Active inference of EFSMs without reset

Extended finite state machines (EFSMs) model stateful systems with internal data variables, and have many software engineering applications, including system analysis and test case generation. Where such models are not available, it is desirable to reverse engineer them by observing system behaviour, but existing approaches are either limited to classical FSM models with no internal data state, or implicitly require the ability to reset the system under inference, which may not always be possible. In this paper, we present an extension to the hW-inference algorithm that can infer EFSM models, complete with guards and internal data update functions, from systems without a reliable reset, although there are currently some restrictions on the type of system and model

Learning EFSM models with registers in guards.

This paper presents an active inference method for Extended Finite State Machines, where inputs and outputs are parametrized, and transitions can be conditioned by guards involving input parameters and internal variables called registers. The method applies to (software) systems that cannot be reset, so it learns an EFSM model of the system on a single trace

Automated Transition Coverage in Behavioural Conformance Testing

International audienceIn the setting of ioco-based conformance testing with test purposes, we propose an automatic approach to generate a test plan (set of test purposes) with its associated test suite (set of test cases) covering all transitions of the IOLTS model of the system. The approach can also be applied to improve an existing test plan, by both, completing the coverage and eliminating redundancies. Implementing our approach on top of the CADP toolbox, we report on experiments with several examples of concurrent systems and discuss possible variants and heuristics to fine-tune the overall performance of the approach, as well as the quality of the computed test plan

Protocol-Inspired Hardware Testing

The relevance of protocol conformance testing techniques to hardware testing is discussed. It is shown that the ioconf (input-output conformance) approach used in protocol testing can be applied to generate tests for a synchronous hardware design using its formal specification. The generated tests are automatically applied to a circuit by a VHDL testbench, thus giving confidence that the hardware design meets its high-level formal specification. Case studies illustrate how the ideas can be applied to standard hardware verification benchmarks such as the Single Pulser and Black-Jack Dealer

Inferring FSM Models of Systems Without Reset

International audienc

Conservação das espécies do género Puffinus nos Açores

Historical data on the Azores breeding Puffinus species is reviewed through the analysis of historical chronicles from the 16th and 17th century. The seabird populations of the Azores suffered dramatic declines following the colonisation of the islands mainly due to habitat destruction, the introduction of predators and direct human exploitation. Inventories of all the seabirds populations became available only recently and the first comprehensive surveys of shearwaters and petrels of the Azores were conducted from 1996 to 1998. The surveys detected 12 new locations of Puffinus puffinus on Flores and Corvo islands, with a total estimated population of 115-235 pairs. A total of 68 new locations of Puffinus assimilis were detected on all islands, except Terceira, with a total estimate of 840-1530 pairs. A revision of the Azores Special Protection Areas Network was proposed on the basis of that information, enlarging the present area by approximately 80%. Management plans for seven Special Protection Areas were produced. The present status of Manx Shearwater Puffinus puffinus and Little Shearwater Puffinus assimilis populations is outlined and conservation-orientated research priorities are discussed.Dados históricos das espécies de Procellariiformes nidificantes nos Açores foram revistos através da análise de crónicas históricas dos séculos XVI e XVII. As populações de aves marinhas dos Açores sofreram declínios dramáticos no seguimento da colonização das ilhas essencialmente devido à destruição do habitat, à introdução de predadores e à exploração directa pelo homem. Inventários de todas as populações de aves marinhas tornaram-se disponíveis apenas recentemente e o primeiro censo exaustivo das espécies de pardelas e painhos que nidificam no arquipélago dos Açores decorreu entre 1996 e 1998. Os censos registaram 12 novas colónias de Pintainho Puffinus assimilis nas ilhas das Flores e Corvo, com uma população total estimada em 115-235 casais. Paralelamente foram registadas 68 novas colónias de Fura-bucho do Atlântico Puffinus puffinus em todas as ilhas, com excepção da Terceira, com uma população total estimada em 840-1530 casais. Com base nessa informação foi proposta uma revisão da rede de Zonas de Protecção Especial dos Açores, que aumenta em cerca de 80% a área designada. Foram produzidos planos de gestão para sete Zonas de Protecção Especial. O actual estatuto de conservação do Fura-bucho do Atlântico Puffinus assimilis e do Pintainho Puffinus puffinus é apresentado e prioridades de investigação aplicadas à conservação são discutidas

Active inference of extended finite state models of software systems

Extended finite state machines (EFSMs) model stateful systems with internal data variables, and have many software engineering applications. It is possible to infer such models by observing system behaviour. Still, existing approaches are either limited to classical FSM models with no internal data state, or implicitly require the ability to reset the system under inference, which may not always be possible. We present an extension to the hW-inference algorithm that can infer EFSM models, with input and output parameters as well as guards and internal registers and their data update functions, from systems without a reliable reset. For the problem to be tractable, we require some assumptions on the observability and determinism of the system. The main restriction is that the control flow of the system must be finite, although data types could be infinite

Techniques for Abstracting SDL Specifications

Abstracting the behaviour of a specification is a key technique for dealing with the complexity of such tasks as reachability analysis and test generation. We adapted classical data-flow analysis techniques to abstract variables in SDL processes and addressed the problem of finding conservative state abstractions. Prototype tools have been developed to implement those techniques and applied to simple applications from the field of telecommunications