import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

/**
 * 自旋锁demo
 * @author tonfay
 *
 */
public class ZiXuanLockDemo {
	
	AtomicReference<Thread> atomic = new AtomicReference<Thread>();
	
	public void lock() {
		Thread t = Thread.currentThread();
		while(!atomic.compareAndSet(null, t)) {
			
		}
		System.out.println(Thread.currentThread().getName() + "\t 获取到锁");
	}
	public void unlock() {
		Thread t = Thread.currentThread();
		atomic.compareAndSet(t, null);
		System.out.println(Thread.currentThread().getName() + "\t 释放锁");
	}
	
	public static void main(String[] args) {
		ZiXuanLockDemo demo = new ZiXuanLockDemo();
		new Thread(new Runnable() {
			@Override
			public void run() {
				demo.lock();
				try {TimeUnit.SECONDS.sleep(5);} catch (InterruptedException e) {e.printStackTrace();}
				demo.unlock();
			}
		},"A").start();
		try {TimeUnit.SECONDS.sleep(1);} catch (InterruptedException e) {e.printStackTrace();}
		new Thread(new Runnable() {
			@Override
			public void run() {
				demo.lock();
				
				demo.unlock();
			}
		},"B").start();
	}
}