Time in State Machines

Issue title: This is a SPECIAL ISSUE ON ASM'05

Article type: Research Article

Authors: Graf, Susanne | Prinz, Andreas

Affiliations: Verimag, Grenoble, France. E-mail: Susanne.Graf@imag.fr | Agder University College, Grimstad, Norway. E-mail: Andreas.Prinz@hia.no

Abstract: State machines are a very general means to express computations in an implementationindependent way. There are ways to extend the abstract state machine (ASM) framework with distribution aspects, but there is no unifying framework for handling time so far. We propose event structures extended with time as a natural framework for representing state machines and their true concurrency model at a semantic level and for discussing associated time models. Constraints on these timed event structures and their traces (runs) are then used for characterising different frameworks for timed computations. This characterisation of timed frameworks is independent of ASM and allows to compare time models of different modelling formalisms. Finally, we propose some specific extensions of ASM for the expressions of time constraints in accordance with the event-based semantic framework and show the applicability of the obtained framework on an example with a standard time model and a set of consistency properties for timed computations.

Keywords: Abstract State Machines, Time Model, Event Structure, Partial Order Semantics

Journal: Fundamenta Informaticae, vol. 77, no. 1-2, pp. 143-174, 2007