7.18 python进程间数据共享

# 管道
# 数据共享  Manager
# 进程池和回调函数 !

# !/usr/bin/env python
# !--*--coding:utf-8 --*--
# !@Time    :2018/7/18 14:23
# !@Author   TrueNewBee
# 管道  实现两进程间的信息传递  
from multiprocessing import Pipe, Process


# 一种使用管道方式
def func(conn3, conn4):
    conn4.close()   # 把多余通道关闭
    while True:
        try:
            msg = conn3.recv()  # 接收消息
            print(msg)
        except EOFError:    # 没有数据可以取的时候抛出异常
            conn3.close()
            break


if __name__ == '__main__':
    conn1, conn2 = Pipe()  # 接收两个参数 两个管道
    Process(target=func, args=(conn1, conn2)).start()
    conn1.close()  # 关闭多余通道
    for i in range(20):
        conn2.send('吃了吗')   # 发送消息
    conn2.close()

# !/usr/bin/env python
# !--*--coding:utf-8 --*--
# !@Time    :2018/7/18 15:01
# !@Author   TrueNewBee

# pipe 数据不安全性  这是一个例子,下面有另外一个解决方案的代码加上锁!
# IPC
import time
import random
from multiprocessing import Process, Pipe


def producer(con1, pro1, name, food):
    """通过管道把生产东西传给消费者"""
    con1.close()
    for i in range(4):
        time.sleep(random.randint(1, 3))
        f = '%s生产%s%s' % (name, food, i)
        print(f)
        pro1.send(f)
    pro1.close()


def consumer(con2, pro2, name1):
    pro2.close()
    while True:
        try:
            food = con2.recv()
            print('%s吃了%s' % (name1, food))
            time.sleep(random.randint(1, 3))
        except EOFError:
            con2.close()
            break


if __name__ == '__main__':
    con, pro = Pipe()
    p = Process(target=producer, args=(con, pro, 'a', '泔水'))
    c1 = Process(target=consumer, args=(con, pro, 'b'))
    c2 = Process(target=consumer, args=(con, pro, 'c'))
    c3 = Process(target=consumer, args=(con, pro, 'd'))
    p.start()
    c1.start()
    c2.start()
    c3.start()
    con.close()
    pro.close()


# 加上锁解决pipe数据不安全问题
# from multiprocessing import Process, Pipe, Lock
#
#
# def consumer(p, name, lock1):
#     produce1, consume1 = p
#     produce1.close()
#     while True:
#         lock1.acquire()
#         food=consume1.recv()
#         lock.release()
#         if food:
#             print('%s 收到包子:%s' %(name,baozi))
#         else:
#             consume1.close()
#             break
#
#
# def producer(p, n):
#     produce2, consume2=p
#     consume2.close()
#     for i in range(n):
#         produce2.send(i)
#     produce2.send(None)
#     produce2.send(None)
#     produce2.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')


# 加锁来控制操作管道的行为 来避免进程之间争抢数据造成的数据不安全现象

# 队列 进程之间数据安全的
# 管道 + 锁

# !/usr/bin/env python
# !--*--coding:utf-8 --*--
# !@Time    :2018/7/18 15:51
# !@Author   TrueNewBee

# 牺牲效率 保障了数据安全
from multiprocessing import Manager, Process, Lock


def main(dic1, lock1):
    lock1.acquire()  # 加上所也是为了数据不安全问题
    dic1['count'] -= 1
    lock1.release()


if __name__ == '__main__':
    m = Manager()
    lock = Lock()
    dic = m.dict({'count': 100})
    p_list = []
    for i in range(50):
        p = Process(target=main, args=(dic, lock))
        p.start()
        p_list.append(p)
    for i in p_list:
        p.join()
    print('主进程:', dic)

管道介绍:

真正在用的时候,底层东西不用,都是拿来主义,面试造核弹,工作拧螺丝!!!