多进程续集

Posted 2021-12-01

1.守护进程

"守护进程的特点"
1.守护进程会在主进程的代码执行完成后终止
2.守护进程内不能再开启子进程，否则抛出异常AssertionError: daemonic processes are not allowed to have children

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: vita
from multiprocessing import Process
import time
import random

def task(name):
    print(‘%s is piaoing‘ %name)
    time.sleep(random.randrange(1,3))
    print(‘%s is piao end‘ %name)

if __name__ == ‘__main__‘:
    p=Process(target=task,args=(‘egon‘,))
    p.daemon=True #一定要在p.start()前设置,设置p为守护进程,禁止p创建子进程,并且父进程代码执行结束,p即终止运行
    p.start()
    print(‘主‘) #只要终端打印出这一行内容，那么守护进程p也就跟着结束掉了

D:\software2\Python3\install\python.exe E:/PythonProject/new-python/python-test/BasicGrammer/test.py
主

Process finished with exit code 0

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
    p1.start()
    p2.start()
    print("main-------") #主进程执行玩这个，p1就停止了

D:\software2\Python3\install\python.exe E:/PythonProject/new-python/python-test/BasicGrammer/test.py
main-------
456
end456

Process finished with exit code 0