How can “while (i == i) ;” be a non-infinite loop in a single threaded application?

Question

I just got a question that I can\'t answer.

Suppose you have this loop definition in Java:

while (i == i) ;

What is the type of

Answer 1

i == i is not atomic. Proved by such program:

static volatile boolean i = true;
public static void main(String[] args) throws InterruptedException
{
    new Thread() {
        @Override
        public void run() {
            while (true) {
                i = !i;
            }
        }
    }.start();

    while (i == i) ;
    System.out.println("Not atomic! i: " + i);
}

Update Here is one more example of not-infinite loop (no new threads are created).

public class NoNewThreads {
    public static void main(String[] args) {
        new NoNewThreads();
        System.gc();
        int i = 500;
        System.out.println("Still Running");
        while (i == i) ;
    }

    @Override
    protected void finalize() throws Throwable {
        super.finalize();
        Thread.sleep(1000);
        System.exit(0);
    }
}