Separation Logic Semantics for Communicating Processes

This paper explores a unification of the ideas of Concurrent Separation Logic with those of Communicating Sequential Processes. It extends separation logic by an operator for separation in time as well as separation in space. It extends CSP in the direction of the pi-calculus: dynamic change of alphabet is achieved by communication of channel names. Separation is exploited to ensure that each channel still has only two ends. For purposes of exploration, the model is the simplest possible, confined to traces without refusals. The treatment is sufficiently general to facilitate extensions by standard techniques for sharing multiplexed channels and heap state.