Automatic Verification of Erlang-Style Concurrency

Abstract

This paper presents an approach to verify safety properties of Erlang-style, higher-order concurrent programs automatically. Inspired by Core Erlang, we introduce λ Actor, a prototypical functional language with pattern-matching algebraic data types, augmented with process creation and asynchronous message-passing primitives. We formalise an abstract model of λ Actor programs called Actor Communicating System (ACS) which has a natural interpretation as a vector addition system, for which some verification problems are decidable. We give a parametric abstract interpretation framework for λ Actor and use it to build a polytime computable, flow-based, abstract semantics of λ Actor programs, which we then use to bootstrap the ACS construction, thus deriving a more accurate abstract model of the input program.