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



class MatMonitor{

    private ArrayList<Mat> matliste = new ArrayList<>();
    private boolean ferdig = false;
    Lock matlaas = new ReentrantLock();
    Condition ikkeTom = matlaas.newCondition();

    public void settInn(Mat mat){
        matlaas.lock();
        try{
            matliste.add(mat);
            ikkeTom.signalAll();
        }
        finally{
            matlaas.unlock();
        }
    }

    public Mat taUt(){
        matlaas.lock();
        try{
            while (matliste.isEmpty()){
                ikkeTom.await();
            }
            return matliste.remove(0);
        } catch (InterruptedException e){
            System.out.println(e);
            return null;
        }
        finally{
            matlaas.unlock();
        }
    }

    public boolean programFerdig(){
        return ferdig;
    }

    public void settFerdig(){
        ferdig = true;
    }
}