consume

gistfile1.java

import java.util.Random;

/**
 * Created by boliver on 03/06/15.
 */
public class Main {

    public static void main(String args[]) {

        Container value = new Container();
        Thread producer1 = new Thread(new Producer(1, value));
        Thread producer2 = new Thread(new Producer(2, value));
        Thread consumer1 = new Thread(new Consumer(1, value));
        Thread consumer2 = new Thread(new Consumer(2, value));
        producer1.start();
        producer2.start();
        consumer1.start();
        consumer2.start();

    }
}

class Container {

    private int value;
    private boolean hasUnreadValue = false;
    private Object lock = new Object();

    public void add(int x) throws InterruptedException {
        synchronized (lock) {
            while (hasUnreadValue) {
                lock.wait();
            }
            lock.notifyAll();
            hasUnreadValue = true;
            value = x;
        }
    }

    public int get() throws InterruptedException {
        synchronized (lock) {
            while (!hasUnreadValue) {
                lock.wait();
            }
            lock.notifyAll();
            hasUnreadValue = false;
            return value;
        }
    }
}


class Producer implements Runnable {

    int id;
    Container value;

    public Producer(int id, Container value) {
        this.id = id;
        this.value = value;
    }

    public void run() {
        Random rand = new Random();
        for (int i = 0; i < 10; i++) {
            int r = rand.nextInt(10);
            System.out.println("called from Producer #" + id + " ... random value is: " + r);
            try {
                value.add(r);
            } catch (InterruptedException e) {}
        }
    }
}

class Consumer implements Runnable {

    int id;
    Container value;

    public Consumer(int id, Container value) {
        this.id = id;
        this.value = value;
    }

    public void run() {
        for (int i = 0; i < 10; i++) {
            try {
                int v = value.get();
                System.out.println("called from Consumer #" + id + " ... container value is : " + v);
            } catch (InterruptedException e) {}
        }
    }
}