Tiles for Reo

Electronic Notes in Theoretical Computer Science, 2004

In this paper we introduce constraint automata and propose them as an operational model for Reo, an exogenous coordination language for compositional construction of component connectors based on a calculus of channels. By providing composition operators for constraint automata and defining notions of equivalence and refinement relations for them, this paper covers the foundations for building tools to address such concerns as the automated construction of the automaton for a given component connector, equivalence-or containment-checking of the behavior of two given connectors, and verification of coordination mechanisms.

Science of Computer Programming, 2012

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.

Journal of Universal Computer Science, 2005

Component-based Software Development is an emerging discipline in the field of Software Engineering. In this context, coordination languages may be used to specify the interactive behavior of software components. Our proposal is oriented towards defining a framework for describing the behavior of components in terms of coordination models. In particular, we define a way to complement interface description languages in order to describe components such that the information about the services provided by a component can be extended with details on how these services should be used. We illustrate our approach by applying the proposed framework to two substantially different coordination models: Linda and Reo; the former representing the family of data-oriented coordination models, and the latter a new channel-based model. Although we consider both models to show the feasibility of our proposal we hope this study help us to define an interaction description language based on Reo for component coordination, as has already been done in the context of Linda.

L'objet, 2006

Engineering of component based software systems requires a formal model for its foundation. Virtually all contemporary component models use some form of object oriented method invocation for their component composition semantics. In contrast, Abstract Behavior Types (ABT) offer a simpler model of components and their composition. Reo is an exogenous coordination language that provides a middleware for dynamically reconfigurable component composition on distributed, mobile platforms. The ABT model serves as a unifying formalism to express the behavior of Reo connectors, as well as that of components. By examples, we show the expressive power of Reo, and the applicability of the ABT model. RÉSUMÉ. L'ingénierie des systèmes logiciels à base de composants nécessite un modèle formel comme fondation. Virtuellement tous les modèles actuels de composants utilisent une forme particulière d'appel de méthode orienté-objet comme base de leur sémantique de composition. À l'opposé, les Abstract Behavior Types (ABT) offrent un modèle plus simple aux composants et à leur composition. Reo est un langage de coordination exogène qui fournit un intergiciel permettant la composition dynamiquement reconfigurable de composants sur les plates-formes distribuées et mobiles. Le modèle ABT sert de formalisme unificateur pour exprimer le comportement des connecteurs Reo ainsi que celui des composants. Au travers d'exemples, nous montrons le pouvoir d'expressivité de Reo et l'applicabilité du modèle ABT.

Electronic Notes in Theoretical Computer Science, 2003

In this paper we introduce constraint automata and propose them as an operational model for Reo, an exogenous coordination language for compositional construction of component connectors based on a calculus of channels. By providing composition operators for constraint automata and defining notions of equivalence and refinement relations for them, this paper covers the foundations for building tools to address such concerns as the automated construction of the automaton for a given component connector, equivalence-or containment-checking of the behavior of two given connectors, and verification of coordination mechanisms.

Future Generation Computer Systems, 2001

One of the most promising approaches in developing component-based (possibly distributed) systems is that of coordination models and languages. Coordination programming enjoys a number of advantages such as the ability to express different software architectures and abstract interaction protocols, support for multi-linguality, reusability and programming-in-the-large, etc. Configuration programming is another promising approach in developing large scale, component-based systems, with the increasing need for supporting the dynamic evolution of components. In this paper we explore and exploit the relationship between the notions of coordination and (dynamic) configuration and we illustrate the potential of control-or event-driven coordination languages to be used as languages for expressing dynamically reconfigurable software architectures. We argue that control-driven coordination has similar goals and aims with the notion of dynamic configuration and we illustrate how the former can achieve the functionality required by the latter.

Lecture Notes in Computer Science, 2002

Software Architecture studies the structure of software systems, as described by Architecture Description Languages (Adls). When these capture structures of change, they are comparable to Coordination Languages. Previous work suggests that the combination with Reflection concepts renders a general framework for the description of such evolving structures. This paper describes a reflective Adl named PiLar designed to provide such a framework. It consists of a structural part, which describes the static skeleton, and a dynamic part, which defines patterns of change. The major novelty is the reification relationship, which structures a description in several meta-layers, such that the architecture is able to reason and act upon itself. The paper includes a complete PiLar example, to show the language's use and some of its most relevant features. It describes a Tuple Space model, illustrating the analogy with existing Coordination Models. We conclude by emphasizing PiLar's generality and applicability. This work has been partially sponsored by the Spanish Comission of Science and Technology through the CICYT Project TEL99-0335-C04-04, and by the Autonomous Government of Castilla and León through the Project JCYL VA61/00B.

2009

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 context-dependent 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.