/** 
 * Simple program using threads.
 *
 */


/**
 * class Counter is runnable, so we can turn a counter object into 
 * a thread (the run() method is run when this happens).
 *
 * This class assigns unique ids to each Counter object, and the run
 * method just counts to ten. Try using each of the run methods
 * (rename the one you want to be executed to "run()" ) to see what
 * happens to the thread scheduling
 */

class Counter implements Runnable { 
    static int id=0; 
    int myid; 
    int x;

    public Counter() {
	myid = id++;
	x=0;
    }

    // this run is used to see what happens (to scheduling) when the
    // threads don't wait for anything (and never call yield).

    public void run1() {
	while (x<10) {
	    System.out.println("Counter["+myid + "]:  value is " + x );
	    x++;
	}
    }


    // name this one run() to see what happens when each thread goes
    // to sleep regularly.
    public void run() {
	try {
	    while (x<10) {
		System.out.println("Counter["+myid + "]:  value is " + x );
		x++;
		// let another thread run
		Thread.currentThread().yield();
	    }
	    // uncomment this to see how having any thread alive keeps
	    // the program from quitting
	    if (myid==0) {
		System.out.println("I refuse to die!");
		while (true) {
		    // wait 100 ms.
		    Thread.currentThread().sleep(100);
		}
	    }
	} catch (InterruptedException ie) {
	    ie.printStackTrace();
	}
	
    }
}


class ThreadPlay {

    // creates 5 counter threads and sets them running.
    public static void main(String [] args) {
	for (int i=0;i<5;i++) {
	    Thread t = new Thread( new Counter());
	    t.start();
	    System.out.println("Started thread " + i );
	}
	System.out.println("main is done - goodbye");
    }

}