Re: [boost] Meta State Machine library review starts Monday

Subject: Re: [boost] Meta State Machine library review starts Monday
From: Darryl Green (darryl.green_at_[hidden])
Date: 2009-11-28 08:06:08

Hi,

This is not a review.

So far I've done little more than read the docs, compile and run some
examples and have a brief look at trying to use msm for a "real world"
use.

I found code size of stripped executables compiled with gcc 4.3 to be
quite reasonable - especially at high optimisation levels, although
still about twice the size (the docs state) VC9 achieves. I'm assuming
that the large sizes mentioned are simply due to the generated files not
being stripped.

I was unable to compile the euml example - I haven't investigated the
errors yet.

I had hoped to pick what I'd consider a realistic use for a high
performance FSM tool (a low level comms protocol) and do a basic mock-up
implementation using MSM. However a reasonably typical layer 2 protocol
(LAPD) has 8 states and a transition table that in a condensed form (row
for each event, column for each state with the column describing the
actions and transition) is 10 pages long, so it is pretty obvious I
can't do that... Its likely that a bit of refactoring could bring the
total number of transitions down somewhat using composite states, but
the number of events to be handled exceeds the typical limits for number
of transitions so this still seems hopeless.

This leaves me fairly stuck for a practical use. I don't find a great
deal of value in a FSM DSEL for really small FSMs. Hopefully someone
else does.

At this point, I really like what msm is trying to do - it just doesn't
quite do it for me in a practical application. Maybe that just means
waiting for Moore's law and compiler technology to catch up?

Regards
Darryl.