1. volatile 修饰的变量和没有volatile 修饰的变量，都不具备原子特性 直接上代码

public class CompareVolatileTest {

    public volatile int inc = 0;

    public int inc1 = 0;


    public static void main(String[] args) {
        final CompareVolatileTest test = new CompareVolatileTest();
        for (int i = 0; i < 1000; i++) {
             new Thread(){
                @Override
                public void run() {
                    for (int j = 0; j < 10; j++) {
                        test.inc++;
                        test.inc1++;
                    }
                    System.out.println("test.inc=================="+test.inc+"==============test.inc1================="+test.inc1);
                }
            }.start();

        }
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(test.inc);
        System.out.println(test.inc1);
    }
}

1. 更高级的写法

public class VolatileTest2 {

    public volatile int inc = 0;

    public void increase() {
        inc++;
    }

    public static void main(String[] args) {
        final VolatileTest2 test = new VolatileTest2();
        final CountDownLatch latch = new CountDownLatch(1000);
        for (int i = 0; i < 1000; i++) {
            new Thread(){
                @Override
                public void run() {
                    for (int j = 0; j < 10; j++) {
                        test.increase();
                    }
                    latch.countDown();
                    System.out.println("test.inc==============================="+test.inc);
                }
            }.start();
        }
        try {
            latch.await();
            System.out.println(test.inc);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }


    }
}

1. 使用join保证原子特性

public class VolatileTest1 {

    public volatile int inc = 0;

    public void increase() {
        inc++;
    }

    public static void main(String[] args) {
        final VolatileTest1 test = new VolatileTest1();
        for (int i = 0; i < 1000; i++) {
            System.out.println("i================================"+i);
            Thread thread = new Thread(){
                @Override
                public void run() {
                    for (int j = 0; j < 10; j++) {
                        test.increase();
                    }
                    System.out.println("test.inc================================"+test.inc);
                }
            };
            thread.start();
            try {
                thread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
        System.out.println(test.inc);
    }
}