Parameterized Memory Models and Concurrent Separation Logic

Abstract

In this paper, we formalize relaxed memory models by giving a parameterized operational semantics to a concurrent programming language. Behaviors of a program under a relaxed memory model are defined as behaviors of a set of related programs under the sequentially consistent model. This semantics is parameterized in the sense that different memory models can be obtained by using different relations between programs. We present one particular relation that is weaker than many memory models and accounts for the majority of sequential optimizations. We then show that the derived semantics has the DRF-guarantee, using a notion of race-freedom captured by an operational grainless semantics. Our grainless semantics bridges concurrent separation logic (CSL) and relaxed memory models naturally, which allows us to finally prove the folklore theorem that CSL is sound with relaxed memory models.