Building fully customisable middleware using an aspect-oriented approach

Applications accrue features in response to the needs of all users, yet the associated code bloating and performance loss often render an application unsuitable for some other users whose needs differ. As a result, developers are often faced with either reinventing pieces of an application, custom tailored to their needs, or they are faced with the daunting task of refactoring an existing application to obtain an appropriate subset of that application´s functionality. In either case, subsequent development, maintenance and testing of the application becomes more complex, due to the effects of future revisions on all of the derived subsets. In the paper, the authors report their experience of using aspect-oriented programming in building a CORBA event channel using a compositional approach to building software. Instead of refactoring a large, feature-rich application, a feature can be added by including that feature´s aspect in the set provided to an aspect compiler. In addition to generic feature management, a study of the effect of the transport layer (CORBA) on overall performance of the event channel is conducted. Finally, experimental results on how such an approach gives fine control over footprint and throughput performance is presented.