Design-level Detection of Interactions in Aspect-UML models using Alloy

Aspect-oriented (AO) programming has emerged as a promising paradigm to improve modularity by providing mechanisms to capture and execute crosscutting concerns in software applications. Among others, AO allows developers to incrementally modify the behavior of a base program, by introducing aspects which implement crosscutting concerns having effects at various points throughout a program. Hence, despite the clean separation of concerns in aspect-oriented systems, it remains difficult to predict the effect of a given aspect on this base program. Once woven, does an aspect still achieve what it was intended for? Does it violate base program properties that should be preserved? Does it interfere with the properties of other aspects? These questions address the well known aspect interaction problem, encountered within the AO paradigm. This article tackles the interaction problem in the context of formal AO system model analysis and verification. To be more precise, this work considers AO models written in Aspect-UML (our UML profile). Aspect-UML does not depend on any AO language specific features nor is it associated with any specific development process. This paper first explains how Aspect-UML models can be translated into Alloy, a simple structural first-order logic modeling language which can be formally analyzed. Given this translation, it then demonstrates how Alloy's model analyzer can be used to verify aspect interactions of an Aspect-UML model.