Parallel Copying Garbage Collection Using Delayed Allocation

We present a new approach to parallel copying garbage collection on symmetric multiprocessor (SMP) machines appropriate for Java and other object-oriented languages. Parallel, in this setting, means that the collector runs in several parallel threads. Our collector is based on a new idea called delayed allocation, which completely eliminates the fragmentation problem of previous parallel copying collectors while still keeping low synchronization, high ee-ciency, and simplicity of collection. In addition to this main idea, we also discuss several other ideas such as improving termination detection , balancing the distribution of work, and dealing with contention during work distribution. Finally, we explain how the ideas presented here can be extended to deal with generational copying garbage collection and replication-based garbage collection. We believe that our ideas can be generalized in a similar manner for other copying-based garbage collection algorithms.