RE: [moca] all-you-can-eat calculi

[sanjiva@xxxxxxxxxxxxxxxxx]

Hi:

Martin wanted an synchonization model that consumed
all the outputs "at one go".  This seems to indicate a synchonous
rather than an asynchronous model.  The all-you can-eat model can
be expressed by choosing an appropriate algebra of actions.  See
Milner's 1983 paper Calculi for Synchrony and Asynchrony, TCS 25:267-310.

I think the following algebra on actions should work:
     a . \overline{a} = a     (1)
where . is commutative and associative.

One can additionally have (agreement on output):
     \overline{a} . \overline{a} = \overline{a}

Multiple input processes (Pawel's question) can be handled by a.a = a

Asynchronous processes can be expressed using delay operators
(encoding uses recursion and unit action).

Pawel rightly also suggests a deeper study of the connections with
distributed computing problems.

Regards,
Sanjiva

> Hi there,
>
> Can't you already express this by the (infinite) recursion operator?
>
>
> Kind regards,
>
> -----Original Message-----
> From: Martin Berger [mailto:martinb@xxxxxxxxxxxxxx]
> Sent: mardi 17 août 2004 17:20
> To: moca; Martin Berger
> Subject: [moca] all-you-can-eat calculi
>
>
> most message passing calculi i know either do point-to-point
> communication or broadcasting. the latter means one output
> interacts with many inputs. i wonder about the 'dual'
> of broadcasting -- i call it "all-you-can-eat" -- where
> one input consumes as many outputs as possible in one go.
> all-you-can-eat in a calculus of pure synchronisation would
> probably have a reduction rule like
>
>     x.P | \overline{x} | ... \overline{x}  --->  P
>
> I'd like to know if calculi with this or similar rules
> have already been studied. in particular, i'd like to hear
> about applications where this form of communication
> is natural. I'd also wish to find out how to generalise
> all-you-can-eat to value passing.
>
> thanks, martin
>
>
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