Building distributed sensor network applications using BIP

International audienceThe exponential increase in the demands for the deployment of large-scale sensor networks, makes the efficient development of functional applications necessary. Nevertheless, the existence of scarce resources and the derived application complexity, impose significant constraints and requires high design expertise. Consequently, the probability of discovering design errors, once the application is implemented, is considerably high. To address these issues, there is a need for the availability of early-stage validation, performance evaluation and rapid prototyping techniques at design time. In this paper we present a novel approach for the co-design of mixed software/hardware applications for distributed sensor network systems. This approach uses BIP, a formal framework facilitating modeling, analysis and implementation of real-time embedded, heterogeneous systems. Our approach is illustrated through the modeling and deployment of a Wireless Multimedia Sensor Network (WMSN) application. We emphasize on its merits, notably validation of functional and non-functional requirements through statistical model-checking and automatic code generation for sensor network platforms

Modeling and Reasoning over Distributed Systems using Aspect-Oriented Graph Grammars

Aspect-orientation is a relatively new paradigm that introduces abstractions to modularize the implementation of system-wide policies. It is based on a composition operation, called aspect weaving, that implicitly modifies a base system by performing related changes within the system modules. Aspect-oriented graph grammars (AOGG) extend the classic graph grammar formalism by defining aspects as sets of rule-based modifications over a base graph grammar. Despite the advantages of aspect-oriented concepts regarding modularity, the implicit nature of the aspect weaving operation may also introduce issues when reasoning about the system behavior. Since in AOGGs aspect weaving is characterized by means of rule-based rewriting, we can overcome these problems by using known analysis techniques from the graph transformation literature to study aspect composition. In this paper, we present a case study of a distributed client-server system with global policies, modeled as an aspect-oriented graph grammar, and discuss how to use the AGG tool to identify potential conflicts in aspect weaving

Analyses et vérification des programmes à aspects

Aspect oriented programming is a paradigm aiming at improving the separation of concerns. Typically, an aspect is defined for a concern that can not be isolated in a module. Aspects are then added to the base program through an automatic process called weaving. However, the expressiveness of general aspect languages allows to completely change the semantics of the base program (e.g., an aspect may insert arbitrary code). This jeopardizes the benefits (readability, maintainability, reusability, etc.) expected from a better modularisation of concerns. In particular, it may become impossible to reason on the base program without examining the woven program. This thesis provides an answer to the above problem by defining categories of aspects whose semantic impact remains under control. For each category of aspects, we specify the class of properties of the base program that is preserved by weaving. The membership of an aspect to a category is guaranteed by construction through aspect languages dedicated to each category. The use of these languages ensures that weaving preserves all properties of the corresponding class. These properties are represented as subsets of LTL and CTL*. We formally prove that, for any program, the weaving of any aspect in a category preserves any property of the related class. These languages and categories are defined in a formal framework independent of any base or aspect language. The expressiveness of that framework is shown by providing the semantics of complex primitives of aspect languages such as AspectJ and CaesarJ, and by proving the correctness of a standard aspect program transformation.La programmation par aspects est un paradigme de programmation qui permet de mieux séparer les préoccupations d'une application. Un aspect est défini pour chaque préoccupation qui ne peut pas être isolée dans un module. Les aspects sont ensuite ajoutés au programme de base par un processus automatique appelé tissage. Cependant, l'expressivité des langages d'aspect généraux permet de modifier totalement la sémantique du programme de base (par ex., un aspect peut remplacer certains appels de méthode par du code arbitraire). Ce comportement peut entraîner la perte des avantages (lisibilité, maintenabilité, réutilisabilité, etc.) d'une meilleure modularisation des préoccupations. Il devient impossible de raisonner sur le programme de base sans regarder le programme tissé. Cette thèse apporte une réponse aux problèmes ci-dessus en définissant des catégories d'aspects dont l'impact sur la sémantique du programme de base reste sous contrôle. Pour chaque catégorie d'aspects, nous déterminons l'ensemble des propriétés du programme de base qui est préservé par tissage. L'appartenance d'un aspect à une catégorie est garantie par construction grâce à des langages d'aspect dédiés pour chaque catégorie. L'utilisation de ces langages assure que le tissage préservera l'ensemble des propriétés associé à la catégorie concernée. Les propriétés préservées sont représentées comme des sous ensembles de LTL et de CTL*. Nous prouvons formellement que quelque soit le programme de base, le tissage de n'importe quel aspect d'une catégorie préserve les propriétés de la catégorie correspondante. Ces langages et catégories sont définis dans un cadre formel indépendant de tout langage de base ou d'aspect. L'expressivité de ce cadre est montrée en décrivant des primitives complexes de langages d'aspect comme AspectJ et CaesarJ et en effectuant une preuve de correction de transformation d'aspect

Specialized aspect languages preserving classes of properties

International audienc

Aspects Preserving Properties

International audienceAspect Oriented Programming can arbitrarily distort the semantics of programs. In particular, weaving can invalidate crucial safety and liveness properties of the base program. In this article, we identify categories of aspects that preserve some classes of properties. Specialized aspect languages are then designed to ensure that aspects belong to a specific category and, therefore, that woven programs will preserve the corresponding properties. Our categories of aspects, inspired by Katz's, comprise observers, aborters, confiners and weak intruders. Observers introduce new instructions and a new local state but they do not modify the base program's state and control-flow. Aborters are observers which may also abort executions. Confiners only ensure that executions remain in the reachable states of the base program. Weak intruders are confiners between two advice executions. These categories (along with two others) are defined formally based on a language independent abstract semantics framework. The classes of preserved properties are defined as subsets of LTL for deterministic programs and CTL* for non-deterministic ones. We can formally prove that, for any program, the weaving of any aspect in a category preserves any property in the related class. We present, for most aspect categories, a specialized aspect language which ensures that any aspect written in that language belongs to the corresponding category. It can be proved that these languages preserve the corresponding classes of properties by construction. The aspect languages share the same expressive pointcut language and are designed w.r.t. a common imperative base language. Each category and language is illustrated by simple examples. The appendix provides se- mantics and two instances of proofs: the proof of preservation of properties by a category and the proof that all aspects written in a language belong to the corresponding category

Analyses et vérifications des programmes à aspects

NANTES-BU Sciences (441092104) / SudocSudocFranceF

Aspects Preserving Properties

Aspect Oriented Programming can arbitrarily distort the semantics of programs. In particular, weaving can invalidate crucial safety and liveness properties of the base program. In this article, we identify categories of aspects that preserve some classes of properties. Specialized aspect languages can be then designed to ensure that aspects belong to a specific category and therefore that woven programs will preserve the corresponding properties. Our categories of aspects, inspired by Katz's, comprise observers, aborters and confiners. Observers introduce new instructions and a new local state but they do not modify the base program's state and control-flow. Aborters are observers which may also abort executions. Confiners only ensure that executions remain in the reachable states of the base program. % These categories (along with three other) are defined precisely based on a language independent abstract semantics framework. The classes of preserved properties are defined as subsets of LTL for deterministic programs and CTL* for non-deterministic ones. We can formally prove that, for any program, the weaving of any aspect in a category preserves any property in the related class. We present, for most aspect categories, a specialized aspect language which ensures that any aspect written in that language belongs to the corresponding category. It can be proved that these languages preserve the corresponding classes of properties by construction. The aspect languages share the same expressive pointcut language and are designed \wrt a common imperative base language. Each category and language are illustrated by simple examples. The appendix provides semantics and examples of proofs: the proof of preservation of properties by a category and the proof that all aspects written in a language belong to the corresponding category

Aspects preserving properties

Aspect Oriented Programming can arbitrarily distort the semantics of programs. In particular, weaving can invalidate crucial safety and liveness properties of the base program. In this article, we identify categories of aspects that preserve some classes of properties. It is then sufficient to check that an aspect belongs to a specific category to know which properties will remain satisfied by woven programs. Our categories of aspects, inspired by Katz’s, comprise observers, aborters and confiners. Observers introduce new instructions and a new local state but they do not modify the base program’s state and control-flow. Aborters are observers which may also abort executions. Confiners only ensure that executions remain in the reachable states of the base program. These categories (along with three other) are defined precisely based on a language independent abstract semantics framework. The classes of properties are defined as subsets of LTL for deterministic programs and CTL* for non-deterministic ones. We can formally prove that, for any program, the weaving of any aspect in a category preserves any property in the related class. We give example