In this thesis, we studied a component-based software design for componentizing Linux kernel. Our goal is to componentize kernel modules and explicitly define the dependency relation of components in the kernel. Componentization can greatly improve composability, evolvability, extensibility and testability of a software system, and can thus increase the productivity of software development and reduce the cost of maintenance. On top of the componentized kernel, we developed a suite of tools to facilitate the operations on kernel components. In the component-based design, the basic software unit is a component. We envision any subsystem in kernel as a composition of components. To realize the concept, we explicitly create the output ports by augmenting the symbol table of a kernel module to record the relocation information, i.e., the locations where the module invokes the functions exported by other modules. We developed tools to discover the data passing among components such that the dependency relation among components can be clearly disclosed. With componentization in place, we are able to implement the hot-swapping technique which allows the system structure to be dynamically changed at run time. The technique makes it possible to test, swap or re-compose components when part of the system cannot be terminated or removed. The proposed system is implemented on Linux kernel 2.6.17.1. While our componentization does not introduce any time overhead when modules are in action, we evaluated our approach in terms of module loading time, memory consumption and hot-swapping time. We found that the module loading time and memory consumption of a componentized module are both proportional to the number of relocations in the module. The hot-swapping time is related to the position of the symbol to be swapped in the symbol table. All these suggest that we still have room to improve the way we realized the componentization in Linux kernel.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 118 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 45-46).

Made available in DSpace on 2014-06-12T15:49:28Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Um grande desafio da Engenharia de Software Baseada em Componentes (ESBC) é a qualidade dos componentes utilizados em um sistema. A confiabilidade de um sistema baseado em componentes depende da confiabilidade dos componentes dos quais ele é composto. Na ESBC, a busca, seleção e avaliação de componentes de software é considerado um ponto chave para o efetivo desenvolvimento de sistemas baseado em componentes. Até agora a indústria de software tem se concentrado nos aspectos funcionais dos componentes de software, deixando de lado uma das tarefas mais árduas, que é a avaliação de sua qualidade. Se a garantia de qualidade de componentes desenvolvidos in-house é uma tarefa custosa, a garantia da qualidade utilizando componentes desenvolvidos externamente os quais frequentemente não se tem acesso ao código fonte e documentação detalhada se torna um desafio ainda maior. Assim, esta Tese introduz um Framework de Qualidade de Componentes de Software, baseado em módulos bem definidos que se complementam a fim de garantir a qualidade dos componentes de software. Por fim, um estudo experimental foi desenvolvido e executado de modo que se possa analisar a viabilidade do framework proposto

Made available in DSpace on 2014-06-12T15:57:59Z (GMT). No. of bitstreams: 2 arquivo3240_1.pdf: 2429983 bytes, checksum: 9b9eff719ea26a708f6868c5df873358 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Universidade de Pernambuco / Um dos maiores desafios para a indústria de embarcados é fornecer produtos com alto nível de qualidade e funcionalidade, a um baixo custo e curto tempo de desenvolvimento, disponibilizando-o rapidamente ao mercado, aumentando assim, o retorno dos investimentos. Os requisitos de custo e tempo de desenvolvimento têm sido abordados com bastante êxito pela engenharia de software baseada em componentes (CBSE) aliada à técnica de reuso de componentes. No entanto, a utilização da abordagem CBSE sem as devidas verificações da qualidade dos componentes utilizados, pode trazer conseqüências catastróficas (Jezequel et al., 1997). A utilização de mecanismos apropriados de pesquisa, seleção e avaliação da qualidade de componentes são considerados pontos chave na adoção da abordagem CBSE. Diante do exposto, esta tese propõe uma Metodologia para Avaliação da Qualidade de Componentes de Software Embarcados sob diferentes aspectos. A idéia é solucionar a falta de consistência entre as normas ISO/IEC 9126, 14598 e 2500, incluindo o contexto de componente de software e estendendo-o ao domínio de sistemas embarcados. Estas normas provêem definições de alto nível para características e métricas para produtos de software, mas não provêem formas de usá-las efetivamente, tornando muito difícil aplicá-las sem adquirir mais informações de outras fontes. A Metodologia é composta de quatro módulos que se complementam em busca da qualidade, através de um processo de avaliação, um modelo de qualidade, técnicas de avaliação agrupadas por níveis de qualidade e uma abordagem de métricas. Desta forma, ela auxilia o desenvolvedor de sistemas embarcado no processo de seleção de componentes, avaliando qual componente melhor se enquadra nos requisitos do sistema. É utilizada por avaliadores terceirizados quando contratados por fornecedores a fim de obter credibilidade em seus componentes. A metodologia possibilita avaliar a qualidade do componente embarcado antes do mesmo ser armazenado em um sistema de repositório, especialmente no contexto do framework robusto para reuso de software, proposto por Almeida (Almeida, 2004)

A software component model is the cornerstone of any Component-based Software Development (CBSD) methodology. Such a model defines the modelling elements for constructing software systems. In software system modelling, it is necessary to capture the three elements of a system's behaviour: (i) control (ii) computation and (iii) data. Within a system, computations are performed according to the flow of control or the flow of data, depending on whether computations are control-driven or data-driven. Computations are function evaluations, assignments, etc., which transform data when invoked by control or data flow. Therefore a component model should be able to model control flow, data flow as well as computations. Current component models all model computations, but beside computations tend to model either control flow only or data flow only, but not both. In this thesis, we present a new component model which can model both control flow and data flow. It contains modelling elements that capture control flow and data flow explicitly. Furthermore, the modelling of control flow is separate from that of data flow; this enables the modelling of both control-driven and data-driven computations. The feasibility of the model is shown by means of an implementation of the model, in the form of a prototype tool. The usefulness of the model is then demonstrated for a specific domain, the embedded systems domain, as well as a generic domain. For the embedded systems domain, unlike current models, our model can be used to construct systems that are both control-driven and data-driven. In a generic domain, our model can be used to construct domain models, by constructing control flows and data flows which together define a domain model.

如同硬體元件的模組化，軟體元件的模組化在應用系統開發領域也取得的普遍的認知。以Web為基礎的應用系統在分散式運算環境中日趨重要。美國昇陽公司開發Servlet & JSP技術來作為網際網路應用系統開發的工具。在本研究中採用 Model-View-Controller架構，就網際網路應用系統開發中的模組化趨勢透過使用 Servlet & JSP技術來加以檢驗。為了實作的需要，採用了農民曆法轉換程式來作為處理Model部份之運算邏輯。最後並自然導引出從系統開發過成中合理有效之人力資源配置原則。 / Just like the modularization of hardware component, the trend of modularization of software component has gained also general recognition in the field of application system development. Recently, web-based application has become more and more important in the distributed computing environment. The Sun Inc. has been developing the servlet & JSP technology to be used for developing interactive web application. In this research, a software component study following the model-view-Controller architecture is inspected to verify the software modularization trend in the web application development using servlet & JSP technology. For implementation purpose, a business logic dealing with Chinese Calendar Transformation is selected as the model part. The implication of human resource allocation from point of view the application system development is also outlined as a deductive conclusion.

系統設計階段的主要目的是將系統分析模型轉換成足以規範實作人員進行程式撰寫的設計模型，以提昇系統效能及再用效益。並且讓設計結果符合非功能需求、實作環境以及效能需求等限制。其重心應放在將系統的設計最佳化，並確保設計模型已涵蓋全部的需求。但對於物件導向程式設計經驗較為不足的開發人員而言，這樣的過程不但費時費力，而且往往浪費資源於解決已有標準解答的問題。若是能將設計樣式的概念融入元件式系統的設計過程中，將可導引系統設計人員快速的將前人所累積的物件導向程式設計經驗應用於開發中元件式系統的設計上，避免無謂的資源浪費。本研究將以Gamma等四位學者所提出的二十三個設計樣式為基礎，發展一套設計樣式導入流程。並以一雛型系統為例，說明系統設計者如何在進行元件式系統設計時，以本研究提供的設計樣式導入流程，將設計樣式逐步導入開發中系統，藉此縮短系統開發時程、提升系統功能擴充性和元件再用性、降低日後維護系統的困難度，並可在系統開發過程中，對所有曾採用的設計樣式進行記錄，做為專案管理以及日後開發類似系統的重要參考。 / The primary purpose of system design phase is to transform the analysis model into the design model which is definite enough to generate programming code. Besides, the result of design should satisfy the nonfunctional requirement, implementation environment and efficiency requirement. The focus should be on the optimization of design to ensure the design model satisfying all kinds of requirements. However, the inexperienced object-oriented system designers usually spend a lot of time and energy to solve problems which already have standard answers. The concept of design patterns can be used in the design phase to guide system designers to apply the accumulated object-oriented programming experience to avoid wasting resources. This research intends to establish a systematic approach for applying the design patterns to the component-based system development process. This approach is based on the most popular twenty-three design patterns provided by Gamma et al. A prototype is also established to demonstrate the step by step process in adopting the design patterns during the component-based system development process. The proposed approach should increase the software reusability and maintenance, as well as reduce the developing schedule and cost. Furthermore, the systematic approach of adopting the design patterns can be incorporated into the project management guidelines as the important reference for future system development.

Business goals of manufacturing systems are typically in a state of constant change and greater rates of change are predicted in the future. Whereas contemporary approaches to the design and construction of these systems often results in inflexible enterprises that cannot readily be tuned to changing business goals. This study has specified and prototyped the use of a new model-driven approach to the design and (re)configuration of"change capable" manufacturing cells. Manufacturing cells represent a typical domain of manufacturing systems in which the existence of inflexible links between tasks and resources can result in sub-optimal performance and an inability to cope with change. The approach is based on a) the use of a semi-generic model of manufacturing cells, that structures and targets the use of CIMOSA modelling constructs (as implemented by the SEWOSA tool) towards producing a requirements specification and conceptual design in the form of a graphical and computer executable model of a particular manufacturing cell, and b) the complementary use of new computer executable modelling constructs and tools, that structure and support the detailed design and runtime operation of a particular cell in the form of an explicit, model-based configuration of cell resources and software components that realise the control processes required in a particular cell. Part of the semi-generic model comprises descriptions of common tasks found in a given domain of manufacturing cells. That part of the model has been captured and formalised by using CIMOSA modelling constructs. A new development of this modelling structure allows pre- modelled tasks to be selected, detailed and organised and suitable resources and reusable control system components (or building blocks) assigned to groups of tasks. Thereby this new approached to designing and building manufacturing cells can facilitate rapid and effective design and reconfiguration of manufacturing cell control systems. General information requirements found during the modelling and real world application of target cells, have also been formally defined and are met by using a suitable modelling structure and specially developed tools. Furthermore, the research has shown how modelled sets of software component building blocks can be specified and implemented as modular, reusable elements of manufacturing cell control systems. New modelling structures have been conceived and fonnalised and examples of their use evaluated under laboratory conditions. The research has also deployed and developed pre-existing enterprise modelling concepts and integration tools, including CIMOSA, STEP, EXPRESS, CIMBIOSYS infrastructure services and component-based software design concepts. This has enable the creation of a prototype tool-set that demonstrates how the concepts can be beneficially applied. The main contributions made by this research are that: a) It proposes and develops an approach to the design of manufacturing cell systems that successfully bridges a previous gap between top-down modelling concepts, methods and tools (that typically support formal modelling of system requirements, tasks and resources) and bottom-up detailed design and build techniques that lead to the operation, control and monitoring of real cells, b) It provides a modelling and implementation structure that 'integrates' the use of a classical enterprise modelling approach (namely CIMOSA), design primarily to support the designers of manufacturing systems, to the emerging component-based design and build concepts, that are becoming popular with software and system vendors.

Dentre as tecnologias de desenvolvimento de software que promovem o reuso com o objetivo de construir sistemas com prazos e custos menores, sem sacrificar a qualidade dos produtos, está o Desenvolvimento Baseado em Componentes (DBC). O Desenvolvimento Baseado em Componentes consiste na construção de sistemas pela composição de componentes de software de acordo com um processo de desenvolvimento específico. Para garantir a qualidade desses sistemas, é importante garantir a qualidade de seus componentes. A falta da garantia da qualidade dos componentes de software destinados à reutilização é um dos fatores de inibição do DBC, e existe certa carência de pesquisas sobre a qualidade de componentes de software. Desta maneira, o principal objetivo deste trabalho foi a definição de um modelo de qualidade específico para componentes de software, fornecendo a base para a especificação de requisitos de qualidade e para a avaliação de qualidade dos mesmos. O Modelo está embasado nas normas ISO/IEC 9126 e ISO/IEC 12119, e também na literatura especializada. Uma ferramenta para apoiar avaliações de componentes (e de produtos de software de forma geral) também foi desenvolvida. Foram realizadas ainda quatro avaliações de componentes através de estudos de casos para verificar a aplicabilidade e utilidade do modelo de qualidade e da ferramenta desenvolvida. Dois questionários foram respondidos pelos avaliadores responsáveis pelas avaliações coletando assim, suas considerações sobre o modelo de qualidade e sobre a ferramenta / Among the software development technologies that promote the reuse aiming to build systems with periods and smaller costs, without sacrificing the quality of products, is the Component-Based Development (CBD). The Component-Based Development consists on the construction of systems by the composition of software components according to a specific development process. To guarantee the quality of those systems, it is important to guarantee the quality of their components. The lack of warranty of the quality of the software components destined to reuse is one of the inhibition factors of CBD, and there is certain lack of researches about quality of software components. This way, the main objective of this work was the formalization of a specific quality model for software components, supplying the base for the specification of quality requirements and for the quality evaluation of the same ones. The model is based on the norms ISO/IEC 9126 and ISO/IEC 12119, and also in the specialized literature. A tool to support components evaluations (and software products in a general way) was also developed. It was realized four components evaluations through case studies to verify the applicability and usefulness of the quality model and the developed tool. Two questionnaires were answered by the appraisers responsible for the evaluations collecting thereby, their considerations on the quality model and the tool

In order to use components that are developed for a domain, domain knowledge is required. If the default relations in a domain are offered by a framework, this can be a starting point for the application engineer as an important kind of domain knowledge. A generic design for creating and saving a domain is implemented in this thesis. This approach starts with creating a domain from components and relations among these components. The relations and components are saved once and used several times. In addition, this generic design helps for code generation by using components. A framework for this design is implemented and applied for GIS domain. A basic code generation approach is also implemented in this framework for demonstration purposes. This framework can be used by domain engineers in order to create a domain and by application engineers to develop custom applications. It has the ability to offer default relations and helps creating new relations between components. Parameters and sequence of function calls can be defined by using a GUI. All the relations including default and userdefined ones can be used for code generation. COSECASE, which offers a tool for component-oriented design is extended with domain operations such as creating domain, saving domain, loading domain, and generating domain code. As the starting point, domain analysis for GIS domain is completed to define the domain. Then the components that have been implemented for GIS domain and relations between these components are saved within the framework. Moreover, some basic applications are generated by using this framework in the GIS domain. Also a sample domain is created to prove that our approach can be applied to any domain. The relations in this sample domain are saved in the framework and same basic applications are generated.