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Asked: 2026-05-11T07:36:27+00:00

I’m looking for some random crashes in an old c++ application. Using sysinternals process

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I’m looking for some random crashes in an old c++ application. Using sysinternals process explorer, I noticed the app losing handles, and extracted the exact situation, where the program is losing handles to a very short piece of code.

DWORD WINAPI MyTestThread( void*  PThread) {  _endthreadex(0);  return 0; }  int WINAPI WinMain( HINSTANCE, HINSTANCE, LPSTR  PParameter, int) {  for (int i=0;i<10000;i++)  {    unsigned int threadID;    HANDLE hThread= (HANDLE)_beginthreadex( (void*)NULL, (unsigned int)32768, (unsigned int (__stdcall *)(void *))MyTestThread, (void*)NULL, (unsigned int)0, &threadID);    WaitForSingleObject((HANDLE)hThread, 1000);    CloseHandle((HANDLE)hThread);  }  return 0; }

My problem: I can’t figure out what’s wrong with this code. It loses exactly 5 handles on every iteration, but it looks OK to me.
Funny thing: it seems not to lose handles on windows vista, but I’d be very surprised if this should be a bug in windows 7.

[Update] I tried using _beginthread/_endthread and CreateThread/ExitThread instead, those two are losing 5 handles, too, just like _beginthreadex.

[2nd Update] the code does run as expected. All return values are good. It is ‘just’ losing handles like there is no tomorrow.

[3rd Update] Big new Info The code only loses handles, if compiled with /clr! And more, if I call GC::Collect() on each iteration the handles will be reclaimed!
So, how do I find what clr-objects are being collected there?

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1 Answer

  1. Check whether some DLL which is linked to your exe is doing something strange in its DLLMain in response to DLL_THREAD_ATTACH notifications.

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