A program with multiple threads does not exit.

Steps to reproduce
compile and run the attached code

class TwoThreadsTest {
   public static void main (String args[])
   {
      Semaphore sem = new Semaphore();
      SyncThread s1 = new SyncThread("Jamaica", sem);
      SyncThread s2 = new SyncThread1("Fiji", sem);

      s1.start();
      s2.start();

/* Add this code to end the program
      try
      {
         s2.join();
      }
      catch (InterruptedException e) {}
*/
       
    }
}

class SyncThread extends Thread
{
   Semaphore mySem;
   public SyncThread(String str, Semaphore sem)
   {
      super(str);
      mySem = sem;
   }

   public void run()
   {
      System.out.println(getName() + ".run()");
      System.out.println(getName() + " getLock()");
      if ( mySem.getLock(2000))
         System.out.println(getName() + " has semaphore");
      else
         System.out.println(getName() + " couldn't get semaphore");
      
   }

}

class Semaphore extends Object
{
   boolean bLock = true;

   public synchronized boolean isLocked()
   {
      return bLock;
   }

   public synchronized boolean getLock(int iWait)
   {
      if (bLock == true)
      {
         try
         {
            if (iWait < 0)
               wait();
            else
               wait(iWait);
         } // end try
         
         catch (InterruptedException e)
         {
            System.out.println(e.getMessage());
         }
   
      } // end if is locked

      // recheck lock, has it been released
      if (bLock != true)
      {
         bLock = true;
         return true;
      }
      else
         return false;

   } // end getLock();

   public synchronized void unLock()
   {
      bLock = false;
      notify();
   }
}


class SyncThread1 extends SyncThread
{
   public SyncThread1(String name, Semaphore sem)
   {
      super(name, sem);
   }

   public void run()
   {
      System.out.println(getName() + ".run()");
      System.out.println(getName() + " sleep");
      
      try { sleep(3000); }
      catch (InterruptedException e) {}

      System.out.println(getName() + " unlock");
      mySem.unLock();

   }
}