操作系统作业—— 请根据自己的实际情况选择一种语言的进程/线程同步工具进行学习，并尝试使用该工具实现睡觉的理发师问题的解决方案

请根据自己的实际情况选择一种语言的进程/线程同步工具进行学习，并尝试使用该工具实现睡觉的理发师问题的解决方案

 

Barber类

public class Barber  implements Runnable {
	Barbershop barbershop;
	int index;
	@Override
	public void run() {
		// TODO Auto-generated method stub
		try {
			barbershop.simulate(index);
			
		}catch(InterruptedException e){
			e.printStackTrace();
		}
	}
	public Barber (Barbershop bs,int i) {
		this.barbershop=bs;
		index=i;
	}
	

}

Barbershop类

import java.util.concurrent.Semaphore;
public class Barbershop {
	static int customer=0;//当前顾客数
	static int MAX=5;//提供的让顾客等待的椅子数
	static int busy=0;//理发师是否忙碌标识
	static Semaphore mutex=new Semaphore(1);//信号量，只允许一个顾客占用理发师
	public synchronized boolean isFull() {
		//判断是否为满
		if(customer==MAX) {
			return true;
			
		}
		return false;
	}
	
	public synchronized boolean isEmpty() {
//		判断是否为空
		if(customer==0) {
			return true;
		}
		return false;
	}
	public void simulate(int index) throws InterruptedException {
//		模拟函数
		System.out.println("customer "+index+" come");
		customer++;
		if(isFull()) {
//			如果为满顾客离开
			System.out.println("no chair for customer,"+"customer "+index+" left");
			customer--;
			
		}
		else {
			if(busy==1) {
//				如果理发师忙碌，顾客等待
				System.out.println("customer "+index+" is waiting for the barber");
			}
			mutex.acquire();
//			信号量减，防止其他进程再进入
			synchronized (this) {
//				同步
				while (busy==1) {
					wait();
//					有人理发等待
				}
			}
			if(customer==1) {
//				只有一个顾客
				System.out.println("there is only customer :customer "+index+" in the barbershop,the barber is working ");
				
			}
			busy=1;
			System.out.println("custoemr "+index+" is having a haircut");
			Thread.sleep(1000);
			//理发时间1000毫秒
			System.out.println("customer "+index+" left");
			customer--;
			mutex.release();
//			释放资源
			synchronized(this) {
//				同步并唤醒
				busy=0;
				notify();
				
			}
			if(customer==0) {
//				没有顾客，理发师睡觉
				System.out.println("the barber start to sleep");
				
			}

		}
		
	}
	public static void main(String[] args) throws InterruptedException {
		Barbershop barbershop= new Barbershop();
		for (int i =1;i<=10;i++) {
//			假设一共有10个顾客
			new Thread(new Barber(barbershop,i)).start();
			Thread.sleep((int)(600-Math.random()*500));
			
		}
	}

}

运行结果：