Re: Proposal for handling bi-directional interactions in a choice

>
> > Gary Brown: Related to the original CDL Challenge email, from the 23rd
> > June, the attached proposal discusses a way in which bi-directional
> > interactions in a choice statement can be described in a simple manner.
> >
> > I would like to raise this issue for discussion on the earliest
> > convenient conference call.
>
> mm1: Gary, we appreciate the input.  From reading your choice proposal,
> it appears you will implicitly assume that the ordering of the
> interactions places some sequential constraint on the actions of the
> roles involved in the relationship. Can you assume this prioritization
> will occur?

Not sure if I understand the issue about the sequential constraint. We would
not be able to control whether either or both roles decided to initiate
their interactions, and therefore they may cross over. What we can guarantee
is that if a role is sending an interaction that is not the highest priority
in the choice, then it will need to be able to handle either the response it
is expecting (i.e. the cancel confirmation) or a higher priority message
from the other role (i.e. order completed). This type of validation can be
performed along with other CDL validation tasks. This is no different to the
solution that Nick proposed in his slides (i.e. ignoring the cross over
message that is lower priority) - the difference is in the simplicity of
presenting this scenario in CDL.

> Should we provide constraints or implementers' hints to
> ensure good behavior (and determinism in the results of those choices)?
> As a minor note, we are implementing the technical interactions, as the
> business aspects are outside of WS-CDL. Thanks.

This behaviour would be generated into the behaviour expected of an
endpoint - which ultimately would be what governs the implementation of that
endpoint.

Received on Tuesday, 13 July 2004 14:18:51 UTC