The Reflex Sandbox : an experimentation environment for an aspect-oriented Kernel

Reflex es un núcleo versátil para la programación orientada aspectos en Java. Provee de las abstracciones básicas, estructurales y de comportamiento, que permiten implementar una variedad de técnicas orientadas a aspectos. Esta tesis estudia dos tópicos fundamentales. En primer lugar, el desarrollo formal, utilizando el lenguaje Haskell, de las construcciones fundamentales del modelo Reflex para reflexión parcial de comportamiento. Este desarrollo abarca el diseño de un lenguaje, llamado Kernel, el cual es una extensión reflexiva de un lenguaje orientado a objetos simple. La semántica operacional del lenguaje Kernel es presentada mediante una máquina de ejecución abstracta. El otro tópico fundamental que estudia esta tesis es validar que el modelo de reflexión parcial de comportamiento es suficientemente expresivo para proveer de semántica a un subconjunto del lenguaje AspectJ. Con este fin, se desarrolló el Reflex Sandbox: un ambiente de experimentación en Haskell para el modelo Reflex. Tanto el desarrollo formal del modelo de reflexión parcial de comportamiento como la validación del soporte de AspectJ, son estudiados en el contexto del Reflex Sandbox. La validación abarca la definición de un lenguaje orientado a aspectos que caracteriza el enfoque de AspectJ a la programación orientada a aspectos, así como la definición de su máquina de ejecución abstracta. También se presenta un compilador que transforma programas escritos en este lenguaje al lenguaje Kernel. Este proceso de compilación provee los fundamentos para entender como dicha transformación puede ser realizada. El proceso de compilación también fue implementado en Java, pero transformando programas AspectJ a programas Reflex. También se presentan mediciones preliminares del desempeño de un programa compilado y ejecutado en Reflex y un programa compilado, y ejecutado con el compilador AspectJ

A theory of distributed aspects

International audienceOver the last five years, several systems have been proposed to take distribution into account in Aspect-Oriented Programming. While they appeared to be fruitful to develop or improve distributed component infrastructures or application servers, those systems are not underpinned with a formal semantics and so do not permit to establish properties on the code to be executed. This paper introduces the aspect join calculus -- an aspect-oriented and distributed language based on the join calculus, a member of the pi-calculus family of process calculi suitable as a programming language. It provides a first formal theory of distributed AOP as well as a base language in which many features of previous distributed AOP systems can be formalized. The semantics of the aspect join calculus is given by a (chemical) operational semantics and a type system is developed to ensure properties satisfied by aspects during the execution of a process. We also give a translation of the aspect join calculus into the core join calculus. The translation is proved to be correct by a bisimilarity argument. In this way, we provide a well-defined version of a weaving algorithm which constitutes the main step towards an implementation of the aspect join calculus directly in JoCaml. We conclude this paper by showing that despite its minimal definition, the aspect join calculus is a convenient language in which existing distributed AOP languages can be formalized. Indeed, many features (such as remote pointcut, distributed advice, migration of aspects, asynchronous and synchronous aspects, re-routing of messages and distributed control flow) can be defined in this simple language

GAMESPECT: A Composition Framework and Meta-Level Domain Specific Aspect Language for Unreal Engine 4

Game engine programming involves a great number of software components, many of which perform similar tasks; for example, memory allocation must take place in the renderer as well as in the creation routines while other tasks such as error logging must take place everywhere. One area of all games which is critical to the success of the game is that of game balance and tuning. These balancing initiatives cut across all areas of code from the player and AI to the mission manager. In computer science, we’ve come to call these types of concerns “cross cutting”. Aspect oriented programming was developed, in part, to solve the problems of cross cutting: employing “advice” which can be incorporated across different pieces of functionality. Yet, despite the prevalence of a solution, very little work has been done to bring cross cutting to game engine programming. Additionally, the discipline involves a heavy amount of code rewriting and reuse while simultaneously relying on many common design patterns that are copied from one project to another. In the case of game balance, the code may be wildly different across two different games despite the fact that similar tasks are being done. These two problems are exacerbated by the fact that almost every game engine has its own custom DSL (domain specific language) unique to that situation. If a DSL could showcase the areas of cross cutting concerns while highlighting the ability to capture design patterns that can be used across games, significant productivity savings could be achieved while simultaneously creating a common thread for discussion of shared problems within the domain. This dissertation sought to do exactly that- create a metalanguage called GAMESPECT which supports multiple styles of DSLs while bringing aspect-oriented programming into the DSL’s to make them DSAL (domain specific aspect languages). The example cross cutting concern was game balance and tuning since it’s so pervasive and important to gaming. We have created GAMESPECT as a language and a composition framework which can assist engine developers and game designers in balancing their games, forming one central place for game balancing concerns even while these concerns may cross different languages and locations inside the source code. Generality was measured by showcasing the composition specifications in multiple contexts and languages. In addition to evaluating generality and performance metrics, effectiveness was be measured. Specifically, comparisons were made between a balancing initiative when performed with GAMESPECT vs a traditional methodology. In doing so, this work shows a clear advantage to using a Metalanguage such as GAMESPECT for this task. In general, a line of code reduction of 9-40% per task was achieved with negligible effects to performance. The use of a metalanguage in Unreal Engine 4 is a starting point to further discussions concerning other game engines. In addition, this work has implications beyond video game programming. The work described highlights benefits which might be achieved in other disciplines where design pattern implementations and cross-cutting concern usage is high; the real time simulation field and the field of Windows GUI programming are two examples of future domains

Distributed aop middleware for large-scale scenarios

En aquesta tesi doctoral presentem una proposta de middleware distribuït pel desenvolupament d'aplicacions de gran escala. La nostra motivació principal és permetre que les responsabilitats distribuïdes d'aquestes aplicacions, com per exemple la replicació, puguin integrar-se de forma transparent i independent. El nostre enfoc es basa en la implementació d'aquestes responsabilitats mitjançant el paradigma d'aspectes distribuïts i es beneficia dels substrats de les xarxes peer-to-peer (P2P) i de la programació orientada a aspectes (AOP) per realitzar-ho de forma descentralitzada, desacoblada, eficient i transparent. La nostra arquitectura middleware es divideix en dues capes: un model de composició i una plataforma escalable de desplegament d'aspectes distribuïts. Per últim, es demostra la viabilitat i aplicabilitat del nostre model mitjançant la implementació i experimentació de prototipus en xarxes de gran escala reals.In this PhD dissertation we present a distributed middleware proposal for large-scale application development. Our main aim is to separate the distributed concerns of these applications, like replication, which can be integrated independently and transparently. Our approach is based on the implementation of these concerns using the paradigm of distributed aspects. In addition, our proposal benefits from the peer-to-peer (P2P) networks and aspect-oriented programming (AOP) substrates to provide these concerns in a decentralized, decoupled, efficient, and transparent way. Our middleware architecture is divided into two layers: a composition model and a scalable deployment platform for distributed aspects. Finally, we demonstrate the viability and applicability of our model via implementation and experimentation of prototypes in real large-scale networks

Conflictos entre aspectos en etapas del desarrollo de software

La ausencia de métodos, estrategias y mecanismos automáticos y flexibles para la detección y resolución de conflictos entre aspectos puede tener consecuencias graves en la ejecución del software. Ante la presencia de determinadas situaciones conflictivas el comportamiento del software se puede tornar impredecible, indeseado e incierto. La construcción y desarrollo de soluciones que superen estas deficiencias resulta una tarea importante para el desarrollo orientado a aspectos [1]. El presente artículo describe el tópico de estudio, los trabajos relacionados al tema y las acciones a realizar a través del proyecto de investigación Conflictos entre Aspectos.Eje: Ingeniería de Software y Base de DatosRed de Universidades con Carreras en Informática (RedUNCI