为什么生产者消费者不停止？

Question

我找到了一个用两个线程表示生产者-消费者的例子。但是，当我向进程发送停止信号时，它没有。它期待第二个信号，例如SIGKILL完全停止。我以为问题出在，task_done()但似乎不是。import timeimport queueimport threadingimport randomclass Producer(threading.Thread):    """    Produces random integers to a list    """    def __init__(self, queue):        """        Constructor.        @param queue queue synchronization object        """        threading.Thread.__init__(self)        self.queue = queue    def run(self):        """        Thread run method. Append random integers to the integers        list at random time.        """        while True:            integer = random.randint(0, 256)            self.queue.put(integer)            print('%d put to queue by %s' % (integer, self.name))            time.sleep(1)class Consumer(threading.Thread):    """    Consumes random integers from a list    """    def __init__(self, queue):        """        Constructor.        @param integers list of integers        @param queue queue synchronization object        """        threading.Thread.__init__(self)        self.queue = queue    def run(self):        """        Thread run method. Consumes integers from list        """        while True:            integer = self.queue.get()            print('%d popped from list by %s' % (integer, self.name))            self.queue.task_done()def main():    q = queue.Queue()    t1 = Producer(q)    t2 = Consumer(q)    t1.start()    t2.start()    t1.join()    t2.join()if __name__ == '__main__':    main()输出：210 put to queue by Thread-1210 popped from list by Thread-2Traceback (most recent call last):  File "/Users/abc/PycharmProjects/untitled1/ssid.py", line 74, in <module>    main()  File "/Users/abc/PycharmProjects/untitled1/ssid.py", line 69, in main    t1.join()