Automata for Context-Dependent Connectors

Abstract

Abstract. Recent approaches to component-based software engineering employ coordinating connectors to compose components into software systems. For maximum flexibility and reuse, such connectors can themselves be composed, resulting in an expressive calculus of connectors whose semantics encompasses complex combinations of synchronisation, mutual exclusion, non-deterministic choice and state-dependent behaviour. A more expressive notion of connector includes also contextdependent behaviour, namely, whenever the choices the connector can take change non-monotonically as the context, given by the pending activity on its ports, changes. Context dependency can express notions of priority and inhibition. Capturing context-dependent behaviour in formal models is non-trivial, as it is unclear how to propagate context information through composition. In this paper we present an intuitive automata-based formal model of context-dependent connectors, and argue that it is superior to previous attempts at such a model for the coordination language Reo.

Compositional Construction of Real-Time Dataflow Networks

“…Clarke et al [9] and Bonsangue et al [6] present approaches for modelling and verifying connectors in the channel-based coordination language Reo. The basic ideas are similar to ours: [9] represents connectors as constraints, and [6] uses an automata-based formal model, which takes into account environmental constraints by modelling presence and absence of requests.…”

“…The basic ideas are similar to ours: [9] represents connectors as constraints, and [6] uses an automata-based formal model, which takes into account environmental constraints by modelling presence and absence of requests. Yet, our framework is more general, in that neither of them considers timing constraints, or distinguishes between input and output ports.…”

“…Sect. 2.3), the encoding ϕ(C) of C is unfolded k times, i.e., instantiated for all steps up to k. The resulting formula is shown in (6). The formula ϕ E (C) j· denotes the variant of ϕ E (C), where j primes have been added to all variable symbols (e.g., ϕ E (C) 3· contains z 3· =z ).…”

A Specification Language for Reo Connectors

“…In this paper, we focus on the coordination language Reo and in a particular semantic model thereof: Reo automata [8,9]. We present a specification language for Reo automata, together with a Kleene-like theorem and sound and complete axiomatizations with respect to three notions of equivalence which enable algebraic reasoning on specifications.…”

Büchi automata for modeling component connectors

“…In such cases, the behavior of a connector can change dramatically with changing context. Both connector coloring and Reo automata [9] address the context-dependency issue, but connector coloring does not include a description of the temporal unfolding of a Reo connector, and Reo automata do not address fair behaviors. Both models are incomplete in that they cannot give semantics to many reasonable connectors.…”