%T Mobile Processes and Call Channels with Variant Interfaces (a Duality)
%A  Eric Bonnici, Peter H. Welch
%E Peter H. Welch,  Adam T. Sampson,  Jan Bækgaard Pedersen,  Jon Kerridge,  Jan F. Broenink,  Frederick R. M. Barnes
%B Communicating Process Architectures 2011
%X The current model of mobile processes in occam\-π
   implements a <em>single</em>
interface for host processes to
   use.
However, different hosts holding different kinds of
   resource will naturally require
different interfaces to
   interact with their visitors.
So, current occam\-&pi;
   mobiles have to offer a single union of all the
   interfaces
needed and hosts must provide dummy arguments for
   those irrelevant to
its particular calls.  This opens the
   possibilty of programming errors
in both hosts and mobile
   should those dummies mistakenly be used.
This talk considers
   a revised model for mobile processes that allows
   <em>many</em>
interfaces.
The talk also proposes a concept
   of <em>variant call channels</em>,
that expands on a
   mechanism proposed for the occam3 language, and shows
a
   simple duality between the revised mobile processes and
   mobile variant
call channels.
An implementation of mobile
   variant call channels, via source\-code transformation
to
   standard occam\-&pi; mobile channel bundles, has been
   devised &ndash;
which gives an implementation route for the
   revised mobile process model and
an operational
   semantics.
If time, the ideas will be illustrated with a
   case study based on the Santa Claus problem,
where the elves
   and reindeer are mobile processes.