%T PICOMS: Prioritised Inferred Choice Over Multiway Synchronisation
%A  Douglas N. Warren
%E Peter H. Welch,  S. Stepney,  F.A.C Polack,  Frederick R. M. Barnes,  Alistair A. McEwan,  G. S. Stiles,  Jan F. Broenink,  Adam T. Sampson
%B Communicating Process Architectures 2008
%X The ability to make a choice over multiway synchronisations
   (COMS) has
always been an integral part of CSP. However, it
   is something that
has been conspicuous by its absence from
   many concurrent languages,
limiting their expressive power.
   Implementation of a 2\-phase commit
protocol to resolve such
   choice can result in large overheads, caused
by
   synchronisation offers having to be withdrawn. The recent
   Oracle
(single\-phase) algorithm resolves COMS efficiently,
   for shared memory
concurrency at least. However, the Oracle
   only deals with
<i>arbitrary</i> choice and does not
   obviously extend to
<i>prioritised</i> choice (where we
   assume the priorities of the
participating processes are not
   in conflict). PICOMS is a proposed
efficient method for
   resolving COMS that honours non\-conflicting
priorities,
   with only a modest increase in complexity over the
   Oracle
method.