Orientador: Rogerio Drummond Burnier Pessoa de Mello Filho

Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da Computação

Resumo: A programação orientada a objetos oferece uma sólida base conceitual para o desenvolvimento de sistemas de informação, com ênfase em modularidade, extensibilidade e robustez. Por outro lado, avanços nas tecnologias de hardware, arquitetura e meios de comunicação propiciaram uma mudança nos...

Resumo: A programação orientada a objetos oferece uma sólida base conceitual para o desenvolvimento de sistemas de informação, com ênfase em modularidade, extensibilidade e robustez. Por outro lado, avanços nas tecnologias de hardware, arquitetura e meios de comunicação propiciaram uma mudança nos padrões de ambiente de processamento de dados: o modelo de mainframes vem sendo substituído pelo modelo distribuído, baseado em redes de estações de trabalho. A combinação desses dois conceitos, objetos e sistemas distribuídos, oferece a curto prazo perspectivas bastante promissoras. Várias iniciativas visando esse objetivo vêm sendo desenvolvidas ou estão já em uso. Embora esses trabalhos adotem diferentes abordagens, eles procuram basicamente unificar conceitos das duas áreas, estabelecendo um modelo único de programação ¿Observação: O resumo, na íntegra poderá ser visualizado no texto completo da tese digital.

Abstract: The concepts introduced by the object paradigm embody a complete, sound framework for developing information systems with improved modularity, extendibility and robustness. On the other hand, technological advances in hardware components, computer architecture and communications have...

Abstract: The concepts introduced by the object paradigm embody a complete, sound framework for developing information systems with improved modularity, extendibility and robustness. On the other hand, technological advances in hardware components, computer architecture and communications have caused standards about computing environments to change: the old mainframe model has been steadily shifted in favor of the distributed model, based on workstations networks instead. Blending these two concepts, objects and distributed systems, offers very promising possibilities in the near future. Indeed, several attempts towards this goal are either under execution or already accomplished. These works while adopting different approaches and solutions, basically aim at unifying related issues from the two areas within a consistent programming model. Current efforts at the A_Hand Research Laboratory target the construction of a complex software development environment, planned to support the design and implementation of very large applications. The programming languages Cm and LegoShell are the basic programming tools in this environment. The Cm language is object-oriented, used to produce reusable software components, which can be brought together through the graphical language LegoShell. In this document, we define a new version for the language Cm, in order to meet inherent requirements of concurrent and distributed programming, thus establishing our underlying model for distributed applications programming. Adapting an existing object-oriented language to address programmng issues in a distributed backgroqnd while preserving its semantic consistency results a hard task, as a number of important aspects must be kept in mind. The main concern in distributed programming systems is location transparency; we have also investigated solutions regarding concurrency, exceptions and inheritance problems. The extensions to the Cm language here proposed include new syntatic constructions, the definition of the "remote object" concept and a set of standard classes and functions.