// concurrency/Ex1.java
// TIJ4 Chapter Concurrency, Exercise 1, page 1120
/** Implement a Runnable. Inside run(), print a message, and then call yield().
* Repeat this three times, and then return from run(). Put a startup message in
* the constructor and a shutdown message when the task terminates. Create a 
* number of these tasks and drive them using threads.
**/

/* 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
* May, 2009
*/

class Ex1RunnerA implements Runnable {
	public Ex1RunnerA() {
		System.out.println("Constructing Ex1RunnerA");
	}
	public void run() {
		for(int i = 0; i < 3; i++) {
			System.out.println("Hi from Ex1RunnerA");		
			Thread.yield();
		}
		System.out.println("Ex1RunnerA task complete.");
		return;				
	}
}

class Ex1RunnerB implements Runnable {
	public Ex1RunnerB() {
		System.out.println("Constructing Ex1RunnerB");
	}
	public void run() {
		for(int i = 0; i < 3; i++) {
			System.out.println("Hi from Ex1RunnerB");		
			Thread.yield();
		}
		System.out.println("Ex1RunnerB task complete.");
		return;
	}
}

class Ex1RunnerC implements Runnable {
	public Ex1RunnerC() {
		System.out.println("Constructing Ex1RunnerC");
	}
	public void run() {
		for(int i = 0; i < 3; i++) {
			System.out.println("Hi from Ex1RunnerC");		
			Thread.yield();
		}
		System.out.println("Ex1RunnerC task complete.");
		return;	
	}
}

public class Ex1 {
	public static void main(String[] args) {
		Thread ta = new Thread(new Ex1RunnerA());		
		Thread tb = new Thread(new Ex1RunnerB());		
		Thread tc = new Thread(new Ex1RunnerC());
		ta.start();
		tb.start();
		tc.start();
	}
}