import java.util.concurrent.*;

class HovedprogramCyclicBarrier{

    public static void main(String[] args) {

        CyclicBarrier barriere = new CyclicBarrier(2, new DoSomething());

        for (int i = 0; i < 4 ; i++){
            Teller teller = new Teller(barriere, i);
            Thread traad = new Thread(teller);
            traad.start();
        }
    }
}


class Teller implements Runnable {

    CyclicBarrier barriere;
    int nummer;

    public Teller(CyclicBarrier barriere, int nummer){
        this.barriere = barriere;
        this.nummer = nummer;
    }

    public void run(){

        System.out.println("Tr?d ("+nummer+") starter opp!");

        try {
            Thread.sleep( (long)(Math.random() * 4000 + 2000));
            System.out.println("Tr?d ("+nummer+") venter");
            barriere.await();
            System.out.println("Tr?d ("+nummer+") fortsetter");
        }
        catch(InterruptedException e){}
        catch(BrokenBarrierException e){}

        System.out.println("Tr?d ("+nummer+") er ferdig!");    }
}






class DoSomething implements Runnable {

    public void run(){
        System.out.println("TO TR?DER HAR KALT P? AWAIT()");
    }
}