問題描述

在測試生產消費者模型的時候遇到這樣一個問題，在繼承線程后 加了個標志位 mark

class Consumer(threading.Thread): def __init__(self, queue):threading.Thread.__init__(self)self._queue = queueself.mark = True def run(self):while self.mark: msg = self._queue.get() if isinstance(msg, str) and msg == ’quit’:break print('I’m a thread, and I received %s!!' % msg)print(’Bye byes!’)

def producer(): q = queue.Queue() worker = Consumer(q) worker.start() # 開啟消費者線程 start_time = time.time() while time.time() - start_time < 5:q.put(’something at %s’ % time.time())time.sleep(1) worker.mark = Flese worker.join()

我原先指望 通過這個標志位來實現線程的結束控制，但實際效果是程序卡死在worker.join()完全沒有退出。

請教下，這是什么原因？

問題解答

class Consumer(threading.Thread): def __init__(self, queue):threading.Thread.__init__(self)self._queue = queueself.mark = True def run(self):while self.mark: try:msg = self._queue.get(block=False) # 非阻塞print('I’m a thread, and I received %s!!' % msg) except:pass print(’self.mark’,self.mark)print(’Bye byes!’)def producer(): q = queue.Queue() worker = Consumer(q) worker.start() # 開啟消費者線程 start_time = time.time() while time.time() - start_time < 5:q.put(’something at %s’ % time.time())time.sleep(1) worker.mark = False worker.join()