线程之间的事件通信答案

【问题标题】：Event communication between threads线程之间的事件通信
【发布时间】：2020-07-15 01:59:32
【问题描述】：

我正在尝试设置 Event 以在 2 个线程之间进行通信，但该事件从未在第二个线程中设置，这是我迄今为止尝试过的：

import multiprocessing
import threading
import time

class Test1(multiprocessing.Process):
    def __init__(self, event):
        super(Test1, self).__init__()
        self.event = event

    def run(self):
        time.sleep(10)
        self.event.set()
        print('event set')

class Test2(multiprocessing.Process):
    def __init__(self, event):
        super(Test2, self).__init__()
        self.event = event

    def run(self):
        while not self.event.isSet():
            self.event.wait()
            print('event wait ended')

if __name__ == '__main__':
    event = threading.Event()

    test1 = Test1(event)
    test2 = Test2(event)

    test1.start()
    test2.start()

    test1.join()
    test2.join()

【问题讨论】：

标签： python python-3.x multithreading events

【解决方案1】：

在multiprocessing 中你必须使用multiprocessing.Event()，而不是threading.Event()

顺便说一句：而multiprocessing.Event() 需要is_set() 而不是isSet()

import multiprocessing
import time

class Test1(multiprocessing.Process):

    def __init__(self, event):
        super().__init__()
        self.event = event

    def run(self):
        time.sleep(3)
        self.event.set()
        print('event set')

class Test2(multiprocessing.Process):

    def __init__(self, event):
        super().__init__()
        self.event = event

    def run(self):
        while not self.event.is_set():  # <--- `is_set()` instead of `isSet()`
            self.event.wait()
            print('event wait ended')

if __name__ == '__main__':
    event = multiprocessing.Event()  # <--- `multiprocessing` isntead of `threading`

    test1 = Test1(event)
    test2 = Test2(event)

    test1.start()
    test2.start()

    test1.join()
    test2.join()

【讨论】：