Treffer: 1 1 Are Patches Cutting it? Structuring Distribution within a JVM using Aspects

Distribution is hard to modularize. Consequently, its addition to a software system can jeopardize fundamental software engineering principles such as maintainability, understandability and evolva-bility. The distributed Java Virtual Machine (dJVM) is a cluster aware implementation of a JVM, designed specifically for evaluating distrib-uted runtime support algorithms [1]. A prototype implementation of the dJVM relies on a patch file applied to IBM’s Jikes Research Virtual Machine (RVM) [6], introducing distribution code into roughly 55 % of the original 1500 files. An initial experiment using AspectJ [7] to in-troduce this same distribution code as aspects demonstrates the benefits of a modularized ap-proach versus the original patched approach. Pre-liminary results show that aspects can improve the overall quality of the implementation from a software engineering perspective. Specifically, the aspects improved the internal structure of dis-tribution code and made its external interaction explicit. Additionally, consolidating and structur-ing previously scattered code reduced its size by a factor of three.