CAS

import java.util.concurrent.atomic.AtomicInteger;

public class CAS {
	//库存
	private static AtomicInteger stock = new AtomicInteger(4);
	public static void main(String[] args) {
		for(int i =0;i<5;i++) {
			new Thread(()->{
				try {
					Thread.sleep(1000);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
				Integer left = stock.decrementAndGet();
				if(left < 0) {
					System.out.println("抢完了...");
					return;
				}
				System.out.println(Thread.currentThread().getName()+"抢了一件商品"+"-->还剩"+left);
			}).start();
		}
	}

}