%T Data Escape Analysis for Process Oriented Systems
%A  Martin Ellis,  Frederick R. M. Barnes
%E Peter H. Welch,  Frederick R. M. Barnes,  Kevin Chalmers,  Jan Bækgaard Pedersen,  Adam T. Sampson
%B Communicating Process Architectures 2012
%X Escape analysis, the technique of discovering the boundaries
   of
dynamically allocated objects, is a well explored
   technique for
object\-orientated languages (such as Java and
   C++) and stems from the
functional programming community. It
   provides an insight into which
objects interact directly
   (and indirectly) and can inform program
correctness
   checking, or be used for directing optimisations
   (e.g.
determining which objects can safely be allocated on a
   function\-local
stack). For process\-oriented languages such
   as occam\-pi and Google\[rs]s Go,
we have explored mobile
   escape analysis, that provides concise
information about the
   movement of objects (mobiles) within networks
   of
communicating processes. Because of the distinction
   between processes
(as execution contexts) and objects
   (dynamically allocated data,
channels and processes),
   combined with strict typing and aliasing rules,
the analysis
   is somewhat simpler then for less strict languages.
   This
analysis is only concerned with dynamically allocated
   blocks of memory
\-\- it does not give any consideration for
   the data contained within
these. However, knowing the extent
   to which data (statically or
dynamically allocated) escapes
   within a network of communicating
processes is arguably
   useful \-\- and is not necessarily a superset of
mobile
   escape. The fringe presentation describes an extension to
   the
mobile escape model that seeks to capture semantic
   information about the
data escape of a process\-oriented
   system. This provides richer semantic
information about a
   process\[rs]s behaviour (that can be used in
verification)
   and has clear application to security (e.g. by
demonstrating
   that particular data does not escape a set of
communicating
   processes).