import java.util.concurrent.CountDownLatch;

public class CountdownEksempel {
    public static void main(String[] args) 
    throws InterruptedException {
        
        int antTrader = 5;

        CountDownLatch barrieren = new CountDownLatch(6);

        for (int i = 0; i < antTrader; i++) {
            new Thread(new Arbeider(barrieren)).start();
        }


        Thread.sleep(3000);
        System.out.println(Thread.currentThread().getName() + " er ferdig");
        barrieren.countDown();
        barrieren.await();
        System.out.println("Programmet er ferdig!");

    }
}



class Arbeider implements Runnable {
    private CountDownLatch barriere;

    Arbeider(CountDownLatch latch) {
        this.barriere = latch;
    }


    public void run() {
        gjorArbeid();
        barriere.countDown();
    }

    void gjorArbeid(){
        System.out.println("Jeg gjør litt arbeid");
    }
}