import java.util.ArrayList;
import java.util.concurrent.locks.*;

class TestLaaser{
  public static void main(String[] args){

    ArrayList<Integer> liste1 = new ArrayList<Integer>();
    liste1.add(1); liste1.add(2); liste1.add(3); liste1.add(4);

    ArrayList<Integer> liste2 = new ArrayList<Integer>();
    liste2.add(10); liste2.add(5); liste2.add(8); liste2.add(7);

    Monitor monitor = new Monitor();

    RegnUt r = new RegnUt(liste1,monitor);
    RegnUt r2 = new RegnUt(liste2,monitor);

    Thread traad1 = new Thread(r);
    Thread traad2 = new Thread(r2);

    traad1.start();
    traad2.start();

    try{
      traad1.join();
      traad2.join();

    }
    catch(InterruptedException e){

    }

    monitor.printResultater();

  }
}

class RegnUt implements Runnable{
  ArrayList<Integer> regnestykker;
  Monitor monitor;

  RegnUt(ArrayList<Integer> rs, Monitor m){
    regnestykker = rs;
    monitor = m;
  }

  @Override
  public void run(){
    int resultat = 0;
    for(int t : regnestykker){
      resultat = resultat + t;
    }
    monitor.leggTil(resultat);
    //System.out.println("Resultat: " + resultat);
  }
}

class Monitor{
  ArrayList<Integer> resultater = new ArrayList<Integer>();

  ReentrantLock laas = new ReentrantLock();

  public void leggTil(int i){

    laas.lock();
    System.out.println("Laaser laas");
    try{
      resultater.add(i);
    }
    finally{
      laas.unlock();
      System.out.println("Laast opp");
    }
  }

  public void printResultater(){
    System.out.print("Resultater: ");
    for(int i : resultater){
      System.out.print(" " + i);
    }
    System.out.println();
  }
}