Oracle Semantics for Concurrent Separation Logic

Abstract

Abstract. We define (with machine-checked proofs in Coq) a modular operational semantics for Concurrent C minor-a language with shared memory, spawnable threads, and first-class locks. By modular we mean that one can reason about sequential control and data-flow knowing almost nothing about concurrency, and one can reason about concurrency knowing almost nothing about sequential control and data-flow constructs. We present a Concurrent Separation Logic with first-class locks and threads, and prove its soundness with respect to the operational semantics. Using our modularity principle, we proved the sequential C.S.L. rules (those inherited from sequential Separation Logic) simply by adapting Appel & Blazy's machine-checked soundness proofs. Our Concurrent C minor operational semantics is designed to connect to Leroy's optimizing (sequential) C minor compiler; we propose our modular semantics as a way to adapt Leroy's compiler-correctness proofs to the concurrent setting. Thus we will obtain end-to-end proofs: the properties you prove in Concurrent Separation Logic will be true of the program that actually executes on the machine.

VeriCool: An Automatic Verifier for a Concurrent Object-Oriented Language

“…Various extensions of separation logic to concurrent programs have been proposed [9,10,16,8,11]. In particular, Gotsman et al [10] propose a variant of concurrent separation logic that supports an unbounded number of dynamically allocated locks and threads, which is similar to our approach in many respects.…”

“…The programming model described above is similar to the techniques used in various extensions of separation logic [8,9,10,11]. We discuss them in Section 4.…”

Parameterized Memory Models and Concurrent Separation Logic

“…The proof should be similar to the proof for standard CSL. We believe other extensions of CSL, such as CSL with storable locks [17,18] and the combination of CSL with Rely-Guarantee reasoning [29,13], can also be proved sound with respect to the grainless semantics. Then their soundness in our relaxed semantics can be derived easily from Lemma 5.4.…”

“…For instance, the soundness of concurrent separation logic (CSL) [23] in sequentially consistent models has been proved in various ways [9,10,14,18], which all show directly or indirectly that CSL-verified programs are race-free. So it seems quite obvious that CSL is sound with any memory model that gives the DRF-guarantee, as Hobor et al [18] argued that it "permits only wellsynchronized programs to execute, so we can [.…”

“…So it seems quite obvious that CSL is sound with any memory model that gives the DRF-guarantee, as Hobor et al [18] argued that it "permits only wellsynchronized programs to execute, so we can [. .…”