<p>Rising complexity in the development of real-time systems has made it crucial to have reusable components and a more flexible way of configuring these components into a coherent system. Aspect-oriented system development (AOSD) is a technique that allows one to put a system’s crosscutting concerns into"modules"that are called aspects. Applying AOSD in real-time and embedded system development one can expect reductions in the complexity of the system design and development. </p><p>A problem with AOSD in its current form is that it does not support predictability in the time domain. Hence, in order to use AOSD in real-time system development, we need to provide ways of analyzing temporal behavior of aspects, components and resulting system (made from weaving aspects and components). Aspect analyzer is a tool that computes the worst-case execution time (WCET) for a set of components and aspects, thus, enabling support for predictability in the time domain of aspect-oriented real-time software. </p><p>A limitation of the aspect analyzer, until now, were that no verification had been made whether the aspect analyzer would produce WCET values that were close to the measured or computed (with another WCET analysis technique) WCET of an aspect-oriented real-time system. Therefore, in this thesis we perform a verification of the correctness of the aspect analyzer using a number of different methods for WCET analysis. These investigations of the correctness of the output from the aspect analyzer gave confidence to the automated WCET analysis. In addition, performing this verification led to the identification of the steps necessary to compute the WCETs of a piece of program, when using a third party tool, which gives the ability to write accurate input files for the aspect analyzer.</p>

<p>During the last years the need for real-time database services has increased due to the growing number of data-intensive applications needing to enforce real-time constraints. The COMponent-based Embedded real-Time database (COMET) is a real-time database developed to meet these demands. COMET is developed using the AspeCtual COmponent-based Real-time system Development (ACCORD) design method, and consists of a number of components and aspects, which can be composed into a number of different configurations depending on system demands, e.g., Quality of Service (QoS) management can be used in unpredictable environments. </p><p>In embedded systems with requirementson high up-time it may not be possible to temporarily shut down the system for reconfiguration. Instead it is desirable to enable dynamic reconfiguration of the system, exchanging components during run-time. This in turn sets demands on the feedback control of the system to adjust to these new conditions, since a new time variant system has been created. </p><p>This thesis project implements improvements in COMET to create a more stable database suitable for further development. A mechanism for dynamic reconfiguration of COMET is implemented, thus, enabling components and aspects to be swapped during run-time. Adaptive feedback control algorithms are also implemented in order to better adjust to workload variations and database reconfiguration.</p>

<p>Increasing complexity of real-time systems and demands for enabling their configurability and tailorability are strong motivations for applying new software engineering principles such as aspect-oriented and component-based software development. The integration of these two techniques into real-time systems development would enable: (i) efficient system configuration from the components in the component library based on the system requirements, (ii) easy tailoring of components and/or a system for a specific application by changing the behavior (code) of the component by aspect weaving, and (iii) enhanced flexibility of the real-time and embedded software through the notion of system configurability and component tailorability.</p><p>In this thesis we focus on applying aspect-oriented and component-based software development to real-time system development. We propose a novel concept of aspectual component-based real-time system development (ACCORD). ACCORD introduces the following into real-time system development: (i) a design method that assumes the decomposition of the real-time system into a set of components and a set of aspects, (ii) a real-time component model denoted RTCOM that supports aspect weaving while enforcing information hiding, (iii) a method and a tool for performing worst-case execution time analysis of different configurations of aspects and components, and (iv) a new approach to modelling of real-time policies as aspects.</p><p>We present a case study of the development of a configurable real-time database system, called COMET, using ACCORD principles. In the COMET example we show that applying ACCORD does have an impact on the real-time system development in providing efficient configuration of the real-time system. Thus, it could be a way for improved reusability and flexibility of real-time software, and modularization of crosscutting concerns.</p><p>In connection with development of ACCORD, we identify criteria that a design method for component-based real-time systems needs to address. The criteria include a well-defined component model for real-time systems, aspect separation, support for system configuration, and analysis of the composed real-time system. Using the identified set of criteria we provide an evaluation of ACCORD. In comparison with other approaches, ACCORD provides a distinct classification of crosscutting concerns in the real-time domain into different types of aspects, and provides a real-time component model that supports weaving of aspects into the code of a component, as well as a tool for temporal analysis of the weaved system.</p> / Report code: LiU-TEK-LIC-2003:23.

Made available in DSpace on 2015-03-03T15:47:44Z (GMT). No. of bitstreams: 1 TassiaAVF.pdf: 1514001 bytes, checksum: a6dbf5832432db823e99d729ccf7fa2b (MD5) Previous issue date: 2009-02-20 / Nowadays, there are many aspect-oriented middleware implementations that take advantage of the modularity provided by the aspect oriented paradigm. Although the works always present an assessment of the middleware according to some quality attribute, there is not a specific set of metrics to assess them in a comprehensive way, following various quality attributes. This work aims to propose a suite of metrics for the assessment of aspect-oriented middleware systems at different development stages: design, refactoring, implementation and runtime. The work presents the metrics and how they are applied at each development stage. The suite is composed of metrics associated to static properties (modularity, maintainability, reusability, exibility, complexity, stability, and size) and dynamic properties (performance and memory consumption). Such metrics are based on existing assessment approaches of object-oriented and aspect-oriented systems. The proposed metrics are used in the context of OiL (Orb in Lua), a middleware based on CORBA and implemented in Lua, and AO-OiL, the refactoring of OIL that follows a reference architecture for aspect-oriented middleware systems. The case study performed in OiL and AO-OiL is a system for monitoring of oil wells. This work also presents the CoMeTA-Lua tool to automate the collection of coupling and size metrics in Lua source code / Atualmente, ha diversas implementa??es de sistemas de middleware orientado a aspectos que aproveitam o suporte a modulariza??o do paradigma de orienta??o a aspectos. Apesar desses trabalhos sempre apresentarem uma avalia??o do middleware de acordo com algum atributo de qualidade, n?o ha ainda um conjunto de metricas especificamente de nidas para avali?-los de forma abrangente, seguindo v?rios atributos de qualidade. Este trabalho tem como objetivo propor um conjunto de metricas para avalia??o de sistemas de middleware orientado a aspectos em diferentes fases de desenvolvimento: design, refatora??o, implementa??o e execu??o. O trabalho apresenta as metricas e como elas s?o aplicadas em cada uma das fases de desenvolvimento. O conjunto e composto por metricas associadas a propriedades estaticas (modularidade, manutenibilidade, reusabilidade, exibilidade, complexidade, estabilidade e tamanho) e din?micas (desempenho e consumo de mem oria). Tais metricas s?o baseadas em abordagens existentes de avalia??o de sistemas orientados a aspectos e a objetos. As metricas propostas s?o utilizadas no contexto do OiL (Orb in Lua), um middleware baseado em CORBA e implementado em Lua, e AO-OiL, uma refatora??o do OIL que segue uma arquitetura de refer?ncia para sistemas de middleware orientados a aspectos. O estudo de caso executado no OiL e no AO-OiL e um sistema de monitoramento de po?os de petroleo. Esse trabalho apresenta ainda a ferramenta CoMeTA-Lua para automatizar a coleta das metricas de tamanho e acoplamento em codigo-fonte Lua

The increasing complexity in the development of a configurable real-time system has emerged new principles of software techniques, such as aspect-oriented software development and component-based software development. These techniques allow encapsulation of the system's crosscutting concerns and increase the modularity of the software. The properties of a component that influences the systems performance or semantics are specified separately in entities called aspects, while basic functionality of the property still remains in the component. When building a real-time system, different sets of configurations of aspects and components can be combined, resulting in different configurations of the system. The temporal behavior of the system changes and a way to ensure the predictability of the system is needed. This thesis presents a tool for aspect-level worst-case execution time analysis, which gives a priori information about the temporal behavior of the system, before the process of composing aspects with components.

Rising complexity in the development of real-time systems has made it crucial to have reusable components and a more flexible way of configuring these components into a coherent system. Aspect-oriented system development (AOSD) is a technique that allows one to put a system’s crosscutting concerns into"modules"that are called aspects. Applying AOSD in real-time and embedded system development one can expect reductions in the complexity of the system design and development. A problem with AOSD in its current form is that it does not support predictability in the time domain. Hence, in order to use AOSD in real-time system development, we need to provide ways of analyzing temporal behavior of aspects, components and resulting system (made from weaving aspects and components). Aspect analyzer is a tool that computes the worst-case execution time (WCET) for a set of components and aspects, thus, enabling support for predictability in the time domain of aspect-oriented real-time software. A limitation of the aspect analyzer, until now, were that no verification had been made whether the aspect analyzer would produce WCET values that were close to the measured or computed (with another WCET analysis technique) WCET of an aspect-oriented real-time system. Therefore, in this thesis we perform a verification of the correctness of the aspect analyzer using a number of different methods for WCET analysis. These investigations of the correctness of the output from the aspect analyzer gave confidence to the automated WCET analysis. In addition, performing this verification led to the identification of the steps necessary to compute the WCETs of a piece of program, when using a third party tool, which gives the ability to write accurate input files for the aspect analyzer.

During the last years the need for real-time database services has increased due to the growing number of data-intensive applications needing to enforce real-time constraints. The COMponent-based Embedded real-Time database (COMET) is a real-time database developed to meet these demands. COMET is developed using the AspeCtual COmponent-based Real-time system Development (ACCORD) design method, and consists of a number of components and aspects, which can be composed into a number of different configurations depending on system demands, e.g., Quality of Service (QoS) management can be used in unpredictable environments. In embedded systems with requirementson high up-time it may not be possible to temporarily shut down the system for reconfiguration. Instead it is desirable to enable dynamic reconfiguration of the system, exchanging components during run-time. This in turn sets demands on the feedback control of the system to adjust to these new conditions, since a new time variant system has been created. This thesis project implements improvements in COMET to create a more stable database suitable for further development. A mechanism for dynamic reconfiguration of COMET is implemented, thus, enabling components and aspects to be swapped during run-time. Adaptive feedback control algorithms are also implemented in order to better adjust to workload variations and database reconfiguration.

Increasing complexity of real-time systems and demands for enabling their configurability and tailorability are strong motivations for applying new software engineering principles such as aspect-oriented and component-based software development. The integration of these two techniques into real-time systems development would enable: (i) efficient system configuration from the components in the component library based on the system requirements, (ii) easy tailoring of components and/or a system for a specific application by changing the behavior (code) of the component by aspect weaving, and (iii) enhanced flexibility of the real-time and embedded software through the notion of system configurability and component tailorability. In this thesis we focus on applying aspect-oriented and component-based software development to real-time system development. We propose a novel concept of aspectual component-based real-time system development (ACCORD). ACCORD introduces the following into real-time system development: (i) a design method that assumes the decomposition of the real-time system into a set of components and a set of aspects, (ii) a real-time component model denoted RTCOM that supports aspect weaving while enforcing information hiding, (iii) a method and a tool for performing worst-case execution time analysis of different configurations of aspects and components, and (iv) a new approach to modelling of real-time policies as aspects. We present a case study of the development of a configurable real-time database system, called COMET, using ACCORD principles. In the COMET example we show that applying ACCORD does have an impact on the real-time system development in providing efficient configuration of the real-time system. Thus, it could be a way for improved reusability and flexibility of real-time software, and modularization of crosscutting concerns. In connection with development of ACCORD, we identify criteria that a design method for component-based real-time systems needs to address. The criteria include a well-defined component model for real-time systems, aspect separation, support for system configuration, and analysis of the composed real-time system. Using the identified set of criteria we provide an evaluation of ACCORD. In comparison with other approaches, ACCORD provides a distinct classification of crosscutting concerns in the real-time domain into different types of aspects, and provides a real-time component model that supports weaving of aspects into the code of a component, as well as a tool for temporal analysis of the weaved system. / <p>Report code: LiU-TEK-LIC-2003:23.</p>

Made available in DSpace on 2014-12-17T15:47:47Z (GMT). No. of bitstreams: 1 AnaLFM.pdf: 903790 bytes, checksum: 70d26a43bc5418b76d2ecdc1716d862c (MD5) Previous issue date: 2008-06-09 / Aspect Oriented approaches associated to different activities of the software development process are, in general, independent and their models and artifacts are not aligned and inserted in a coherent process. In the model driven development, the various models and the correspondence between them are rigorously specified. With the integration of aspect oriented software development (DSOA) and model driven development (MDD) it is possible to automatically propagate models from one activity to another, avoiding the loss of information and important decisions established in each activity. This work presents MARISA-MDD, a strategy based on models that integrate aspect-oriented requirements, architecture and detailed design, using the languages AOV-graph, AspectualACME and aSideML, respectively. MARISA-MDD defines, for each activity, representative models (and corresponding metamodels) and a number of transformations between the models of each language. These transformations have been specified and implemented in ATL (Atlas Definition Language), in the Eclipse environment. MARISA-MDD allows the automatic propagation between AOV-graph, AspectualACME, and aSideML models. To validate the proposed approach two case studies, the Health Watcher and the Mobile Media have been used in the MARISA-MDD environment for the automatic generation of AspectualACME and aSideML models, from the AOV-graph model / As abordagens orientadas a aspectos relacionadas a diferentes atividades do processo de desenvolvimento de software s?o, em geral, independentes e os seus modelos e artefatos n?o est?o alinhados ou inseridos em um processo coerente. No desenvolvimento orientado a, modelos, os diversos modelos e a correspond?ncia entre eles s?o especificados com rigor. Com a integra??o do desenvolvimento orientado a aspectos (DSOA) e o desenvolvimento baseado em modelos (MDD) pode-se automaticamente propagar modelos de uma atividade para outra atividade, evitando a perda de informa??es e de decis?es importantes estabelecidas em cada atividade. Este trabalho apresenta MARISA-MDD, uma estrat?gia baseada em modelos que integra as atividades de requisitos, arquitetura e projeto detalhado orientado a aspectos, usando as linguagens AOV-graph, AspectualACME e aSideML, respectivamente. MARISA-MDD define, para cada atividade, modelos representativos (e metamodelos correspondentes) e um conjunto de transforma??es entre os modelos de cada linguagem. Tais transforma??es foram especificadas e implementadas em ATL (Atlas Definition Language), no ambiente Eclipse. MARISA-MDD permite a propaga??o autom?tica entre modelos AOV-graph, AspectualACME e aSideML. Para validar a abordagem proposta dois estudos de caso, o Health Watcher e o Mobile Media foram usados no ambienteMARISA-MDD para gera??o autom?tica dos modelos AspectualACME e aSideML, a partir do modelo AOV-graph

Made available in DSpace on 2014-12-17T15:47:51Z (GMT). No. of bitstreams: 1 GeamCA_3.pdf: 4100171 bytes, checksum: a5754ac2b6b60fbd217e904c104737e4 (MD5) Previous issue date: 2009-08-11 / This paper proposes a systematic approach to management of variability modelsdriven and aspects using the mechanisms of approaches Aspect-Oriented Software Development (AOSD) and Model-Driven Development (MDD). The main goal of the approach, named CrossMDA-SPL, is to improve the management(ger?ncia), modularization and isolation ou separation of the variability of the LPSs of architecture in a high level of abstraction (model) at the design and implementing phases of development Software Product Lines (SPLs), exploiting the synergy between AOSD and MDD. The CrossMDA-SPL approach defines some artifacts basis for advance the separation clear in between the mandatory (bounden) and optional features in the architecture of SPL. The artifacts are represented by two models named: (i) core model (base domain) - responsible for specify the common features the all members of the SPL, and (ii) variability model - responsible for represent the variables features of SPL. In addition, the CrossMDA-SPL approach is composed of: (i) guidelines for modeling and representation of variability, (ii) CrossMDA-SPL services and process, and (iii) models of the architecture of SPL or product instance of SPL. The guidelines use the advantages of AOSD and MDD to promote a better modularization of the variable features of the architecture of SPL during the creation of core and variability models of the approach. The services and sub-processes are responsible for combination automatically, through of process of transformation between the core and variability models, and the generation of new models that represent the implementation of the architecture of SPL or a instance model of SPL. Mechanisms for effective modularization of variability for architectures of SPL at model level. The concepts are described and measured with the execution of a case study of an SPL for management systems of transport electronic tickets / Este trabalho prop?e uma abordagem sistem?tica para ger?ncia de variabilidades dirigida por Modelos e Aspectos usando os mecanismos das abordagens de Desenvolvimento de Software Orientado a Aspectos (DSOA) e Desenvolvimento Dirigido por Modelos (DDM). O objetivo central da abordagem, denominada CrossMDA-SPL, ? melhorar a ger?ncia, modulariza??o e isolamento das variabilidades da arquitetura de LPSs em um n?vel de abstra??o alto (modelo) nas fases de projeto e implementa??o de dom?nio de desenvolvimento de Linhas de Produto de Software (LPSs), explorando a sinergia entre o DSOA e DDM. A abordagem CrossMDA-SPL define alguns artefatos base para promover a separa??o clara entres as features mandat?rias (obrigat?rias) e opcionais na arquitetura da LPS. Os artefatos s?o representados por dois modelos denominados: (i) modelo do n?cleo (dom?nio base) respons?vel por especificar as features comuns a todos os membros da LPS; e (ii) modelo de variabilidades respons?vel por representar as features vari?veis da LPS. Em adi??o, a abordagem CrossMDA-SPL ? composta por: (i) diretrizes para modelagem e representa??o das variabilidades; (ii) servi?os e processo CrossMDA-SPL; e (iii) modelos da arquitetura da LPS ou inst?ncia do produto da LPS. As diretrizes utilizam as vantagens de DSOA e DDM para promover uma melhor modulariza??o das features vari?veis da arquitetura da LPS durante a cria??o dos modelos do n?cleo e de variabilidades da abordagem. Os servi?os e subprocessos s?o respons?veis pela combina??o autom?tica, atrav?s de processos de transforma??o, entre os modelos de n?cleo e variabilidades, e a gera??o dos novos modelos que representam a implementa??o da arquitetura de LPS ou um modelo de inst?ncia da LPS. Apresentamos mecanismos para uma eficaz modulariza??o de variabilidades para arquiteturas de LPS no n?vel de modelo. Os conceitos s?o mostrados e avaliados com a execu??o de um estudo de caso de uma LPS para sistemas de gerenciamento de bilhetes eletr?nicos de transporte.