Gordon J. Pace

LARVA --- Safer Monitoring of Real-Time Java Programs (Tool Paper)

The use of runtime verification, as a lightweight approach to guarantee properties of systems, has been increasingly employed on real-life software. In this paper, we present the tool LARVA, for the runtime verification of properties of Java programs, including real-time properties. Properties can be expressed in a number of notations, including timed-automata enriched with stopwatches, Lustre, and a subset of the duration calculus. The tool has been successfully used on a number of case-studies, including an industrial system handling financial transactions. LARVA also performs analysis of real-time properties, to calculate, if possible, an upper-bound on the memory and temporal overheads induced by monitoring. Moreover, through property analysis, LARVA assesses the impact of slowing down the system through monitoring, on the satisfaction of the properties.

Dynamic Event-Based Runtime Monitoring of Real-Time and Contextual Properties

Given the intractability of exhaustively verifying software, the use of runtime-verification, to verify single execution paths at runtime, is becoming popular. Although the use of runtime verification is increasing in industrial settings, various challenges still are to be faced to enable it to spread further. We present dynamic communicating automata with timers and events to describe properties of systems, implemented in Larva, an event-based runtime verification tool for monitoring temporal and contextual properties of Java programs. The combination of timers with dynamic automata enables the straightforward expression of various properties, including replication of properties, as illustrated in the use of Larva for the runtime monitoring of a real life case study -- an online transaction system for credit card. The features of Larva are also benchmarked and compared to a number of other runtime verification tools, to assess their respective strengths in property expressivity and overheads induced through monitoring.

Automatic Conflict Detection on Contracts

Many software applications are based on collaborating, yet competing, agents or virtual organisations exchanging services. Contracts, expressing obligations, permissions and prohibitions of the different actors, can be used to protect the interests of the organisations engaged in such service exchange. However, the potentially dynamic composition of services with different contracts, and the combination of service contracts with local contracts can give rise to unexpected conflicts, exposing the need for automatic techniques for contract analysis. In this paper we look at automatic analysis techniques for contracts written in the contract language

CLAN: A Tool for Contract Analysis and Conflict Discovery

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Model checking contracts: a case study

. We present a trace semantics of

Recovery within long-running transactions

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SPeeDI - A Verification Tool for Polygonal Hybrid Systems

suitable for conflict analysis, and a decision procedure for detecting conflicts (together with its proof of soundness, completeness and termination). We also discuss its implementation and look into the applications of the contract analysis approach we present. These techniques are applied to a small case study of an airline check-in desk.

Safer asynchronous runtime monitoring using compensations

As Service-Oriented Architectures are more widely adopted, it becomes more important to adopt measures for ensuring that the services satisfy functional and non-functional requirements. One approach is the use of contracts based on deontic logics, expressing obligations, permissions and prohibitions of the different actors. A challenging aspect is that of service composition, in which the contracts composed together may result in conflicting situations, so there is a need to analyse contracts and ensure their soundness. In this paper, we present CLAN, a tool for automatic analysis of conflicting clauses of contracts written in the contract language

polyLARVA: runtime verification with configurable resource-aware monitoring boundaries

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Challenges in the Specification of Full Contracts

. We present a small case study of an airline check-in desk illustrating the use of the tool.