day 13 通过Queue实现多进程简单通信

[Aprilhui]

from multiprocessing import Process,Queue,set_start_method
from time import sleep
counter = 0


def sub_task(string,q):
    a = q.get()
    sleep(0.01)
    while a < 10:
        if q.empty():
            q.put(a+1)
            sleep(0.01)
            print(string, end = '', flush=True)
            a = q.get() 
    if q.empty():
        q.put(a+1)
        sleep(0.1)
    return 

def main():
    #mac os 上运行会有错误
    set_start_method('fork')
    q = Queue()
    q.put(0)
    p1 = Process(target=sub_task,args=('ping',q))
    p2 = Process(target=sub_task,args=('pong',q))
    p1.start()
    p2.start()
    
if __name__ == '__main__':
    main()

[tmKnight01]

我昨天在mac中也遇到了这个error 看来还真的会区分系统

[MCbrandon2003]

macOS 从 Python 3.8 开始默认使用 'spawn' 方法以避免与 Objective-C 运行时的冲突。

以下是修改后的代码，它将自动检测操作系统并相应地设置适当的进程启动方法。此外，我还添加了一些错误处理以确保主进程等待子进程完成，并适当地关闭队列。

import os
from multiprocessing import Process, Queue, set_start_method, get_start_method
from time import sleep


def sub_task(string, q):
    a = q.get()
    sleep(0.01)
    while a < 10:
        if q.empty():
            q.put(a + 1)
            sleep(0.01)
            print(string, end='', flush=True)
            a = q.get()
    if q.empty():
        q.put(a + 1)
        sleep(0.1)


def main():
    set_start_method("spawn")

    q = Queue()
    q.put(0)
    p1 = Process(target=sub_task, args=('Ping', q))
    p2 = Process(target=sub_task, args=('Pong', q))

    # 启动进程
    p1.start()
    p2.start()

    # 等待进程完成
    p1.join()
    p2.join()

    print("\nProcesses completed.")


if __name__ == '__main__':
    main()