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

Static Type Checking of Model Transformation Programs

Model transformation is seen as a promising approach to automate software development and verification, thus improving quality and reducing production costs significantly. However, errors of transformation programs can propagate into the generated artifacts complicating the detection of errors. The current paper proposes a static type checking approach for early detection of typing errors of partially typed transformation programs. The approach describes type safety as constraint satisfaction problems, and uses a dedicated back-annotation mechanism for error feedback

Static deadlock detection for concurrent go by global session graph synthesis

© 2016 ACM.Go is a programming language developed at Google, with channelbased concurrent features based on CSP. Go can detect global communication deadlocks at runtime when all threads of execution are blocked, but deadlocks in other paths of execution could be undetected. We present a new static analyser for concurrent Go code to find potential communication errors such as communication mismatch and deadlocks at compile time. Our tool extracts the communication operations as session types, which are then converted into Communicating Finite State Machines (CFSMs). Finally, we apply a recent theoretical result on choreography synthesis to generate a global graph representing the overall communication pattern of a concurrent program. If the synthesis is successful, then the program is free from communication errors. We have implemented the technique in a tool, and applied it to analyse common Go concurrency patterns and an open source application with over 700 lines of code

Static analysis techniques for the synthesis of efficient asynchronous circuits

technical reportIn the context of deriving asynchronous circuits from high-level descriptions, determining whether two actions are potentially concurrent (overlapped execution) or serial (non-overlapped execution) has several advantages. This knowledge can be utilized to efficiently implement shared variables, support speculative guard evaluation, and optimize resources (circuitry) by sharing. In a distributed environment with several concurrent processes, determining whether two actions are potentially concurrent or not, automatically, is often difficult to formulate and computationally expensive. In this paper, we present techniques to overcome these problems. First, we present a tool called parComp which infers the composite behavior of a collection of modules, and then we present an algorithm called conCur to analyze the inferred behavior to detect the seriality of two actions. Simple heuristics are presented for the abstraction of the inferred behavioral descriptions and improving the efficiency of conCur. The algorithms parComp and conCur are illustrated in the hopCP framework and implemented in Standard ML of New Jersey. Execution times of the algorithms are reported on a variety of examples. The results are quite encouraging

Behavioural Models for Distributed Fractal Components

This paper presents a formal behavioural specification framework together with its applications in different contexts for specifying and verifying the correct behaviour of distributed Fractal components. Our framework allows us to build behavioural models for applications ranging from sequential Fractal components, to distributed objects, and finally distributed components. Our models are able to characterise both functional and non-functional behaviours, and the interaction between the two concerns. Finally, this work has resulted in the development of tools allowing the non-expert programmer to specify the behaviour of his components, and automatically, or semi-automatically verify properties of his application

Buffer Sharing in Rendezvous Programs

Most compilers focus on optimizing performance, often at the expense of memory, but efficient memory use can be just as important in constrained environments such as embedded systems. This paper presents a memory reduction technique for rendezvous communication, which is applied to the deterministic concurrent programming language SHIM. It focuses on reducing memory consumption by sharing communication buffers among tasks. It determines pairs of buffers that can never be in use simultaneously and use a shared region of memory for each pair. The technique produces a static abstraction of a SHIM program's dynamic behavior, which is then analyzed to find buffers that are never occupied simultaneously. Experiments show the technique runs quickly on modest-sized programs and can sometimes reduce memory requirements by half

Symbolic Reachability Analysis of B through ProB and LTSmin

We present a symbolic reachability analysis approach for B that can provide a significant speedup over traditional explicit state model checking. The symbolic analysis is implemented by linking ProB to LTSmin, a high-performance language independent model checker. The link is achieved via LTSmin's PINS interface, allowing ProB to benefit from LTSmin's analysis algorithms, while only writing a few hundred lines of glue-code, along with a bridge between ProB and C using ZeroMQ. ProB supports model checking of several formal specification languages such as B, Event-B, Z and TLA. Our experiments are based on a wide variety of B-Method and Event-B models to demonstrate the efficiency of the new link. Among the tested categories are state space generation and deadlock detection; but action detection and invariant checking are also feasible in principle. In many cases we observe speedups of several orders of magnitude. We also compare the results with other approaches for improving model checking, such as partial order reduction or symmetry reduction. We thus provide a new scalable, symbolic analysis algorithm for the B-Method and Event-B, along with a platform to integrate other model checking improvements via LTSmin in the future