Towards Dynamic Evolution of Runtime Variability Based on Computational Reflection

Abstract

Given the frequently changing nature of the user requirements and environments in software systems, runtime variability in today’s software systems should be capable of evolving during execution. Computational reflection is required to facilitate accessing and customizing runtime variability during this evolution process. However, realizing this computational reflection includes various practical complexities since the runtime variability is typically neither explicitly represented in software systems nor changeable during runtime. To address this problem, this paper proposes a software architecture to support computational reflection of runtime variability, along with a corresponding causal-connection mechanism to realize the introspection and intercession (i.e. representing runtime variability model, and adding, removing, replacing variability elements and their relations). The proposed software architecture consists of a meta level that represents runtime variability model using objectification, and a base level that organizes and manipulates the implementation of variability elements via reconfiguration. The causal-connection mechanism integrated in our proposed model is designed to synchronize the representation and the implementation. Further, we developed a Reflective Runtime Variability Framework (R2VF) to support the development and operation of the systems with the reflection of runtime variability. The effectiveness and applicability of our approach has been evaluated by applying R2VF to Personal Data Resource Network.