Self-adaptation of event-driven component-oriented middleware using aspects of assembly

Pervasive devices are becoming popular and smaller. Those mobile systems should be able to adapt to changing requirements and execution environments. But it requires the ability to reconfigure deployed codes, which is considerably simplified if applications are component-oriented rather than monolithic blocks of codes. So, we propose a middleware called WComp which federates an event-driven component-oriented approach to compose distributed services for devices. This approach is coupled with adaptation mechanisms dealing with separation of concerns. In such mechanisms, aspects (called Aspects of Assembly) are selected either by the user or by a self-adaptive process and composed by a weaver with logical merging of high-level specifications. The result of the weaver is then projected in terms of pure elementary modifications of components assemblies with respect to blackbox properties of COTS components. Our approach is validated by analyzing the results of different experiments drawn from sets of application configurations randomly generated and by showing its advantages while evaluating the additional costs on the reaction time to context changing.