java中如何实现可重入的自旋锁

public class ReentrantSpinLock {

    private AtomicReference<Thread> owner = new AtomicReference<>();

    // 可重入次数

    private int count = 0;

    // 加锁

    public void lock() {

        Thread current = Thread.currentThread();

        if (owner.get() == current) {

            count++;

            return;

        }

        while (!owner.compareAndSet(null, current)) {

            System.out.println("--我在自旋--");

        }

    }

    //解锁

    public void unLock() {

        Thread current = Thread.currentThread();

        //只有持有锁的线程才能解锁

        if (owner.get() == current) {

            if (count > 0) {

                count--;

            } else {

                //此处无需CAS操作，因为没有竞争，因为只有线程持有者才能解锁

                owner.set(null);

            }

        }

    }

    public static void main(String[] args) {

        ReentrantSpinLock spinLock = new ReentrantSpinLock();

        Runnable runnable = () -> {

            System.out.println(Thread.currentThread().getName() + "开始尝试获取自旋锁");

            spinLock.lock();

            try {

                System.out.println(Thread.currentThread().getName() + "获取到了自旋锁");

                Thread.sleep(4000);

            } catch (InterruptedException e) {

                e.printStackTrace();

            } finally {

                spinLock.unLock();

                System.out.println(Thread.currentThread().getName() + "释放了了自旋锁");

            }

        };

        Thread thread1 = new Thread(runnable);

        Thread thread2 = new Thread(runnable);

        thread1.start();

        thread2.start();

    }

}