package reeaselock;
public class Machine extends Thread{
	private Counter counter;
	public Machine(Counter counter)
	{
		this.counter=counter;
		start();
	}
	public void run(){

	for(int i=0;i<100;i++)
	 {
	 	counter.add();
	 }
	 }
	 public static void main(String args[])throws InterruptedException {
	 	Counter counter1=new Counter();
	 	Counter counter2=new Counter();
	 	
	 	counter1.setFriend(counter2);
	 	counter2.setFriend(counter1);
	 	
	 	Machine machine1=new Machine(counter1);
	 	Machine machine2=new Machine(counter2);
	 }
	 }
class Counter{
	private int a;
	private Counter friend;
	public void setFriend(Counter friend){this.friend=friend;}
	public synchronized void add()
	{a++;
	 Thread.yield();
	 friend.delete();
	 System.out.println(Thread.currentThread().getName()+":add");
	 }
	 public synchronized void delete()
	 {a--;
	  System.out.println(Thread.currentThread().getName()+":delete");
	 
	 }
						
	}