Dynamic slicing of concurrent specification languages

This is the author’s version of a work that was accepted for publication in Parallel Computing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Parallel Computing, 53, 1-22., (2016). DOI 10.1016/j.parco.2016.01.006.[EN] Dynamic slicing is a technique to extract the part of the program (called slice) that influences or is influenced, in a particular execution, by a given point of interest in the source code (called slicing criterion). Since a single execution is considered, the technique often uses a trace of this execution to analyze data and control dependencies. In this work we present the first formulation and implementation of dynamic slicing in the context of CSP. Most of the ideas presented can be directly applied to other concurrent specification languages such as Promela or CCS, but we center the discussion and the implementation on CSP. We base our technique on a new data structure to represent CSP computations called track. A track is a data structure which represents the sequence of expressions that have been evaluated during the computation, and moreover, it is labeled with the location of these expressions in the specification. The implementation of a dynamic slicer for CSP is useful for debugging, program comprehension, and program specialization, and it is also interesting from a theoretical perspective because CSP introduces difficulties such as heavy concurrency and non-determinism, synchronizations, frequent absence of data dependence, etc. © 2016 Elsevier B.V. All rights reservedThis work has been partially supported by the EU (FEDER) and the Spanish Ministerio de Economia y Competitividad under Grant TIN2013-44742-C4-1-R and by the Generalitat Valenciana under Grant PROMETEOII/2015/013 (SmartLogic). Salvador Tamarit was partially supported by Madrid regional projects N-GREENS Software-CM (S2013/ICE-2731), and by European Union project POLCA (STREP FP7-ICT-20133.4 610686).Llorens Agost, ML.; Oliver Villarroya, J.; Silva, J.; Tamarit Muñoz, S. (2016). Dynamic slicing of concurrent specification languages. Parallel Computing. 53:1-22. https://doi.org/10.1016/j.parco.2016.01.006S1225

Regional distribution patterns predict bird occurrence in Mediterranean cropland afforestations

Part of the abandoned cropland in Mediterranean landscapes is being subjected to afforestation dominated by pines. Here we simultaneously evaluate the effect of three categories of factors as predictors of the interspecific variation in bird habitat occupancy of fragmented afforestations, namely regional distribution, habitat preferences, and life-history traits of species. We use the ‘‘natural experiment’’ that highly fragmented pine plantations of central Spain represent due to the prevailing pattern of land ownership of small properties. Many species with marked habitat preferences for woodland habitats were very scarce or were never recorded in this novel habitat within a matrix of deforested agricultural landscape. Interspecific variability in occurrence was mainly explained by regional distribution patterns: occurrence was significantly and positively associated with the proportion of occupied 10 x 10 UTM km squares around the study area, habitat breadth, and population trend of species in the period 1998–2011. It was also positively associated with regional occupancy of mature and large pine plantations. Other predictor variables related to habitat preferences (for woodland, agricultural and urban habitats) or life-history traits (migratory strategy, body mass, and clutch size) were unrelated to the occurrence of species. Thus, small man-made pinewood islands funded by the Common Agrarian Policy within a landscape dominated by Mediterranean agricultural habitats only capture widespread and habitat generalist avian species with increasing population trends, not contributing to enhance truly woodland species

Estudio preliminar sobre la presencia y características fenotípicas de resistencia a los antibióticos de las cepas de Staphylococcus aureus aisladas en una población de équidos y en las personas relacionadas con ellos

La infección por Staphylococcus aureus, y en particular si se trata de cepas resistentes a la Meticilina, puede ser un riesgo para la salud humana y para los animales domésticos, incluidos los équidos. Diversos estudios observan que la transmisión de estas cepas puede ocurrir en todos los sentidos entre estas especies, y se hace necesario determinar la presencia de cepas resistentes a Meticilina en ambientes animales y humanos, con la finalidad de aplicar medidas de control de su difusión. En este estudio se ha pretendido detectar la presencia y las características fenotípicas de resistencia a los antibióticos de las cepas de Staphylococcus aureus aisladas en 35 équidos y 35 personas relacionadas con ellos. Paralelamente, se investigó la presencia de Staphylococcus del grupo intermedius que también han adquirido importancia en Salud Pública y Veterinaria. Se recogieron datos de las características de las personas participantes en el estudio (edad, presencia de animales en el hogar, tratamiento antibiótico recibido, contacto con ambientes hospitalarios, etc.) y de los équidos con los que estaban relacionadas (edad, raza, tratamientos recibidos, alojamiento, contacto con otros animales, procedencia hospitalaria o comunitaria, etc.). Mediante hisopos estériles se recogieron muestras, de fosas nasales y lesiones (en équidos enfermos) y de fosas nasales y espacios interdigitales en el caso de las personas. Tras el cultivo de las muestras en el laboratorio, se aislaron e identificaron 12 cepas de S. aureus (7 en caballos y 5 en personas) y ninguna del grupo S. intermedius. La mayoría de las cepas estaban relacionadas con el ámbito hospitalario y se aislaron a partir de fosas nasales. La determinación de la resistencia a los antibióticos, se realizó mediante el método de difusión en disco de Kirby-Bauer, frente a un grupo de antibióticos de importancia clínica en Medicina Humana y Animal. La resistencia a β-lactámicos y Glicopéptidos se ha corroborado mediante la prueba de la Mínima Dosis Inhibitoria. De este modo, se detectó la presencia de una cepa resistente a la Meticilina (SARM), a partir de la supuración de la incisión realizada en la cirugía (laringoplastia) de un caballo, de la que se sospecha un origen humano (“Humanosis”). En estudios posteriores se determinará el origen y el patrón genético de las cepas de S. aureus aisladas

A Research-Oriented Course on Advanced Multicore Architecture

©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Multicore processors have become ubiquitous in our real life in devices like smartphones, tablets, etc. In fact, they are present in almost all segments of the computing market, from supercomputers to embedded devices. The huge market competence have lead industry and academia to develop vertiginous technological and architectural advances. The fast evolution that are still experiencing current multicores makes difficult for instructors to offer computer architecture courses with updated contents, preferably showing the industry and academia research trends. To deal with this shortcoming, authors consider that a research-oriented course is the most appropriate solution. This paper presents an advanced computer architecture course called Advanced Multicore Architectures, offered in 2015. The course covers the basic topics of multicore architecture and has been organized in four main modules regarding multicore basis, performance evaluation, advanced caching, and main memory organization. The course follows a research-oriented approach that covers theoretical concepts at lectures in which recent research papers are analyzed to provide students a wide view of current trends. Moreover, additional teaching methods like lab sessions with a state-of-the-art multicore simulator or research-oriented exercises have been used with the aim of introducing students to research in these topics. To achieve this fully research-oriented methodology, about 40% of the time is devoted to labs and exercises.This work was supported by the Spanish Ministerio de Economía y Competitividad (MINECO) and by FEDER funds under Grant TIN2012-38341-C04-01, and by the Intel Early Career Faculty Honor Program Award.Sahuquillo Borrás, J.; Petit Martí, SV.; Selfa Oliver, V.; Gómez Requena, ME. (2015). A Research-Oriented Course on Advanced Multicore Architecture. IEEE Computer Society. https://doi.org/10.1109/IPDPSW.2015.46

A Hardware Approach to Fairly Balance the Inter-Thread Interference in Shared Caches

[EN] Shared caches have become the common design choice in the vast majority of modern multi-core and many-core processors, since cache sharing improves throughput for a given silicon area. Sharing the cache, however, has a downside: the requests from multiple applications compete among them for cache resources, so the execution time of each application increases over isolated execution. The degree in which the performance of each application is affected by the interference becomes unpredictable yielding the system to unfairness situations. This paper proposes Fair-Progress Cache Partitioning (FPCP), a low-overhead hardware-based cache partitioning approach that addresses system fairness. FPCP reduces the interference by allocating to each application a cache partition and adjusting the partition sizes at runtime. To adjust partitions, our approach estimates during multicore execution the time each application would have taken in isolation, which is challenging. The proposed approach has two main differences over existing approaches. First, FPCP distributes cache ways incrementally, which makes the proposal less prone to estimation errors. Second, the proposed algorithm is much less costly than the state-of-the-art ASM-Cache approach. Experimental results show that, compared to ASM-Cache, FPCP reduces unfairness by 48 percent in four-application workloads and by 28 percent in eight-application workloads, without harming the performance.This work was supported in part by the Spanish Ministerio de Economia y Competitividad (MINECO) and Plan E funds, under grants TIN2014-62246-EXP and TIN2015-66972-C5-1-R.Selfa-Oliver, V.; Sahuquillo Borrás, J.; Petit Martí, SV.; Gómez Requena, ME. (2017). A Hardware Approach to Fairly Balance the Inter-Thread Interference in Shared Caches. IEEE Transactions on Parallel and Distributed Systems. 28(11):3021-3032. https://doi.org/10.1109/TPDS.2017.2713778S30213032281

A research-oriented course on Advanced Multicore Architecture: Contents and active learning methodologies

[EN] The fast evolution of multicore processors makes it difficult for professors to offer computer architecture courses with updated contents. To deal with this shortcoming that could discourage students, the most appropriate solution is a research-oriented course based on current microprocessor industry trends. Additionally, we also seek to improve the students' skills by applying active learning methodologies, where teachers act as guiders and resource providers while students take the responsibility for their learning. In this paper, we present the Advanced Multicore Architecture (AMA) course, which follows a research-oriented approach to introduce students in architectural breakthroughs and uses active learning methodologies to enable students to develop practical research skills such as critical analysis of research papers or communication abilities. To this end five main activities are used: (i) lectures dealing with key theoretical concepts, (ii) paper review & discussion, (iii) research-oriented practical exercises, (iv) lab sessions with a state-of-the-art multicore simulator, and (v) paper presentation. An important part of all these activities is driven by active learning methodologies. Special emphasis is put on the practical side by allocating 40% of the time to labs and exercises. This work also includes an assessment study that analyzes both the course contents and the used methodology (both of them compared to other courses).This work was supported in part by the Spanish Ministerio de Economia y Competitividad (MINECO) and by Plan E funds under Grant TIN2014-62246-EXP and Grant TIN2015-66972-C5-1-R, and by Generalitat Valenciana under grant AICO/2016/059. Authors also would like to thank Onur Mutlu for making available online his valuable teaching material.Petit Martí, SV.; Sahuquillo Borrás, J.; Gómez Requena, ME.; Selfa-Oliver, V. (2017). A research-oriented course on Advanced Multicore Architecture: Contents and active learning methodologies. Journal of Parallel and Distributed Computing. 105:63-72. https://doi.org/10.1016/j.jpdc.2017.01.011S637210

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 to Generate the Context-sensitive Synchronized Control-Flow Graph (extended)

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 dras- tically 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.Tamarit Muñoz, S.; Silva Galiana, JF.; Llorens Agost, ML.; Oliver Villarroya, FJ. (2010). A Semantics to Generate the Context-sensitive Synchronized Control-Flow Graph (extended). http://hdl.handle.net/10251/839

Música y violencia de género en España. Estudio comparado por estilos musicales

La violencia contra las mujeres continúa siendo un problema de primer orden en las sociedades contemporáneas. El objetivo de este trabajo es estudiar cómo se trata dicho problema en las canciones de música popular en España, estableciendo una relación entre los diferentes estilos musicales y la descripción que hacen de la violencia de género. Para ello, se ha optado por desarrollar una metodología cuantitativa basada en el análisis de contenido de una muestra integrada por un total de 210 canciones, las cuales poseen esta temática, acumuladas a lo largo de las últimas cuatro décadas. La presente investigación pretende mostrar cómo las canciones de música popular pueden ser una herramienta de comunicación ideal para concienciar a la sociedad sobre las dimensiones del problema de la violencia de género

The influence of students distribution on their grades

This position paper defends the opinion that the distance of students to the professor in the classroom is directly related to their grades. This opinion is based on the results obtained in a large experiment performed during two academic years in various degrees, courses and semesters of two engineering schools. The experiment collected and processed data about the distribution of students in lectures and their final grades. Our results quantitatively confirm that grades can vary up to 14% depending on the distance to the professor.This work has been partially supported by the Spanish MEC under grant TIN2008-06622-C03-02 and by the Generalitat Valenciana under grant PROMETEO/2011/052. Salvador Tamarit was partially supported by the Spanish MICINN under FPI grant BES-2009-015019.Herrero Cuco, C.; Llorens Agost, ML.; Oliver Villarroya, J.; Silva Galiana, JF.; Tamarit Muñoz, S. (2013). The influence of students distribution on their grades. En Proceeding ITiCSE '13 Proceedings of the 18th ACM conference on Innovation and technology in computer science education. Association for Computing Machinery (ACM). 316-316. https://doi.org/10.1145/2462476.2465575S31631