How to test transaction timeout

[LBOD]

I tried to test a timeout in a transactional method by adding this piece of code :
Thread.sleep(10000);
The timeout was set to 1 second. The method was successfully completed, and there wasn't any rollback.

Any idea of what happens, or another way to test the timeout ?

Thanks.

[LBOD]

I tried to replace the Thread.sleep() by an endless loop after doing some modifications in the database. The modifications are not commited (good point) but the execution of the method is not stopped ...

Any explanations ?

Thanks