Work

Zoo: A Framework for the Verification of Concurrent OCaml 5 Programs using Separation Logic

Year: 2026

Type: article

Abstract: The release of OCaml 5, which introduced parallelism in the OCaml runtime, drove the need for safe and efficient concurrent data structures. New libraries like Saturn address this need. This is an opportunity to apply and further state-of-the-art program verification techniques. We present Zoo, a framework for verifying fine-grained concurrent OCaml 5 algorithms. Following a pragmatic approach, we defined a limited but sufficient fragment of the language to faithfully express these algorithms: ZooLang. We formalized its semantics carefully via a deep embedding in the Rocq proof assistant, uncovering subtle aspects of physical equality. We provide a tool to translate source OCaml programs into ZooLang syntax embedded inside Rocq, where they can be specified and verified using the Iris concurrent separation logic. To illustrate the applicability of Zoo, we verified a subset of the standard library and a collection of fined-grained concurrent data structures from the Saturn and Eio libraries. In the process, we also extended OCaml to more efficiently express certain concurrent programs.

Source: Proceedings of the ACM on Programming Languages

DOI: 10.1145/3776701

Authors: Clément Allain, Gabriel Scherer

Institutions: Institut national de recherche en sciences et technologies du numérique, CAMBIUM: Langages de programmation : systèmes de types, concurrence, preuve de programme, Université Paris Cité, Institut de Recherche en Informatique Fondamentale

Language: English

Topic: Logic, programming, and type systems

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: diamond

OpenAlex ID: W4406121715

FWCI: 7.436

Cites:

Cited by: 2

Related to: 10