please Explain This question

[Chitta Ranjan Mahato]

   
public class Messenger implements Runnable
   {
                    public static void main(String args[])
                                {
                                       new Thread(new Messenger("Hello")).start(); 
                                       new Thread(new Messenger("World")).start(); 
                                 }
                            private String name;
                            public Messenger(String name)
                                {
                                          this.name =name;
                                 }
                            public void run()
                                 {
                                         message(1);
                                         message(2);
                                  }
                             private synchronized void message(int n)
                                  {
                                          System.out.println(name + "-" +n +" ");
                                   }
}

[Sridhar Gudipalli]

What is the doubt you have and what is the question? Its a simple program. I could not find any question here?

[Jesper de Jong]

You didn't ask any question, but here's one thing that I see in this program.

The method message(int n) is synchronized, but that doesn't do anything in this case, because you are creating two distinct Messenger objects. You're starting two threads, and you pass a Messenger object to each of the threads. The threads synchronize on the Messenger objects that you passed to them. But since there are two Messenger objects, each with their own synchronization lock, the two threads will never have to wait for each other.

The synchronization would become important when you would use just one Messenger object:

Messenger m = new Messenger("JavaRanch");

// Start two threads with the same Messenger object
new Thread(m).start();
new Thread(m).start();

[Chitta Ranjan Mahato]

Thanks