//Thread2.java
//basic thread
//sleep

class Y implements Runnable {      //change from X because X.class differs...
    public void run() {   
	System.out.println( "hi from " + 
			    Thread.currentThread().getName() +
			    " before my nap" );

	try {
	    //Thread class static method sleep(int ms) causes thread not to run
	    //for at least this amount of time.
	    Thread.sleep( (int)(Math.random()*2000) );
	}
	//sleep can throw this checked exception, so try catch is required
	catch (InterruptedException e) {}  //don't do anything...

	//real reasons for sleeping: 1.slow it down, 
	//2.try to force taking turns
	//3.execute code periodically

	System.out.println( "bye from " + 
			    Thread.currentThread().getName() +
			    " awake again." );
    }
}


public class Threads2 {
    public static void main( String[] args ) {
	Y x1 = new Y();     

	Thread t2 = new Thread( x1 );
	Thread t3 = new Thread( x1 );
	Thread t4 = new Thread( x1 );
	t2.setName( "gilligan" );
	t3.setName( "professor" );
	t4.setName( "his wife" );
	//they'll sleep for different amounts of time, so wakeup and continuation
	//order will vary.
	t2.start();
	t3.start();
	t4.start();
    }
}