I have two MFC programs communicating over multiple sockets.  At
present,during development, both programs are running on the same NT
machine.  I am using Winsock2, with the overlapped I/0 model.
 The programs start out by exchanging a fixed set of messages.
Sometimes the communication fails at a particular point, and sometimes
it works.  I haven't been able to figure out a pattern.
 The error occurs in the client, which is waiting for an
acknowledgement of a command that it sent to the server. The client is
running WSAWaitForMultipleEvents in a thread. When the event is
signaled, the thread posts a message to the main thread. The main
thread runs WSAGetOverlappedResult, which, when the error occurs,
returns FALSE. The error returned by WSAGetLastError() is 995. 995 is
a system error code called ERROR_OPERATION_ABORTED, "The I/O operation
has been aborted because of either a thread exit or an application
request. "  I can't figure out how to apply this message to my
situation.
  The server is not reporting any errors.
  Thanks very much !
        Elaine

  Here are some fragments of the code:

  // The following code runs in a thread on the client

    while (TRUE)
     {
       if ((Index = WSAWaitForMultipleEvents(MAXCONNECTIONS,
                        ptp->EventArray,FALSE,WSA_INFINITE,FALSE))
                        == WSA_WAIT_FAILED)
                {
                   // handle error
                }              

                Index -= WSA_WAIT_EVENT_0;

                WSAResetEvent(ptp->EventArray[Index])

        // post a message to the main thread, so that the main thread
handles the
        // socket event
        while (::PostMessage(ptp->hWnd,SOCKET_THREADMESSAGE,
                (WPARAM) Index,(LPARAM)0) != TRUE)
                        {
                        }
        }

  // Code in the main thread. This is the call that fails.

                DWORD BytesTransferred=0;
                DWORD Flags;
                BOOL retval=TRUE;
                WSASetLastError(0);
                if ((retval=WSAGetOverlappedResult(m_Socket,&m_Overlapped,&BytesTransferred,
                        FALSE,&Flags))== FALSE || BytesTransferred == 0)
                {
                        sprintf(m_errMsg," error %d",
                                WSAGetLastError());
                }