Graph generation to statically represent CSP processes

The CSP language allows the specification and verification of complex concurrent systems. Many analyses for CSP exist that have been successfully applied in different industrial projects. However, the cost of the analyses performed is usually very high, and sometimes prohibitive, due to the complexity imposed by the non-deterministic execution order of processes and to the restrictions imposed on this order by synchronizations. In this work, we define a data structure that allows us to statically simplify a specification before the analyses. This simplification can drastically reduce the time needed by many CSP analyses. We also introduce an algorithm able to automatically generate this data structure from a CSP specification. The algorithm has been proved correct and its implementation for the CSP's animator ProB is publicly available. © 2011 Springer-Verlag.This work has been partially supported by the Spanish Ministerio de Ciencia e Innovación under grant TIN2008-06622-C03-02, by the Generalitat Valenciana under grant ACOMP/2010/042, and by the Universidad Politécnica de Valencia (Program PAID-06-08). Salvador Tamarit was partially supported by the Spanish MICINN under FPI grant BES-2009-015019.Llorens Agost, ML.; Oliver Villarroya, J.; Silva Galiana, JF.; Tamarit Muñoz, S. (2011). Graph generation to statically represent CSP processes. En Logic-Based Program Synthesis and Transformation. Springer Verlag (Germany). 6564:52-66. https://doi.org/10.1007/978-3-642-20551-4_4S52666564Brassel, B., Hanus, M., Huch, F., Vidal, G.: A Semantics for Tracing Declarative Multi-paradigm Programs. In: Moggi, E., Warren, D.S. (eds.) 6th ACM SIGPLAN Int’l Conf. on Principles and Practice of Declarative Programming (PPDP 2004), pp. 179–190. ACM, New York (2004)Butler, M., Leuschel, M.: Combining CSP and B for specification and property verification. In: Fitzgerald, J., Hayes, I.J., Tarlecki, A. (eds.) FM 2005. LNCS, vol. 3582, pp. 221–236. Springer, Heidelberg (2005)Hoare, C.A.R.: Communicating Sequential Processes. Prentice-Hall, Upper Saddle River (1985)Kavi, K.M., Sheldon, F.T., Shirazi, B., Hurson, A.R.: Reliability Analysis of CSP Specifications using Petri Nets and Markov Processes. In: 28th Annual Hawaii Int’l Conf. on System Sciences (HICSS 1995). Software Technology, vol. 2, pp. 516–524. IEEE Computer Society, Washington, DC, USA (1995)Ladkin, P., Simons, B.: Static Deadlock Analysis for CSP-Type Communications. In: Responsive Computer Systems (Ch. 5). Kluwer Academic Publishers, Dordrecht (1995)Leuschel, M., Butler, M.: ProB: an Automated Analysis Toolset for the B Method. Journal of Software Tools for Technology Transfer 10(2), 185–203 (2008)Leuschel, M., Llorens, M., Oliver, J., Silva, J., Tamarit, S.: Static Slicing of CSP Specifications. In: Hanus, M. (ed.) 18th Int’l Symp. on Logic-Based Program Synthesis and Transformation (LOPSTR 2008), pp. 141–150. Technical report, DSIC-II/09/08, Universidad Politécnica de Valencia (July 2008)Leuschel, M., Llorens, M., Oliver, J., Silva, J., Tamarit, S.: SOC: a Slicer for CSP Specifications. In: Puebla, G., Vidal, G. (eds.) 2009 ACM SIGPLAN Symposium on Partial Evaluation and Semantics-based Program Manipulation (PEPM 2009), pp. 165–168. ACM, New York (2009)Leuschel, M., Llorens, M., Oliver, J., Silva, J., Tamarit, S.: The MEB and CEB static analysis for CSP specifications. In: Hanus, M. (ed.) LOPSTR 2008. LNCS, vol. 5438, pp. 103–118. Springer, Heidelberg (2009)Llorens, M., Oliver, J., Silva, J., Tamarit, S.: A Semantics to Generate the Context-sensitive Synchronized Control-Flow Graph (extended). Technical report DSIC, Universidad Politécnica de Valencia, Valencia, Spain (June 2010), http://www.dsic.upv.es/~jsilvaLlorens, M., Oliver, J., Silva, J., Tamarit, S.: Transforming Communicating Sequential Processes to Petri Nets. In: Topping, B.H.V., Adam, J.M., Pallarés, F.J., Bru, R., Romero, M.L. (eds.) Seventh Int’l Conference on Engineering Computational Technology (ICECT 2010). Civil-Comp Press, Stirlingshire, UK, Paper 26 (2010)Roscoe, A.W., Gardiner, P.H.B., Goldsmith, M., Hulance, J.R., Jackson, D.M., Scattergood, J.B.: Hierarchical Compression for Model-Checking CSP or How to Check 1020 Dining Philosophers for Deadlock. In: Brinksma, E., Cleaveland, R., Larsen, K.G., Margaria, T., Steffen, B. (eds.) TACAS 1995. LNCS, vol. 1019, pp. 133–152. Springer, Heidelberg (1995)Roscoe, A.W.: The Theory and Practice of Concurrency. Prentice Hall, Upper Saddle River (2005

A Semantics for Tracing Declarative Multi-Paradigm Programs

We introduce the theoretical basis for tracing lazy functional logic computations in a declarative multi-paradigm language like Curry. Tracing computations is a difficult task due to the subtleties of the underlying operational semantics which combines laziness and non-determinism. In this work, we define an instrumented operational semantics that generates not only the computed values and bindings but also an appropriate data structure—a sort of redex trail—which can be used to trace computations at an adequate level of abstraction. In contrast to previous approaches, which rely solely on a transformation to instrument source programs, the formal definition of a tracing semantics improves the understanding of the tracing process. Furthermore, it allows us to formally prove the correctness of the computed trail. A prototype implementation of a tracer based on this semantics demonstrates the usefulness of our approach

A Semantics for Tracing Declarative Multi-Paradigm Programs

We introduce the theoretical basis for tracing lazy functional logic computations in a declarative multi-paradigm language like Curry. Tracing computations is a difficult task due to the subtleties of the underlying operational semantics which combines laziness and non-determinism. In this work, we define an instrumented operational semantics that generates not only the computed values and bindings but also an appropriate data structure—a sort of redex trail—which can be used to trace computations at an adequate level of abstraction. In contrast to previous approaches, which rely solely on a transformation to instrument source programs, the formal definition of a tracing semantics improves the understanding of the tracing process. Furthermore, it allows us to formally prove the correctness of the computed trail. A prototype implementation of a tracer based on this semantics demonstrates the usefulness of our approach

Analysis Techniques for Concurrent Programming Languages

Los lenguajes concurrentes est an cada d a m as presentes en nuestra sociedad, tanto en las nuevas tecnolog as como en los sistemas utilizados de manera cotidiana. M as a un, dada la actual distribuci on de los sistemas y su arquitectura interna, cabe esperar que este hecho siga siendo una realidad en los pr oximos a~nos. En este contexto, el desarrollo de herramientas de apoyo al desarrollo de programas concurrentes se vuelve esencial. Adem as, el comportamiento de los sistemas concurrentes es especialmente dif cil de analizar, por lo que cualquier herramienta que ayude en esta tarea, a un cuando sea limitada, ser a de gran utilidad. Por ejemplo, podemos encontrar herramientas para la depuraci on, an alisis, comprobaci on, optimizaci on, o simpli caci on de programas. Muchas de ellas son ampliamente utilizadas por los programadores hoy en d a. El prop osito de esta tesis es introducir, a trav es de diferentes lenguajes de programaci on concurrentes, t ecnicas de an alisis que puedan ayudar a mejorar la experiencia del desarrollo y publicaci on de software para modelos concurrentes. En esta tesis se introducen tanto an alisis est aticos (aproximando todas las posibles ejecuciones) como din amicos (considerando una ejecuci on en concreto). Los trabajos aqu propuestos di eren lo su ciente entre s para constituir ideas totalmente independientes, pero manteniendo un nexo com un: el hecho de ser un an alisis para un lenguaje concurrente. Todos los an alisis presentados han sido de nidos formalmente y se ha probado su correcci on, asegurando que los resultados obtenidos tendr an el grado de abilidad necesario en sistemas que lo requieran, como por ejemplo, en sistemas cr ticos. Adem as, se incluye la descripci on de las herramientas software que implementan las diferentes ideas propuestas. Esto le da al trabajo una utilidad m as all a del marco te orico, permitiendo poner en pr actica y probar con ejemplos reales los diferentes an alisis. Todas las ideas aqu presentadas constituyen, por s mismas, propuestas aplicables en multitud de contextos y problemas actuales. Adem as, individualmente sirven de punto de partida para otros an alisis derivados, as como para la adaptaci on a otros lenguajes de la misma familia. Esto le da un valor a~nadido a este trabajo, como bien atestiguan algunos trabajos posteriores que ya se est an bene ciando de los resultados obtenidos en esta tesis.Concurrent languages are increasingly present in our society, both in new technologies and in the systems used on a daily basis. Moreover, given the current systems distribution and their internal architecture, one can expect that this remains so in the coming years. In this context, the development of tools to support the implementation of concurrent programs becomes essential. Futhermore, the behavior of concurrent systems is particularly difficult to analyse, so that any tool that helps in this task, even if in a limited way, will be very useful. For example, one can find tools for debugging, analysis, testing, optimisation, or simplification of programs, which are widely used by programmers nowadays. The purpose of this thesis is to introduce, through various concurrent programming languages, some analysis techniques that can help to improve the experience of the software development and release for concurrent models. This thesis introduces both static (approximating all possible executions) and dynamic (considering a specific execution) analysis. The topics considered here differ enough from each other to be fully independent. Nevertheless, they have a common link: they can be used to analyse properties of a concurrent programming language. All the analyses presented here have been formally defined and their correctness have been proved, ensuring that the results will have the reliability degree which is needed for some systems (for instance, for critical systems). It also includes a description of the software tools that implement the different ideas proposed. This gives the work a usefulness well beyond the theoretical aspect, allowing us to put it in practice and to test the different analyses with real-world examples All the ideas here presented are, by themselves, approaches that can be applied in many current contexts and problems. Moreover, individually they serve as a starting point for other derived analysis, as well as for the adaptation to other languages of the same family. This gives an added value to this work, a fact confirmed by some later works that are already benefiting from the results obtained in this thesis.Tamarit Muñoz, S. (2013). Analysis Techniques for Concurrent Programming Languages [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31651TESI