On Jul 24, 2006, at 2:07 PM, Pete Wyckoff wrote:
[EMAIL PROTECTED] wrote on Mon, 24 Jul 2006 14:47 -0400:
3) the state machine language has a keyword that lets you state
that the
next state is "terminate" which could be used to finish the state
machine, but right now the code has logic that detects this and
prints a
warning that you should NOT use this. I don't know why we created
this
method and then made it illegal. Go figure!
I prefer #3 by a large margin over the other options. It's
explicit, not racy, doesn't over-use the return value for a
conceptually different event, and doesn't rely on modifying
parent state. Wonder why it was disabled.
I think terminate ended up being more of a placeholder...we still use
it in quite a few of our state machines, but the last state action is
expected to call server_state_machine_complete which prevents the SM
from transitioning to the 'terminate' state. I've thought of it as
an assert: if you get here you're forgetting something.
It sounds like option 3 is best. My only concern would be using the
state machine definition to define completion makes me forget about
cleaning up in the last action (or actions). I wouldn't mind seeing
option 3 and option 4 being required: check the return code and make
sure the next state is 'terminate'. If one of those fails there's a
bug in the code. I think that might help (at least me) verify that
state actions that are meant to complete need to do cleanup first.
-sam
Regarding names, STATE_COMPLETE and STATE_MACHINE_TERMINATED seem
like find candidates as you have sort of suggested.
My pocket change.
-- Pete
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