生产者与消费者synchronized +wait/notifAll 和Lock+await/singalAll分别实现

最新推荐文章于 2025-01-24 18:09:20 发布

Ysdo

最新推荐文章于 2025-01-24 18:09:20 发布

阅读量323

点赞数

分类专栏： juc java多线程

本文链接：https://blog.youkuaiyun.com/qq_42183409/article/details/100691129

版权

java多线程同时被 2 个专栏收录

8 篇文章

订阅专栏

juc

7 篇文章

订阅专栏

本文通过生产者消费者模式，深入解析了Java中synchronized关键字配合wait和notifyAll方法，以及Lock接口配合Condition的await和signalAll方法在多线程环境下的应用。展示了如何在商品库存为零或满的情况下，使线程等待并通知所有线程的状态变更。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

synchronized +wait/notifAll实现


public class ProductAndConsumer  {
    public static void main(String[] args) {
        Clerk clerk = new Clerk();

        Product product = new Product(clerk);
        Consumer consumer = new Consumer(clerk);
        new Thread(product,"生产者A").start();
        new Thread(consumer,"消费者A").start();
        new Thread(product,"生产者B").start();
        new Thread(consumer,"消费者B").start();

    }

}

class Clerk{
    private int product=0;

    //进货
    public synchronized  void get() {
    //为了防止虚假唤醒，建议用while而不是判断
        while(product>=1){

            System.out.println("产品已满");
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
            System.out.println(Thread.currentThread().getName()+":"+ ++product);
        this.notifyAll();


    }
    //卖货
    public synchronized void set(){
        while(product<=0){
            System.out.println("产品缺货");
            try {

                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
            System.out.println(Thread.currentThread().getName()+":"+ --product);
            this.notifyAll();

    }
}

class Product implements Runnable{
  private Clerk clerk;

    public Product(Clerk clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        for (int i = 0; i <20 ; i++) {
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            clerk.get();
        }
    }
}

class Consumer implements Runnable{
    private Clerk clerk;
    public Consumer(Clerk clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        for (int i = 0; i <20 ; i++) {

            clerk.set();
        }
    }
}

Lock+await/singalAll实现


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

public class ProductAndConsumer2  {
    public static void main(String[] args) {
        Clerk2 clerk2 = new Clerk2();

        Product2 product = new Product2(clerk2);
        Consumer2 consumer = new Consumer2(clerk2);
        new Thread(product,"生产者A").start();
        new Thread(consumer,"消费者A").start();
        new Thread(product,"生产者B").start();
        new Thread(consumer,"消费者B").start();

    }

}

class Clerk2{
    private int product=0;
   private Lock lock = new ReentrantLock();
   private Condition condition = lock.newCondition();


    //进货
    public   void get() {
    //为了防止虚假唤醒，建议用while而不是判断
        lock.lock();
        try {
            while(product>=1){
                System.out.println("产品已满");
                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }
            System.out.println(Thread.currentThread().getName()+":"+ ++product);
            condition.signalAll();
        }finally {

            lock.unlock();
        }


    }
    //卖货
    public synchronized void set(){
        lock.lock();
        try {
            while(product<=0){
                System.out.println("产品缺货");
                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }
            System.out.println(Thread.currentThread().getName()+":"+ --product);
           condition.signalAll();

        }finally {
            lock.unlock();
        }
    }
}

class Product2 implements Runnable{
  private Clerk2 clerk2;

    public Product2(Clerk2 clerk2) {
        this.clerk2 = clerk2;
    }

    @Override
    public void run() {
        for (int i = 0; i <20 ; i++) {
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            clerk2.get();
        }
    }
}

class Consumer2 implements Runnable{
    private Clerk2 clerk2;
    public Consumer2(Clerk2 clerk2) {
        this.clerk2 = clerk2;
    }

    @Override
    public void run() {
        for (int i = 0; i <20 ; i++) {

            clerk2.set();
        }
    }
}