queues.py 文件源码

def get(self, timeout=None):
        """Remove and return an item from the queue.

        Returns a Future which resolves once an item is available, or raises
        `tornado.gen.TimeoutError` after a timeout.
        """
        future = Future()
        try:
            future.set_result(self.get_nowait())
        except QueueEmpty:
            self._getters.append(future)
            _set_timeout(future, timeout)
        return future