queues_test.py 文件源码

def test_producer_consumer(self):
        q = queues.Queue(maxsize=3)
        history = []

        # We don't yield between get() and task_done(), so get() must wait for
        # the next tick. Otherwise we'd immediately call task_done and unblock
        # join() before q.put() resumes, and we'd only process the first four
        # items.
        @gen.coroutine
        def consumer():
            while True:
                history.append((yield q.get()))
                q.task_done()

        @gen.coroutine
        def producer():
            for item in range(10):
                yield q.put(item)

        consumer()
        yield producer()
        yield q.join()
        self.assertEqual(list(range(10)), history)