RE: New state tables

[Peter Furniss <peter.furniss@choreology.com>]

> >> > There is no longer a VOTE with different values, but just
> READY. If the
> >> > inferior ever determines that it is going to cancel, it sends
> CANCELLED,
> >> > whether before (and instead of) sending READY, after sending
> (=heuristic
> >> or
> >> > expired participant timeout) or in response to CANCEL.
> >>
> >> Do I have to boxcar now in order to get the equivalent of a readonly
> vote?
>
> > No, you send RESIGN. "before (and instead of) sending READY" is really
> > "before (and instead of) sending READY or CANCEL".
> >
> > If RESIGN is sent before PREPARE is received, it asks for a response; if
> > sent after it does not ask for a resonse.
>
> It's not the same thing though, since RESIGN appears to have to be sent
> prior to PREPARE. If RESIGN is a valid response to PREPARE as well, then
> that's fine.

RESIGN is unchanged (since about the London model group meeting) - it is
effectively a spontaneous readonly vote when sent before receiving PREPARE,
effectively a responding readonly vote when sent after.

>              If it isn't then I have a problem with you removing the vote
> types. BTW, I haven't seen any discussion about this on the mailing lists,
> so was it discussed anywhere outside of Choreology?

This was an outcome of the "Sanjay simplification": that an inferior, if
asked to vote repeatedly could not change its vote (which could only be from
/ready to /cancel) and was covered in that email thread.  However an
inferior, after it has voted ready could make a heuristic/apply timeout and
cancel (and in fact the most plausible reason for asking it to vote again
was to see if the timeout had in fact gone off). So it would certainly have
been possible for an inferior to send (ignoring PREPAREs)

 time   message sent
 9:00    VOTE/ready/cancel/20mins
 9:15    VOTE/ready/cancel/10mins    // giving 5 mins extra
 9:30    CANCELLED                   // I warned you !

If that CANCELLED is received by the superior before it has ordered confirm
(or has itself voted uptree), then the superior can treat it as it would a
VOTE/cancel, and cancel everything. So why not replace VOTE/cancel by
CANCELLED (but when sent before VOTE/ready then it doesn't need a replying
CANCEL).  But then VOTE can only be VOTE/ready, so make it say what it
means.

Peter