A Taxonomy of Race Conditions

abstract Parallel programs are frequently non-deterministic, meaning they can give diierent results when provided the same input. These diierent results arise because variations in the timing of the multiple threads cause the threads to access shared resources in diierent orders. The phenomena that cause the non-deterministic behavior have been (and continue to be) variously referred to as access anomalies, race conditions or just races. In a recent paper, Netzer and Miller made an important contribution to formalizing and standardizing adjectives that can be applied to \races." In this paper we continue this eeort by presenting a reened taxonomy for races in parallel programs. The terminology we suggest is not always consistent with that used previously and we describe why we believe our terminology is more descriptive.