package com.jiucaiyuan.net.juc.lock;



import java.util.Random;

import java.util.concurrent.Semaphore;

import java.util.concurrent.TimeUnit;



/**

 * 信号灯（许可数量）

 * 6辆车，3个车位

 * @Author jiucaiyuan  2022/3/13 22:57

 * @mail services@jiucaiyuan.net

 */



public class SemaphoreDemo {



    public static void main(String[] args) {

        //创建许可数量

        Semaphore semaphore = new Semaphore(3);

        for(int i=1;i<=6;i++){

            new Thread(()->{

                try {

                    semaphore.acquire();

                    System.out.println(Thread.currentThread().getName()+"停进车位");

                    //随机停车时间

                    TimeUnit.SECONDS.sleep(new Random().nextInt(5));

                    System.out.println(Thread.currentThread().getName()+"离开了车位");

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }finally {

                    semaphore.release();

                }



            },String.valueOf(i)).start();

        }

    }

}