/*
 * ThreadExample2
 * by Robert Keller
 *
 * Two threads are created. Each sleeps for an amount 'delay' of
 * milliseconds, then wakes up and prints its step number.
 * Each runs for a designated number of steps.
 * 
 * The main program awaits for each thread to terminate, using 'join',
 * and prints when termination occurs.
 */

class ThreadExample2 implements Runnable
{
Thread myThread;	// Thread object for control

int myID;		// Identifier for this "thread"

int step;		// Step number of this "thread"

int totalSteps;         // Total number of steps

int delay; 		// delay milliseconds

/**
 * Construct a ThreadExample2 with the specified ID and delay value.
 */

public ThreadExample2(int myID, int delay, int totalSteps)
    {
    this.myID = myID;
    this.delay = delay;
    this.totalSteps = totalSteps;
    myThread = new Thread(this);
    step = 1;
    }

/**
 * Start this thread.
 * The run method will be called.
 */

public void start()
    {
    myThread.start();
    }


/**
 * Join with this thread, meaning wait until it has completed.
 */

public void join() throws InterruptedException
    {
    myThread.join();
    }


/**
 * The run() method required to implement the Runnable interface.
 */

public void run()
    {
    while( step <= totalSteps )
        {
        // try/catch is needed because sleep can throw an exception.

        try
            {
            myThread.sleep(delay);
            System.out.println("thread " + myID + " is at step " + step);
            step++;
            }
        catch( Exception e )
            {
            }
        }
    }

public static void main(String arg[])
    {
    ThreadExample2 thread1 = new ThreadExample2(1, 1000, 10);
    ThreadExample2 thread2 = new ThreadExample2(2, 500, 10);

    thread1.start();
    thread2.start();

    try
        {
        thread2.join();
        System.out.println("thread 2 terminates");

        thread1.join();
        System.out.println("thread 1 terminates");
        }
    catch( InterruptedException e )
        {
        }
    }

}