On observing dynamic prioritised actions in SOC

Rosario Pugliese, Francesco Tiezzi, and Nobuko Yoshida

Dipartimento di Sistemi e Informatica, Universita' di Firenze
Department of Computing, Imperial College London


We study the impact on observational semantics for SOC of priority
mechanisms which combine dynamic priority with local pre-emption. We define
manageable notions of strong and weak labelled bisimilarities for COWS, a
process calculus for SOC, and provide alternative characterisations in terms of
open barbed bisimilarities. These semantics show that COWS’s priority mechanisms
partially recover the capability to observe receive actions (that could not be
observed in a purely asynchronous setting) and that high priority primitives for
termination impose specific conditions on the bisimilarities.