title: What does tomcat do when session expires?
body: <p>What does tomcat do when session expires?</p>
  
  <p>Does it set the session object invalidated?</p>
  
  <p>Does it unlink all references to the session object so that I may not be able to get the expired session object by calling <code>request.getSession(false)</code> ?</p>
  
  <p>I'm using Servlet 2.5 spec. Thanks.</p>