我找到了一个代表具有两个线程的producer-consumer的示例。但是，当我向进程发送信号停止时，它不会。它期望第二信号，例如SIGKILL完全停止。我认为问题出在task_done()上，但似乎没有。
import time
import queue
import threading
import random
class 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-1
210 popped from list by Thread-2
Traceback (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()
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 1056, in join
self._wait_for_tstate_lock()
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 1072, in _wait_for_tstate_lock
elif lock.acquire(block, timeout):
KeyboardInterrupt
244 put to queue by Thread-1
244 popped from list by Thread-2
85 put to queue by Thread-1
85 popped from list by Thread-2
160 put to queue by Thread-1
160 popped from list by Thread-2
这是因为只有主线程被KeyboardInterrupt停止了。您可以通过让您的子线程打印threading.enumerate()来观察这一点，import time
import queue
import threading
import random
class Producer(threading.Thread):
def __init__(self, queue):
super().__init__()
self.queue = queue
def run(self):
while True:
integer = random.randint(0, 256)
self.queue.put(integer)
print(f'{integer} put to queue by {self.name} '
f'threads: {threading.enumerate()}')
time.sleep(1)
class Consumer(threading.Thread):
def __init__(self, queue):
super().__init__()
self.queue = queue
def run(self):
while True:
integer = self.queue.get()
print(f'{integer} popped from list by {self.name} '
f'threads:{threading.enumerate()}')
self.queue.task_done()
def main():
q = queue.Queue()
t1 = Producer(q)
t2 = Consumer(q)
# t1.daemon = True
# t2.daemon = True
t1.start()
t2.start()
t1.join()
t2.join()
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
print('got KeyboardInterrupt')
返回所有活动线程+主线程。
97 put to queue by Thread-1 threads: [<_MainThread(MainThread, started
139810293606208)>, <Producer(Thread-1, started 139810250913536)>,
<Consumer(Thread-2, started 139810242520832)>]
97 popped from list by Thread-2 threads:[<_MainThread(MainThread, started
139810293606208)>, <Producer(Thread-1, started 139810250913536)>,
<Consumer(Thread-2, started 139810242520832)>]
got KeyboardInterrupt
92 put to queue by Thread-1 threads: [<_MainThread(MainThread, stopped
139810293606208)>, <Producer(Thread-1, started 139810250913536)>,
<Consumer(Thread-2, started 139810242520832)>]
92 popped from list by Thread-2 threads:[<_MainThread(MainThread, stopped
139810293606208)>, <Producer(Thread-1, started 139810250913536)>,
<Consumer(Thread-2, started 139810242520832)>]
使用KeyboardInterrupt输出示例。注意在KeyboardInterrupt之后列为'stopped'的MainThread：
docs
您可以使子线程守护程序让它们与主线程一起退出。但是，只有在您的线程没有任何资源的情况下才应该考虑：
注意守护程序线程在关闭时突然停止。他们的资源（例如打开文件，数据库事务等）可能无法正确发布。如果您希望线程正常停止，请使它们成为非守护进程并使用合适的信号机制，例如事件
KeyboardInterrupt。
更好的方法是像上面的代码一样捕获qazxswpoi，并在队列中向子线程发送一个sentinel值，让他们知道他们应该完成，允许他们在退出之前进行清理。