blocking

package blockingtest;

/**
 * Hello world!
 */
public class Sync implements Runnable {
    int n;

    public static void main(String[] args) {
        Sync sync = new Sync();
        new Thread(sync, "Sync1").start();
        new Thread(sync, "Sync2").start();
        new Thread(sync, "Sync3").start();
    }

    public void run() {
        for (int i = 0; i < 3; i++) {
            inc();
        }
    }

    public synchronized void inc() {
        n++;
        System.out.print(Thread.currentThread().getName() + "\n");
        try {
            Thread.sleep(10000);
        } catch (Exception ex) {
            System.out.print(ex.getMessage());
        }

    }
}