import javax.swing.text.StyleContext;
import java.sql.SQLOutput;
import java.util.concurrent.Semaphore;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class Main {
    public static void main(String[] args) throws  InterruptedException{
        Incrementor i = new Incrementor();
        Incrementor i2 = new Incrementor();
        MyThread t1 = new MyThread(1, i);
        MyThread t2 = new MyThread(2, i2);
       t1.start();
       t2.start();
       t1.join();
       t2.join();
        System.out.println(i.getCount());
        System.out.println(i2.getCount());
    }
}
class MyThread extends Thread {
    int id;
    Incrementor incrementor;
    public MyThread(int _id, Incrementor i) {
        id = _id;
        incrementor = i;
    }
    @Override
    public void run() {

        for(int i = 0; i < 20; i++) {
//            System.out.println("Thread " + id + " " + i);
            incrementor.safe_semaphore_increment();
        }

    }
}
class Incrementor {
    private static int count = 0;
    private static Lock lock = new ReentrantLock();
    private static Semaphore semaphore = new Semaphore(2);
    public static void not_safe_increment() {
        ++count;
        try {
            Thread.sleep(5);
        }
        catch (InterruptedException ei) {
            System.out.println(ei);
        }
        }
        public  void safe_increment() {
            synchronized (this) {
                count++;
            }
        }
        public static void safe_mutex_increment() {
        lock.lock();
        count++;
        lock.unlock();
        }
        public static void safe_semaphore_increment() {
        try {
            semaphore.acquire();
            count++;
            semaphore.release();
        }
        catch (InterruptedException ie) {
            System.out.println(ie);
        }

        }
    public static int getCount() {
        return count;
    }
}