Aspect-Oriented Programming

Aspect-oriented programming is a promising idea that can improve the quality of software by reduce the problem of code tangling and improving the separation of concerns. At ECOOP'97, the first AOP workshop brought together a number of researchers interested in aspect-orientation. At ECOOP'98, during the second AOP workshop the participants reported on progress in some research topics and raised more issues that were further discussed. \ud \ud This year, the ideas and concepts of AOP have been spread and adopted more widely, and, accordingly, the workshop received many submissions covering areas from design and application of aspects to design and implementation of aspect languages

Composing Software from Multiple Concerns: A Model and Composition Anomalies

Constructing software from components is considered to be a key requirement for managing the complexity of software. Separation of concerns makes only sense if the realizations of these concerns can be composed together effectively into a working program. Various publications have shown that composability of software is far from trivial and fails when components express complex behavior such as constraints, synchronization and history-sensitiveness. We believe that to address the composability problems, we need to understand and define the situations where composition fails. To this aim, in this paper we (a) introduce a general model of multi-dimensional concern composition, and (b) define so-called composition anomalies

Towards a Taxonomy of Aspect-Oriented Programming.

As programs continue to increase in size, it has become increasingly difficult to separate concerns into well localized modules, which leads to code tangling- crosscutting code spread throughout several modules. Thus, Aspect-Oriented Programming (AOP) offers a solution to creating modules with little or no crosscutting concerns. AOP presents the notion of aspects, and demonstrates how crosscutting concerns can be taken out of modules and placed into a centralized location. In this paper, a taxonomy of aspect-oriented programming, as well as a basic overview and introduction of AOP, will be presented in order to assist future researchers in getting started on additional research on the topic. To form the taxonomy, over four-hundred research articles were organized into fifteen different primary categories coupled with sub-categories, which shows where some of the past research has been focused. In addition, trends of the research were evaluated and paths for future exploration are suggested

Weaving Aspects in a Persistent Environment

This paper discusses two mechanisms for weaving aspects in persistent environments founded on object-oriented databases. The first mechanism is based on exploiting existing aspect languages and their associated weavers while the second mechanism is based on building weaving functionality into the database management system (DBMS). The first mechanism has been used to integrate AspectJ and its associated weaver with the Jasmine ODBMS. The second approach has been used to implement a weaver within the SADES object database evolution system

Experience with statically-generated proxies for facilitating Java runtime specialisation

Issues pertaining to mechanisms which can be used to change the behaviour of Java classes at runtime are discussed. The proxy mechanism is compared to, and contrasted with other standard approaches to this problem. Some of the problems the proxy mechanism is subject to are expanded upon. The question of whether statically-developed proxies are a viable alternative to bytecode rewriting was investigated by means of the JavaCloak system, which uses statically-generated proxies to alter the runtime behaviour of externally-developed code. The issues addressed include ensuring the type safety, dealing with the self problem, object encapsulation, and issues of object identity and equality. Some performance figures are provided which demonstrate the load the JavaCloak proxy mechanism places on the system

Project-Team RMoD 2013 Activity Report

Activity Report 2013 Project-Team RMOD Analyses and Languages Constructs for Object-Oriented Application Evolutio

Run-time Variability with First-class Contexts

Software must be regularly updated to keep up with changing requirements. Unfortunately, to install an update, the system must usually be restarted, which is inconvenient and costly. In this dissertation, we aim at overcoming the need for restart by enabling run-time changes at the programming language level. We argue that the best way to achieve this goal is to improve the support for encapsulation, information hiding and late binding by contextualizing behavior. In our approach, behavioral variations are encapsulated into context objects that alter the behavior of other objects locally. We present three contextual language features that demonstrate our approach. First, we present a feature to evolve software by scoping variations to threads. This way, arbitrary objects can be substituted over time without compromising safety. Second, we present a variant of dynamic proxies that operate by delegation instead of forwarding. The proxies can be used as building blocks to implement contextualization mechanisms from within the language. Third, we contextualize the behavior of objects to intercept exchanges of references between objects. This approach scales information hiding from objects to aggregates. The three language features are supported by formalizations and case studies, showing their soundness and practicality. With these three complementary language features, developers can easily design applications that can accommodate run-time changes

Toward a modularization of Pharo: Analysis of the design space for a new module system.

International audienceSmalltalk is a fully reflexive object-oriented programming language created in the early 70's. Over the years, it has been influencing many other programming languages and evolved into many variants. However, it has no notion of visibility, providing a single namespace. Because all classes and global variables were visible from every point of the system, numerous dependencies appeared and it turned into a monolithic system. As a descendant of Smalltalk, Pharo should provide a programming construct to make the platform more modular. Designing such a construct is a challenge because of two migration constraints: it must support circular dependencies and local class extensions. In this context, this article present an analysis of the design space for a module system through three design axis: encapsulation, dependency resolution, and module combination

A Conceptual Framework for Adapation

This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

Fault Tolerance as an aspect using JReplica

Reliability and availability are very important trends in the development process of distributed systems. In order to improve these features, object replication mechanisms have been introduced. Programming replication policies for a given application is not an easy task, and this is the reason why transparency for the programmer has been one of the most important properties offered by all replication models. However, this transparency for the programmer is not always desirable. In this paper we present a replication model, JReplica, based on Aspect Oriented Programming (AOP). JReplica allows the separated specification of the replication code from the functional behaviour of objects, providing not only a high degree of transparency, as done by previous models, but also the possibility for programmers to introduce new behaviour to specify different fault tolerance requirements. Moreover, the replication aspect has been introduced at design time, and in this way, UML has been extended in order to consider replication issues separately when designing fault tolerance systems.Comisión Interministerial de Ciencia y Tecnología TIC99-1083-C02-0