Scoping strategies for distributed aspects

Dynamic deployment of aspects brings greater flexibility and reuse potential, but requires a proper means for scoping aspects. Scoping issues are particularly crucial in a distributed context: adequate treatment of distributed scoping is necessary to enable the propagation of aspect instances across host boundaries and to avoid inconsistencies due to unintentional spreading of data and computations in a distributed system. We motivate the need for expressive scoping of dynamically-deployed distributed aspects by an analysis of the deficiencies of current approaches for distributed aspects. Extending recent work on scoping strategies for non-distributed aspects, we then introduce a set of high-level strategies for specifying locality of aspect propagation and activation, and illustrate the corresponding gain in expressiveness. We present the operational semantics of our proposal using Scheme interpreters, first introducing a model of distributed aspects that covers the range of current proposals, and then extending it with dynamic aspect deployment and scoping strategies. This work shows that, given some extensions to their original execution model, scoping strategies are directly applicable to the expressive scoping of distributed aspects.