Java 并发编程学习笔记(11) ----Phaser-awaitAdvance(int phase),forceTermination(),isTerminated()

51.awaitAdvance(int phase)

 作用：如果传入参数Phase和当前getPhase()方法返回值一样，就在屏障处等待，否则继续向下运行。

52.代码

package com.lhc.concurrent.phaser.awaitAdvance;

import java.util.concurrent.Phaser;

public class ThreadA extends Thread{
    private Phaser phaser;

    public ThreadA(Phaser phaser) {
        super();
        this.phaser = phaser;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + " begin " + System.currentTimeMillis());
        phaser.arriveAndAwaitAdvance();
        System.out.println(Thread.currentThread().getName() + " end " + System.currentTimeMillis());
    }
}

package com.lhc.concurrent.phaser.awaitAdvance;

import java.util.concurrent.Phaser;

public class ThreadB extends Thread{
    private Phaser phaser;

    public ThreadB(Phaser phaser) {
        super();
        this.phaser = phaser;
    }

    @Override
    public void run() {
        try {
            System.out.println(Thread.currentThread().getName() + " begin " + System.currentTimeMillis());
            Thread.sleep(3000);
            phaser.awaitAdvance(0);
            System.out.println(phaser.getPhase());
            System.out.println(Thread.currentThread().getName() + " end " + System.currentTimeMillis());
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }
}

package com.lhc.concurrent.phaser.awaitAdvance;

import java.util.concurrent.Phaser;

public class ThreadC extends Thread{
    private Phaser phaser;

    public ThreadC(Phaser phaser) {
        super();
        this.phaser = phaser;
    }

    @Override
    public void run() {
        try {
            System.out.println(Thread.currentThread().getName() + " begin " + System.currentTimeMillis());
            Thread.sleep(5000);
            phaser.arriveAndAwaitAdvance();
            System.out.println(Thread.currentThread().getName() + " end " + System.currentTimeMillis());
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }
}

53.测试类

package com.lhc.concurrent.phaser.awaitAdvance;

import java.util.concurrent.Phaser;

public class Test {
    public static void main(String[] args){
        Phaser phaser = new Phaser(3);
        ThreadA a1 = new ThreadA(phaser);
        a1.setName("a1");
        a1.start();

        ThreadA a2 = new ThreadA(phaser);
        a2.setName("a2");
        a2.start();

        ThreadB b = new ThreadB(phaser);
        b.setName("b");
        b.start();

        ThreadC c = new ThreadC(phaser);
        c.setName("c");
        c.start();
    }
}

54.输出结果

a1 begin 1556538438489
a2 begin 1556538438489
b begin 1556538438504
c begin 1556538438520
c end 1556538443535
a2 end 1556538443535
a1 end 1556538443535
1
b end 1556538443535

61.方法forceTermination()和 方法isTerminated()

方法forceTermination使Phaser对象的屏障功能失效
方法isTerminated()判断Phaser对象是否已经呈销毁状态

62.代码

package com.lhc.concurrent.phaser.force;


import java.util.concurrent.Phaser;

public class MyThread extends Thread{
    private Phaser phaser;

    public MyThread(Phaser phaser) {
        super();
        this.phaser = phaser;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + " begin " + System.currentTimeMillis());
        phaser.arriveAndAwaitAdvance();
        System.out.println(Thread.currentThread().getName() + " end " + System.currentTimeMillis());
    }

    public static void main(String[] args){
        Phaser phaser = new Phaser(3);
        MyThread myThread = new MyThread(phaser);
        myThread.setName("myThread");
        myThread.start();

        MyThread myThread1 = new MyThread(phaser);
        myThread1.setName("myThread1");
        myThread1.start();

        try{
            Thread.sleep(1000);
            //使屏障功能失效
            phaser.forceTermination();
            //判断是否销毁
            System.out.println(phaser.isTerminated());
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }
}

63.输出结果

myThread begin 1556540166856
myThread1 begin 1556540166856
true
myThread1 end 1556540167863
myThread end 1556540167863