import java.util.concurrent.CountDownLatch;
import java.util.concurrent.locks.*;
import java.util.Random;

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

        MonitorStorstTall monitor = new MonitorStorstTall();
        int antallTraader = 10;
        CountDownLatch count = new CountDownLatch(antallTraader);

        for (int i = 0; i < antallTraader; i++){
            Arbeider a = new Arbeider(monitor, count);
            Thread t = new Thread(a);
            t.start();
        }

        try {
            count.await();
        }
        catch(InterruptedException e){
            System.out.println(e);
        }

        System.out.println("Storste tall er: " + monitor.hentTall());
    }
}


class MonitorStorstTall {

    int storstTall = 0;
    Lock laas = new ReentrantLock();

    public void giTall(int tall){
        laas.lock();
        try {
            if (tall > storstTall){
                storstTall = tall;
            }
        }
        finally {
            laas.unlock();
        }
    }

    public int hentTall(){
        return storstTall;
    }
}


class Arbeider implements Runnable {

    MonitorStorstTall monitor;
    CountDownLatch count;

    public Arbeider(MonitorStorstTall monitor, CountDownLatch count){
        this.monitor = monitor;
        this.count = count;
    }

    public void run(){

        Random r = new Random();
        int tall = r.nextInt(100);

        try {
            Thread.sleep(tall * 15);
        }
        catch(InterruptedException e){
            System.out.println(e);
        }

        monitor.giTall(tall);
        count.countDown();
        System.out.println("Traad la til tallet: " + tall);

    }
}