Garbage collection for strongly-typed languages using run-time type reconstruction

Abstract

Garbage collectors perform two functions: live-object detection and dead-object reclamation . In this paper, we present a new technique for live-object detection based on run-time type reconstruction for a strongly typed, polymorphic language. This scheme uses compile-time type information together with the run-time tree of activation frames to determine the exact type of every object participating in the computation. These reconstructed types are then used to identify and traverse the live heap objects during garbage collection. We describe an implementation of our scheme for the Id parallel programming language compiled for the *T multiprocessor architecture. We present simulation studies that compare the performance of type-reconstructing garbage collection with conservative garbage collection and compiler-directed storage reclamation.