import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;


public class BrusMaskin{

    private Lock lock = new ReentrantLock();
    private Condition erTom = lock.newCondition();
    private Condition harBrus = lock.newCondition();

    private int storrelse;
    private int antallBrus;

    BrusMaskin(int storrelse){
      this.storrelse = storrelse;
    }


    public void kjopBrus(){
      lock.lock();

      try{
        while(antallBrus == 0){
          harBrus.await();
        }

        System.out.println("Kjoper en brus :) Antall brus igjen: " + --antallBrus);

        if(antallBrus == 0){
          erTom.signal();
        }

      }catch (InterruptedException e){
      }finally{
        lock.unlock();
      }
    }

    public void fyllpaa(){
      lock.lock();

      try{
        while(antallBrus > 0){
          erTom.await();
        }

        antallBrus = storrelse;
        System.out.println("Brusmaskienen er fullt opp!");

        harBrus.signalAll();

      }catch (InterruptedException e){
      }finally{
        lock.unlock();
      }
    }
}