生产消费者模型（进程通信，队列）

# Author：Winter Liu is coming!
# 队列自动加锁

import time
import random
from multiprocessing import Process, Queue


def customer(q, name):
    while True:
        food = q.get()
        if food:
            print("{}吃了{}".format(name, food))
        else:
            break


def producer(q, name, food):
    for i in range(6):
        time.sleep(random.random())
        print("{}:{}做了{}".format(i+1, name, food))
        q.put("{}的{}".format(name, food))


if __name__ == '__main__':
    q = Queue()  # 创建队列，并将队列传给子进程
    p1 = Process(target=producer, args=(q, "大嘴", "馒头"))
    p2 = Process(target=producer, args=(q, "小郭", "炊饼"))
    c = Process(target=customer, args=(q, "小六"))
    p1.start()
    p2.start()
    c.start()
    p1.join()  # 主进程等待生产子进程结束
    p2.join()
    q.put(None)  # 生产子进程结束后在队列中放入标志，告诉消费子进程生产结束