java并发编程实战wwj----------------------第一阶段--------------16-17-18-19-20

public class ThreadCloseGraceful {

    private static class Worker extends Thread {
        private volatile boolean start = true;

        @Override
        public void run() {
            while (start) {
                //
            }
            System.out.println("停止");
        }

        public void shutdown() {
            this.start = false;
        }
    }

    public static void main(String[] args) {
        Worker worker = new Worker();
        worker.start();

        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        worker.shutdown();
    }
}

代码：charapter6

1.开关的方式

2.打断的方式

public class ThreadCloseGraceful2 {
    private static class Worker extends Thread {

        @Override
        public void run() {
            while (true) {
                if (Thread.interrupted()){
                    System.out.println("打断");
                    break;
                }

            }
            //-------------
            //-------------
            //-------------
        }
    }

    public static void main(String[] args) {
        Worker worker = new Worker();
        worker.start();

        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        worker.interrupt();
    }
}

有一个问题，假设我们没有判断interrupted的机会呢？也不能判断flag，此时以上的两个方法都不可以了。

状态：cnblogs.com/soulmatesjc/p/11213884.html

package chapter6;

/***************************************
 * @author:Alex Wang
 * @Date:2017/2/19 QQ:532500648
 * QQ交流群:286081824
 ***************************************/
public class ThreadService {
    private Thread executeThread;
    private boolean finished = false;

    public void execute(Runnable task) {
        executeThread = new Thread() {
            @Override
            public void run() {
                Thread runner = new Thread(task);
                runner.setDaemon(true);
                runner.start();
                try {
                    runner.join();
                    //这里是为了什么?executeThread起来了执行到start()就结束了，可能守护线程还没来得及执行呢。join下，知直到runner执行死掉为止。
                    finished = true;
                } catch (InterruptedException e) {
                    e.printStackTrace();
                    System.out.println("all over");
                }
            }
        };
        executeThread.start();
    }

    public void shutdown(long mills) {
        long currentTime = System.currentTimeMillis();
        while (!finished) {
            if ((System.currentTimeMillis() - currentTime) >= mills) {
                System.out.println("任务超时，需要结束他!");
                executeThread.interrupt();
                break;
            }
            try {//没有执行结束也没有超时
                executeThread.sleep(1);
            } catch (InterruptedException e) {
                System.out.println("执行线程被打断!");
                break;
            }
        }
        finished = false;
    }
}

package chapter6;

/***************************************
 * @author:Alex Wang
 * @Date:2017/2/19 QQ:532500648
 * QQ交流群:286081824
 ***************************************/
public class ThreadCloseForce {


    public static void main(String[] args) {

        ThreadService service = new ThreadService();
        long start = System.currentTimeMillis();
        service.execute(() -> {
            //load a very heavy resource.
            while (true) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.print(123);
            }
//            try {
//                Thread.sleep(5000);
//            } catch (InterruptedException e) {
//                e.printStackTrace();
//            }//假设5秒搞定了
        });
        service.shutdown(10000);
        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }
}

线程中断：https://blog.csdn.net/u014543872/article/details/90549240

                  https://blog.csdn.net/u014543872/article/details/90549240

---------------------16-----17----------优雅的停止线程------------------

代码：chapter7

index是499

三个线程都是进入这个位置：

进入了箭头位置。

解决：

 synchronized (MONITOR) {
                if (index > MAX)
                    break;
                try {
                    Thread.sleep(5);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread() + " 的号码是:" + (index++));
            }

---------------------------------------18------------------------线程安全----------------

synchronized到底是什么东西呢？

public class SynchronizedTest {

    private final static Object LOCK = new Object();

    public static void main(String[] args) {

        Runnable runnable = () -> {
            synchronized (LOCK) {
                try {
                    Thread.sleep(200_000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };

        Thread t1 = new Thread(runnable);
        Thread t2 = new Thread(runnable);
        Thread t3 = new Thread(runnable);
        t1.start();
        t2.start();
        t3.start();

    }
}

共享数据去串行化去运行。

------------------------------------------------19----------------synchronized----------------------------------------------

代码：chapter/demo3   小把戏而已。

读：共享数据你读的时候可能被修改了

改：同样

-----------------------------------------------20------------同步代码块和同步方法区别----------------------------------

来源：CSDN

作者：菜鸟级别选手

链接：https://blog.csdn.net/qq_28764557/article/details/103457242