Lutin: A Language for Specifying and Executing Reactive Scenarios

Abstract

This paper presents the language Lutin and its operational semantics. This language specifically targets the domain of reactive systems, where an execution is a (virtually) infinite sequence of input/output reactions. More precisely, it is dedicated to the description and the execution of constrained random scenarios. Its first use is for test sequence specification and generation. It can also be useful for early simulation of huge systems, where Lutin programs can be used to describe and simulate modules that are not yet fully developed. Basic statements are input/output relations expressing constraints on a single reaction. Those constraints are then combined to describe non deterministic sequences of reactions. The language constructs are inspired by regular expressions and process algebra (sequence, choice, loop, concurrency). Moreover, the set of statements can be enriched with user-defined operators. A notion of stochastic directives is also provided in order to finely influence the selection of a particular class of scenarios.

Polychronous automata and their use for formal validation of AADL models

“…A first attempt was made a few years ago to define polychronous mode automata [23], but compared to our current proposal, it did not allow to manipulate automata as specific objects that can be used, for instance, to specify dynamic properties of events. In its spirit, our approach, which is based on constraint specification relating occurrence of events, is relatively close to that taken for Lutin [24], but with a different purpose. In Lutin, statements describe sequences of non deterministic atomic reactions expressing constraints on input/output values.…”

Generating test case chains for reactive systems

“…There are many approaches to reactive system testing: While random testing [22] is still commonly used, approaches have been developed that combine random testing with symbolic and concrete execution (Dart [23], Cute [24], Klee [20]) to guide exhaustive path enumeration. Scenario-based testing employ test specifications to guide test case generation towards a particular functionality (e.g., Lutess [25], Lurette [26], Lutin [27]). These methods restrict the input space using static analysis and apply (non-uniform) random test case generation.…”

Chaining Test Cases for Reactive System Testing

“…There are many approaches to reactive system testing: While random testing [21] is still commonly used, approaches have been developed that combine random testing with symbolic and concrete execution (Dart [22], Cute [23], Klee [19]) to guide exhaustive path enumeration. Scenario-based testing employ test specifications to guide test case generation towards a particular functionality (e.g., Lutess [24], Lurette [25], Lutin [26]). These methods restrict the input space using static analysis and apply (non-uniform) random test case generation.…”