// concurrency/Ex18.java
// TIJ4 Chapter Concurrency, Exercise 18, page 1191
/** Create a non-task class with a method that calls sleep() for a long
* interval. Create a task that calls the method in the non-task class.
* In main(), start the task, then call interrupt() to teminate it. Make
* sure that the task shuts down safely.
**/

/* My solution to one of the exercises in 
* Thinking in Java 4th Edition (by Bruce Eckel).
* It compiles and runs correctly using JDK 1.6.0
* @author Greg Gordon
* @author www.greggordon.org
* June, 2009
*/

import java.util.concurrent.*;

class Nontask {
	public static void rest() {
		try {
			TimeUnit.SECONDS.sleep(5);
		} catch(InterruptedException e) {
			System.out.println("Sleep interrupted");
		} finally {
			System.out.println("Good Bye");
		}
	}
}

class Worker implements Runnable {
	public void run() {
		Nontask.rest();		
	}
}

public class Ex18 {
	public static void main(String[] args) { 
		// 3 ways to do it: 
		// use Thread:
		Thread t = new Thread(new Worker());
		t.start();
		t.interrupt();
		// use Executor execute:
		ExecutorService exec = Executors.newSingleThreadExecutor();
		exec.execute(new Worker());		
		exec.shutdownNow();
		// use Executor submit:
		ExecutorService exec2 = Executors.newSingleThreadExecutor();
		Future<?> f = exec2.submit(new Worker());
		try {
			TimeUnit.MILLISECONDS.sleep(100); // start task
		} catch(InterruptedException e) {
			System.out.println("Sleep interrupted in main()");
		}
		f.cancel(true);
		exec2.shutdown();		
	}
}