Re: Memory leak after closing thread.

From:

Michael Doubez <michael.doubez@free.fr>

Newsgroups:

comp.lang.c++

Date:

Wed, 2 Dec 2009 09:09:52 -0800 (PST)

Message-ID:

<2a9926c7-8e53-4fc5-a37c-6f69529129a5@v25g2000yqk.googlegroups.com>

On 1 d=E9c, 16:07, Michal <mmatuszewski...@gmail.com> wrote:

Before I explain exactly where is the problem I will show my code:
(Platform - Windows CE 5, VisualStudio 2005)

The interesting part of source code is below:

/**************************************************************/
class classA {
        public:
        static DWORD WINAPI testingThread(LPVOID lpvoid);
        HANDLE m_hThread;
        void startthread();

};

DWORD WINAPI classA::testingThread(LPVOID lpvoid)
{
        return 1;

}

void classA::startthreadk()
{
        for(int counter = 0 ; counter < 100 ; counter++) {
                MEMORYSTATUS memInfo;
                memInfo.dwLength = sizeof(memInfo);
                GlobalMemoryStatus(&memInfo);
                DWORD dwThreadId = 0;
                m_hThread = CreateThread(NULL, 0, testi=

ngThread, this,

0,
&dwThreadId);
DWORD dwRet = WaitForSingleObject(m_hTh=

read,

INFINITE);
if(WAIT_OBJECT_0 != dwRet) {
TRACE(_T("Something wrong=

!!! \n"));

}
int returnHandle = CloseHandle(m_hThrea=

d);

                TRACE(_T("After closing handle = %d
\n"),returnHandle);
                m_hThread = NULL;
                MEMORYSTATUS memInfo1;
                memInfo1.dwLength = sizeof(memInfo1);
                GlobalMemoryStatus(&memInfo1);
                TRACE(_T("%d Test %d\n"),counter, memInfo=

..dwAvailPhys

-
memInfo1.dwAvailPhys);
}

}

/**************************************************************/

The problem is that I don't know why but sometimes (usually one per
three times)
I can see the memory leak of 4096 bytes. Why? Do I do something wrong
with closing
thread? (Of course the program without creating thread works ok).
Closehandle
always returns 1, so everything should be ok.

The memeory is managed by your OS. It may not be returned to the
system immediately but kept a little time for future allocation (it
saves requests to the system).

That's what usually happen under Linux and I expect the same happens
in Windows.

--
Michael