61 resultados para optimising compiler
Resumo:
Ciao is a public domain, next generation multi-paradigm programming environment with a unique set of features: Ciao offers a complete Prolog system, supporting ISO-Prolog, but its novel modular design allows both restricting and extending the language. As a result, it allows working with fully declarative subsets of Prolog and also to extend these subsets (or ISO-Prolog) both syntactically and semantically. Most importantly, these restrictions and extensions can be activated separately on each program module so that several extensions can coexist in the same application for different modules. Ciao also supports (through such extensions) programming with functions, higher-order (with predicate abstractions), constraints, and objects, as well as feature terms (records), persistence, several control rules (breadth-first search, iterative deepening, ...), concurrency (threads/engines), a good base for distributed execution (agents), and parallel execution. Libraries also support WWW programming, sockets, external interfaces (C, Java, TclTk, relational databases, etc.), etc. Ciao offers support for programming in the large with a robust module/object system, module-based separate/incremental compilation (automatically -no need for makefiles), an assertion language for declaring (optional) program properties (including types and modes, but also determinacy, non-failure, cost, etc.), automatic static inference and static/dynamic checking of such assertions, etc. Ciao also offers support for programming in the small producing small executables (including only those builtins used by the program) and support for writing scripts in Prolog. The Ciao programming environment includes a classical top-level and a rich emacs interface with an embeddable source-level debugger and a number of execution visualization tools. The Ciao compiler (which can be run outside the top level shell) generates several forms of architecture-independent and stand-alone executables, which run with speed, efficiency and executable size which are very competive with other commercial and academic Prolog/CLP systems. Library modules can be compiled into compact bytecode or C source files, and linked statically, dynamically, or autoloaded. The novel modular design of Ciao enables, in addition to modular program development, effective global program analysis and static debugging and optimization via source to source program transformation. These tasks are performed by the Ciao preprocessor ( ciaopp, distributed separately). The Ciao programming environment also includes lpdoc, an automatic documentation generator for LP/CLP programs. It processes Prolog files adorned with (Ciao) assertions and machine-readable comments and generates manuals in many formats including postscript, pdf, texinfo, info, HTML, man, etc. , as well as on-line help, ascii README files, entries for indices of manuals (info, WWW, ...), and maintains WWW distribution sites.
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We present and evaluate a compiler from Prolog (and extensions) to JavaScript which makes it possible to use (constraint) logic programming to develop the client side of web applications while being compliant with current industry standards. Targeting JavaScript makes (C)LP programs executable in virtually every modern computing device with no additional software requirements from the point of view of the user. In turn, the use of a very high-level language facilitates the development of high-quality, complex software. The compiler is a back end of the Ciao system and supports most of its features, including its module system and its rich language extension mechanism based on packages. We present an overview of the compilation process and a detailed description of the run-time system, including the support for modular compilation into separate JavaScript code. We demonstrate the maturity of the compiler by testing it with complex code such as a CLP(FD) library written in Prolog with attributed variables. Finally, we validate our proposal by measuring the performance of some LP and CLP(FD) benchmarks running on top of major JavaScript engines.
Resumo:
SIMLIDAR is an application developed in Cþþ that generates an artificial orchard using a Lindenmayer system. The application simulates the lateral interaction between the artificial orchard and a laser scanner or LIDAR (Light Detection and Ranging). To best highlight the unique qualities of the LIDAR simulation, this work focuses on apple trees without leaves, i.e. the woody structure. The objective is to simulate a terrestrial laser sensor (LIDAR) when applied to different artificially created orchards and compare the simulated characteristics of trees with the parameters obtained with the LIDAR. The scanner is mounted on a virtual tractor and measures the distance between the origin of the laser beam and the nearby plant object. This measurement is taken with an angular scan in a plane which is perpendicular to the route of the virtual tractor. SIMLIDAR determines the distance measured in a bi-dimensional matrix N M, where N is the number of angular scans and M is the number of steps in the tractor route. In order to test the data and performance of SIMLIDAR, the simulation has been applied to 42 different artificial orchards. After previously defining and calculating two vegetative parameters (wood area and wood projected area) of the simulated trees, a good correlation (R2 ¼ 0.70e0.80) was found between these characteristics and the wood area detected (impacted) by the laser beam. The designed software can be valuable in horticulture for estimating biomass and optimising the pesticide treatments that are performed in winter.
Resumo:
Dynamic scheduling increases the expressive power of logic programming languages, but also introduces some overhead. In this paper we present two classes of program transformations designed to reduce this additional overhead, while preserving the operational semantics of the original programs, modulo ordering of literals woken at the same time. The first class of transformations simplifies the delay conditions while the second class moves delayed literals later in the rule body. Application of the program transformations can be automated using information provided by compile-time analysis. We provide experimental results obtained from an implementation of the proposed techniques using the CIAO prototype compiler. Our results show that the techniques can lead to substantial performance improvement.
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This paper presents a conditional parallelization process for and-parallelism based on the notion of non-strict independence, a more relaxed notion than the traditional of strict independence. By using this notion, a parallelism annotator can extract more parallelism from programs. On the other hand, the intrinsic complexity of non-strict independence poses new challenges to this task. We report here on the implementation we have accomplished of an annotator for non-strict independence, capable of producing both static and dynamic execution graphs. This implementation, along with the also implemented independence checker and their integration in our system, have resulted what is, to the best of our knowledge, the first parallelizing compiler based on nonstrict independence which produces dynamic execution graphs. The paper also presents a preliminary assessment of the implemented tools, comparing them with the existing ones for strict independence, which shows encouraging results.
Resumo:
In this report we discuss some of the issues involved in the specialization and optimization of constraint logic programs with dynamic scheduling. Dynamic scheduling, as any other form of concurrency, increases the expressive power of constraint logic programs, but also introduces run-time overhead. The objective of the specialization and optimization is to reduce as much as possible such overhead automatically, while preserving the semantics of the original programs. This is done by program transformation based on global analysis. We present implementation techniques for this purpose and report on experimental results obtained from an implementation of the techniques in the context of the CIAO compiler.
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The Andorra Kernel language scheme was aimed, in principle, at simultaneously supporting the programming styles of Prolog and committed choice languages. Within the constraint programming paradigm, this family of languages could also in principle support the concurrent constraint paradigm. This happens for the Agents Kernel Language (AKL). On the other hand, AKL requires a somewhat detailed specification of control by the user. This could be avoided by programming in CLP to run on AKL. However, CLP programs cannot be executed directly on AKL. This is due to a number of factors, from more or less trivial syntactic differences to more involved issues such as the treatment of cut and making the exploitation of certain types of parallelism possible. This paper provides a translation scheme which is a basis of an automatic compiler of CLP programs into AKL, which can bridge those differences. In addition to supporting CLP, our style of translation achieves independent and-parallel execution where possible, which is relevant since this type of parallel execution preserves, through the translation, the user-perceived "complexity" of the original program.
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This paper presents improved unification algorithms, an implementation, and an analysis of the effectiveness of an abstract interpreter based on the sharing + freeness domain presented in a previous paper, which was designed to accurately and concisely represent combined freeness and sharing information for program variables. We first briefly review this domain and the unification algorithms previously proposed. We then improve these algorithms and correct them to deal with some cases which were not well analyzed previously, illustrating the improvement with an example. We then present the implementation of the improved algorithm and evaluate its performance by comparing the effectiveness of the information inferred to that of other interpreters available to us for an application (program parallelization) that is common to all these interpreters. All these systems have been embedded in a real parallelizing compiler. Effectiveness of the analysis is measured in terms of actual final performance of the system: i.e. in terms of the actual speedups obtained. The results show good performance for the combined domain in that it improves the accuracy of both types of information and also in that the analyzer using the combined domain is more effective in the application than any of the other analyzers it is compared to.
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We present a new free library for Constraint Logic Programming over Finite Domains, included with the Ciao Prolog system. The library is entirely written in Prolog, leveraging on Ciao's module system and code transformation capabilities in order to achieve a highly modular design without compromising performance. We describe the interface, implementation, and design rationale of each modular component. The library meets several design goals: a high level of modularity, allowing the individual components to be replaced by different versions; highefficiency, being competitive with other TT> implementations; a glass-box approach, so the user can specify new constraints at different levels; and a Prolog implementation, in order to ease the integration with Ciao's code analysis components. The core is built upon two small libraries which implement integer ranges and closures. On top of that, a finite domain variable datatype is defined, taking care of constraint reexecution depending on range changes. These three libraries form what we call the TT> kernel of the library. This TT> kernel is used in turn to implement several higher-level finite domain constraints, specified using indexicals. Together with a labeling module this layer forms what we name the TT> solver. A final level integrates the CLP (J7©) paradigm with our TT> solver. This is achieved using attributed variables and a compiler from the CLP (J7©) language to the set of constraints provided by the solver. It should be noted that the user of the library is encouraged to work in any of those levels as seen convenient: from writing a new range module to enriching the set of TT> constraints by writing new indexicals.
Resumo:
Today's motivation for autonomous systems research stems out of the fact that networked environments have reached a level of complexity and heterogeneity that make their control and management by solely human administrators more and more difficult. The optimisation of performance metrics for the air traffic management system, like in other networked system, has become more complex with increasing number of flights, capacity constraints, environmental factors and safety regulations. It is anticipated that a new structure of planning layers and the introduction of higher levels of automation will reduce complexity and will optimise the performance metrics of the air traffic management system. This paper discusses the complexity of optimising air traffic management performance metrics and proposes a way forward based on higher levels of automation.
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Este Trabajo de Fin de Grado recoge el diseño e implementación de un compilador y una librería de entorno de ejecución para el lenguaje específico del dominio TESL, un lenguaje de alto nivel para el análisis de series temporales diseñado por un grupo de investigación de la Universidad Politécnica de Madrid. Este compilador es el primer compilador completo disponible para TESL y sirve como base para la continuación del desarrollo del lenguaje, estando ideado para permitir su adaptación a cambios en el mismo. El compilador ha sido implementado en Java siguiendo la arquitectura clásica para este tipo de aplicaciones, incluyendo un Analizador Léxico, Sintáctico y Semántico, así como un Generador de Código. Se ha documentado su arquitectura y las decisiones de diseño que han conducido a la misma. Además, se ha demostrado su funcionamiento con un caso práctico de análisis de eventos en métricas de servidores. Por último, se ha documentado el lenguaje TESL, en cuyo desarrollo se ha colaborado. ---ABSTRACT---This Bachelor’s Thesis describes the design and implementation of a compiler and a runtime library for the domain-specific language TESL, a high-level language for analyzing time series events developed by a research group from the Technical University of Madrid. This is the first fully implemented TESL compiler, and serves as basis for the continuation of the development of the language. The compiler has been implemented in Java following the classical architecture for this kind of systems, having a four phase compilation with a Lexer, a Parser, a Semantic Analyzer and a Code Generator. Its architecture and the design decisions that lead to it have been documented. Its use has been demonstrated in an use-case in the domain of server metrics. Finally, the TESL language itself has been extended and documented.
Resumo:
A raíz de la aparición de los procesadores dotados de varios “cores”, la programación paralela, un concepto que, por otra parte no era nada nuevo y se conocía desde hace décadas, sufrió un nuevo impulso, pues se creía que se podía superar el techo tecnológico que había estado limitando el rendimiento de esta programación durante años. Este impulso se ha ido manteniendo hasta la actualidad, movido por la necesidad de sistemas cada vez más potentes y gracias al abaratamiento de los costes de fabricación. Esta tendencia ha motivado la aparición de nuevo software y lenguajes con componentes orientados precisamente al campo de la programación paralela. Este es el caso del lenguaje Go, desarrollado por Google y lanzado en 2009. Este lenguaje se basa en modelos de concurrencia que lo hacen muy adecuados para abordar desarrollos de naturaleza paralela. Sin embargo, la programación paralela es un campo complejo y heterogéneo, y los programadores son reticentes a utilizar herramientas nuevas, en beneficio de aquellas que ya conocen y les son familiares. Un buen ejemplo son aquellas implementaciones de lenguajes conocidos, pero orientadas a programación paralela, y que siguen las directrices de un estándar ampliamente reconocido y aceptado. Este es el caso del estándar OpenMP, un Interfaz de Programación de Aplicaciones (API) flexible, portable y escalable, orientado a la programación paralela multiproceso en arquitecturas multi-core o multinucleo. Dicho estándar posee actualmente implementaciones en los lenguajes C, C++ y Fortran. Este proyecto nace como un intento de aunar ambos conceptos: un lenguaje emergente con interesantes posibilidades en el campo de la programación paralela, y un estándar reputado y ampliamente extendido, con el que los programadores se encuentran familiarizados. El objetivo principal es el desarrollo de un conjunto de librerías del sistema (que engloben directivas de compilación o pragmas, librerías de ejecución y variables de entorno), soportadas por las características y los modelos de concurrencia propios de Go; y que añadan funcionalidades propias del estándar OpenMP. La idea es añadir funcionalidades que permitan programar en lenguaje Go utilizando la sintaxis que OpenMP proporciona para otros lenguajes, como Fortan y C/C++ (concretamente, similar a esta última), y, de esta forma, dotar al usuario de Go de herramientas para programar estructuras de procesamiento paralelo de forma sencilla y transparente, de la misma manera que lo haría utilizando C/C++.---ABSTRACT---As a result of the appearance of processors equipped with multiple "cores ", parallel programming, a concept which, moreover, it was not new and it was known for decades, suffered a new impulse, because it was believed they could overcome the technological ceiling had been limiting the performance of this program for years. This impulse has been maintained until today, driven by the need for ever more powerful systems and thanks to the decrease in manufacturing costs. This trend has led to the emergence of new software and languages with components guided specifically to the field of parallel programming. This is the case of Go language, developed by Google and released in 2009. This language is based on concurrency models that make it well suited to tackle developments in parallel nature. However, parallel programming is a complex and heterogeneous field, and developers are reluctant to use new tools to benefit those who already know and are familiar. A good example are those implementations from well-known languages, but parallel programming oriented, and witch follow the guidelines of a standard widely recognized and accepted. This is the case of the OpenMP standard, an application programming interface (API), flexible, portable and scalable, parallel programming oriented, and designed for multi-core architectures. This standard currently has implementations in C, C ++ and Fortran. This project was born as an attempt to combine two concepts: an emerging language, with interesting possibilities in the field of parallel programming, and a reputed and widespread standard, with which programmers are familiar with. The main objective is to develop a set of system libraries (which includes compiler directives or pragmas, runtime libraries and environment variables), supported by the characteristics and concurrency patterns of Go; and that add custom features from the OpenMP standard. The idea is to add features that allow programming in Go language using the syntax OpenMP provides for other languages, like Fortran and C / C ++ (specifically, similar to the latter ), and, in this way, provide Go users with tools for programming parallel structures easily and, in the same way they would using C / C ++.
Resumo:
El paradigma de procesamiento de eventos CEP plantea la solución al reto del análisis de grandes cantidades de datos en tiempo real, como por ejemplo, monitorización de los valores de bolsa o el estado del tráfico de carreteras. En este paradigma los eventos recibidos deben procesarse sin almacenarse debido a que el volumen de datos es demasiado elevado y a las necesidades de baja latencia. Para ello se utilizan sistemas distribuidos con una alta escalabilidad, elevado throughput y baja latencia. Este tipo de sistemas son usualmente complejos y el tiempo de aprendizaje requerido para su uso es elevado. Sin embargo, muchos de estos sistemas carecen de un lenguaje declarativo de consultas en el que expresar la computación que se desea realizar sobre los eventos recibidos. En este trabajo se ha desarrollado un lenguaje declarativo de consultas similar a SQL y un compilador que realiza la traducción de este lenguaje al lenguaje nativo del sistema de procesamiento masivo de eventos. El lenguaje desarrollado en este trabajo es similar a SQL, con el que se encuentran familiarizados un gran número de desarrolladores y por tanto aprender este lenguaje no supondría un gran esfuerzo. Así el uso de este lenguaje logra reducir los errores en ejecución de la consulta desplegada sobre el sistema distribuido al tiempo que se abstrae al programador de los detalles de este sistema.---ABSTRACT---The complex event processing paradigm CEP has become the solution for high volume data analytics which demand scalability, high throughput, and low latency. Examples of applications which use this paradigm are financial processing or traffic monitoring. A distributed system is used to achieve the performance requisites. These same requisites force the distributed system not to store the events but to process them on the fly as they are received. These distributed systems are complex systems which require a considerably long time to learn and use. The majority of such distributed systems lack a declarative language in which to express the computation to perform over incoming events. In this work, a new SQL-like declarative language and a compiler have been developed. This compiler translates this new language to the distributed system native language. Due to its similarity with SQL a vast amount of developers who are already familiar with SQL will need little time to learn this language. Thus, this language reduces the execution failures at the time the programmer no longer needs to know every single detail of the underlying distributed system to submit a query.
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En el proceso general de la sociedad por la mejora continua hacia la Calidad, el sector de la construcción, y más específicamente la actividad de los Arquitectos con la redacción de los proyectos, no pueden, ni deben, quedar al margen. La presente investigación apunta un procedimiento para el control técnico de los proyectos y demuestra la eficacia y rentabilidad de éste o cualquier otro método de control, avanzando una aproximación a los modelos de costes de calidad de los estudios de arquitectura. El método de trabajo que se ha previsto para el desarrollo de la tesis cuenta con una base principal consistente en definir un procedimiento general de revisión de los proyectos, tipificando los principales errores (sistema de puntos de inspección), analizando las causas que los generan, su repercusión en el plazo, durabilidad y satisfacción del cliente, así como en definir un método de cuantificación que nos aproxime a la "importancia" (económica) que tienen o inducen los errores e indefiniciones detectadas. Para demostrar la validez de la hipótesis inicial sobre la rentabilidad de aplicar un sistema de control técnico del proyecto, se ha aplicado una parte del procedimiento general particularizado para la evaluación sistemática de los problemas, indefiniciones y fallos detectados, al que llamamos de forma simplificada Método Partícula Éste se aplica sobre una muestra de proyectos que se revisan y que, para que los resultados del análisis sean representativos, se seleccionaron de forma aleatoria, respondiendo topológicamente en sus variables definitorias a la población que se pretende estudiar: la totalidad de proyectos de ejecución de viviendas producidos en el ámbito territorial de Madrid (Comunidad) en el plazo comprendido entre los años 1990 y 1995. Pero además esta representatividad está condicionada a la mayor o menor exactitud de la valoración que se haga de los sobrecostos que puedan generar los errores e indefiniciones de los proyectos. Se hace pues imprescindible el tratar de objetivar al máximo los criterios de valoración de los mismos. Con los datos generados en la revisión de cada proyecto se analizan la totalidad de resultados de la muestra objeto de estudio, sacando conclusiones sobre frecuencia e importancia de los errores, incidencia de las variables que influyen, y posibles combinaciones de variables que incrementan el riesgo. Extrapolando el análisis al método general y a la población objeto de estudio, se extraen conclusiones significativas respecto a la eficacia del control técnico de proyectos, así como de las formas de optimizar las inversiones realizadas en el mismo, depurando y optimizando selectivamente el método general definido. Con el análisis de los modelos de coste de calidad se puede constatar cómo las inversiones en desarrollar sistemas de aseguramiento de la calidad de los proyectos, o, de forma más modesta, controlando la calidad técnica de los mismos, los estudios de arquitectura, amén del mejor servicio ofrecido a los clientes, y lo que ésto supone de permanencia en el mercado, mejoran significativamente su competitividad y su margen de beneficio, demostrando que son muy rentables tanto para los propios arquitectos, como para la sociedad en general. ABSTRACT The construction sector as a whole, and especifically architects as project drafters, must fully participate in the general process of society for continuous improvement towards quality. Our research outlines a procedure for the technical control of projects and shows the efficacy and cost-effectiveness of this or any other control method, putting fonvard an approach to quality cost-models in Architecture offices. Our procedure consists mainly in defining a general method of revising projects, typifying main errors (Points of inspection system), analysing their causes, their repercussion in clients' durability and satisfaction. It wHI also define a quantitative method to assess tfie economic importance of detected errors and indefinitions. To prove our initial hypothesis on the cost-effectiveness of applying a system of tecfinical control to projects we have applied part of the general procedure, adjusting it to the systematic evaluation of problems, indefinitions and errors we have found. This will be simply called Particular Method. We will use it on a sample of projects which were randomly selected, for the sake of representativeness, and which, in their defining variables, match the population under study topologically: every housing project in Madrid (Región) between 1.990 and 1.995. Furthermore, this representativeness is related to the accuracy of the assessment of the additional costs due to errors or lack of definition in the projects. We must therefore try to be precise in the evaluation of their costs. With data obtained from the revision of each project, we analyze every result from the sample under study, drawing conclusions about the frequency and importance of each error, their causing variables, and the combination of variables which are risk-increasing. By extrapolating this analysis to the General Method and the population under study, we draw significant conclusions on the effectiveness of the technical control of projects, as well as of the ways to optimise the investment in it, improving and optimising the General Method in a selective way. Analyzing quality cost-models, we can show how the investment in developing systems that will guarantee quality projects, or, more modestly, controlling the technical quality of them, Architecture firms will not only serve their clients best, with its impact on the firm's durability, but also improve their competitivity and their profit margin proving that they are profitable both for architects themselves and for the general public.
Resumo:
Este proyecto fin de grado presenta dos herramientas, Papify y Papify-Viewer, para medir y visualizar, respectivamente, las prestaciones a bajo nivel de especificaciones RVC-CAL basándose en eventos hardware. RVC-CAL es un lenguaje de flujo de datos estandarizado por MPEG y utilizado para definir herramientas relacionadas con la codificación de vídeo. La estructura de los programas descritos en RVC-CAL se basa en unidades funcionales llamadas actores, que a su vez se subdividen en funciones o procedimientos llamados acciones. ORCC (Open RVC-CAL Compiler) es un compilador de código abierto que utiliza como entrada descripciones RVC-CAL y genera a partir de ellas código fuente en un lenguaje dado, como por ejemplo C. Internamente, el compilador ORCC se divide en tres etapas distinguibles: front-end, middle-end y back-end. La implementación de Papify consiste en modificar la etapa del back-end del compilador, encargada de la generación de código, de modo tal que los actores, al ser traducidos a lenguaje C, queden instrumentados con PAPI (Performance Application Programing Interface), una herramienta utilizada como interfaz a los registros contadores de rendimiento (PMC) de los procesadores. Además, también se modifica el front-end para permitir identificar cierto tipo de anotaciones en las descripciones RVC-CAL, utilizadas para que el diseñador pueda indicar qué actores o acciones en particular se desean analizar. Los actores instrumentados, además de conservar su funcionalidad original, generan una serie de ficheros que contienen datos sobre los distintos eventos hardware que suceden a lo largo de su ejecución. Los eventos incluidos en estos ficheros son configurables dentro de las anotaciones previamente mencionadas. La segunda herramienta, Papify-Viewer, utiliza los datos generados por Papify y los procesa, obteniendo una representación visual de la información a dos niveles: por un lado, representa cronológicamente la ejecución de la aplicación, distinguiendo cada uno de los actores a lo largo de la misma. Por otro lado, genera estadísticas sobre la cantidad de eventos disparados por acción, actor o núcleo de ejecución y las representa mediante gráficos de barra. Ambas herramientas pueden ser utilizadas en conjunto para verificar el funcionamiento del programa, balancear la carga de los actores o la distribución por núcleos de los mismos, mejorar el rendimiento y diagnosticar problemas. ABSTRACT. This diploma project presents two tools, Papify and Papify-Viewer, used to measure and visualize the low level performance of RVC-CAL specifications based on hardware events. RVC-CAL is a dataflow language standardized by MPEG which is used to define video codec tools. The structure of the applications described in RVC-CAL is based on functional units called actors, which are in turn divided into smaller procedures called actions. ORCC (Open RVC-CAL Compiler) is an open-source compiler capable of transforming RVC-CAL descriptions into source code in a given language, such as C. Internally, the compiler is divided into three distinguishable stages: front-end, middle-end and back-end. Papify’s implementation consists of modifying the compiler’s back-end stage, which is responsible for generating the final source code, so that translated actors in C code are now instrumented with PAPI (Performance Application Programming Interface), a tool that provides an interface to the microprocessor’s performance monitoring counters (PMC). In addition, the front-end is also modified in such a way that allows identification of a certain type of annotations in the RVC-CAL descriptions, allowing the designer to set the actors or actions to be included in the measurement. Besides preserving their initial behavior, the instrumented actors will also generate a set of files containing data about the different events triggered throughout the program’s execution. The events included in these files can be configured inside the previously mentioned annotations. The second tool, Papify-Viewer, makes use of the files generated by Papify to process them and provide a visual representation of the information in two different ways: on one hand, a chronological representation of the application’s execution where each actor has its own timeline. On the other hand, statistical information is generated about the amount of triggered events per action, actor or core. Both tools can be used together to assert the normal functioning of the program, balance the load between actors or cores, improve performance and identify problems.