Function kwsysProcessDisablePipeThreads

Source/kwsys/ProcessWin32.c:2524–2573

}

static void kwsysProcessDisablePipeThreads(kwsysProcess* cp)
{
  int i;

  /* If data were just reported data, release the pipe's thread.  */
  if (cp->CurrentIndex < KWSYSPE_PIPE_COUNT) {
    KWSYSPE_DEBUG((stderr, "releasing reader %d\n", cp->CurrentIndex));
    ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Reader.Go, 1, 0);
    cp->CurrentIndex = KWSYSPE_PIPE_COUNT;
  }

  /* Wakeup all reading threads that are not on closed pipes.  */
  for (i = 0; i < KWSYSPE_PIPE_COUNT; ++i) {
    /* The wakeup threads will write one byte to the pipe write ends.
       If there are no data in the pipe then this is enough to wakeup
       the reading threads.  If there are already data in the pipe
       this may block.  We cannot use PeekNamedPipe to check whether
       there are data because an outside process might still be
       writing data if we are disowning it.  Also, PeekNamedPipe will
       block if checking a pipe on which the reading thread is
       currently calling ReadPipe.  Therefore we need a separate
       thread to call WriteFile.  If it blocks, that is okay because
       it will unblock when we close the read end and break the pipe
       below.  */
    if (cp->Pipe[i].Read) {
      KWSYSPE_DEBUG((stderr, "releasing waker %d\n", i));
      ReleaseSemaphore(cp->Pipe[i].Waker.Go, 1, 0);
    }
  }

  /* Tell pipe threads to reset until we run another process.  */
  while (cp->PipesLeft > 0) {
    /* The waking threads will cause all reading threads to report.
       Wait for the next one and save its index.  */
    KWSYSPE_DEBUG((stderr, "waiting for reader\n"));
    WaitForSingleObject(cp->Full, INFINITE);
    cp->CurrentIndex = cp->SharedIndex;
    ReleaseSemaphore(cp->SharedIndexMutex, 1, 0);
    KWSYSPE_DEBUG((stderr, "got reader %d\n", cp->CurrentIndex));

    /* We are done reading this pipe.  Close its read handle.  */
    cp->Pipe[cp->CurrentIndex].Closed = 1;
    kwsysProcessCleanupHandle(&cp->Pipe[cp->CurrentIndex].Read);
    --cp->PipesLeft;

    /* Tell the reading thread we are done with the data.  It will
       reset immediately because the pipe is closed.  */
    ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Reader.Go, 1, 0);
  }
}

/* Global set of executing processes for use by the Ctrl handler.
   This global instance will be zero-initialized by the compiler.