server.c

C~C++程序员实用大全——C~C++最佳编程指南的源代码

     MessageBox (*hWnd, errorBuf, lpBuffer,
                 MB_ICONINFORMATION | MB_OK | MB_APPLMODAL);
     };

                                       // Block until a client connects.
   ConnectNamedPipe(hPipe, NULL);

                                       // Create and init overlap for writing.
   hEventWrt = CreateEvent (NULL, TRUE, FALSE, NULL);
   memset (&OverLapWrt, 0, sizeof(OVERLAPPED));
   OverLapWrt.hEvent = hEventWrt;

                                       // Set the clientIndex, then increment
                                       // the count.  Fill in the structure
                                       // for this client in the array.
   clientIndex = clientCount++;
   clients[clientIndex].hPipe   = hPipe;
   clients[clientIndex].live    = TRUE;
   clients[clientIndex].overLap = OverLapWrt;
   clients[clientIndex].hEvent  = hEventWrt;

                                       // Create and init overlap for reading.
   hEventRd = CreateEvent(NULL,TRUE,FALSE,NULL);
   memset (&OverLapRd, 0, sizeof(OVERLAPPED));
   OverLapRd.hEvent = hEventRd;

                                       // Read from the client, the first
                                       // first message should always be
                                       // the clients user name.
   retCode = ReadFile (hPipe, inBuf, PLEASE_READ, &bytesRead, &OverLapRd);

   if (!retCode)
    lastError = GetLastError();

   if (lastError == ERROR_IO_PENDING)  // Wait on read if need be.
     WaitForSingleObject (hEventRd, (DWORD)-1);

                                       // Put client's name in the array.
   strcpy (clients[clientIndex].Name, inBuf);

                                       // Create a thread which will make
                                       // another server instance of the
                                       // named pipe.
   CreateThread ((LPSECURITY_ATTRIBUTES)NULL,        // No security attributes.
                 (DWORD)0,                           // Use same stack size.
                 (LPTHREAD_START_ROUTINE)ServerProc, // Thread procedure.
                 (LPVOID)hWnd,                       // Parameter to pass.
                 (DWORD)0,                           // Run immediately.
                 (LPDWORD)&ServerThreadID);          // Thread identifier.

   TellAll("");                        // Forces a paint, draws a red spool
                                       // and name for this client.

                                       // Do loop which basically reads from
                                       // this specific client, and then
                                       // uses TellAll() to broadcast the
                                       // message to all the connected
                                       // clients.
   do{
                                       // Read the pipe.
      retCode = ReadFile (hPipe, inBuf, PLEASE_READ, &bytesRead, &OverLapRd);

                                       // Check for three kinds of errors:
                                       // If Error = IO_PENDING, wait til
                                       // the event handle signals success,
                                       // If BROKEN_PIPE, exit the do loop.
                                       // Any other error, flag it to the
                                       // user and exit the do loop.
      if (!retCode)
        {
        lastError = GetLastError();

        switch (lastError)
          {
                                       // IO_PENDING, wait on the event.
           case ERROR_IO_PENDING:
             WaitForSingleObject (hEventRd, (DWORD)-1);
             break;
                                       // Pipe is broken, exit the loop.
           case ERROR_BROKEN_PIPE:
             ExitLoop = TRUE;
             break;
                                       // Something else is wrong, exit the
                                       // the loop after telling the user.
           default:
             LoadString(hInst, IDS_READERROR, lpBuffer, sizeof(lpBuffer));
             wsprintf (errorBuf, lpBuffer, lastError);
             LoadString(hInst, IDS_DEBUGINFO, lpBuffer, sizeof(lpBuffer));
             MessageBox (*hWnd, errorBuf, lpBuffer, MB_OK);
             ExitLoop = TRUE;
             break;
          }
        }

      if (!ExitLoop)
        {
        GetOverlappedResult (hPipe, &OverLapRd, &bytesTransRd, FALSE);

                                       // Use TellAll to broadcast the message.
        if (bytesTransRd)
          TellAll(inBuf);
        else
          TellAll("");
        }

   }while(!ExitLoop);

   clients[clientIndex].live = FALSE;  // Turns spool gray.
   CloseHandle (hPipe);                // Close handles.
   CloseHandle (hEventRd);
   CloseHandle (hEventWrt);
   DisconnectNamedPipe (hPipe);        // Close pipe instance.
   ExitThread(0);                      // Clean up and die.
  }


/*  To write the buffer (input parameter) to all of the clients listed
    in the global array "clients". Clients is a global array which hold information on each client
    connected to the named pipe.  This procedure recieves a buffer.
    It then steps through this global array, and for each client it
    writes the buffer.  */

VOID TellAll( CHAR *buffer )
  {
    DWORD i;                           // Index through array.
    DWORD bytesWritten;                // Used in WriteFile().
    DWORD retCode;                     // Traps return codes.
    CHAR  Buf[LINE_LEN];               // Message Buffer.
    DWORD lastError;                   // Traps returns from GetLastError().

    for(i=0; i < clientCount; i++)     // For all clients in the array.
      {
                                       // If client isn't alive, don't waste
                                       // time writing to it.
      if (clients[i].live)
        {
        retCode = WriteFile (clients[i].hPipe, buffer, strlen(buffer),
                             &bytesWritten, &clients[i].overLap);

                                       // Check 3 kinds of errors: IO_PENDING,
                                       // NO_DATA, or other.  Wait on event
                                       // handle if IO_PENDING, else, if it's
                                       // anything other than NO_DATA (pipe
                                       // client disconnected), flag the user.
                                       // In any case, if it's not IO_PENDING,
                                       // clients[i].live = FALSE, spool turns
                                       // gray.
        if (!retCode)
          {
          lastError = GetLastError();

                                       // IO_PENDING, wait on event handle.
          if (lastError == ERROR_IO_PENDING)
            {
            WaitForSingleObject (clients[i].hEvent, (DWORD)-1);
            }
          else
            {
                                       // If not NO_DATA, flag user.
            if (lastError != ERROR_NO_DATA)
              {
              LoadString(hInst, IDS_DEBUGLAST, lpBuffer, sizeof(lpBuffer));
              wsprintf (Buf, "%s = %d", buffer, GetLastError());
              MessageBox(hWnd, Buf, lpBuffer, MB_OK);
              }
            clients[i].live = FALSE;
            }
          }
        } //if client.live
      } // for loop
                                       // Paint window with new information.
    InvalidateRect(hWnd, NULL, TRUE);
  }



/*
    To draw one of four bitmaps for each client, depending upon the clients
    status (alive = red spool, dead or disconnected = gray), and location in
    the array.  It also draws the clients user name beside the spool.
    This procedure is executed when the WM_PAINT message is trapped.  */

VOID DrawBranch(HDC hDC)
{
                                       // Spool bitmaps.
  HBITMAP hEndLive, hEndDead, hMidLive, hMidDead, hBitMap;

  HDC hDCMem;
  int X, Y;
  BITMAP bm;
  POINT ptSize, ptOrg;
  DWORD index;

                                       // Load bitmaps: two red (live),
                                       // two dead (gray).  End = end
                                       // of tree (last client to connect),
                                       // mid means in the middle somewhere.
       hEndLive = LoadBitmap (hInst, "EndLive");
       hEndDead = LoadBitmap (hInst, "EndDead");

       hMidLive = LoadBitmap (hInst, "MidLive");
       hMidDead = LoadBitmap (hInst, "MidDead");

                                       // For each client, determine if
                                       // if alive or not, and position;
                                       // then blt appropriate map and
                                       // clients name.
    for (index = 0; index < clientCount; index++)
      {

      if (index < clientCount - 1)     // ClientCount - 1 = last (end) client.
       {
        if(clients[index].live)        // If live = red, else = gray.
         hBitMap = hMidLive;
        else
         hBitMap = hMidDead;
       }
      else
       {
        if(clients[index].live)        // If live = red, else = gray.
         hBitMap = hEndLive;
        else
         hBitMap = hEndDead;
       }
                                       // Calculate coordinates:
      X = BITMAP_X;                    // X position is constant.
      Y = index * BITMAP_Y;            // Y is based on index in the array.

                                       // Blt the chosen map.
      hDCMem = CreateCompatibleDC(hDC);
      SelectObject(hDCMem, hBitMap);
      SetMapMode(hDCMem, GetMapMode(hDC));

      GetObject(hBitMap, sizeof(BITMAP), &bm);

      ptSize.x = bm.bmWidth;
      ptSize.y = bm.bmHeight;
      DPtoLP (hDC, &ptSize, 1);

      ptOrg.x = 0;
      ptOrg.y = 0;
      DPtoLP (hDCMem, &ptOrg, 1);

      BitBlt(hDC, X, Y, ptSize.x, ptSize.y,
             hDCMem, ptOrg.x, ptOrg.y, SRCCOPY);


      X =  NAME_X;                     // Relocate X,Y for clients name.
      Y += NAME_Y;
                                       // Write name next to spool.
      TextOut (hDC, X, Y, clients[index].Name, strlen(clients[index].Name));
      DeleteDC(hDCMem);
      }


}