The Design and Implementation of Guaraná

Several reflective architectures have attempted to improve meta-object reuse by supporting composition of meta-objects, but have done so using limited mechanisms such as Chains of Responsibility. We advocate the adoption of the Composite pattern to define meta-configurations. In the meta-object protocol (MOP) of Guaraná, a composer meta-object can control reconfiguration of its component meta-objects and their interactions with base-level objects, resolving conflicts that may arise and establishing meta-level security policies. Guaraná is currently implemented as an extension of Kaffe OpenVM ^TM, a free implementation of the Java¹ Virtual Machine. Nevertheless, most design decisions presented in this paper can be transported to other programming languages and MOPs, improving their flexibility, reconfigurability, security and meta-level code reuse. We present performance figures that show that it is possible to introduce run-time reflection support in a language like Java without much impact on execution speed.