Toward optimized code generation through model-based optimization

International audienceModel-Based Development (MBD) provides an additional level of abstraction, the model, which lets engineers focus on the business aspect of the developed system. MBD permits automatic treatments of these models with dedicated tools like synthesis of system's application by automatic code generation. Real-Time and Embedded Systems (RTES) are often constrained by their environment and/or the resources they own in terms of memory, energy consumption with respect to performance requirements. Hence, an important problem to deal with in RTES development is linked to the optimization of their software part. Although automatic code generation and the use of optimizing compilers bring some answers to application optimization issue, we will show in this paper that optimization results may be enhanced by adding a new level of optimizations in the modeling process. Our arguments are illustrated with examples of the Unified Modeling Language (UML) state machines diagrams which are widely used for control aspect modeling of RTES. The well-known Gnu Compiler Collection (GCC) is used for this study. The paper concludes on a proposal of two step optimization approach that allows reusing as they are, existing compiler optimizations

Incremental Consistency Checking in Delta-oriented UML-Models for Automation Systems

Automation systems exist in many variants and may evolve over time in order to deal with different environment contexts or to fulfill changing customer requirements. This induces an increased complexity during design-time as well as tedious maintenance efforts. We already proposed a multi-perspective modeling approach to improve the development of such systems. It operates on different levels of abstraction by using well-known UML-models with activity, composite structure and state chart models. Each perspective was enriched with delta modeling to manage variability and evolution. As an extension, we now focus on the development of an efficient consistency checking method at several levels to ensure valid variants of the automation system. Consistency checking must be provided for each perspective in isolation, in-between the perspectives as well as after the application of a delta.Comment: In Proceedings FMSPLE 2016, arXiv:1603.0857

Runtime observable and adaptable UML state machine-based software components generation and verification: [email protected] approach

Cyber-Physical Systems (CPSs) are embedded computing systems in which computation interacts closely with the physical world through sensors and actuators. CPSs are used to control context aware systems. These types of systems are complex systems that will have different configurations and their control strategy can be configured depending the environmental data and current situation of the context. Therefore, in current industrial environments, the software of embedded and Cyber-Physical systems have to cope with increasing complexity, uncertain scenarios and safe requirements at runtime. The UML State Machine is a powerful formalism to model the logical behaviour of these types of systems, and in Model Driven Engineering (MDE) we can generate code automatically from these models. MDE aims to overcome the complexity of software construction by allowing developers to work at the high-level models of software systems instead of low-level codes. However, determining and evaluating the runtime behaviour and performance of models of CPSs using commercial MDE tools is a challenging task. Such tools provide little support to observe at model-level the execution of the code generated from the model, and to collect the runtime information necessary to, for example, check whether defined safe properties are met or not. One solution to address these requirements is having the software components information in model terms at runtime ([email protected]). Work on [email protected] seeks to extend the applicability of models produced in MDE approaches to the runtime environment. Having the model at runtime is the first step towards the runtime verification. Runtime verification can be performed using the information of model elements (current state, event, next state,etc.) This thesis aims at advancing the current practice on generating automatically Unified Modeling Language - State Machine (UML-SM) based software components that are able to provide their internal information in model terms at runtime. Regarding automation, we propose a tool supported methodology to automatically generate these software components. As for runtime monitoring, verification and adaptation, we propose an externalized runtime module that is able to monitor and verify the correctness of the software components based on their internal status in model terms at component and system level. In addition, if an error is detected, the runtime adaptation module is activated and the safe adaptation process starts in the involved software components. All things considered, the overall safe level of the software components and CPSs is enhanced.Sistema Ziber-Fisikoak, konputazio sistema txertatuez osatuta daude. Konputazio sistema txertatu hauek, mundu birtuala mundu fisikoarekin uztartzeko gaitasuna eskaintzen dute. Sistema ziberfisikoak orokorrean sistema konplexuak izan ohi dira eta inguruan gertazen denaren araberako konfigurazio desberdinak izan ohi dituzte. Gaur egungo industria ingurunetan, sistema hauek daramaten kontroleko softwarea asko handitu da eta beren konplexutasunak ere gorakada handia izan du: aurrez ezagunak ez diren baldintza eta inguruetan lan egin beharra dute askotan, denbora errealeko eskakizunak eta segurtasun eskakizunak ere beteaz. UML State Machine formalismoa, goian aipaturiko sistema mota horien portaera logikoa modelizatzeko erabiltzen den formalismo indartsu bat da. Formalismo honen baitan eta Model Driven Engineering (MDE) enfokea jarraituaz, sistema modelatzeko erabilitako grafikoetatik sisteman txertatua izango den kodea automatikoki sor genezake. MDEk softwarea sortzeko orduan izan genezakeen konplexutasuna gainditu nahi du, garatzailei software-sistemen goi-mailako ereduetan lan egiteko aukera emanez. Hala ere, MDE-an oinarrituriko tresna komertzialak erabiliaz, zaila izaten da berauen bidez sorturiko kodearen errendimendua eta portaera sistema exekuzioan dagoenean ebaluatzea. Tresna horiek laguntza gutxi eskaintzen dute modelotatik sortutako kodea exekutatzen ari denean sisteman zer gertatzen ari denaren informazioa modeloaren terminoetan jasotzeko. Beraz, exekuzio denboran, oso zaila izaten da sistemaren portaera egokia den edo ez aztertzea modelo mailako informazio hori erabiliaz. Eskakizun horiek kudeatzeko modu bat, software modeloaren informazioa denbora errealean izatea da ([email protected] enfokea). [email protected] enfokearen helburu nagusietako bat, MDE enfokearekin garapen fasean sortutako modeloak exekuzio denboran (runtime-en) erabilgarri izatean datza. Exekuzio denboran egiaztapen edo testing-a egin ahal izateko lehen urratsa, testeatu nahi den software horren modeloa exekuzio denboran eskuragarri izatea da. Honela, exekuzio denborako egiaztapen edo berifikazioak softwarea modelatzeko erabili ditugun elementu berberak erabiliaz egin daitke (egungo egoera, gertaera, hurrengo egoera, eta abar). Tesi honen helburutako bat UML-State Machine modeloetan oinarritutako eta exekuzio denboran beren barne egoeraren informazioa modeloko elementu bidez probestu ahalko duten software osagaiak modu automatikoan sortzea da. Automatizazioari dagokionez, lehenik eta behin, software-osagai horiek automatikoki sortzen dituzten tresnak eskaintzen dituen metodologia proposatzen dugu. Bigarrenik, UMLSM oinarritutako software osagaiak automatikoki sortuko dituen herraminta bera proposatzen dugu. Exekuzio denboran eguneraketen jarraipenari, egiaztatzeari eta egokitzeari dagokionez, barne egoera UML-SM modelo terminoetan eskaintzen duten software osagaiak egiaztatzeko eta egokitzeko gai den kanpo exekuzio modulo bat proposatzen dugu. Honela, errore bat detektatzen bada, exekuzio garaian egokitze modulua aktibatuko da egokitzapen prozesu segurua martxan jarriaz. Honek, dagokion software osagaiari abixua bidaliko dio egokitzapena egin dezan. Gauza guztiak kontuan hartuta, software osagaien eta CPSen segurtasun maila orokorra hobetua izango da.Los sistemas cyber-físicos (CPSs) son sistemas de computación embebidos en los que la computación interactúa estrechamente con el mundo físico a través de sensores y actuadores. Los CPS se utilizan para controlar sistemas que proveen conocimiento del contexto. Este tipo de sistemas son sistemas complejos que suelen tener diferentes configuraciones y su estrategia de control puede configurarse en función de los datos del entorno y de la situación actual del contexto. Por lo tanto, en los entornos industriales actuales, el software de los sistemas embebidos tiene que hacer frente a la creciente complejidad, los escenarios inciertos y los requisitos de seguridad en tiempo de ejecución. Las máquinas de estado UML son un formalismo muy utilizado en industria para modelar el comportamiento lógico de este tipo de sistemas, y siguiendo el enfoque Model Driven Engineering (MDE) podemos generar código automáticamente a partir de estos modelos. El objetivo de MDE es superar la complejidad de la construcción de software permitiendo a los desarrolladores trabajar en los modelos de alto nivel de los sistemas de software en lugar de tener que codificar el control mediante lenguajes de programación de bajo nivel. Sin embargo, determinar y evaluar el comportamiento y el rendimiento en tiempo de ejecución de estos modelos generados mediante herramientas comerciales de MDE es una tarea difícil. Estas herramientas proporcionan poco apoyo para observar a nivel de modelo la ejecución del código generado a partir del modelo. Por lo tanto, no son muy adecuadas para poder recopilar la información de tiempo de ejecución necesaria para, por ejemplo, comprobar si se cumplen o no las restricciones definidas. Un enfoque para gestionar estos requisitos, es tener la información de los componentes de software en términos de modelo en tiempo de ejecución ([email protected]). El trabajo en [email protected] busca ampliar la aplicabilidad de los modelos producidos en fase de desarrollo mediante el enfoque MDE al entorno de tiempo de ejecución. Tener el modelo en tiempo de ejecución es el primer paso para poder llevar a cabo la verificación en tiempo de ejecución. Así, esta verificación se podrá realizar utilizando la información de los elementos del modelo (estado actual, evento, siguiente estado, etc.). El objetivo de esta tesis es avanzar en la práctica actual de generar automáticamente componentes software basados en Unified Modeling Language - State Machine (UML-SM) que sean capaces de proporcionar información interna en términos de modelos en tiempo de ejecución. En cuanto a la automatización, en primer lugar, proponemos una metodología soportada por herramientas para generar automáticamente estos componentes de software. En segundo lugar, proponemos un marco de trabajo de generación de componentes de software basado en UML-SM. En cuanto a la monitorización, verificación y adaptación en tiempo de ejecución, proponemos un módulo de tiempo de ejecución externalizado que es capaz de monitorizar y verificar la validez de los componentes del software en función de su estado interno en términos de modelo. Además, si se detecta un error, se activa el módulo de adaptación en tiempo de ejecución y se inicia el proceso de adaptación seguro en el componente de software correspondiente. Teniendo en cuenta todo esto, el nivel de seguridad global de los componentes del software y de los CPS se ve mejorado

Specifying UML protocol state machines in Alloy

A UML Protocol State Machine (PSM) is a behavioral diagram for the specification of the external behavior of a class, interface or component. PSMs have been used in the software development process for different purposes, such as requirements analysis and testing. However, like other UML diagrams, they are often difficult to validate and verify, specially when combined with other artifacts, such as Object Constraint Language (OCL) specifications. This drawback can be overcome by application of an off-the-shelf formal method, namely one supporting automatic validation and verification. Among those, we have the increasingly popular Alloy, based on a simple relational flavor of first-order logic. This paper presents a model transformation from PSMs, optionally complemented with OCL specifications, to Alloy. Not only it enables automatic verification and validation of PSMs, but also a smooth integration of Alloy in current software development practices.Fundação para a Ciência e a Tecnologi

Towards MARTE++ : an enhanced UML-based language to Model and Analyse Real-Time and Embedded Systems for the IoT age

This paper presents requirements for an enhanced version of the UML Profile for MARTE, the current standard of the OMG for the modelling and analysis of real-time embedded systems. Since its adoption by the OMG in 2009 and after the various additions along recent years, MARTE has been essayed in a number of application domains and validation approaches. This paper makes a review of these various efforts describing extensions, additional functionality, and modeling needs that may serve as inputs for the preparation of a formal request for proposals (RFP) at the OMG. Aspects that have been found useful to have in it include modern platforms like Multi-core, Many-core and GPUs, networking for broader domains like the Internet of Things, federation of all modelling artifacts involved in the development process, including tracing mechanisms embedded in the language to link design and run-time artifacts, and more elaborated kinds of quantitative analyses and extra functional properties, like energy and memory consumption, heat dissipation, and temperature distribution. Also methodological aspects like its specification as a profile and/or as a meta-model will need to be discussed. Finally, the standard needs to be reviewed against the new executable UML related specifications; particularly to be in alignment with those semantics of state machines and composite structures.This work receives funding from the Spanish Government under grant number TIN2014-56158-C4-2-P (M2C2), and from the Electronic Component Systems for European Leadership Joint Undertaking under grant agreement No 737494 (MegaM@RT2). This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and Sweden, France, Spain, Italy, Finland, Czech Republic. We thank the anonymous reviewers for their insights and proposals of improvement

Automating Regression Test Selection for Web Services

As Web services grow in maturity and use, so do the methods which are being used to test and maintain them. Regression Testing is a major component of most major testing systems but has only begun to be applied to Web services. The majority of the tools and techniques applying regression test to Web services are focused on test-case generation, thus ignoring the potential savings of regression test selection. Regression test selection optimizes the regression testing process by selecting a subset of all tests, while still maintaining some level of confidence about the system performing no worse than the unmodified system. A safe regression test selection technique implies that after selection, the level of confidence is as high as it would be if no tests were removed. Since safe regression test selection techniques generally involve code-based (white-box) testing, they cannot be directly applied to Web services due to their loosely-coupled, standards-based, and distributed nature. A framework which automates both the regression test selection and regression testing processes for Web services in a decentralized, end-to-end manner is proposed. As part of this approach, special consideration is given to the concurrency issues which may occur in an autonomous and decentralized system. The resulting synchronization method will be presented along with a set of algorithms which manage the regression testing and regression test selection processes throughout the system. A set of empirical results demonstrate the feasibility and benefit of the approach

Contracts for Model Execution Verification

International audienceOne of the main goals of model-driven engineering is the manipulation of models as exclusive software artifacts. Model execution is in particular a means to substitute models for code. We focus in this paper on verifying model executions. We use a contract-based approach to specify an execution semantics for a meta-model. We show that an execution semantics is a seamless extension of a rigorous meta-model specification and is composed of complementary levels, from static element definition to dynamic elements, execution specifications as well. We use model transformation contracts for controlling the dynamic consistent evolution of a model during its execution. As an illustration, we apply our approach to UML state machines using OCL as the contract expression language