Python - multiprocessing, multithreading

multiprocessing

refer to:

1. https://docs.python.org/3.6/library/multiprocessing.html

1. Multi-process concept

multiprocessing is a package that supports spawning processes using an API similar to the threading module. The multiprocessing package offers both local and remote concurrency, effectively side-stepping the Global Interpreter Lock by using subprocesses instead of threads. Due to this, the multiprocessing module allows the programmer to fully leverage multiple processors on a given machine. It runs on both Unix and Windows.

Example 1. Multiprocessing

from multiprocessing import Process
import os
import time 

def info(title):
    print(title)
    print('module name:', __name__)
    print('parent process:', os.getppid())
    print('process id:', os.getpid())
    print()
 
def f(name):
    info('\033[31;1mfunction f\033[0m')
    print('hello', name)
 
if __name__ == '__main__':

    info('\033[32;1mmain process line\033[0m')
    
    p1 = Process(target=f, args=('Allen',))
    p1.start()

    p2 = Process(target=f, args=('Joyce',))
    p2.start()
    #把p1,p2 join到caller程序（线程），待p1,p2运行结束后，caller程序（线程）继续运行
    p1.join()
    p2.join()

    time.sleep(1)
    print()
    print('End')

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Multithreading (multithreading), leave the pit