Python：IPC-Pipe与IPC-Manger

1，IPC-PIPE：

管道 pipe

from multiprocessing import Process
from multiprocessing import Pipe
p1,p2 = Pipe()  #支持双向通信
# send
p1.send('菠萝蜜干')
# recv
print(p2.recv())
p2.send('酸奶')
# p2.close()
print(p1.recv())
print(p1.recv())  #管道里没有值会报错： EOFError

2，用管道也能实现生产者消费者模型

from multiprocessing import Process,Pipe,Lock

def consumer(p,name,lock):
    produce, consume=p
    produce.close()
    while True:
        lock.acquire()
        baozi=consume.recv()
        lock.release()
        if baozi:
            print('%s 收到菠萝蜜干:%s' %(name,baozi))
        else:
            consume.close()
            break

def producer(p,n):
    produce, consume=p
    consume.close()
    for i in range(n):
        produce.send(i)
    produce.send(None)
    produce.send(None)
    produce.close()

if __name__ == '__main__':
    produce,consume=Pipe()
    lock = Lock()
    c1=Process(target=consumer,args=((produce,consume),'c1',lock))
    c2=Process(target=consumer,args=((produce,consume),'c2',lock))
    p1=Process(target=producer,args=((produce,consume),10))
    c1.start()
    c2.start()
    p1.start()

    produce.close()
    consume.close()

    c1.join()
    c2.join()
    p1.join()
    print('主进程')

3，IPC-Manager

import time
from multiprocessing import Manager
from multiprocessing import Process
# Manager是一个类 就提供了可以进行数据共享的一个机制 提供了很多数据类型 dict list
def func(dic):
    print(dic)
    while True:
        print(dic)
        time.sleep(3)
if __name__ == '__main__':
    m = Manager()
    d = m.dict({'count':0})
    print(d)
    p = Process(target=func,args=(d,))
    p.start()
    d['count'] = 0

from multiprocessing import Manager,Process,Lock
def work(d,lock):
    lock.acquire()
    d['count'] -= 1
    lock.release()

if __name__ == '__main__':
        lock= Lock()
        m = Manager()
        dic=m.dict({'count':100})   # 共享的数据
        l = []
        for i in range(100):
            p=Process(target=work,args=(dic,lock))
            p.start()
            l.append(p)
        [p.join() for p in l]
        print(dic)