Trading obliviousness for modularity with cooperative aspect-oriented programming

• Authors: Kevin Hoffman;Patrick Eugster
• Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) - In memoriam, fault detection and localization, formal methods, modeling and design
• Year: 2013

The potential of aspect-oriented programming to adequately capture crosscutting concerns has yet to be fully realized. For example, authors have detailed significant challenges in creating reusable aspect component libraries. One proposed solution is to introduce Explicit Join Points (EJPs) to increase modularity by reducing obliviousness, enabling a Cooperative Aspect-Oriented Programming (Co-AOP) methodology where base code and aspects synergistically collaborate. This article explores the trade-offs between obliviousness and modularity. We briefly introduce EJPs and Co-AOP, and hypothesize how to balance obliviousness and modularity using Co-AOP. We build upon a prior empirical study to refactor three real-life Java applications to implement the exception handling concern using three distinct strategies: (1) using fully oblivious aspects in AspectJ, (2) using EJPs in a fully explicit fashion, and (3) using EJPs while following the Co-AOP methodology. We study other crosscutting concerns by refactoring a fourth application, JHotDraw. The differences in terms of common code metrics are analyzed, and the impact on modularity is assessed using design structure matrices. Results indicate that the Co-AOP methodology can in many cases significantly improve code quality attributes versus fully oblivious or fully explicit approaches. We conclude with guiding principles on the proper use of EJPs within the Co-AOP methodology.