CountDownLatch.await() timeout doesn't affect waiting time

I try to run an Android JUnit test of a multi-threaded code. I used a CountDownLatch in order to assert from the Handler. The problem is that I never reach the timeout of the await() method. If I type Thread.sleep(3000) in the Thread for instance, and await() for 50 milliseconds, it'll still wait 3 seconds.

This is the code example:

private static boolean called;
private static Handler handler = new Handler(){
    public void handleMessage(android.os.Message msg) {
        called = true;
    };
};

public final void testSuccessfulFetch() throws Throwable {
    final CountDownLatch signal = new CountDownLatch(1);

    runTestOnUiThread(new Runnable() {
        @Override
        public void run() {
            try {
                Thread.sleep(3000);
                Message msg = handler.obtainMessage();
                handler.sendMessage(msg);
                signal.countDown();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }


        }
    });       

    signal.await(50, TimeUnit.MILLISECONDS);
    assertTrue("handler wasn't called", called);
}

What am I missing?

Thanks!