Java中的volatile例子

public class StudyWhileLoopMain {
    private volatile static int tag = 0;
    public static void main(String[] args) {
        System.out.println("主函数开始执行");
        MyThread myThread = new MyThread();
        myThread.start();
        System.out.println("线程已经开始");
        /** tag如果不加volatile修复则一直不结束 */
        while (tag == 0);
        System.out.println("标记通过");
    }

    protected static class MyThread extends java.lang.Thread {
        @Override
        public void run() {
            super.run();
            System.out.println("线程开始");
            try {
                Thread.sleep(9000);
            } catch (java.lang.InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("线程赋值标记为1");
            tag = 1;
        }
    }
}