java.lang.IllegalStateException relation with weblogic idle thread

The following stacktrace appears with the attached program code. And it was found the weblogic idle thread dropped to 0 and required weblogic restart eventually.    What will be the cause and how can it be avoided?

java.lang.IllegalStateException: Session invalidation is in progress with different thread

        at weblogic.servlet.internal.session.SessionData.invalidate(SessionData.java:792)

doGet(HttpServletRequest request, HttpServeletResponse reponse)
{

    HttpSession session = request.getSession();
    session.setAttribute("logout","true");
    session.invalidate();
}