

Not even close - A Feature Request

SergeyKostrov — Thu, 28 Jun 2012 00:23:57 GMT

Quoting Mark Dewing (Intel)

...
int *make_reachable_leak()
{
// Still accessible through global pointer
// Will not be reported by Inspector XE
int *tmp = (int *)malloc(sizeof(int));
return tmp;
}
...

Mark,

>>// Will not be reported by Inspector XE

I think it has to be fixed because this is wrong. In both cases memory is allocated from a heap and
a Win32 API function 'HeapAlloc' is used. I will provide two reports from built-in Memory Leaks detection systems
implemented by Microsoft and for the ScaLib project.

Best regards,
Sergey

Not even close - A Feature Request

SergeyKostrov — Thu, 28 Jun 2012 23:30:50 GMT

Here are Test-Cases:

[cpp]... RTint *g_iPointer = RTnull; RTint * MakeUnreachableLeak( RTvoid ) // Will be reported by Inspector XE { // RTint *iTmp = ( RTint * )malloc( sizeof( RTint ) ); // RTint *iTmp = ( RTint * )new RTint( 777 ); RTint *iTmp = ( RTint * )CrtNew RTint( 777 ); return ( RTint * )RTnull; } // Accessible through global pointer RTint * MakeReachableLeak( RTvoid ) // Will not be reported by Inspector XE { // RTint *iTmp = ( RTint * )malloc( sizeof( RTint ) ); // RTint *iTmp = ( RTint * )new RTint( 777 ); RTint *iTmp = ( RTint * )CrtNew RTint( 777 ); return ( RTint * )iTmp; } ... ... // Sub-Test 2.1 - Microsoft MLD { RTbool bOk = RTfalse; _CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ); _CrtSetReportMode( _CRT_ERROR, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_WNDW ); MakeUnreachableLeak(); g_iPointer = MakeReachableLeak(); _CrtDumpMemoryLeaks(); } ... or ... // Sub-Test 2.2 - ScaLib MLD { RTbool bOk = RTfalse; MakeUnreachableLeak(); g_iPointer = MakeReachableLeak(); bOk = MemoryTracerData(); bOk = MemoryTracerIntegrity(); } ... [/cpp]

Not even close - A Feature Request

SergeyKostrov — Thu, 28 Jun 2012 23:31:11 GMT

Note: MLD stands for Memory Leaks Detection.

Here are results:

>> Microsoft MLD - CRT-function 'malloc' is used <<
...
Detected memory leaks!
Dumping objects ->
{76} normal block at 0x02124470, 4 bytes long.
Data: < > CD CD CD CD
{75} normal block at 0x02124430, 4 bytes long.
Data: < > CD CD CD CD
Object dump complete.
...

>> Microsoft MLD - C++ operator 'new' is used <<
...
Detected memory leaks!
Dumping objects ->
{76} normal block at 0x02124470, 4 bytes long.
Data: < > 09 03 00 00
{75} normal block at 0x02124430, 4 bytes long.
Data: < > 09 03 00 00
Object dump complete.
...

>> ScaLib MLD - C++ operator 'CrtNew' is used ( the same as 'new' ) <<
...
* Memory Block: 0 *
..\common\prttests.cpp(6527)
Memory Block State: 1 - Allocated by CrtNew
* Memory Block: 1 *
..\common\prttests.cpp(6534)
Memory Block State: 1 - Allocated by CrtNew

Memory Blocks Allocated : 2
Memory Blocks Released : 0
Memory Blocks NOT Released: 2
Memory Tracer Integrity Verified - Memory Leaks Detected
...

Not even close - A Feature Request

SergeyKostrov — Fri, 29 Jun 2012 23:50:51 GMT

Please take a look attwo comments.

Quoting Sergey Kostrov

>> Microsoft MLD - CRT-function 'malloc' is used <<
...
Detected memory leaks!
Dumping objects ->
{76} normal block at 0x02124470, 4 bytes long.
Data: < > CD CD CD CD [SergeyK] Not initialized by 'malloc'
...

>> Microsoft MLD - C++ operator 'new' is used <<
...
Detected memory leaks!
Dumping objects ->
{76} normal block at 0x02124470, 4 bytes long.
Data: < > 09 03 00 00 [SergeyK] Initialized with a value 777 ( 0x00000309) by 'new'
...

Best regards,
Sergey

Not even close - A Feature Request

SergeyKostrov — Mon, 09 Jul 2012 12:32:06 GMT

Are there any updates on the problem?

Best regards,
Sergey

Not even close - A Feature Request

Bernard — Sun, 22 Jul 2012 07:13:42 GMT

I would suggest to use windbg for memory leaks detection, because of large set of commands and very good extensions for example !heap command can you save a lot of pain caused by manually walk the heap.

Here is good tutorial for the memory leaks detection with the help of windbg : http://www.codeproject.com/Articles/31382/Memory-Leak-Detection-Using-Windbg

Not even close - A Feature Request

SergeyKostrov — Sun, 22 Jul 2012 18:40:02 GMT

Quoting iliyapolak

In 2007 I worked for an image processingproject and it had more than 30,000 memory leaks...
Some developers / users on the forumare dealing with even more memory leaks, something like 100,000, and
take a look at posts...

WinDbg is a great externalutility but it is not integrated with a Visual Studio IDE by default.

Intel Inspector XE, or Microsoft Memory Leaks Detection ( MLD )API of the CRT library, orScaLib MLD APIare able to point
exactly to a source line where a memory was allocated ( because they could beintergated, or already integrated by default,
withVS IDE )and in that case adeveloper doesn't need to "walk the heap" trying to find something suspicious.

On middle- or large-scale software projects developers arealwaysbusy with completely different things related to
implementation of somenew functionality, or stabilization of some codes, etc.

Here is a short example:

...
* Memory Block: 0 *
..\common\prttests.cpp(6527) [SergeyK]It reports to a line where a new C++ operator was used
Memory Block State: 1 - Allocated by CrtNew
* Memory Block: 1 *
..\common\prttests.cpp(6534) [SergeyK]It reports to a line where a new C++ operator was used
Memory Block State: 1 - Allocated by CrtNew

Memory Blocks Allocated : 2
Memory Blocks Released : 0
Memory Blocks NOT Released: 2
Memory Tracer Integrity Verified - Memory Leaks Detected
...

Best regards,
Sergey

Not even close - A Feature Request

Bernard — Mon, 23 Jul 2012 16:23:53 GMT

WinDbg is a great externalutility but it is not integrated with a Visual Studio IDE by default

Windbg will be integrated with the next release of Visual Studio.

>>and in that case adeveloper doesn't need to "walk the heap" trying to find something suspicious

@Sergey I was talking from the "debugging" point of view:)

Btw I have used extensively windbg and I must say that this tool is outstanding and very versatile.

>> middle- or large-scale software projects developers arealwaysbusy with completely different things related to
implementation of somenew functionality, or stabilization of some codes

Who is responsible for software - OS interaction debugging when something goes wrongand who do it atmachine code level ?

Not even close - A Feature Request

SergeyKostrov — Tue, 24 Jul 2012 00:57:49 GMT

Please consider it as a programmer'sjoke:

Quoting iliyapolak

Who is responsible for software...

A manager... Because he/shetells software developers what they should do and what they shouldn't... :)

Best regards,
Sergey

Not even close - A Feature Request

Bernard — Tue, 24 Jul 2012 07:05:03 GMT

A manager... Because he/shetells software developers what they should do and what they shouldn't... :)

@Sergey
Do you have an escalation engineers in your team?