day 13 通过Queue实现多进程简单通信

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()

Run the provided Python snippet on macOS, starting with main() and the set_start_method('fork') call, and capture the reported error. Check the Queue and Process interaction, with completion defined by the example running as intended on macOS or clearly documenting the platform limitation.