public class VolatileTest1 {
    private static boolean isOver = false;

    public static void main(String[] args) {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                int a=0;

                while (!isOver){
                    a=5;
                } ;

              /* while (true){
                    a=5;
                    if(!isOver)break;
                } ;*/
                System.out.println(a);
            }
        });
        thread.start();
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        isOver = true;
    }

}

public class VolatileTest2 {
    private static boolean isOver = false;

    public static void main(String[] args) {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                int a=0;

              /*  while (!isOver){
                    a=5;
                } ;*/

               while (true){
                    a=5;
                    if(!isOver)break;
                } ;
                System.out.println(a);
            }
        });
        thread.start();
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        isOver = true;
    }

}