JAVA: 多线程编程 实现 生产者和消费者问题 (天天向上系列)

生产者和消费者 是 操作系统种比较经典的问题, 两个共用一个临界区进行互斥访问.

JAVA 中 我们采用 Runable 和 Thread 来实现 多线程编程问题;

重写 Thread 里的 Run 函数

根据分析:   用 产生随机数, 并让线程进行睡眠,  模拟真实的情况

写一个MsgQueue 队列存储信息 实现 Push 和 Pop 

并用 synchronized  实现锁区  保证 函数不被打断

wait 和 notify 是 操作系统中 wait 和sigema 操作

public class MsgQueue {
    private final int COUNT = 10;
    private int[] Catch = new int[COUNT];
    private  int idex = 0;
    MsgQueue(){
        idex = 0;

    }
    public synchronized void PutMsg(int num) throws InterruptedException {
        if(idex < 0 || idex > COUNT) {
            wait();
        }

        Catch[ idex++] =  num;
        notify();

    }
    public synchronized void PopMsg() throws InterruptedException {
        if( idex > COUNT || idex <0 ){
            wait();
        }
        int num = Catch[idex--];
        System.out.println("Consumer : "+ num);
        notify();
    }
}

对生产者 进行编写: Producer.java

import java.util.Random;

public class Producer implements Runnable {
    private  MsgQueue  queue;
    Producer(MsgQueue queue){
        super();
        this.queue = queue;
    }
    @Override
    public void run() {
        Random random = new Random();
        while (true){
            int num = random.nextInt(1000);
            try {
                Thread.sleep(num);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            try {
                System.out.println("produce: "+num);
                queue.PutMsg(num);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

对消费者进行编写: Consum.java

import java.util.Random;

public class Consumer implements Runnable {
    private  MsgQueue  queue;
    Consumer(MsgQueue queue){
        super();
        this.queue = queue;
    }
    @Override
    public void run() {
        Random random = new Random();
        while (true){
            try {
                int num = random.nextInt(1000);
                if( num <0)
                    continue;
                Thread.sleep(num);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            try {
                 queue.PopMsg();


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

1Test 测试 main 中

       MsgQueue queue = new MsgQueue();
       Producer producer = new Producer(queue);
       Consumer consumer = new Consumer(queue);

       new Thread(producer).start();
       new Thread(consumer).start();