Complementary Garbage Collector

This paper describes the design and the evaluation of Complementary Garbage Collector that is a fundamental algorithm for the parallel and incremental garbage collector. Our algorithm is a combination of two types of fundamental algorithms, incremental update and snapshot-at-beginning, which are complementary to each other. The algorithm has the advantages of both types: great e ciency of the garbage collection and ease of consistent implementation. This algorithm can be substituted for the snapshot-at-beginning algorithm widely used in several types of parallel and incremental garbage collectors. Measurements of this algorithm in a parallel and an incremental mark-sweep GC indicate that it improves the e ciency of the collection making it equivalent to the stop garbage collector. Consequently, the execution time of the list processing is shortened and the range of non-stop processing is extended.