In Java 7 64-bit my program freezes on a loop
<p>This is my simple program:</p>

<pre><code>public class Test {
    public static Object obj = null;

    public static void main(String[] args) {
        obj = null;
        System.out.println("Start");
        MyThread myThread = new MyThread();
        myThread.start();
        while(obj == null) {
            //System.out.println("");
        }
        System.out.println("Stop");

    }
}

class MyThread extends Thread {

    @Override
    public void run() {
        System.out.println("Thread 1");
        try {
            sleep(1);
        } catch (InterruptedException ex) {
        }
        System.out.println("Thread 2");
        Test.obj = new Object();
        System.out.println("Thread 3");
    } 
}
</code></pre>

<p>As you can see, I run MyThread thread and while loop of Test class. The loop checks if obj is null and if it is not, I stop it and print "2". MyThread assigns a value to obj. And now the problem:</p>

<p>Under Java 7 64-bit, in case of empty while loop, it is never stopped. However, if I uncomment System.out.print(""), "Stop" under the loop is printed. But for other statements inside the loop (e.g. int i = 1;) my program freezes. Under Java 32-bit everything works fine for all cases.</p>

<p>Could someone explain me this strange behaviour?</p>

<p>Thanks!</p>
