Synchronised Shared Memory and Model Checking: A Proof of Concept

Abstract

Synchronous Programming (SP) is a model of computation that supports concurrent thread composition and provides deterministic observable behaviour. A recent theory has extended SP with more and higher level clock-synchronised shared memory data types. The present paper implements this clock-synchronised shared memory (CSM) theory and applies it from a model checking perspective. In the CSM theory, types are equipped with a synchronisation policy prescribing how concurrent calls to its methods must be organised. In a policy-constructive system all access methods of all objects can be scheduled in a policy-conformant manner without deadlocking. A policy-constructive system exhibits deterministic behaviour. In our modelling, synchronous policies get codified as never-claims in PROMELA allowing the Spin model checker to be used for searching an execution (interleaving) that satisfies the synchronous product of the never-claims. This interleaving, if exists, provides a policy-conformant schedule for the system model. This schedule verifies that the system is policy-constructive meaning that any policy-conformant schedule results in the same deterministic, observable input-output behaviour for the system.