%T Conditional Communication in the Presence of Priority
%A  Gerald H. Hilderink,  Jan F. Broenink
%E Peter H. Welch,  Andr\[`e] W. P. Bakkers
%B Communicating Process Architectures 2000
%X In this paper the behavior of conditional communication in
   the presence of priority will be described. In the theory of
   CSP, conditional communications are expressed by a
   (external) choice construct (also known as the alternative
   construct) by which the choice of one communication out of a
   set of communications is non\-deterministic. In practice,
   some communication can be more important than others, so
   that, the choice is deterministic. Therefore, one can
   distinguish two prioritized alternative constructs; a
   symmetric alternative construct (ALT) and an asymmetric
   alternative construct (PRIALT). Current formal semantics and
   implementations of the ALT and PRIALT are based on the
   priorities of communication and not related to the
   surrounding priorities of communicating processes. This can
   result in a structural mismatch that can cause performance
   problems. In this paper a practical solution for realizing
   fair and unfair conditional communication in the presence of
   the PAR and the PRIPAR will be discussed.