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


class RunObjekt implements Runnable { // en oppgave
    Monitor monitor;
    private static int sum = 0;

    public RunObjekt(Monitor monitor) {
        this.monitor = monitor;
    }

    @Override
    public void run() { // oppgaven en tr?d kan utf?re
        int teller = 0;
        while (teller < 35) {
            teller++;
            //"l?s den delte ressursen her, andre tr?der m? vente p? tur"
            monitor.increment();
            System.out.println("sum: " + monitor.getSum());
                //"?pne den delte ressursen her, andre tr?der kan n? kalle p? sum++"
        }
        System.out.println("Produsent ferdig, sum: " + monitor.getSum());
    }
}

class Konsument implements Runnable {
    private Monitor monitor;

    public Konsument(Monitor monitor) {
        this.monitor = monitor;
    }


    @Override
    public void run() {
        int teller = 0;
        while (teller < 10) {
            teller++;

            monitor.decrement();
            System.out.println("sum: " + monitor.getSum());
        }
        System.out.println("Konsument ferdig, sum: " + monitor.getSum());
    }
}

class Monitor {
    Lock laas = new ReentrantLock();
    Condition ventPaaProdusent = laas.newCondition();
    int sum = 0;


    public void increment() {

        laas.lock();
        try {
            sum++;
            ventPaaProdusent.signal();
        } finally {
            laas.unlock();
        }

    }

    public void decrement() {

        laas.lock();
        try {
            if (sum <= 0) {
                ventPaaProdusent.await();
            }
            sum--;

        } catch (InterruptedException e) {
            System.out.println(e);
        } finally {
            laas.unlock();
        }

    }

    public int getSum() {
        return sum;
    }
}


class Hovedprogram {
    public static void main(String[] args) {
        Monitor monitor = new Monitor();

        RunObjekt run1 = new RunObjekt(monitor);
        RunObjekt run2 = new RunObjekt(monitor);

        Konsument kons1 = new Konsument(monitor);
        // run1.run();
        // run1.run();

        Thread traad1 = new Thread(run1);
        Thread traad2 = new Thread(run2);


        Thread traad3 = new Thread(kons1);
        Thread traad4 = new Thread(kons1);
        Thread traad5 = new Thread(kons1);
        traad1.start(); // oker sum
        traad2.start();
        traad3.start(); // senker sum
        traad4.start();
        traad5.start();
    }
}