python - 多重处理:池和 map 以及sys.exit()

我想在这里我需要一些建议。下面是我的代码:

from multiprocessing import Pool
import time
import sys

def testing(number):
    count = 0
    while True:
        print('Count: {}'.format(count))
        count += 1

        if count > number:
            print('Exiting...')
            sys.exit()
        else:
            print('Looping Over')
            time.sleep(1)

if __name__ == '__main__':

    with Pool(2) as p:
        p.map(testing, [3, 2])

预期结果:

一旦所有子线程都退出，程序(主线程)应退出。

实际结果:

$ python3 test_exit.py
Count: 0
Looping Over
Count: 0
Looping Over
Count: 1
Looping Over
Count: 1
Looping Over
Count: 2
Looping Over
Count: 2
Exiting...   <<< Exited 1st thread.
Count: 3
Exiting...   <<< Exited 2nd thread.
....and it stays here as if stuck or something. It never gives control back to Shell.

预期结果:

$ python3 test_exit.py
Count: 0
Looping Over
Count: 0
Looping Over
Count: 1
Looping Over
Count: 1
Looping Over
Count: 2
Looping Over
Count: 2
Exiting...
Count: 3
Exiting...
$   <<< Note: I am expecting to be dropped back to Shell prompt

问题:

就池/映射的使用而言，我的方法有什么问题吗？

最佳答案

一旦所有子线程都退出，程序(主线程)应退出。

通过终止其目标函数testing()(通过关键循环中的break语句完成)来完成一个过程
进程池完成后，

退出主线程/程序。

from multiprocessing import Pool, current_process
import time
import sys

def testing(number):
    count = 0
    while True:
        print('Count: {}'.format(count))
        count += 1

        if count > number:
            print('Exiting...', current_process().name)
            break
        else:
            print('Looping Over')
            time.sleep(1)

if __name__ == '__main__':

    with Pool(2) as p:
        p.map(testing, [3, 2])
    sys.exit()

输出:

Count: 0
Looping Over
Count: 0
Looping Over
Count: 1
Looping Over
Count: 1
Looping Over
Count: 2
Looping Over
Count: 2
Exiting... ForkPoolWorker-2
Count: 3
Exiting... ForkPoolWorker-1
$

关于python - 多重处理:池和 map 以及sys.exit()，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/56698824/