On Asynchronous Session Semantics

This paper studies a behavioural theory of the π-calculus with session types under the fundamental principles of the practice of distributed computing — asynchronous communication which is order-preserving inside each connection (session), augmented with asynchronous inspection of events (message arrivals). A new theory of bisimulations is introduced, distinct from either standard asynchronous or synchronous bisimilarity, accurately capturing the semantic nature of session-based asynchronously communicating processes augmented with event primitives. The bisimilarity coincides with the reduction-closed barbed congruence. We examine its properties and compare them with existing semantics. Using the behavioural theory, we verify that the program transformation of multithreaded into event-driven session based processes, using Lauer-Needham duality, is type and semantic preserving

Distributed Implementation of Message Sequence Charts

International audienc

Arbiters: an exercise in specifying and decomposing asynchronously communicating components

AbstractA method is presented for the formal specification and decomposition of asynchronously communicating components. The method is demonstrated by the design of some arbiters. An arbiter is a hardware primitive that realizes the mutual exclusive access of processes to their critical sections. It is shown how large arbiters can be decomposed into small ones, and how the communication behaviour of arbiters can be specified concisely and conveniently in a simple program notation. Furthermore, it is shown that the syntax of a program may guide the designer in the verification, and even derivation, of possible decompositions in a calculational style

Compositional bisimulation metric reasoning with Probabilistic Process Calculi

We study which standard operators of probabilistic process calculi allow for compositional reasoning with respect to bisimulation metric semantics. We argue that uniform continuity (generalizing the earlier proposed property of non-expansiveness) captures the essential nature of compositional reasoning and allows now also to reason compositionally about recursive processes. We characterize the distance between probabilistic processes composed by standard process algebra operators. Combining these results, we demonstrate how compositional reasoning about systems specified by continuous process algebra operators allows for metric assume-guarantee like performance validation