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

public class TraadEksempelMedMonitor {
    public static void main(String[] args) {
        TelleMonitor minMon = new TelleMonitor();
        Runnable oppg = new TelleOppgave(minMon);
        Thread arbeider1 = new Thread(oppg);
        Thread arbeider2 = new Thread(oppg);
        arbeider1.start();
        arbeider2.start();
    }
}

class TelleMonitor {
    private final Lock laas;
    private int fellesTeller;

    public TelleMonitor() {
        laas = new ReentrantLock();
        fellesTeller = 0;
    }

    public void oekMed1() {
        laas.lock();
        try {
            fellesTeller++;
        } finally {
            laas.unlock();
        }
    }

    public int hentTeller() {
        return fellesTeller;
    }

}

class TelleOppgave implements Runnable {
    private final int MAX_TELLER = 10000; // hvor mange ganger lokken skal gaa
    private int fellesTeller = 0; // felles teller som alle traadene vil oeke
    private TelleMonitor mon;

    public TelleOppgave(TelleMonitor mon) {
        this.mon = mon;
    }

    public void run() {
        System.out.println("Starter! Felles teller = " + mon.hentTeller());
        for (int i = 0; i < MAX_TELLER; i++) {
            mon.oekMed1();
        }
        System.out.println("Ferdig! Felles teller = " + mon.hentTeller());
    }
}