From: Andreas Huber (ah2003_at_[hidden])
Date: 2004-05-27 18:11:57
E. Gladyshev wrote:
> As for unstable states.
> Does this idiom mean that any exception event handling
> state must be considered as an implicit *inner* state of
> any other state that throws?
> So that *only* the exception handling states
> can be considered as *most inner* states.
No. Please have a look at http://tinyurl.com/2uzs5 (the whole section on
Exception Handling) again. I think it clearly explains how it all works.
> I think that one of the most important goals of
> the state machines design is to achieve
> a completely deterministic behavior.
Yes, this is important for me also.
> Doesn't your default exception handling
> idiom compromise this objective?
Do you think so because finding a handler for an exception might take
non-deterministic time? That is true on some platforms. On others you *can*
establish upper limits for finding a handler.
I chose the default this way because I believe that a majority of the users
will not have deterministic reaction time requirements. In real-time
projects you often disable exceptions anyway so the problem won't arise. I
will add a remark that real-time projects should consider not using
exceptions or check that the compilers exception handling implementation is
deterministic.
Regards,
Andreas