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


public class Main3 {
    public static void main(String[] args) {
        Runnable task = new MyTask3();
        Thread thread1 = new Thread(task);
        Thread thread2 = new Thread(task);
        thread1.start(); thread2.start(); // Will make a call to task.run()
    }
}


class MyTask3 implements Runnable {
    private final Lock lock = new ReentrantLock();
    private final int MAX_COUNT = 10000; private int sharedCounter = 0;


    public void run() {
        System.out.println("Starting! Shared counter = " + getSharedCounter());
        for (int i = 0; i < MAX_COUNT; i++) {
            lock.lock();
            try {
                sharedCounter = sharedCounter + 1;
            } finally {
                lock.unlock();
            }
        }
        System.out.println("Done! Shared counter = " + getSharedCounter());
    }


    private int getSharedCounter() {
        lock.lock();
        try {
            return sharedCounter;
        } finally {
            lock.unlock();
        }
    }

}