如何从python中的多处理过程中退出主程序

How to exit a main program from the Multiprocessing Process in python

我使用multiprocessing.process生成3个进程并等待它们完成。如果其中一个失败，那么我想停止所有其他进程以及主程序。但是当我使用sys.exit时，执行只是停止进程而不是主程序。这是代码的片段。

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proc1=process(function1)
proc2=process(function2)
proc3=process(function3)
proc1.start
proc2.start
proc3.start
proc1.join
proc2.join
proc3.join

。
。
。

我在函数1,2和3中运行一些任务。我在每个函数中都有一个条件来检查任务的返回码，如果返回码不成功，那么我想停止proc1，proc2和proc3并停止执行主程序。当我在函数内部执行sys.exit时，它刚刚从该进程中出来而不是主程序。

为此，您需要在工作进程和主进程之间进行通信。可能最简单的方法是使用multiprocessing.Event。

在开始进程之前，创建一对multiprocessing.Event。给他们有意义的名字，如stop_main和stop_workers。为了便于携带，应该将这些Event添加到为Process目标给出的参数中。

当工作进程希望主程序退出时，它应该调用stop_main.set()。工作进程也应定期调用stop_workers.is_set()，并在返回True时退出。

在主进程启动所有工作程序之后，它应该继续轮询stop_main.is_set()。当返回True时，它应该调用stop_workers.set()，join工作者并退出。

更新：

编辑使其更短，并希望它在ms-windows上工作。

一个例子：

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import multiprocessing as mp
import time

def worker(num, sw, sm):
if num == 5:
print('This is worker', num)
time.sleep(1)
print('Worker', num, 'signalling main program to quit')
sm.set()
while not sw.is_set():
print('This is worker', num)
time.sleep(0.7)
else:
print('Worker', num, 'signing off..')

if __name__ == '__main__':
stop_worker = mp.Event()
stop_main = mp.Event()

workers = [mp.Process(target=worker, args=(n, stop_worker, stop_main))
for n in range(1, 6)]
for w in workers:
w.start()
while not stop_main.is_set():
time.sleep(1)
print('MAIN: Received stop event')
print('MAIN: Sending stop event to workers')
stop_worker.set()
for c, w in enumerate(workers, start=1):
w.join()
print('worker', c, 'joined')

它运行如下：

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This is worker 1
This is worker 2
This is worker 3
This is worker 4
This is worker 5
This is worker 2
This is worker 3
This is worker 1
This is worker 4
Worker 5 signalling main program to quit
This is worker 5
This is worker 2
This is worker 3
This is worker 1
This is worker 4
This is worker 5
MAIN: Received stop event
MAIN: Sending stop event to workers
Worker 3 signing off..
Worker 1 signing off..
Worker 2 signing off..
worker 1 joined
worker 2 joined
worker 3 joined
Worker 4 signing off..
worker 4 joined
Worker 5 signing off..
worker 5 joined