Python实现的生产者、消费者问题完整实例

yipeiwu_com6年前Python基础

本文实例讲述了Python实现的生产者、消费者问题。分享给大家供大家参考,具体如下:

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:

# -*- coding:utf-8 -*-
#! python2
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: 78
!--product still in list, wait consumer to get it..
:::Consumer fetch: 78
:::Producer put: 99
!--product still in list, wait consumer to get it..
:::Consumer fetch: 99
!--No product now, wait producer put in...
:::Producer put: 12
:::Consumer fetch: 12
:::Producer put: 91
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 91
!--No product now, wait producer put in...
:::Producer put: 63
:::Consumer fetch: 63
:::Producer put: 85
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 85
!--No product now, wait producer put in...
:::Producer put: 1
:::Consumer fetch: 1
:::Producer put: 26
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 26
!--No product now, wait producer put in...
:::Producer put: 8
:::Consumer fetch: 8
:::Producer put: 19
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 19
!--No product now, wait producer put in...
:::Producer put: 74
!--product still in list, wait consumer to get it..
:::Consumer fetch: 74
:::Producer put: 50
!--product still in list, wait consumer to get it..
:::Consumer fetch: 50
!--No product now, wait producer put in...
:::Producer put: 97
:::Consumer fetch: 97
:::Producer put: 69
!--product still in list, wait consumer to get it..
!--product still in list, wait consumer to get it..
:::Consumer fetch: 69
!--No product now, wait producer put in...
:::Producer put: 41
!--product still in list, wait consumer to get it..
:::Consumer fetch: 41
:::Producer put: 6
!--product still in list, wait consumer to get it..
:::Consumer fetch: 6
!--No product now, wait producer put in...

更多关于Python相关内容感兴趣的读者可查看本站专题:《Python数据结构与算法教程》、《Python函数使用技巧总结》、《Python字符串操作技巧汇总》、《Python入门与进阶经典教程》及《Python数学运算技巧总结

希望本文所述对大家Python程序设计有所帮助。

相关文章

python 匹配url中是否存在IP地址的方法

因为需要检测一个一个链接中是否包含了IP地址,在这里需要使用到正则表达式 ,python完美的支持了正则表达式,在这里使用re模块来完成,对正则表达式并不是很熟练,每次都是需要用的时候现...

Python机器学习之决策树算法实例详解

Python机器学习之决策树算法实例详解

本文实例讲述了Python机器学习之决策树算法。分享给大家供大家参考,具体如下: 决策树学习是应用最广泛的归纳推理算法之一,是一种逼近离散值目标函数的方法,在这种方法中学习到的函数被表示...

使用Python的Tornado框架实现一个简单的WebQQ机器人

我打算将WebQQ单独出来运行, 一开始直接拷贝了pyxmpp2的mainloop, 但是跑起来问题多多, 所以我又研究了利用Tornado进行网络编程(这里), 所以我放弃了Pyxmp...

基于python list对象中嵌套元组使用sort时的排序方法

在list中嵌套元组,在进行sort排序的时候,产生的是原数组的副本,排序过程中,先根据第一个字段进行从小到大排序,如果第一个字段相同的话,再根据第二个字段进行排序,依次类推,当涉及到字...

python 容器总结整理

python 容器总结整理 list 可变数组 tuple 不可变数组 dict 键值对(key-value)的字典(dictionary) 初始化: a={‘lyt':90}...