A case study on the lightweight verification of a multi-threaded task server

Abstract

We present a case study of verifying the design of a commercial multi-threaded task server (MTTS), developed by the Novabase company, used for massively parallelising computational tasks. In a first stage, we employed the Plural tool, which is designed to perform lightweight verification of Java programs using a Data Flow Analysis (DFA) framework, to specify and verify the MTTS. We wrote the Plural specification for the MTTS based on the code developed by Novabase, its informal documentation, and our discussions with Novabase engineers, who validated our understanding of the MTTS application. The Plural specification language is based on typestates and access permissions. In a second stage, we developed the Pulse tool that enhances the analysis performed by Plural, and used the tool on the MTTS specifications. Pulse translates Plural specifications into an abstract state-machine model that captures the semantics of all the possible concurrent programs implementing the given specifications, and uses the evmdd-smc symbolic model-checker to verify the machine model. The experimental results on the MTTS specification show that the exhaustive model-checking approach scales reasonably well and is efficient at finding errors in specifications that were not previously detected with the Data Flow Analysis (DFA) capabilities of Plural.

Automatic Inference of Symbolic Permissions for Sequential Java Programs

“…Pulse [41,17] is a permission-based model-checking tool implemented as Java Eclipse plug-in. It takes a Plural annotated program i.e., a Java program annotated with access permission contracts and typestate information, as input.…”

“…The dataset for the evaluation consists of benchmark programs and realistic Java applications widely used in the research community [16,2,17,1,43,23] to evaluate the permission-based program verification approaches and to gain performance improvements in automatic parallelization approaches. A brief characteristic of the benchmark programs is given below.…”

“…Furthermore, inference of fractional and quantified permissions has been investigated by Peter Müller and his colleagues [22,20] to verify classbased concurrent programs based on the abstract interpretations [18]. Similarly, permission-based specifications have been used in many formal approaches to address issues related to safe concurrency, security and verification of functional and domain specific properties [35,31,15,47,29,41,17,30,26,37,28].…”

Engaging Millennials into Learning Formal Methods

“…-Specification and verification of a multi-threaded task server [10,27]. This modeling example demonstrates how a real-life server can be specified and verified using access permissions, capabilities that can be associated with references in a program [7].…”

Improving the Reliability of Mobility Applications

“…In spite of some misconception about their cost-effectiveness (results do not outweigh the investment in time and money), Formal Methods (FMs) have proven their potential to dramatically increase the quality of software systems as conceived and developed by the IT industry as shown in various case studies presented by the author [7,9,8,11]. This paper discusses about the use of heavyweight FMs techniques to check the design of Android applications.…”