手撕自旋锁

自旋锁是指尝试获取锁的线程不会因为获取锁失败而阻塞，而是采用循环的方式去尝试获取锁，也就是说用循环替代了阻塞，好处是减少线程上下文切换的消耗，缺点是会消耗CPU

/*手撕自旋锁*/
public class SpinLock {
    AtomicReference<Thread> atomicReference = new AtomicReference<>();
    public void lock(){
        Thread thread = Thread.currentThread();
        while (!atomicReference.compareAndSet(null,thread)){
        }
    }
    public void unlock(){
        Thread thread = Thread.currentThread();
        atomicReference.compareAndSet(thread,null);
    }
}