Relaxed Memory Models: An Operational Approach
📜 Abstract
We give semantics to relaxed memory models using a small, simple operational model. We define several relaxed memory models by parameterizing this model. We illustrate how our method enables us to prove correctness of concurrent algorithms with respect to a weak memory model and to reason about the subtle behaviors that can arise. We show that our model is expressive by relating it to various hardware and programming language models, and coherent in that the programming idioms it supports are those in practice.
✨ Summary
This paper presents a unified operational approach to understanding relaxed memory models, which are critical for designing and verifying concurrent systems, especially those involving weak memory behaviors often found in modern hardware and programming languages. The authors provide a small operational model that can be used to define various memory models through parameterization. This approach supports proving the correctness of concurrent algorithms and allows reasoning about complex memory behaviors. The paper demonstrates the model’s expressiveness by relating it to existing hardware and language models, showing coherence with practical programming idioms.
The influence of this paper is evident in its citations in works such as ‘Weak Memory Models in Practice’ by Alglave et al., published in the ACM Queue in 2014 (https://queue.acm.org/detail.cfm?id=2699022) and ‘Programming and reasoning with weak memory models’ by Owens et al., from SIGPLAN Notices in 2012 (https://dl.acm.org/doi/10.1145/2365426.2365445). These references discuss practical implementations and further formalizations of weak memory models, substantiating the operational approach advocated in the 2009 paper. This operational framework is a significant contribution to the formal methods and concurrency control domains, influencing both academic research and industry practices in reasoning about memory ordering and execution consistency.