Namedpipe

[charian0920]

Hi! Good day :) I have this problem about synchronization on namedpipe ... I have this namedpipe server that allows multiple instances. The algorithm I have is I'll wait for a client to connect to the namedpipe then spawn a thread which will read the message from the namedpipe. My expectation on the spawned thread is that when the client has disconnected the spawned thread will end also. But when I tried testing my code, the thread count keeps on increasing due to the spawned thread, which i think means I was not able to detect that the client had disconnected or something else :( Any help is greatly appreciated. Below are my codes: 1. Createnamedpipe, wait for a client to connect, and spawned a thread. UINT fnRcvMsgsFrmNamedpipeThread(LPVOID pParam) { DWORD dwResult = SUCCEED; CString strLog( _T( "" ) ); OVERLAPPED stClientConnectOverLap = {0}; stClientConnectOverLap.hEvent = CreateEvent( NULL, // no security attributes TRUE, // manual reset event FALSE, // not-signalled NULL); // no name if( stClientConnectOverLap.hEvent == NULL ) { return 0; } HANDLE hEvents; hEvents = stClientConnectOverLap.hEvent; CString strFormatPipeName( _T( "" ) ); strFormatPipeName.Format( "\\\\%s\pipe\mypipename", STR_PERIOD ); HANDLE hClientReqPipe; while ( TRUE ) { hClientReqPipe = CreateNamedPipe( strFormatPipeName, FILE_FLAG_OVERLAPPED | PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES, 0, 0, 10000, NULL ); if( hClientReqPipe == INVALID_HANDLE_VALUE ) { dwResult = GetLastError(); break; } if( !ConnectNamedPipe( hClientReqPipe, &stClientConnectOverLap ) ) { if( GetLastError() != ERROR_PIPE_CONNECTED ) { DWORD dwRet = WaitForSingleObject( hEvents, INFINITE ); if( dwRet != WAIT_OBJECT_0 ) { dwResult = GetLastError(); break; } } } CWinThread *pReadMsgThread = AfxBeginThread( fnReadMsgFrmNamedpipe, (LPVOID) hClientReqPipe ); if( NULL == pReadMsgThread ) { break; } } // Close handles ::CloseHandle( hClientReqPipe ); ::CloseHandle( stClientConnectOverLap.hEvent ); return dwResult; } 2. Spawned thread UINT fnReadMsgFrmNamedpipe(LPVOID pParam) { I32L dwResult = SUCCEED; CString strLog( _T("") ); HANDLE hClientReqPipe = (HANDLE) pParam; OVERLAPPED stClientRecOverLap

[Mark Salsbery]

Have you tried putting a breakpoint (or several) in the thread proc and watching what is happening? The debugger is your friend! Mark

Mark Salsbery Microsoft MVP - Visual C++ "Great job team! Head back to base for debriefing and cocktails."

[charian0920]

hi mark, yup I already did that ... the funny thing is that the spawned thread is terminating when I run it with breakpoints and when I put messageboxes.