simplest thread program doesn't work

[Spiritofamerica]

DWORD WINAPI tredu (LPVOID lpParam ); int APIENTRY WinMain(HINSTANCE a,HINSTANCE b,LPSTR comanda,int arata) { HANDLE hThread; DWORD dwID,dwThrdParam = 1; hThread = CreateThread (NULL, 0,tredu ,&dwThrdParam, 0, &dwID); if (hThread==NULL) MessageBox(0,"a","a",MB_OK); return 0; } DWORD WINAPI tredu (LPVOID lpParam ) { Beep(1000,1000); MessageBox(0,"a","b",MB_OK); return 0; } this does nothing? where am I going wrong the handle is not NULL but nothing happens I am using VC 7.0

[Cedric Moonen]

Your main thread exits as soon as it has created the second thread, so probably it destroys the second thread.

[Hans Ruck]

The main thread ends too soon. Try:

if (hThread==NULL)
MessageBox(0,"a","a",MB_OK);
else
MessageBox(0,"b","a",MB_OK);

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"tous les sifflets des trains, toutes les sirènes des bateaux   m'ont chanté cent fois la chanson de l'Eldorado" rechi+

[Marc Soleda]

It works fine in VC6. I can't test in VC7 ... ... she said you are the perfect stranger she said baby let's keep it like this... Tunnel of Love, Dire Straits.

[Bob Ciora]

As mentioned, the main is exiting before the thread can even execute. To wait for the thread to terminate, you can do a WaitForSingleObject(hThread, INFINITE);. This will wait for the thread handle to become "invalid," which occurs when the thread terminates. At that point, you should also do a CloseHandle(hThread); before exiting. Bob Ciora

[LighthouseJ]

I agree with cedric. I recommend you look into events, they help control synchronization between the thread and your app. Here's what I'd usually do: struct threadPkg {   HANDLE hStartup, hStopNow, hShutdown; }; UINT ThreadFunc (LPVOID lpParam) {   threadPkg * pkg = (threadPkg *) lpParam;   ::SetEvent(pkg->hStartup);   while (true) {     switch (::WaitForSingleObject(pkg->hStopNow, 10)) {       case WAIT_OBJECT_0: {         ::SetEvent(pkg->hShutdown);         AfxEndThread(0, true);         return 0;           } break;       case WAIT_TIMEOUT: {         // do some work here           } break;       }    } } bool StartThread (threadPkg * pkg) {   CWinThread * thread = AfxBeginThread(ThreadFunc, pkg, THREAD_PRIORITY_IDLE, 0, 0, NULL);   switch (::WaitForSingleObject(pkg->hStartup, INFINITE)) {     case WAIT_OBJECT_0: { return true; } break;     case WAIT_TIMEOUT: {    // should never be reached, INFINITE is a very long time,     return false;        // but I like to totally define all possible program paths         } break;     } } void StopThread (threadPkg * pkg) {   ::SetEvent(pkg->hStopNow);   switch (::WaitForSingleEvent(pkg->hShutdown, INFINITE)) {     case WAIT_OBJECT_0: break;   } } void main () {   threadPkg * pkg = new threadPkg;   pkg->hStartup = ::CreateEvent(NULL, true, false, "startup sequence, thread->main");   pkg->hStopNow = ::CreateEvent(NULL, true, false, "signal to stop now, main->thread");   pkg->hShutdown = ::CreateEvent(NULL, true, false, "thread has shut down, thread->main");   if (StartThread(pkg)) {     // thread is running, do what I need     StopThread(pkg);   } else {     MessageBox(NULL, "Error: The worker thread was not started.", "Critica