Reuse is not a new concept in software engineering. Ideas, abstractions, and processes have been reused by programmers since the very early days of software development. In the beginning, since storage media was very expensive, software reuse was basically to serve computers and their mechanical resources, as it substantially conserved memory. When the limitations on physical resources started to diminish, software engineers began to invent reuse approaches to save human resources as well. In addition, as the size and complexity of software systems constantly grow, organized and systematic reuse becomes essential in order to develop those systems in timely and cost-effective fashion. That is one main reason why new technologies and approaches for building software systems, such as object-oriented and component-based development, emerged in the last two or three decades. The focus of this thesis is on software components as building blocks of today's software systems. We consider components as software black boxes whose specification and external behavior are known. We assume that this information can somehow be extracted for each deployed software component. The first and basic assumption then would be the availability of a searchable repository of software components and their external behavioral specifications. Web services are a good example of such components. The most important advantage of software components is that they can be reused repeatedly in building different software systems. Reuse presents challenging problems, one of which is studied in this thesis. This problem, the composition problem, simply is creating a composite component from a collection of available components that, by interacting with each other, provide a requested functionality. When there are a large number of components available to be reused, finding a solution to the composition problem manually would require a considerable time and human effort. This could make the search practically impossible or unwieldy. However, performing the search automatically would save a significant amount of development time, cost and human effort. Solving this problem would be a huge step forward in the component-based software development. In this thesis, we concentrate on a subproblem of the composition problem, composition planning or synthesis, which is defined as finding a collection of useful components from the repository and the necessary communications among them to satisfy a requested functionality. For scalability purposes, we study automatic solutions to composition planning and propose two approaches in this regard. In one, we take advantage of graphs to model the repository, which is the collection of available components along with their behavioral specification. Graph search algorithms and a few composition-specific algorithms are used to find solutions for given component requests. In the other approach, we extend a logical reasoning algorithm and come up with algorithms for solving the composition planning problem. In both approaches we provide algorithms for finding the possibility of a composition, as well as finding the composition itself. We propose different types of composition and show how applying each would impact the behavior of a composite component. We provide the necessary formalism for capturing these types of composition through two different models: interface automata and composition algebra. Interface automata is an automaton-based model for representing the behavior of software components. The other model in this regard is composition algebra, which is an algebraic model based on CSP (Communicating Sequential Processes), CCS (Calculus of Communicating Systems), and interface automata. These formal models are used to validate the results returned by the composition approaches. We also compare the two composition approaches and show why each of them is suitable for specific types of the problem according to the repository attributes. We then evaluate the performance of the reasoning-based approach and provide some experimental results. In these experiments, we study how different attributes of the repository components could impact the performance of the reasoning-based approach in solving the composition planning problem.

Reuse is not a new concept in software engineering. Ideas, abstractions, and processes have been reused by programmers since the very early days of software development. In the beginning, since storage media was very expensive, software reuse was basically to serve computers and their mechanical resources, as it substantially conserved memory. When the limitations on physical resources started to diminish, software engineers began to invent reuse approaches to save human resources as well. In addition, as the size and complexity of software systems constantly grow, organized and systematic reuse becomes essential in order to develop those systems in timely and cost-effective fashion. That is one main reason why new technologies and approaches for building software systems, such as object-oriented and component-based development, emerged in the last two or three decades. The focus of this thesis is on software components as building blocks of today's software systems. We consider components as software black boxes whose specification and external behavior are known. We assume that this information can somehow be extracted for each deployed software component. The first and basic assumption then would be the availability of a searchable repository of software components and their external behavioral specifications. Web services are a good example of such components. The most important advantage of software components is that they can be reused repeatedly in building different software systems. Reuse presents challenging problems, one of which is studied in this thesis. This problem, the composition problem, simply is creating a composite component from a collection of available components that, by interacting with each other, provide a requested functionality. When there are a large number of components available to be reused, finding a solution to the composition problem manually would require a considerable time and human effort. This could make the search practically impossible or unwieldy. However, performing the search automatically would save a significant amount of development time, cost and human effort. Solving this problem would be a huge step forward in the component-based software development. In this thesis, we concentrate on a subproblem of the composition problem, composition planning or synthesis, which is defined as finding a collection of useful components from the repository and the necessary communications among them to satisfy a requested functionality. For scalability purposes, we study automatic solutions to composition planning and propose two approaches in this regard. In one, we take advantage of graphs to model the repository, which is the collection of available components along with their behavioral specification. Graph search algorithms and a few composition-specific algorithms are used to find solutions for given component requests. In the other approach, we extend a logical reasoning algorithm and come up with algorithms for solving the composition planning problem. In both approaches we provide algorithms for finding the possibility of a composition, as well as finding the composition itself. We propose different types of composition and show how applying each would impact the behavior of a composite component. We provide the necessary formalism for capturing these types of composition through two different models: interface automata and composition algebra. Interface automata is an automaton-based model for representing the behavior of software components. The other model in this regard is composition algebra, which is an algebraic model based on CSP (Communicating Sequential Processes), CCS (Calculus of Communicating Systems), and interface automata. These formal models are used to validate the results returned by the composition approaches. We also compare the two composition approaches and show why each of them is suitable for specific types of the problem according to the repository attributes. We then evaluate the performance of the reasoning-based approach and provide some experimental results. In these experiments, we study how different attributes of the repository components could impact the performance of the reasoning-based approach in solving the composition planning problem.

This thesis describes the primary goal of the HelenOS microkernel multiserver operating system. The primary goal of the HelenOS project is to create a comprehensive research and development platform in the domain of general-purpose operating systems that would support state-of-the-art approaches and methods (such as verification of correctness) while at the same time focusing on practical relevance. The text of the thesis describes what specific means in terms of design (based on software components), implementation, development process and verification are used to achieve the primary goal. The thesis also evaluates the current state of HelenOS. Powered by TCPDF (www.tcpdf.org)

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A contribuiÃÃo das tradicionais bibliotecas cientÃcas mostra-se consolidada na construÃÃo de aplicaÃÃes de alto desempenho. No entanto, tal artefato de desenvolvimento possui algumas limitaÃÃes de integraÃÃo, de produtividade em aplicaÃÃes de larga escala e de exibilidade para mudanÃas no contexto do problema. Por outro lado, a tecnologia de desenvolvimento baseada em componentes, recentemente proposta como alternativa viÃvel para a arquitetura de aplicaÃÃes de ComputaÃÃo de Alto Desempenho (CAD), tem fornecido meios para superar esses desaos. Vemos assim, que as bibliotecas cientÃcas e a programaÃÃo orientada a componentes sÃo tÃcnicas complementares na melhoria do processo de desenvolvimento de aplicaÃÃes modernas de CAD. Dessa forma, este trabalho tem por objetivo propor um mÃtodo sistemÃtico para integraÃÃo de bibliotecas cientÃcas sobre a plataforma de componentes paralelos HPE (Hash Programming Environment ), buscando oferecer os aspectos vantajosos complementares do uso de componentes e de bibliotecas cientÃcas aos desenvolvedores de programas paralelos que implementam aplicaÃÃes de alto desempenho. A proposta deste trabalho vai alÃm da construÃÃo de um simples encapsulamento da biblioteca em um componente, visa proporcionar ao uso das bibliotecas cientÃcas os benefÃcios de integraÃÃo, de produtividade em aplicaÃÃes de larga escala e da exibilidade para mudanÃas no contexto do problema. Como forma de exemplicar e validar o mÃtodo, temos incorporado bibliotecas de resoluÃÃo de sistemas lineares ao HPE, elegendo trÃs representantes significativos: PETSc, Hypre e SuperLU. / The contribution of traditional scientic libraries shows to be consolidated in the construction of high-performance applications. However, such an artifact of development possesses some limitations in integration, productivity in large-scale applications, and exibility for changes in the context of the problem. On the other hand, the development technology based on components recently proposed a viable alternative for the architecture of High-Performance Computing (HPC) applications, which has provided a means to overcome these challenges. Thus we see that the scientic libraries and programming orientated at components are complementary techniques in the improvement of the development process of modern HPC applications. Accordingly, this work aims to propose a systematic method for the integration of scientic libraries on a platform of parallel components, HPE (Hash Programming Environment), to oer additional advantageous aspects for the use of components and scientic libraries to developers of parallel programs that implement high-performance applications. The purpose of this work goes beyond the construction of a simple encapsulation of the library in a component; it aims to provide the benets in integration, productivity in large-scale applications, and the exibility for changes in the context of a problem in the use of scientic libraries. As a way to illustrate and validate the method, we have incorporated the libraries of linear systems solvers to HPE, electing three signicant representatives: PETSc, Hypre, e SuperLU.

Sistemas distribuídos têm se mostrado altamente heterogêneos e dinâmicos, mudanças acontecem constantemente e rapidamente. Uma abordagem largamente adotada no desenvolvimentode sistemas distribuídos é a do desenvolvimento baseado em componentes, que permite desenvolver softwares flexíveis através da composição de componentes individuais.Mas, com a grande diversidade de modelos de componentes, cada modelo possui sua especificidade de desenvolvimento e nativamente estes não possuem interoperabilidade. O desenvolvimento de métodos de comunicação remota e o deployment distribuído são tarefas difíceis que contribuem no aumento da complexidade. Considerando toda essa complexidade, os esforços destinados ao desenvolvimento de código técnico para sistemas distribuídos são obstáculos que desencorajam desenvolvedores. Neste cenário apresentamos o HighFrame - uma solução integrada para desenvolvimento em alto nível e deployment automático que tem como propósito reduzir a complexidade do desenvolvimento de sistemas distribuídos baseados em componentes heterogêneos. Com esta solução o desenvolvedor mantém o foco de desenvolvimento no negócio da aplicação. Ele utiliza anotações e um planejador gráfico para definir componentes e a arquitetura do sistema distribuído. O HighFrame desempenha o processo de deployment automaticamente e abstrai do desenvolvedor a complexidade de modelos de componentes, métodos de comunicação remota e interoperabilidade entre componentes heterogêneos.

[pt] O desenvolvimento baseado em sistemas de componentes de software consiste em compor sistemas a partir de unidades de sotfware prontas e reutilizáveis. Muitos sistemas de componentes software em produção, precisam ficar disponíveis durante 24 horas por dia nos 7 dias da semana. Atualizações dinâmicas permitem que os sistemas sejam atualizados sem interromperem a execução dos seus serviços, aplicando a atualização em tempo de execução. Muitas técnicas de atualização dinâmica, na literatura, utilizam aplicações feitas especificamente para cobrir os pontos implementados e poucas utilizam um histórico de necessidades de um sistema real. Este trabalho estuda os principais casos de atualizações que ocorrem em um sistema de componentes de uso extenso, o Openbus, que consiste em uma infraestrutura de integração responsável pela comunicação de diversas aplicações de aquisição, processamento e interpretação de dados. Além deste estudo, implementamos uma solução de atualização dinâmica para acomodar as necessidades deste sistema. Depois, utilizando a solução implementada, apresentamos um teste de sobrecarga e algumas aplicações de atualizações do Openbus. / [en] The component-based development of software systems consists on composing systems from ready and reusable sotfware units. Many software componente systems on production, need to be available 24 hours a day 7 days a week. Dynamic updates allow systems to be upgraded without interrupting the execution of its services, applying the update at runtime. Many dynamics software update techniques in the literature use applications specically implemented to cover the presented points and only a few use a historical need of a real system. This work studies the main cases of updates that occur in a system of components with extensive use, the Openbus, which consists of an integration infrastructure responsible for communication of various applications for acquisition, processing and interpretation of data. In addition to this study, we implement a solution of dynamic software update to accommodate the needs of this system. After, using the implemented solution, we present an overhead test and applications of updates on Openbus.

[pt] Este trabalho apresenta uma plataforma para aplicações baseadas em serviços. Esta plataforma foi concebida para dar suporte ao compartilhamento de informações serviços usando diferentes dispositivos. Através do uso de padrões abertos e de uma abordagem totalmente distribuída, Everyware permite que os usuários finais possam disponibilizar serviços sem necessidade de configuração ou administração. Estes serviços podem ser marcados semanticamente e integrados à Web semântica, o que permite que sejam processados automaticamente por máquinas. A plataforma ainda oferece uma arquitetura padrão para o desenvolvimento de aplicações e uma API para o desenvolvimento de mecanismos de coordenação de serviços que integra os diversos aspectos presentes em aplicações baseadas em serviços. / [en] This work addresses issues on the development of service- oriented web applications on the semantic web. It presents a platform conceived to support information sharing among different services accessed by different devices and hardware infraestructure. Using open standards and a totally distributed approach, everyware allows users to publish their services without need to configuration and administration. Services can also be semantically tagged and integrated to the Semantic Web, so they can be easily preocessed by machines. Everyware platform offers a standard architecture to application development and an API to the development of coordination mechanisms. It integrates most concerns that are present in service- oriented applications.

Our main focus in this thesis is on providing guidelines, methods, and tools for design, configuration, and analysis of configurable and reusable real-time software, developed using a combination of aspect-oriented and component-based software development. Specifically, we define a reconfigurable real-time component model (RTCOM) that describes how a real-time component, supporting aspects and enforcing information hiding, could efficiently be designed and implemented. In this context, we outline design guidelines for development of real-time systems using components and aspects, thereby facilitating static configuration of the system, which is preferred for hard real-time systems. For soft real-time systems with high availability requirements we provide a method for dynamic system reconfiguration that is especially suited for resourceconstrained real-time systems and it ensures that components and aspects can be added, removed, or exchanged in a system at run-time. Satisfaction of real-time constraints is essential in the real-time domain and, for real-time systems built of aspects and components, analysis is ensured by: (i) a method for aspectlevel worst-case execution time analysis; (ii) a method for formal verification of temporal properties of reconfigurable real-time components; and (iii) a method for maintaining quality of service, i.e., the specified level of performance, during normal system operation and after dynamic reconfiguration. We have implemented a tool set with which the designer can efficiently configure a real-time system to meet functional requirements and analyze it to ensure that non-functional requirements in terms of temporal constraints and available memory are satisfied. In this thesis we present a proof-of-concept implementation of a configurable embedded real-time database, called COMET. The implementation illustrates how our methods and tools can be applied, and demonstrates that the proposed solutions have a positive impact in facilitating efficient development of families of realtime systems.

Made available in DSpace on 2014-12-17T15:47:50Z (GMT). No. of bitstreams: 1 IvanilsonFVJ.pdf: 1175067 bytes, checksum: 36d08791e1658b3543761ec05cd15028 (MD5) Previous issue date: 2009-03-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / To manage the complexity associated with the management of multimedia distributed systems, a solution must incorporate concepts of middleware in order to hide specific hardware and operating systems aspects. Applications in these systems can be implemented in different types of platforms, and the components of these systems must interact each with the other. Because of the variability of the state of the platforms implementation, a flexible approach should allow dynamic substitution of components in order to ensure the level of QoS of the running application . In this context, this work presents an approach in the layer of middleware that we are proposing for supporting dynamic substitution of components in the context the Cosmos framework , starting with the choice of target component, rising taking the decision, which, among components candidates will be chosen and concluding with the process defined for the exchange. The approach was defined considering the Cosmos QoS model and how it deals with dynamic reconfiguration / Para tratar a complexidade associada ao gerenciamento dos sistemas multim?dia distribu?dos, uma solu??o deve incorporar conceitos de middleware de forma a abstrair especificidades de hardware e sistemas operacionais. Aplica??es nesses sistemas podem ser executadas em diferentes tipos de plataformas, e os componentes destes sistemas precisam interagir uns com os outros. Devido ? variabilidade dos estados das plataforma de execu??o, uma abordagem flex?vel deve permitir a troca din?mica de componentes visando garantir o n?vel de QoS da aplica??o em execu??o. Neste contexto, o presente trabalho apresenta uma abordagem na camada de middleware para a realiza??o de troca din?mica de componentes no contexto do framework Cosmos, iniciando com a escolha do componente alvo para a troca, passando pela tomada de decis?o de qual, entre os componentes candidatos, ser? escolhido e concluindo com o processo definido para a troca. A abordagem foi definida com base nos requisitos de QoS considerados no framework Cosmos de maneira a suportar a reconfigura??o din?mica de componentes

[pt] Groupware é evolutivo e é difícil de construir e de manter, e acaba tendo um código desorganizado e difícil de evoluir. Nesta tese é proposta uma abordagem de desenvolvimento de groupware baseado em componentes concebidos em função do modelo 3C de colaboração. No modelo 3C, a colaboração é analisada a partir da comunicação, coordenação e cooperação. Na abordagem proposta, partese das necessidades de colaboração do grupo, analisadas com base no modelo, e componentes de software também organizados em função do modelo são utilizados para compor a solução. Como estudo de caso, a abordagem é aplicada no desenvolvimento da nova versão do ambiente AulaNet, cujo código padece dos problemas mencionados anteriormente. Neste estudo de caso, são desenvolvidos component kits para instanciar os serviços de comunicação do ambiente. Os componentes possibilitam compor, recompor e customizar os serviços de modo a refletir alterações na dinâmica de colaboração. / [en] Groupware is evolutionary and difficult to develop and maintain. Thus, its code becomes unstructured and difficult to evolve. In this thesis, a groupware development approach based on components organized according to the 3C collaboration model is proposed. In this model, collaboration is analyzed based on communication, coordination and cooperation. Collaboration necessities of the group, analyzed based on the 3C model, are mapped to software components, also organized according to the model, in order to compose the system. The proposed approach is applied as a case study to the development of the new version of the AulaNet environment. The environment´s code currently suffers the mentioned problems. In order to instantiate the communication services of the environment, for the case study, 3C based component kits were developed. The components allow the composition, re-composition and customization of the services in order to reflect collaboration dynamics changes.