A Unified Theory of Shared Memory Consistency

TL;DR

This paper introduces a unified framework for shared memory consistency models by defining four fundamental properties, enabling the derivation of all existing models within a single theoretical structure.

Contribution

The paper presents a set of four core consistency properties that unify and generalize all previously defined shared memory consistency models.

Findings

All existing consistency models can be derived from the four properties.

The four properties form a comprehensive foundation for shared memory consistency.

The unified theory simplifies understanding and comparing different consistency models.

Abstract

Memory consistency models have been developed to specify what values may be returned by a read given that, in a distributed system, memory operations may only be partially ordered. Before this work, consistency models were defined independently. Each model followed a set of rules which was separate from the rules of every other model. In our work we have defined a set of four consistency properties. Any subset of the four properties yields a set of rules which constitute a consistency model. Every consistency model previously described in the literature can be defined based on our four properties. Therefore, we present these properties as a unfied theory of shared memory consistency.