An Observational Approach to Defining Linearizability on Weak Memory Models

Abstract

In this paper we present a framework for defining linearizability on weak memory models. The purpose of the framework is to be able to define the correctness of concurrent algorithms in a uniform way across a variety of memory models. To do so linearizability is defined within the framework in terms of memory order as opposed to program order. Such a generalisation of the original definition of linearizability enables it to be applied to non-sequentially consistent architectures. It also allows the definition to be given in terms of observable effects rather than being dependent on an understanding of the weak memory model architecture. We illustrate the framework on the TSO (Total Store Order) weak memory model, and show that it respects existing definitions of linearizability on TSO.