Coordinating action systems

Abstract

We develop an action systems based approach that supports the separation of design of the functional or computation aspects of a system under construction from the coordination and synchronization issues. The computation aspects are modelled as nondeterministic actions that work in parallel with the coordination actions, which impose some control on this nondeterministic part. We define a special form of action systems that models this type of coordination activity. Certain forms of real time scheduling and coordination as well as exception handling are shown to be special cases of our approach. We show how the coordinators can be stepwise brought about from a high-level specification of the target system and how the reasoning about their behaviours is carried out separately from the computation aspects of the system within the refinement calculus.