Python多进程

1.linux多进程

import os
import time
pid = os.fork()

if pid == 0:
    print('子进程:{}父进程{}'.format(os.getpgid(),os.getppid()))
else:
    print('我是父进程{}'.format(pid))
time.sleep(2)

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2.跨平台多进程multiprocessing

import time
from concurrent.futures import ProcessPoolExecutor
import multiprocessing
def get_html(n):
    time.sleep(n)
    print(n)
    print(33)
    return n
if __name__=='__main__':
 
    pro = multiprocessing.Process(target=get_html, args=(2,))
    pro.start()
    pro.join()

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3.使用进程池

import time
from concurrent.futures import ProcessPoolExecutor
import multiprocessing
def get_html(n):
    print('逆火')
    time.sleep(n)
    print(n)

    return n
if __name__=='__main__':
    print("合数{}".format(multiprocessing.cpu_count()))
    Pool = multiprocessing.Pool(multiprocessing.cpu_count())
    # result = Pool.apply_async(get_html, args=(3,))
    # #等待全部任务完成
    # Pool.close()
    # Pool.join()
    # print(result.get())

    for ret in Pool.imap(get_html, [1,5,3]):
        print('返回值{}'.format(ret))

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4.进程间的通讯

　　使用queue

from multiprocessing import Manager,Queue,Process
import time
def shengchan(que):
    n = 0
    while True:
        time.sleep(1)

        n+=1
        print('生产者{}'.format(n))
        que.put(n)
def xiaofeizhe(que):
    while True:
        time.sleep(1)
        print('消费者{}'.format(que.get()))




if __name__=='__main__':
    queue = Queue(10)
    pro = Process(target=shengchan, args=(queue,))
    pro1 = Process(target=xiaofeizhe , args=(queue,))
    pro.start()
    pro1.start()
    pro.join()
    pro1.join()

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　　使用Manager

　　使用进程池的话 没法用queue进行通讯  就要使用到Manager.queue进行通讯

import time
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import Manager,Pool,cpu_count
def shengchan(que):
    n = 0
    while True:

        n+=1
        print('生产者{}'.format(n))
        que.put(n)
        time.sleep(1)
def xiaofeizhe(que):
     while True:
        print('消费者{}'.format(que.get()))
    
        time.sleep(1)
if __name__=='__main__':
    que = Manager().Queue(10)
    pool = Pool(cpu_count())
    result = pool.apply_async(shengchan, args=(que,))
    result1 = pool.apply_async(xiaofeizhe, args=(que,))
    #等待全部任务完成
    pool.close()
    pool.join()

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　　使用pipe

import time
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import Manager,Pool,cpu_count,Pipe
def shengchan(pipe):
    n = 0
    while True:

        n+=1
        print('生产者{}'.format(n))
        pipe.send(n)
        time.sleep(1)
def xiaofeizhe(pipe):
     while True:
        print('消费者{}'.format(pipe.recv()))

        time.sleep(1)
if __name__=='__main__':
    recevie_pipe, send_pipe = Pipe()
    pool = Pool(cpu_count())
    result = pool.apply_async(shengchan, args=(send_pipe,))
    result1 = pool.apply_async(xiaofeizhe, args=(recevie_pipe,))
    #等待全部任务完成
    pool.close()
    pool.join()

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