[orchestra] transaction token patch, session timeout fix

[Simon Kitching <sk...@apache.org>]

Hi Bernd,

I'm keen to look at your patch in JIRA, but it will probably have to
wait until this weekend. I hope that's ok
  https://issues.apache.org/jira/browse/ORCHESTRA-40

This reminds me that you did a follow-up patch (r759100) to your
previous Orchestra patch, and Mario had a few comments on it. We both
have been busy though, and haven't got around to emailing about it.

Your commit was about preventing a "cannot remove current contexxt
conversation" exception while clearing conversations. I presume this
actually happened for you, but neither Mario nor I can figure out why
that would ever happen. Is there a chance you can look into what
actually causes this? Or suggest how we could duplicate this? The
SessionListener should never have a FrameworkAdapter in its thread, and
so should never have any request param that references a conversation
context id. So it's puzzling why you would get that exception.

It would also be nice if the new code in the SessionListener would use a
finally block to reset the FrameworkAdapter to null, so that if anything
does throw an exception then we don't "leak" the threadlocal var. I can
do that myself later .. but if you're investigating the question above,
then maybe you could test this at the same time? Also, it might be nice
to remove the context from the wiper thread before destroying it, rather
than after...

Cheers,
Simon