Well, look.
Tomcat is open source. So you could get the source code of Tomcat and answer this question for yourself in the Tomcat context. That's not to say that Websphere or
JBoss or any of the other servers do the same thing, though. I think we are all bemused why you care about this question.
My usual question is "What would you do differently based on the answer to this question?" but I try to avoid posting that in the certification forums, where it doesn't apply. However in this case I don't think the question is going to be asked on any certification exam, so perhaps it could be asked.