AA Ex

gistfile1.txt

Hello World
Hello World
Hello World
Hello World
Hello World
Hello World
Hello World
Hello World
Hello World
java.lang.Exception: An exception!
        at aa.race.ThreadDemo.run(ThreadDemoExc.java:49)
        at java.lang.Thread.run(Unknown Source)
Hello World
Hello World
Hello World
java.lang.Exception: An exception!
        at aa.race.ThreadDemo.run(ThreadDemoExc.java:49)
        at java.lang.Thread.run(Unknown Source)
===== end loop =====

ThreadDemoExc.java

package aa.race;

import java.util.Random;
import java.util.concurrent.locks.*; 
/**
 * Created by kevinsteppe on 2/10/15.
 */
public class ThreadDemoExc
{
    public static final int numLoops = 8;
    private static int num_threads = 4;
    private static Lock lock = new ReentrantLock();

    public static void main(String[] args) throws Exception
    {
        Thread t1 = new Thread(new ThreadDemo(0, lock));
        Thread t2 = new Thread(new ThreadDemo(1, lock));
        t1.start();
        t2.start();
        t1.join();
        t2.join(); //wait for both
        System.out.println("===== end loop =====");
    }
}

class ThreadDemo implements Runnable
{
    int id;
    Random random = new Random();
    Lock lock;
    
    public ThreadDemo(int i, Lock lock)
    {
        id = i;
        this.lock = lock;
    }

    public void run()
    {
        lock.lock();
        try
        {
            for (int i = 0; i < 10; i++)
            {
                System.out.println("Hello World");
                Thread.yield();
                int x = random.nextInt(4);
                if (x == id)
                    throw new Exception("An exception!");
            }
        } catch (Exception e)
        {
            e.printStackTrace();   
        }
        lock.unlock(); 
    }
}