Real-time and Probabilistic Temporal Logics: An Overview

Over the last two decades, there has been an extensive study on logical formalisms for specifying and verifying real-time systems. Temporal logics have been an important research subject within this direction. Although numerous logics have been introduced for the formal specification of real-time and complex systems, an up to date comprehensive analysis of these logics does not exist in the literature. In this paper we analyse real-time and probabilistic temporal logics which have been widely used in this field. We extrapolate the notions of decidability, axiomatizability, expressiveness, model checking, etc. for each logic analysed. We also provide a comparison of features of the temporal logics discussed

Specifying real-time systems with interval logic

Pure temporal logic makes no reference to time. An interval temporal logic and an extension to that logic which includes real time constraints are described. The application of this logic by giving a specification for the well-known lift (elevator) example is demonstrated. It is shown how interval logic can be extended to include a notion of process. How the specification language and verification environment of EHDM could be enhanced to support this logic is described. A specification of the alternating bit protocol in this extended version of the specification language of EHDM is given

Bevezetés a programozásba

A mű digitális megjelenítése az Oktatási Minisztérium támogatásával, a Felsőoktatási Tankönyv- és Szakkönyv-támogatási Pályázat keretében történt

Desarrollo de software para sistemas de tiempo real basado en UML. Un enfoque formal basado en metamodelado

El presente trabajo propone una metodología de desarrollo de sistemas de tiempo real que hace un énfasis especial en la consideración de los requisitos no funcionales característicos de este tipo de sistema como los requisitos temporales, la concurrencia, la asignación de prioridades o la interacción con dispositivos físicos. La metodología toma elementos de otras ya existentes, como SOMT y OCTOPUS y propone mecanismos propios para solventar parcialmente problemas como el paso del modelo de objetos al modelo de proceso y la asignación de prioridades. La metodología se divide en cuatro fases divididas en dos áreas distintas, la de los aspectos funcionales y los no funcionales. Durante toda la metodología se usa orientación objetivo y UML. Para aprovechar las ventajas de los métodos formales, como simulación, validación y generación de códigos se propone una semántica formal para parte de los aspectos dinámicos de UML, concretamente las acciones y las máquinas de estados. La semántica propuesta se basa en metamodelado y en el lenguaje MML. En ellas se distingue entre los la sintaxis abstracta y el dominio semántico. Los elementos válidos de ambos conjuntos se definen mediante diagramas de clases, de los que han de ser instancias válidas, y restricciones expresadas en el lenguaje funcional OCL. Los elementos de ambos conjuntos están relacionados entre si a través de la semántica, que implica una relación de uno (en la sintaxis abstracta, el extremo "OF") a muchos (en el dominio semántico, el extremo "instances").Con este esquema, se ha definido una semántica para acciones y ejecuciones, con una jerarquía de clases para los diferentes tipos de acciones y ejecuciones, En el primer nivel de esa jerarquía se distinguen acciones primitivas y compuestas. Una acción se define como un procedimiento computacional que modifica el estado de un elemento del sistema

Formal Specification and Runtime Verification of Parallel Systems using Interval Temporal Logic (ITL)

Runtime Verification (RV) is the discipline that allows monitoring systems at runtime in order to check the satisfaction or violation of a given correctness property. Parallel systems are more complicated than sequential systems. Therefore, systems that run in parallel need a parallel runtime verification framework to monitor their behaviour and guarantee correctness properties. Parallel systems have correctness properties different from correctness properties of sequential systems. For instance, as a correctness property of parallel systems, absence of deadlock has to be guaranteed and mutual exclusion mechanism has to be applied in case a resource is shared between more than one system and the parallelism form is true concurrency. Therefore, sequential runtime verification framework can not handle systems that run in parallel due to the singularity issue of this kind of framework as they are built to handle a single system at a time, whereas for parallel systems a framework has to handle many systems at a time. AnaTempura is a runtime verification tool which can handle single systems at a time. To solve this problem, I evolved AnaTempura to be able to handle parallel systems. In this thesis, I propose a Parallel Runtime Verification Framework (PRVF) that can handle systems which use architectures of parallelism in their design such as multi-core processor architecture. The proposed model can check system behaviour at runtime in order to either guarantee satisfaction or detect violations of correctness properties. My technique is based on Interval Temporal Logic (ITL) and its executable subset Tempura to verify properties at runtime using the AnaTempura tool. I use, as a demonstration, the case study of private L2 cache memory of multi-core processor architecture. My objectives are to i) design MSI protocol compliant with cache memory coherence and ii) fulfil main memory consistency model at runtime. I achieve this via a formal Tempura specification of the cache controller which is then verified at runtime against my objectives for memory consistency and cache coherence using AnaTempura. The presented specifications allow to extend it allow to extend it to not only capture correctness but also monitor the performance of a cache memory controller. The case study is then evaluated via integrating AnaTempura with MATLAB in order to check correctness properties such as memory consistency and cache coherence