process.py 文件源码

def Pop(self):
    frame = self.stack.pop()
    #log('< Pop %s', frame)
    for saved, orig in reversed(frame.saved):
      try:
        os.dup2(saved, orig)
      except OSError as e:
        log('dup2(%d, %d) error: %s', saved, orig, e)
        raise
      os.close(saved)
      #log('dup2 %s %s', saved, orig)
      self.next_fd -= 1  # Count down

    for fd in frame.need_close:
      #log('Close %d', fd)
      try:
        os.close(fd)
      except OSError as e:
        log('Error closing descriptor %d: %s', fd, e)
        raise

    # Wait for here doc processes to finish.
    for proc, waiter in frame.need_wait:
      unused_status = proc.WaitUntilDone(waiter)