生产者消费者模型

1、程序中有两类角色，产生数据，消费数据

2、解决问题是解决程序解偶合，平衡生产者和消费者之间的速度差

from multiprocessing import Process,Queue
import time
def producer(q):
    for i in range(3):
        res="包子%s" % i
        time.sleep(1)
        q.put(res)
        print("生产者生产了%s" % res)
def consumer(q):
    while True:
        time.sleep(1)
        res=q.get()
        if res==None:
            break
        print("消费者吃了%s" % res)

if __name__ == "__main__":
    q=Queue()
    p=Process(target=producer,args=(q,))
    c = Process(target=consumer, args=(q,))
    p.start()
    c.start()
    p.join()
    q.put(None)
    print("主线程")

 JoinableQueue

from multiprocessing import Process,Queue,JoinableQueue
import time
def producer(q):
    for i in range(3):
        res="包子%s" % i
        time.sleep(1)
        q.put(res)
        print("生产者生产了%s" % res)
    q.join()
def consumer(q):
    while True:
        time.sleep(1)
        res=q.get()
        if res==None:
            break
        print("消费者吃了%s" % res)
        q.task_done()
if __name__ == "__main__":
    q=JoinableQueue()
    p=Process(target=producer,args=(q,))
    c = Process(target=consumer, args=(q,))
    p.start()
    c.start()
    print("主线程")