并发编程-守护进程

from multiprocessing import Process
import time

def task(name):
    print(‘%s is running‘ %name)
    time.sleep(2)
    p=Process(target=time.sleep,args=(3,))
    p.start()

if __name__ == ‘__main__‘:
    p = Process(target=task,args=(‘子进程1‘,))
    p.daemon = True  # 守护进程
    p.start()

    p.join()  # 子程序先运行，后运行主程序
    print(‘主‘)  # 守护进程会在主进程代码执行结束后就终止

#练习题
from multiprocessing import Process

import time
def foo():
    print(123)
    time.sleep(1)
    print("end123")

def bar():
    print(456)
    time.sleep(3)
    print("end456")

if __name__ == ‘__main__‘:
    p1=Process(target=foo)
    p2=Process(target=bar)

    p1.daemon=True  # 主进程运行完毕，守护进程也就结束掉了
    p1.start()
    p2.start()
    print("main-------")