queues.py 文件源码

def put(self, item, timeout=None):
        """Put an item into the queue, perhaps waiting until there is room.

        Returns a Future, which raises `tornado.gen.TimeoutError` after a
        timeout.
        """
        try:
            self.put_nowait(item)
        except QueueFull:
            future = Future()
            self._putters.append((item, future))
            _set_timeout(future, timeout)
            return future
        else:
            return gen._null_future