在一个线程T1中如何优雅终止线程T2?这里的【优雅】指的是给T2一个料理后事的机会。

package com.xzp.juc.test1;


import lombok.extern.slf4j.Slf4j;

@Slf4j
public class Test6 {
    public static void main(String[] args) throws InterruptedException {
        TPTInterrupt tptInterrupt = new TPTInterrupt();
        log.debug("开始start");
        tptInterrupt.start();
        log.debug("结束start");
        Thread.sleep(3500);
        log.debug("开始stop");
        tptInterrupt.stop();
        log.debug("结束stop");
    }
}
@Slf4j
class TPTInterrupt{
    private Thread thread;
    public void start() {
        thread = new Thread(() -> {
            while (true) {
                Thread currented = Thread.currentThread();
                log.debug("1打断标记{}",currented.isInterrupted());
                if(currented.isInterrupted()){
                    log.debug("料理后事");
                    break;
                }
                try {
                    Thread.sleep(1000);//情况一,这个时候被打断会把打断标记编程假，所以还要执行一次 currented.interrupt();
                    log.debug("执行监控记录");//情况二，这个时候打断，不会将打断标记变成true，程序继续执行
                } catch (InterruptedException e) {
                    log.debug("2打断标记{}",currented.isInterrupted());
                    currented.interrupt();
                    log.debug("3打断标记{}",currented.isInterrupted());
                    e.printStackTrace();
                }
            }
        },"t1");
        thread.start();
    }
    public void stop() {
        log.debug("4打断标记{}",thread.isInterrupted());
        thread.interrupt();
        log.debug("5打断标记{}",thread.isInterrupted());
    }
}

执行逻辑

改进，加入volatile，实现JMM的可见性进行实现，可见性 - 保证指令不会受 cpu 缓存的影响。

@Slf4j
public class Test2 {
    public static void main(String[] args) throws InterruptedException {
        TwoPhaseTermination tptInterrupt = new TwoPhaseTermination();
        log.debug("开始start");
        tptInterrupt.start();
        log.debug("结束start");
        Thread.sleep(3500);
        log.debug("开始stop");
        tptInterrupt.stop();
        log.debug("结束stop");
    }
}
@Slf4j
class TwoPhaseTermination{
    private Thread monitorThread;
    private volatile boolean stop = false;
    public void start() throws InterruptedException{
        monitorThread =new Thread(() -> {
            while (true){
                if(stop){
                    log.debug("料理后事");
                    break;
                }
                try {
                    Thread.sleep(1000);
                    log.debug("执行监控记录");
                }catch (InterruptedException e){
                    e.printStackTrace();
                }
            }
        },"monitor");
        monitorThread.start();
    }
    public void stop(){
        stop = true;
        //        防止try里面业务太长，直接打断，节省时间直接处理后事
        monitorThread.interrupt();
    }
}