Linear Parametric Model Checking of Timed Automata

We present an extension of the model checker Uppaal capable of synthesizing linear parameter constraints for the correctness ofparametric timed automata. The symbolic representation of the (parametric) state-space is shown to be correct. A second contribution of thispaper is the identification of a subclass of parametric timed automata(L/U automata), for which the emptiness problem is decidable, contraryto the full class where it is know to be undecidable. Also we present anumber of lemmas enabling the verification effort to be reduced for L/Uautomata in some cases. We illustrate our approach by deriving linearparameter constraints for a number of well-known case studies from theliterature (exhibiting a flaw in a published paper)

Mechanical Verification of the IEEE 1394a Root Contention Protocol using Uppaal2k

This paper reports a mechanical verification of the IEEE 1394 root contention protocol. This is an industrial leader election protocol, in which timing parameters play an essential role. In this case study, we used the Uppaal2k tool and stepwise verification to investigate the timing constraints on the parameters which are necessary and sufficient for correct protocol operation. A manual verification of this protocol using I/O automata has been published in [19]. We improve the communication model from that paper and by analyzing large numbers of protocol instances with Uppaal, we derived the required timing constraints

Time At Your Service: Schedulability Analysis of Real-Time and Distributed Services

The software today is distributed over several processing units. At a large scale this may span over the globe via the internet, or at the micro scale, a software may be distributed on several small processing units embedded in one device. Real-time distributed software and services need to be timely and respond to the requests in time. The Quality of Service of real time software depends on how it schedules its tasks to be executed. The state of the art in programming distributed software, like in Java, the scheduling is left to the underlying infrastructure and in particular the operating system, which is not anymore in the control of the applications. In this thesis, we introduce a software paradigm based on object orientation in which real-time concurrent objects are enabled to specify their own scheduling strategy. We developed high-level formal models for specifying distributed software based on this paradigm in which the quality of service requirements are specified as deadlines on performing and finishing tasks. At this level we developed techniques to verify that these requirements are satisfied. This research has opened the way to a new approach to modeling and analysis of a range of applications such as continuous planning in the context of logistics software in a dynamic environment as well as developing software for multi-core systems. Industrial companies (DEAL services) and research centers (the Uppsala Programming for Multicore Architectures Resrearch Center UPMARC) have already shown interest in the results of this thesis.LEI Universiteit LeidenFoundations of Software Technolog