Python 3.x asyncio.Queue.get（）卡在空队列上

在下面的代码中，我有一个生产者在它自己的线程中运行，生成可运行的对象，并将它们放入asyncio.Queue中。消费者作为ayncio事件循环中的任务运行。只要队列不是空的，一切正常一旦

等待队列.get（）

遇到空队列，即使将项目添加到队列中，它也不会返回。我使用的是python版本3.7.6

import threading
import asyncio
import random
import time
import logging

logger = logging.getLogger()
logger.setLevel(0)
formatter = logging.Formatter('%(asctime)-15s %(levelname)-5s| %(name)s: %(funcName)s: %(message)s')
consoleHandler = logging.StreamHandler()
consoleHandler.setFormatter(formatter)
logger.addHandler(consoleHandler)


#=======================================================================
class Runnable(object):
    def __init__(self, id, load):
        self.id = id
        self.load = load
        return

    async def run(self):
        logger.info(f"Running: {self.id}, load: {self.load}")
        await asyncio.sleep(self.load)
        logger.info(f"Done Running: {self.id}, load: {self.load}")
        return

    
#=======================================================================
def producer(queue):
    logger.info("Starting producer")
    eventId = 0
    
    while(True):
        eventId += 1
        load = random.uniform(1, 5)
        r = Runnable(eventId, load)
        queue.put_nowait(r)
        logger.info(f"Added runnable. qsize: {queue.qsize()}")
        time.sleep(3)
    return


async def consumer(queue):
    logger.info("Starting consumer")
    while(True):
        logger.info(f"Waiting for runnable. qsize: {queue.qsize()}")
        r = await queue.get()
        logger.info("Received runnable")
        await r.run()
        logger.info("Done with processing runnable")
    return


def main():
    # create and start a producer
    queue = asyncio.Queue(20)
    prodThd = threading.Thread(target=producer, args=(queue,))
    prodThd.start()

    # start consuming on the async event_loop
    loop = asyncio.get_event_loop()
    task = loop.create_task(consumer(queue))
    loop.run_until_complete(task)
    return

#=======================================================================
if (__name__ == '__main__'):
    main()

样本输出：

2020-06-26 19:52:13,555 DEBUG| asyncio: __init__: Using selector: SelectSelector
2020-06-26 19:52:13,561 INFO | root: producer: Starting producer
2020-06-26 19:52:13,561 INFO | root: producer: Added runnable. qsize: 1
2020-06-26 19:52:13,561 INFO | root: consumer: Starting consumer
2020-06-26 19:52:13,561 INFO | root: consumer: Waiting for runnable. qsize: 1
2020-06-26 19:52:13,561 INFO | root: consumer: Received runnable
2020-06-26 19:52:13,561 INFO | root: run: Running: 1, load: 1.320570165693137
2020-06-26 19:52:14,882 INFO | root: run: Done Running: 1, load: 1.320570165693137
2020-06-26 19:52:14,882 INFO | root: consumer: Done with processing runnable
2020-06-26 19:52:14,882 INFO | root: consumer: Waiting for runnable. qsize: 0
2020-06-26 19:52:16,562 INFO | root: producer: Added runnable. qsize: 1
2020-06-26 19:52:19,562 INFO | root: producer: Added runnable. qsize: 2
2020-06-26 19:52:22,564 INFO | root: producer: Added runnable. qsize: 3
2020-06-26 19:52:25,565 INFO | root: producer: Added runnable. qsize: 4
2020-06-26 19:52:28,566 INFO | root: producer: Added runnable. qsize: 5
2020-06-26 19:52:31,568 INFO | root: producer: Added runnable. qsize: 6
2020-06-26 19:52:34,569 INFO | root: producer: Added runnable. qsize: 7
2020-06-26 19:52:37,569 INFO | root: producer: Added runnable. qsize: 8
2020-06-26 19:52:40,569 INFO | root: producer: Added runnable. qsize: 9
2020-06-26 19:52:43,570 INFO | root: producer: Added runnable. qsize: 10
2020-06-26 19:52:46,571 INFO | root: producer: Added runnable. qsize: 11
2020-06-26 19:52:49,572 INFO | root: producer: Added runnable. qsize: 12
2020-06-26 19:52:52,573 INFO | root: producer: Added runnable. qsize: 13
2020-06-26 19:52:55,574 INFO | root: producer: Added runnable. qsize: 14
2020-06-26 19:52:58,575 INFO | root: producer: Added runnable. qsize: 15
2020-06-26 19:53:01,576 INFO | root: producer: Added runnable. qsize: 16
2020-06-26 19:53:04,576 INFO | root: producer: Added runnable. qsize: 17
2020-06-26 19:53:07,577 INFO | root: producer: Added runnable. qsize: 18
2020-06-26 19:53:10,579 INFO | root: producer: Added runnable. qsize: 19
2020-06-26 19:53:13,579 INFO | root: producer: Added runnable. qsize: 20

---

您试图从事件循环之外的完全不同的线程向队列添加项目。异步IO队列只能从事件循环中安全地与进行交互。他们正在引用这些文件：

这个类不是线程安全的

---

您试图从事件循环之外的完全不同的线程向队列添加项目。异步IO队列只能从事件循环中安全地与进行交互。他们正在引用这些文件：

这个类不是线程安全的

---

有关从多个线程使用

asyncio.Queue

的方法，请参阅。明白了。感谢您的帮助。有关从多个线程使用

asyncio.Queue

的方法，请参阅。明白了。谢谢你的帮助。