Re: [IMP] synchronization on session object in Cocoon

[Ralph Goers]

I ran through this thread and made some observations:
1. There can only be one Cocoon Session per HttpSession. Creation of 
this must be thread safe.
2. The code propsed will not work:

public Session getSession(boolean create) {
   // we must assure a 1:1-mapping of server session to cocoon session
   javax.servlet.http.HttpSession serverSession = this.req.getSession(create);
   if (serverSession != null) {
       synchronized (serverSession) {
           // retrieve existing wrapper
           this.session =
(HttpSession)serverSession.getAttribute(HTTP_SESSION);
           if (this.session == null) {
               // create wrapper
               this.session = new HttpSession(serverSession);
               serverSession.setAttribute(HTTP_SESSION, this.session);
           }
       }
   } else {
       // invalidate
       this.session = null;
   }
   return this.session;
}
serverSession is a local variable. Synchronizing it accomplishes nothing 
since every caller gets their own copy.  Sytnchronizing on a member of 
the HttpRequest object also accomplishes nothing.

I'm still trying to think of a solution I like.
Ralph