Java并发编程- CAS原理

例子：

/**
 * CAS原理
 * @author wufei
 * @create 2019-07-23 19:03
 **/
public class CAS1 {

    private static  volatile  int m =0;

    //原子性的保证
    private static AtomicInteger atomicInteger = new AtomicInteger(0);

    private static void incress1(){
        m ++;
    }
    private static void incress2(){
        atomicInteger.incrementAndGet();
    }
    public static void main(String[] args) throws InterruptedException{

        Thread[] th1 = new Thread[20];

        for (int i = 0; i < 20; i++) {
            th1[i] = new Thread(new Runnable() {
                public void run() {
                    CAS1.incress1();
                }
            });
            th1[i].start();
            th1[i].join();
        }


        Thread[] th2 = new Thread[20];
        for (int i = 0; i < 20; i++) {
            th2[i] =new Thread(new Runnable() {
                public void run() {
                    CAS1.incress2();
                }
            });
            th2[i].start();
            th2[i].join();
        }
        System.out.println("m: "+m);
        System.out.println("atomicInteger: "+atomicInteger.get());

    }
}

运行都是输出20 20

Java并发编程- CAS原理

反编译：

javap -v CAS1.class

javap -c CAS1.class

我们查看的只需要incress1()和incress2（）

Java并发编程- CAS原理