unbounded_buffer, _CrtSetDbgFlag and memory leaks

Question

I am trying to use one of the new features - asynchronous agents library. I just added a

unbounded_buffer m_myDataBuffer; to my C++ class, nothing more - no agent running yet.

To enable memory leak detection in my application, I am using:

#ifdef _DEBUG
    _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
#endif

But after closing my application window (I am using simple Win 32 GUI application) Visual Studio shows a bunch of memory leaks:

Detected memory leaks!

Dumping objects ->
{261} normal block at 0x007C4EB8, 288 bytes long.
 Data: <              5 > 00 00 02 00 02 00 00 00 10 02 00 00 10 B1 35 00 
{260} normal block at 0x007C4E70, 12 bytes long.
 Data: <        HM| > 00 00 00 00 00 02 00 00 48 4D 7C 00 
{259} normal block at 0x007C4E18, 28 bytes long.
 Data: <                > 00 00 00 00 CD CD CD CD 00 00 00 00 00 00 00 00 
{258} normal block at 0x0035AEF0, 28 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{257} normal block at 0x007C4D48, 144 bytes long.
 Data: <   U            > A4 C2 F4 55 CD CD CD CD 00 00 00 00 00 00 00 00 
{255} normal block at 0x007C0AB8, 16388 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{254} normal block at 0x0035CF30, 12 bytes long.
 Data: <          | > 01 10 00 00 01 00 00 00 B8 0A 7C 00 
{253} normal block at 0x007C0978, 256 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{252} normal block at 0x007C08A8, 148 bytes long.
 Data: < ! U            > 8C 21 F5 55 01 00 00 00 00 00 00 00 00 00 00 00 
{251} normal block at 0x0035FEB8, 256 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{250} normal block at 0x0035FDE8, 148 bytes long.
 Data: < ! U            > 8C 21 F5 55 01 00 00 00 00 00 00 00 00 00 00 00 
{249} normal block at 0x007C0068, 2048 bytes long.
 Data: <  5             > A0 FD 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{248} normal block at 0x0035FDA0, 12 bytes long.
 Data: <` 5         > 60 F9 35 00 00 00 00 00 FF FF FF FF 
{247} normal block at 0x0035F960, 1024 bytes long.
 Data: <  5   |         > E8 FD 35 00 A8 08 7C 00 00 00 00 00 00 00 00 00 
{246} normal block at 0x0035F8B8, 104 bytes long.
 Data: <  5   5         > 10 B1 35 00 98 D0 35 00 02 00 00 00 02 00 00 00 
{245} normal block at 0x0035F078, 2048 bytes long.
 Data: <0 5             > 30 F0 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{244} normal block at 0x0035F030, 12 bytes long.
 Data: <  5         > F0 EB 35 00 00 00 00 00 FF FF FF FF 
{243} normal block at 0x0035EBF0, 1024 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{242} normal block at 0x0035E3B0, 2048 bytes long.
 Data: <h 5             > 68 E3 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{241} normal block at 0x0035E368, 12 bytes long.
 Data: <( 5         > 28 DF 35 00 00 00 00 00 FF FF FF FF 
{240} normal block at 0x0035DF28, 1024 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{239} normal block at 0x0035DE08, 224 bytes long.
 Data: <   U      5     > 98 13 F5 55 00 00 00 00 0C DE 35 00 00 00 00 00 
{238} normal block at 0x0035D5C8, 2048 bytes long.
 Data: <  5             > 80 D5 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{237} normal block at 0x0035D580, 12 bytes long.
 Data: <@ 5         > 40 D1 35 00 00 00 00 00 FF FF FF FF 
{236} normal block at 0x0035D140, 1024 bytes long.
 Data: <  5             > 08 DE 35 00 00 00 00 00 00 00 00 00 00 00 00 00 
{235} normal block at 0x0035D098, 104 bytes long.
 Data: <  5   5   5     > 10 B1 35 00 B8 F8 35 00 08 DE 35 00 CD CD CD CD 
{234} normal block at 0x0035D008, 80 bytes long.
 Data: <,  U\  U        > 2C C4 F4 55 5C C1 F4 55 00 00 00 00 00 00 00 00 
{233} normal block at 0x0035CF78, 80 bytes long.
 Data: <,  U\  U        > 2C C4 F4 55 5C C1 F4 55 00 00 00 00 00 00 00 00 
{231} normal block at 0x0035CEF0, 4 bytes long.
 Data: <    > 00 00 00 00 
{230} normal block at 0x0035CE58, 88 bytes long.
 Data: <            | 5 > 01 00 00 00 00 00 00 00 01 00 00 00 7C CF 35 00 
{229} normal block at 0x0035C300, 44 bytes long.
 Data: <                > 03 00 00 00 02 00 00 00 02 00 00 00 00 00 00 00 
{228} normal block at 0x0035C5E0, 2104 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
{227} normal block at 0x0035C4D0, 208 bytes long.
 Data: <l  U      5 0 5 > 6C 0A F5 55 00 00 00 00 E8 C0 35 00 30 C1 35 00 
{225} normal block at 0x0035C2C0, 4 bytes long.
 Data: <  5 > B8 F8 35 00 
{224} normal block at 0x0035C280, 4 bytes long.
 Data: <  5 > 98 D0 35 00 
{223} normal block at 0x0035C200, 64 bytes long.
 Data: <  5             > 10 C5 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{222} normal block at 0x0035C488, 8 bytes long.
 Data: <        > 00 00 00 00 01 00 00 00 
{221} normal block at 0x0035C418, 48 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 
{220} normal block at 0x0035C3D8, 4 bytes long.
 Data: <    > 00 00 00 00 
{219} normal block at 0x0035C378, 36 bytes long.
 Data: <                > 03 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 
{217} normal block at 0x0035C130, 148 bytes long.
 Data: <l  U            > 6C D7 F4 55 02 00 00 00 01 00 00 00 10 00 00 00 
{216} normal block at 0x0035C0E8, 8 bytes long.
 Data: <   U  5 > C0 11 F5 55 10 B1 35 00 
{215} normal block at 0x0035B8A8, 2048 bytes long.
 Data: <  5             > 00 AE 35 00 CD CD CD CD CD CD CD CD CD CD CD CD 
{214} normal block at 0x0035AE00, 12 bytes long.
 Data: <h 5         > 68 B4 35 00 00 00 00 00 FF FF FF FF 
{213} normal block at 0x0035B468, 1024 bytes long.
 Data: < N|             > 18 4E 7C 00 00 00 00 00 00 00 00 00 00 00 00 00 
{212} normal block at 0x0035AF50, 36 bytes long.
 Data: <                > 00 00 00 00 02 00 00 00 01 00 00 00 01 00 00 00 
{211} normal block at 0x0035B110, 368 bytes long.
 Data: <   UP 5         > CC 1D F5 55 50 AF 35 00 00 00 00 00 00 00 00 00 
Object dump complete.

Leaks go away right after I comment out the

unbounded_buffer<int> m_myDataBuffer;

or after I comment out

_CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );

Is there anything special about unbounded_buffer I have to do to release it even if it is not used? Or do I need to set _CrtSetDbgFlag in some special way? Is _CrtSetDbgFlag the cause of mem leaks or it is somehow creating false detections in this case and there are no real memory leaks? What am I missing here?

I am 100% sure that those leaks do not come from my code because I also have

#ifdef _DEBUG
#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>
#define new new(_NORMAL_BLOCK,__FILE__, __LINE__)

in my stdafx.h so memory leaks from my code have filenames and lines. But those of unbounded_buffer do not have such info, so I guess that means they come from agents library.

Answer 1

Ok, I found out that _CRTDBG_LEAK_CHECK_DF flag makes automatic call of _CrtDumpMemoryLeaks(); at the end of application. But it seems it is happening not at the very end. I removed _CRTDBG_LEAK_CHECK_DF and called _CrtDumpMemoryLeaks() at the end of main() and now it reports memory leaks correctly ... I hope so.

Also there is a bug report in Microsoft MSDN about some memory leaks in PPL libraries, hope they'll fix them soon.