Re: Other message patterns

Jean-Jacques Moreau wrote:

> "Williams, Stuart" wrote:
>
> > I happen to believe that it (request/response) is and should be primitive in
> > our case [...]
>
> I agree.

If we're weighing in on this, I agree too.

Earlier, the discussion of this seemed to focus on the question "can we model
'request/response' in terms of a single (one-way) primitive?" (i.e. prove it). I
think that's the wrong question, because I think the answer is clearly, we can. I
think the relevant question is "at what cost?" , in complexity, that is. The
request/response pair allow you to model a single abstract state-machine (multiple
concurrent RPC transactions are implemented as multiple instances of the single
state machine). With a single primitive, you simply can't model this as a single
state machine, and you have to expose the pairing of requests with responses. At
best, the conservation of complexity principle applies here.

--Ray


--
Ray Denenberg
Library of Congress
rden@loc.gov
202-707-5795