Re: returning from worker thread

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Fri, 11 Aug 2006 23:04:04 -0400
Steve Russell wrote:

 // first call for thread
 m_pAudioThread = AfxBeginThread(AudioCallback, this, 0, 0,
 m_pAudioThread->m_bAutoDelete = false;
 . . .
 if(waveOutWrite(m_hWaveOut, m_WaveHdr, sizeof(WAVEHDR)))
 . . .

How do I make subsequent calls to the worker thread's function, i.e.

To keep the thread alive for the life of the app the thread is going to
be started one time only and consist of a "do forever" loop.

You don't "call" a thread, you signal to it. You can use a worker
thread or a message-driven thread. For the worker thread case like you
have now the new thread function would look about like this...

UINT AudioCallback(LPVOID param)
{ CSomeClass* p = (CSomeClass*)param;
    { DWORD signal = WaitForMultipleObjects(
             p->hcount, p->handles, FALSE, INFINITE);
       { case ... break;
          case ... break;
    return 0;

While no event is signaled the thread is suspended in
WaitForMultipleObjects. You signal to the thread using SetEvent, which
causes one of the case statements to execute. The first case should be
a shutdown command that makes the thread exit during app shutdown.

A message-driven thread is better in many cases, but since you already
have a worker thread I guessed you probably want to try this approach.

I suggest you change the name of the thread function - callback is

Scott McPhillips [VC++ MVP]

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