Design Patterns in Garbage Collection

This thesis presents an examination of design patterns within the context of garbage collection. Initially, I review garbage collection and design patterns. Four garbage collectors are then examined and the design patterns found described. Both domain speci c and generic patterns are described. The domain speci c patterns are TriColour and RootSet, the generic patterns are Adaptor, Facade, Iterator and Proxy. It is hoped that by, applying these patterns, systems designers have access to a less e cient, but simpler and more exible way of implementing and reusing garbage collectors in programming languages. The requirements analysis for a garbage collector for a real-time object-oriented microkernel is then performed, and a design prepared using the design patterns found in the other garbage collectors. The garbage collector is then implemented in Java using appropriate data structures. Due to timing di culties in the runtime environment, timing was ruled out as a method of performance analysis. Algorithmic analysis is performed to evaluate the worst-case performance of the collector, which is found to be satisfactory in all but one method of the RootSet implementation. An approach to remedying this is suggested. i