/**
 * 存在   a=1;b=3
 * 不存在 b=3;a=1
 */
public class Test {
    volatile int a = 1;
    volatile int b = 2;

    private void write() {
        a = 3;
        b = a;
    }

    private void read() {
        System.out.println("a=" + a + ";b=" + b);
        System.out.println("b=" + b + ";a=" + a);
    }

    public static void main(String[] args) {
        for (int i = 0; i < 200000; i++) {
            Test test = new Test();
            new Thread(() -> {
                try {
                    Thread.sleep(1);
                    test.write();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }).start();

            new Thread(() -> {
                try {
                    Thread.sleep(1);
                    test.read();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }).start();
        }
    }
}