Memory leak when creating new thread.

Question

Hi,
Each time i create a thread, it causes 8 bytes memory leak. The testing code is as below and you can see mem usage increasing in Windows Task Manager. But if i don't call ::OCIEnvCreate(), no memory leak.
Memory validator shows the following call stack information:
........largest allocation 8 bytes at .......
=>OraOCIEI10.dll ss_mem_thread_attach
=>OraOCIEI10.dll sscoresetserverflag
=>OraOCIEI10.dll slzgetevar
=>ntdll.dll LdrInitializeThunk
Anyone knows what is goiing on?
/Yue
#include <stdio.h>
#include <windows.h>
#include <process.h>
#include <oci.h>
static OCIEnv *env;
static unsigned int counter = 0;
unsigned __stdcall ThreadFunc(void* pArg)
counter++;
printf( "In %uth thread...\n", counter );
Sleep(100);
_endthreadex( 0 );
return 0;
int main( int argc, const char* argv[] )
     sword rc = ::OCIEnvCreate(&env, OCI_DEFAULT, NULL, NULL, NULL, NULL, 0, NULL );
     for(;;)
          HANDLE hThread;
          unsigned threadID;
          // Create the second thread.
          hThread = (HANDLE)_beginthreadex( NULL, 0, &ThreadFunc, NULL, 0, &threadID );
          WaitForSingleObject( hThread, INFINITE );
          // Destroy the thread object.
          CloseHandle( hThread );
     return 0;
}

Answer 1

Hi,
I'm not suprised.
OCI offers the feature OCIThreadKey that allow you to store a pointer within a thread context (without using OCIThread, just using natives threads).
So OCI needs to catch thread creation to be able to register storage for its OCIThread key value and be able, once the thread is finished to call a callback with the pointer value associated with the thread....