The relationship between subprograms of python concurrent programming

Let’s first recall the problem we explained last time

Review
1. Two ways to create a process
Method 1:
from multiprocessing import Process

def task(name):
print('%s is running' %name)

if __name__ == '__main__':
obj=Process(taget=task,args=('egon',))
obj.start() # send a signal to the operating system
print('main')
task('xxx')

Method 2:
from multiprocessing import Process

class MyTask(Process):
def run(self):
print('%s is running' %self.name)

if __name__ == '__main__':
obj=MyTask()
obj.start() # Send a signal to the operating system

2. Address space isolation between
processes 3. Other methods of process objects
obj.join(1)

obj.terminate()
obj.is_alive()

obj.pid
obj.name

4. Zombie process and orphan process

 

 

Today's content:
Daemon process (understanding) is based on the process of turning the child process into a daemon process. As long as the parent process ends, the daemon process will also end. Please see the following code demonstration

# !/usr/bin/env python
# -*- coding:utf-8 -*-
# author:Albert

from multiprocessing import Process
import time

def task(name):
    print('%s is running' % name)
    time.sleep(2)

if __name__ == '__main__':
    obj = Process(target=task,args=( ' egon ' ,))
     # obj.daemon = True # This is the daemon code, with this line, there will be child processes, without this line, only the main process 
    obj.start ()
     print ( ' this is the main process ' )

 

 

 

 

 

 

Mutual exclusion lock
IPC mechanism (queue, pipeline)
producer consumer model (key)
process pool (key)