JUC- 线程间定制化通信

JUC- 线程间定制化通信

目录

• 案例
• demo

案例

场景：
A 线程打印 5 次 A，B 线程打印 10 次 B，C 线程打印 15 次 C,按照 此顺序循环 10 轮

步骤说明：

1. 创建资源类，定义属性和 *** 作方法
2. 判断；干活；通知—通知：先修改标志位，再通知其他线程
3. 创建多个线程， *** 作资源类的方法

demo

package com.java.juc.lock;

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


class ShareResource{
    
    private int flag = 1;

    
    private Lock lock = new ReentrantLock();

    
    private Condition c1 = lock.newCondition();
    private Condition c2 = lock.newCondition();
    private Condition c3 = lock.newCondition();

    
    public void print5(int loop) throws InterruptedException {
        //上锁
        lock.lock();
        try{
            //第二步 判断 干活 通知
            //number != 0,则等待;number = 0,+1;
            while( flag != 1 ){
                c1.await();
            }
            //干活
            for(int i = 1;i <= 5; i++){
                System.out.println("第" + loop + "轮：print5===" + Thread.currentThread().getName() + " :: " + i);
            }
            //先修改标志位
            flag=2;
            //通知其他线程
            c2.signal();
        } finally {
            //解锁
            lock.unlock();
        }
    }

    
    public void print10(int loop) throws InterruptedException {
        //上锁
        lock.lock();
        try{
            //第二步 判断 干活 通知
            //number != 0,则等待;number = 0,+1;
            while( flag != 2 ){
                c2.await();
            }
            //干活
            for(int i = 1;i <= 10; i++){
                System.out.println("第" + loop + "轮：print10===" + Thread.currentThread().getName() + " :: " + i);
            }
            //先修改标志位
            flag=3;
            //通知其他线程
            c3.signal();
        } finally {
            //解锁
            lock.unlock();
        }
    }
    
    public void print15(int loop) throws InterruptedException {
        //上锁
        lock.lock();
        try{
            //第二步 判断 干活 通知
            //number != 0,则等待;number = 0,+1;
            while( flag != 3 ){
                c3.await();
            }
            //干活
            for(int i = 1;i <= 15; i++){
                System.out.println("第" + loop + "轮：print15===" + Thread.currentThread().getName() + " :: " + i);
            }
            //先修改标志位
            flag=1;
            //通知其他线程
            c1.signal();
        } finally {
            //解锁
            lock.unlock();
        }
    }

}



public class ThreadDemo3 {
    public static void main(String[] args) {
        ShareResource share = new ShareResource();
        //创建线程
        new Thread(()->{
            for(int i = 1; i <= 10; i++){
                try {
                    share.print5(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"AA").start();

        new Thread(()->{
            for(int i = 1; i <= 10; i++){
                try {
                    share.print10(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();

        new Thread(()->{
            for(int i = 1; i <= 10; i++){
                try {
                    share.print15(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"CC").start();

    }
}