[转载] Java实现生产者消费者问题
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了[转载] Java实现生产者消费者问题,小编现在分享给大家,供广大互联网技能从业者学习和参考。文章包含4085字,纯文字阅读大概需要6分钟。
内容图文
![[转载] Java实现生产者消费者问题](/upload/InfoBanner/zyjiaocheng/1209/390b65ae113e434ab8aa2915778143db.jpg)
引言
生产者和消费者问题是线程模型中的经典问题:生产者和消费者在同一时间段内共用同一个存储空间,如下图所示,生产者向空间里存放数据,而消费者取用数据,如果不加以协调可能会出现以下情况:
生产者消费者图
存储空间已满,而生产者占用着它,消费者等着生产者让出空间从而去除产品,生产者等着消费者消费产品,从而向空间中添加产品。互相等待,从而发生死锁。
JAVA解决线程模型的三种方式
1、wait()和notify()
import java.util.LinkedList; public class ProducerConsumer { private LinkedList<Object> storeHouse = new LinkedList<Object>(); private int MAX = 10; public ProducerConsumer() { } public void start() { new Producer().start(); new Comsumer().start(); } class Producer extends Thread { public void run() { while (true) { synchronized (storeHouse) { try { while (storeHouse.size() == MAX) { System.out.println("storeHouse is full , please wait"); storeHouse.wait(); } Object newOb = new Object(); if (storeHouse.add(newOb)) { System.out.println("Producer put a Object to storeHouse"); Thread.sleep((long) (Math.random() * 3000)); storeHouse.notify(); } } catch (InterruptedException ie) { System.out.println("producer is interrupted!"); } } } } } class Comsumer extends Thread { public void run() { while (true) { synchronized (storeHouse) { try { while (storeHouse.size() == 0) { System.out.println("storeHouse is empty , please wait"); storeHouse.wait(); } storeHouse.removeLast(); System.out.println("Comsumer get a Object from storeHouse"); Thread.sleep((long) (Math.random() * 3000)); storeHouse.notify(); } catch (InterruptedException ie) { System.out.println("Consumer is interrupted"); } } } } } public static void main(String[] args) throws Exception { ProducerConsumer pc = new ProducerConsumer(); pc.start(); } }
2、await()和signal(),即线程锁的方式
package sort; import java.util.LinkedList; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; public class ProducerConsumer { private LinkedList<Object> myList = new LinkedList<Object>(); private int MAX = 10; private final Lock lock = new ReentrantLock(); private final Condition full = lock.newCondition(); private final Condition empty = lock.newCondition(); public ProducerConsumer() { } public void start() { new Producer().start(); new Consumer().start(); } public static void main(String[] args) throws Exception { ProducerConsumer s2 = new ProducerConsumer(); s2.start(); } class Producer extends Thread { public void run() { while (true) { lock.lock(); try { while (myList.size() == MAX) { System.out.println("warning: it‘s full!"); full.await(); } Object o = new Object(); if (myList.add(o)) { System.out.println("Producer: " + o); empty.signal(); } } catch (InterruptedException ie) { System.out.println("producer is interrupted!"); } finally { lock.unlock(); } } } } class Consumer extends Thread { public void run() { while (true) { lock.lock(); try { while (myList.size() == 0) { System.out.println("warning: it‘s empty!"); empty.await(); } Object o = myList.removeLast(); System.out.println("Consumer: " + o); full.signal(); } catch (InterruptedException ie) { System.out.println("consumer is interrupted!"); } finally { lock.unlock(); } } } } }
3、阻塞队列的方式
import java.util.concurrent.*; public class ProducerConsumer { // 建立一个阻塞队列 private LinkedBlockingQueue<Object> queue = new LinkedBlockingQueue<Object>(10); public ProducerConsumer() { } public void start() { new Producer().start(); new Consumer().start(); } public static void main(String[] args) throws Exception { ProducerConsumer s3 = new ProducerConsumer(); s3.start(); } class Producer extends Thread { public void run() { while (true) { try { Object o = new Object(); // 取出一个对象 queue.put(o); System.out.println("Producer: " + o); } catch (InterruptedException e) { System.out.println("producer is interrupted!"); } // } } } } class Consumer extends Thread { public void run() { while (true) { try { // 取出一个对象 Object o = queue.take(); System.out.println("Consumer: " + o); } catch (InterruptedException e) { System.out.println("producer is interrupted!"); } // } } } } }
结论
三种方式原理一致,都是对独占空间加锁,阻塞和唤醒线程,第一种方式比较传统,第三种方式最简单,只需存储和取用,线程同步的操作交由LinkedBlockingQueue全权处理。
原文:http://www.cnblogs.com/scott19820130/p/4649913.html
内容总结
以上是互联网集市为您收集整理的[转载] Java实现生产者消费者问题全部内容,希望文章能够帮你解决[转载] Java实现生产者消费者问题所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错,欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 gblab@vip.qq.com 举报,一经查实,本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。