Efficient Retrieval and Ranking of Undesired Package Cycles in Large Software Systems

International audienceMany design guidelines state that a software system architecture should avoid cycles between its packages. Yet such cycles appear again and again in many programs. We believe that the existing approaches for cycle detection are too coarse to assist developers to remove cycles from their programs. In this paper, we describe an efficient algorithm that performs a fine-grained analysis of cycles among application packages. In addition, we define multiple metrics to rank cycles by their level of undesirability, prioritizing cycles that are the more undesired by developers. We compare these multiple ranking metrics on four large and mature software systems in Java and Smalltalk

Efficient Retrieval and Ranking of Undesired Package Cycles in Large Software Systems

International audienceMany design guidelines state that a software system architecture should avoid cycles between its packages. Yet such cycles appear again and again in many programs. We believe that the existing approaches for cycle detection are too coarse to assist the developers to remove cycles from their programs. In this paper, we describe an efficient algorithm that performs a fine-grained analysis of the cycles among the packages of an application. In addition, we define a metric to rank cycles by their level of undesirability, prioritizing the cycles that seems the more undesired by the developers. Our approach is validated on two large and mature software systems in Java and Smalltalk

Activity Report 2012. Project-Team RMOD. Analyses and Languages Constructs for Object-Oriented Application Evolution

Activity Report 2012 Project-Team RMOD Analyses and Languages Constructs for Object-Oriented Application Evolutio

OZONE: Layer Identification in the presence of Cyclic Dependencies

International audienceA layered software architecture helps understanding the role of software entities (e.g., packages or classes) in a system and hence, the impact of changes on these entities. However, the computation of an optimal layered organization in the presence of cyclic dependencies is difficult. In this paper, we present an approach that (i) provides a strategy supporting the automated detection of cyclic dependencies, (ii) proposes heuristics to break cyclic dependencies, and (iii) computes an organization of software entities in multiple layers even in presence of cyclic dependencies. Our approach performs better than the other existing approaches in terms of accuracy and interactivity, it supports human inputs and constraints. In this paper, we present this approach and compare it to existing solutions. We applied our approach on two large software systems to identify package layers and the results are manually validated by software engineers of the two systems

Project-Team RMoD (Analyses and Language Constructs for Object-Oriented Application Evolution) 2011 Activity Report

This is the yearly report of the RMOD team (http://rmod.lille.inria.fr/). A good way to understand what we are doing

Aide à l'Évolution Logicielle dans les Organisations

Software systems are now so intrinsically part of our lives that we don't see them any more. They run our phones, our cars, our leisures, our banks, our shops, our cities … This brings a significant burden on the software industry. All these systems need to be updated, corrected, and enhanced as the users and consumers have new needs. As a result, most of the software engineering activity may be classified as Software Maintenance, “the totality of activities required to provide cost-effective support to a software system”.In an ecosystem where processing power for computers, and many other relevant metrics such as disk capacity or network bandwidth, doubles every 18 months (“Moore's Law”), technologies evolve at a fast pace. In this ecosystem, software maintenance suffers from the drawback of having to address the past (past languages, existing systems, old technologies). It is often ill-perceived, and treated as a punishment. Because of this, solutions and tools for software maintenance have long lagged far behind those for new software development. For example, the antique approach of manually inserting traces in the source code to understand the execution path is still a very valid one.All my research activity focused on helping people to do software maintenance in better conditions or more efficiently. An holistic approach of the problem must consider the software that has to be maintained, the people doing it, and the organization in which and for which it is done. As such, I studied different facets of the problem that will be presented in three parts in this document: Software: The source code is the center piece of the maintenance activity. Whatever the task (ex: enhancement or bug correction), it typically comes down to understand the current source code and find out what to change and/or add to make it behave as expected. I studied how to monitor the evolution of the source code, how to prevent it's decaying and how to remedy bad situations; People: One of the fundamental asset of people dealing with maintenance is the knowledge they have, of computer science (programming techniques), of the application domain, of the software itself. It is highly significant that from 40% to 60% of software maintenance time is spent reading the code to understand what it does, how it does it, how it can be changed; Organization: Organizations may have a strong impact on the way activities such as software maintenance are performed by their individual members. The support offered within the organization, the constraints they impose, the cultural environment, all affect how easy or difficult it can be to do the tasks and therefore how well or badly they can be done. I studied some software maintenance processes that organizations use.In this document, the various research topics I addressed, are organized in a logical way that does not always respect the chronological order of events. I wished to highlight, not only the results of the research, through the publications that attest to them, but also the collaborations that made them possible, collaboration with students or fellow researchers. For each result presented here, I tried to summarize as much as possible the discussion of the previous state of the art and the result itself. First because, more details can easily be found in the referenced publications, but also because some of this research is quite old and sometimes fell in the realm of “common sense”.Les systèmes logiciels font maintenant partie intrinsèque de nos vies à tel point que nous ne les voyons plus. Ils pilotent nos téléphones, nos voitures, nos loisirs, nos banques, nos magasins, nos villes, … Cela apporte de lourdes contraintes à l'industrie du logiciel car tous ces systèmes doivent être continuellement mis à jour, corrigés, étendus quand les utilisateurs et consommateurs expriment de nouveaux besoins. Le résultat en est que la plus grande part de l'activité de génie logiciel peut être classifié comme de la Maintenance Logicielle, « La totalité des activités requises pour fournir un support efficient d'un système logiciel ».Dans un écosystème où la puissance de calcul des ordinateurs, ou beaucoup d'autres métriques reliées comme la capacité des disques, ou le débit des réseaux, double tous les 18 mois (« loi de Moore »), les technologies évoluent rapidement. Dans cet écosystème la maintenance logiciel souffre de l'inconvénient de devoir traiter le passé (langages du passé, systèmes existants, vielles technologies). Elle est souvent mal perçue et traitée comme une punition. À cause de cela, les solutions et les outils pour la maintenance logicielle sont depuis toujours très en retard sur ceux pour le développement. Par exemple, l'antique méthode de correction de problème consistant à insérer des instructions pour retracer et comprendre le flot d'exécution d'un programme est toujours complètement actuelle.Toute mon activité de recherche s'est concentrée à aider les gens à faire de la maintenance logicielle dans de meilleures conditions ou plus efficacement. Une approche holistique du problème doit considérer le logiciel qui doit être maintenu, les gens qui le font et les organisations dans lesquelles et pour lesquelles cela est fait. Pour cela, j'ai étudié différents aspects du problème qui seront présentés en trois parties dans ce document : Le Logiciel : Le code source est la pièce centrale de l'activité de maintenance logicielle. Quelque soit la tâche (ex : amélioration ou correction d'erreur), elle revient typiquement à comprendre le code source actuel pour trouver quoi changer et/ou ajouter pour obtenir le comportement souhaité. J'ai étudié comment contrôler l'évolution du code source, comment prévenir son délitement et comment remédier à des mauvaises situations ; les Gens : L'un des principaux avantages des personnes qui traitent de maintenance logicielle est les connaissances qu'elles ont de l'informatique (techniques de programmation), du domaine d'application, du logiciel lui-même. Il est très significatif que de 40 % à 60 % du temps de maintenance logicielle soit passé à lire le code pour comprendre ce qu'il fait, comment il le fait et comment il peut-être changé ; les Organisations : Elles peuvent avoir un profond impact sur la façon dont des activités comme la maintenance logicielle sont exécutées par les individus. Le support offert à l'intérieur des organisations, ou les contraintes qu'elles imposent, l’environnement culturel, peuvent tous affecter la facilité ou difficulté de ces tâches et donc la qualité qui en résultera. J'ai étudié quelques processus liés à la maintenance logicielle utilisés dans les organisations.Dans ce document, les différents sujets de recherche que j'ai considéré sont présentés de façon logique qui ne respecte pas toujours l'ordre chronologique des évènements. J'ai souhaité aussi mettre en valeur, non uniquement les résultats scientifiques de mes recherches, au travers des publications qui les attestent, mais aussi les collaborations qui les ont rendus possibles, collaborations avec des étudiants ou des collègues chercheurs. Pour chaque résultat présenté ici, j'ai tenté de résumer le plus possible les discussions sur l'état de l'art antérieur et les résultats eux-mêmes. Ce d'abord parce que de plus amples détails peuvent facilement être trouvés dans les publications citées, mais aussi parce que une part de cette recherche est maintenant vielle et peux parfois être tombé dans le domaine du « sens commun »

D7.1. Criteria for evaluation of resources, technology and integration.

This deliverable defines how evaluation is carried out at each integration cycle in the PANACEA project. As PANACEA aims at producing large scale resources, evaluation becomes a critical and challenging issue. Critical because it is important to assess the quality of the results that should be delivered to users. Challenging because we prospect rather new areas, and through a technical platform: some new methodologies will have to be explored or old ones to be adapted