Re: [certi-dev] Time advancement

[Eric Noulard]

Hi,

The Uppaal model (see http://www.uppaal.org/)
should now reflect the state of the current time management code
(with some detail abstracted away).

The model itself can be found in:
certi/doc/CERTI-tickHandling.xml

I attach screenshot of automaton diagrams for libRTI/Federate and
corresponding RTIA.
Those models are 'template' which can be instantiated.

I'll try to do some model-checking with this in order to check for
potential deadlock
or other unexpected/unwanted properties.

I did add some more comments about time management in
both libRTI and RTIA source code files.
I think it's definitely better than before but like I said
the code in this part is not simple because

1) Federate and RTIA are different "asynchronous" process
   and even if Federate believes it's "only calling tick()" several
   messages may be exchange behind the scene

2) RTIA **needs** somehow to be asynchronous w.r.t. Federate because
   it should always be ready to receive message from RTIG
   (potential callbacks originating in other federate)

3) The code was simpler than the current one, but it got more complicated
    because of the introduction of the "timeout" version of "tick" which
    is handled asynchronously in one process (RTIA) and "look-like"
synchronously
    in libRTI but not quite.

May be this part of the code needs re-thinking/design, however it works for many
of us but Michael so, that we have to fix it but carefully...

Michael, would you be able to provide us with a strip-down autonomous
example which exhibit the problem?

I'll definitely help on this but I do not currently have enough free
time to take it down now.

-- 
Erk
Membre de l'April - « promouvoir et défendre le logiciel libre » -
http://www.april.org

libRTI-model-shot.png
Description: PNG image

RTIA-model-shot.png
Description: PNG image