生产者、消费者问题，python实现

来源：互联网发布：石家庄软件开发培训编辑：程序博客网时间：2024/05/21 17:30

生产者、消费者问题，经典的线程同步问题：假设有一个缓冲池(列表)，生产者往里面放东西，消费者从里面取，规则是：列表为空的时候，生产者才能放东西；列表不为空的时候，消费者才能取东西；为了简单起见，暂定缓冲池中最多只能有一个产品。这里生产者和消费者共同操作一个资源：缓冲池，因此每次操作的时候，需要给资源加锁，操作结束时，释放锁，这样才能做到资源同步。使用python实现，需要继承Thread类，获取锁对象，代码如下：

from threading import Thread
from threading import Lock
import time,random

pro_list = []
lock = Lock()

class Producer(Thread):
    def run(self):
        global pro_list
        while True:
            i = random.randint(0, 100)
            lock.acquire()
            if len(pro_list) > 0:
                print "!--product still in list, wait consumer to get it.."
            else:
                pro_list.append(i)
                print ":::Producer put:", pro_list[0]
            lock.release()
            time.sleep(2)

class Consumer(Thread):
    def run(self):
        global pro_list
        while True:
            lock.acquire()
            if len(pro_list) == 0:
                print "!--No product now, wait producer put in..."
            else:
                print ":::Consumer fetch:", pro_list[0]
                pro_list.pop(0)
            lock.release()
            time.sleep(2)

Producer().start()
Producer().start()
Consumer().start()
Producer().start()
Producer().start()
Consumer().start()
Consumer().start()

这里使用多个生产者和消费者，共同操作缓冲池，部分执行结果如下：

:::Producer put: 12
!--product still in list, wait consumer to get it..
:::Consumer fetch: 12
:::Producer put: 75
!--product still in list, wait consumer to get it..
:::Consumer fetch: 75
!--No product now, wait producer put in...
:::Producer put: 28
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 28
:::Producer put: 94
:::Consumer fetch: 94

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