Java多线程之生产者与消费者模式

最新推荐文章于 2020-12-11 22:36:40 发布

原创最新推荐文章于 2020-12-11 22:36:40 发布 · 421 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#多线程 #java #并发编程 #thread

多线程专栏收录该内容

6 篇文章

订阅专栏

本文探讨了Java中实现生产者与消费者模式的两种方法：synchronized版本和Lock版本。通过示例展示了如何在多线程环境下，确保数据的正确同步和线程间的有效协作。

Java多线程之生产者与消费者模式

synchronized版

问题:有2个线程,一个线程+1,一个线程-1,这样循环加减1,10次

public class ThreadWaitNotifyDemo {
    private int number = 0;

    //此方法实现对number+1操作
    public synchronized void increment() throws Exception{
        //此处一定要主要使用while判断,不能使用if判断,防止线程间的虚假唤醒
        while(number != 0){
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName() + "\t" + number);
        this.notifyAll();
    }

    //此方法实现对number-1操作
    public synchronized void decrement() throws InterruptedException{
        while(number == 0){
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName() + "\t" + number);
        this.notifyAll();
    }
}
class Main{
    public static void main(String[] args) {
        ThreadWaitNotifyDemo threadWaitNotifyDemo = new ThreadWaitNotifyDemo();
        new Thread(() ->{
            for (int i = 0; i < 10; i++) {
                try{
                    threadWaitNotifyDemo.increment();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"AAA").start();

        new Thread(() ->{
            for (int i = 0; i < 10; i++) {
                try{
                    threadWaitNotifyDemo.decrement();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"BBB").start();
    }
}

Lock版

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreadWaitNotifyDemo {
    private int number = 0;
    private Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();

    //此方法实现对number+1操作
    public void increment(){
        lock.lock();
        try{
            while(number != 0){
                condition.await();
            }
            number++;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            condition.signalAll();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    //此方法实现对number-1操作
    public void decrement(){
        lock.lock();
        try{
            while(number == 0){
                condition.await();
            }
            number--;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            condition.signalAll();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
}
class Main{
    public static void main(String[] args) {
        ThreadWaitNotifyDemo threadWaitNotifyDemo = new ThreadWaitNotifyDemo();
        new Thread(() ->{
            for (int i = 0; i < 10; i++) {
                try{
                    threadWaitNotifyDemo.increment();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"AAA").start();

        new Thread(() ->{
            for (int i = 0; i < 10; i++) {
                try{
                    threadWaitNotifyDemo.decrement();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"BBB").start();
    }
}