b02251132.java~2~

SleepingBarber的java文件

//package b02251132;
/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author :黄增博    b02251132
 * @version 1.0
 */

public class b02251132
{
  public static Semophore sem=new Semophore(1);
  public static void main(String[] args)
  {
    WaitingRoom myWaitRoom=new WaitingRoom(3);//Three seats at all.
    Barber myBarber=new Barber(myWaitRoom);
    //Start the two thread.
    myWaitRoom.start();
    myBarber.start();
    while(true)
    {
	//Whether there is customer and barber is free
      if(myWaitRoom.customers>0&&myBarber.status==1)
      {
        System.out.println("One customer wake up the barber.");
        myBarber.resume();//Make the barber's thread continue.
        myBarber.status=0;//Reset the status,barber is working.
      }
    }
  }
}



//That is the Semophore.
class Semophore
{
  private int value;
  public Semophore(){
	  value=0;
  }
  public Semophore(int v){
	  value=v;
  }
  public synchronized void p(){
	  while(value<=0){
		  try{
			  wait();
		  }
		  catch (InterruptedException e){}
	  }
	  value--;
  }
    public synchronized void v(){
		++value;
		notify();
	}
}


class Barber extends Thread
{
  public int status=0;//Reset the barber's working status.
  WaitingRoom room;
  public Barber(WaitingRoom room)
  {
    room=room;
  }
  public void run()
  {
    while(true)
    {
      if(room.customers>0)
      {
        b02251132.sem.p();
        room.customers--;//One customer begin to be servered by the barber.
        System.out.println("Barber begin to serve a customer.");
        System.out.println("There is "+(room.seats-room.customers)+" Seat(s)");
        b02251132.sem.v();
                try {
		          sleep(2000);//Now,the barber is working,it should be 2 seconds.
		        }
        catch (InterruptedException e) {}
        System.out.println("Barber finished a customer,the customer leaves.");
        System.out.println("There is "+(room.seats-room.customers)+" Seat(s)");
      }
      else
      {
        status=1;//Set the barber's working status become free.
        System.out.println("No more customers,so barber go to sleep.");
        suspend();//Make the barber's thread pause.

      }
    }
  }
}



class WaitingRoom extends Thread
{
  public int seats;
  public int customers;
  public WaitingRoom(int n)
  {
    customers=0;
    seats=n;
  }
  public void run()
  {
    while(true)
    {
      try
      {
        sleep(1000);//Time between two customers' coming time.(1 second)
      }catch(InterruptedException e){}
    if(customers<seats)//If there is free seats available.
    {
      b02251132.sem.p();
      customers++;//A customer come and occupy the seat.
      b02251132.sem.v();
      {
        System.out.println("One customer comes and sits in the waiting room.");
        System.out.println("There is "+(seats-customers)+" Seat(s)");
      }
     }
      else
      {
        System.out.println("One customer arrives, but no free seats, so he leaves.");
      }
    }
  }
}