Sistema Aldeia : programação paralela e distribuída em Java sobre Infiniband e DECK

Esse trabalho de dissertação está incluído no contexto das pesquisas realizadas no Grupo de Processamento Paralelo e Distribuído da UFRGS. Ele aborda as áreas da computação de alto desempenho, interfaces simples de programação e de sistemas de interconexão de redes velozes. A máquina paralela formada por agregados (clusters) tem se destacado por apresentar os recursos computacionais necessários às aplicações intensivas que necessitam de alto desempenho. Referente a interfaces de programação, Java tem se mostrado uma boa opção para a escrita de aplicações paralelas por oferecer os sistemas de RMI e de soquetes que realizam comunicação entre dois computadores, além de todas as facilidades da orientação a objetos. Na área a respeito de interconexão de rede velozes está emergindo como uma tentativa de padronização a nova tecnologia Infiniband. Ela proporciona uma baixa latência de comunicação e uma alta vazão de dados, além de uma série de vantagens implementadas diretamente no hardware. É neste contexto que se desenvolve o presente trabalho de dissertação de mestrado. O seu tema principal é o sistema Aldeia que reimplementa a interface bastante conhecida de soquetes Java para realizar comunicação assíncrona em agregados formados por redes de sistema. Em especial, o seu foco é redes configuradas com equipamentos Infiniband. O Aldeia objetiva assim preencher a lacuna de desempenho do sistema padrão de soquetes Java, que além de usar TCP/IP possui um caráter síncrono. Além de Infiniband, o Aldeia também procura usufruir dos avanços já realizados na biblioteca DECK, desenvolvida no GPPD da UFRGS. Com a sua adoção, é possível realizar comunicação com uma interface Java sobre redes Myrinet, SCI, além de TCP/IP. Somada a essa vantagem, a utilização do DECK também proporciona a propriedade de geração de rastros para a depuração de programas paralelos escritos com o Aldeia. Uma das grandes vantagens do Aldeia está na sua capacidade de transmitir dados assincronamente. Usando essa técnica, cálculos da aplicação podem ser realizados concorrentemente com as operações pela rede. Por fim, os canais de dados do Aldeia substituem perfeitamente aqueles utilizados para a serialização de objetos. Nesse mesmo caminho, o Aldeia pode ser integrado à sistemas que utilizem a implementação de soquetes Java, agora para operar sobre redes de alta velocidade. Palavras-chave: Arquitetura Infiniband, agregado de computadores, linguagem de programação Java, alto desempenho, interface de programação.

Caracteres (em Java)

O professor apresenta a utilização de caracteres nas linguagens de programação Java e C++. Ilustra como utilizar e tratar conjuntos de caracteres nas linguagens de programação.

Interface com o Usuário (em Java)

O professor apresenta interfaces orientadas a objetos na linguagem de programação Java. Ilustra como e quando são utilizadas as interfaces orientadas a objetos em Java.

JCML: A specification language for the runtime verification of Java Card programs

COSTA, Umberto Souza; MOREIRA, Anamaria Martins; MUSICANTE, Matin A.; SOUZA NETO, Plácido A. JCML: A specification language for the runtime verification of Java Card programs. Science of Computer Programming. [S.l]: [s.n], 2010.

Uma perspectiva de extensão do modelo de aceitação de tecnologia para explicar o uso de linguagens de desenvolvimento WEB: pesquisa com desenvolvedores Pyton e Java

The spread of the Web boosted the dissemination of Information Systems (IS) based on the Web. In order to support the implementation of these systems, several technologies came up or evolved with this purpose, namely the programming languages. The Technology Acceptance Model TAM (Davis, 1986) was conceived aiming to evaluate the acceptance/use of information technologies by their users. A lot of studies and many applications have used the TAM, however, in the literature it was not found a mention of the use of such model related to the use of programming languages. This study aims to investigate which factors influence the use of programming languages on the development of Web systems by their developers, applying an extension of the TAM, proposed in this work. To do so, a research was done with Web developers in two Yahoo groups: java-br and python-brasil, where 26 Java questionnaires and 39 Python questionnaires were fully answered. The questionnaire had general questions and questions which measured intrinsic and extrinsic factors of the programming languages, the perceived usefulness, the perceived ease of use, the attitude toward the using and the programming language use. Most of the respondents were men, graduate, between 20 and 30 years old, working in the southeast and south regions. The research was descriptive in the sense of its objectives. Statistical tools, descriptive statistics, main components and linear regression analysis were used for the data analysis. The foremost research results were: Java and Python have machine independence, extensibility, generality and reliability; Java and Python are more used by corporations and international organizations than supported by the government or educational institutions; there are more Java programmers than Python programmers; the perceived usefulness is influenced by the perceived ease of use; the generality and the extensibility are intrinsic factors of programming languages which influence the perceived ease of use; the perceived ease of use influences the attitude toward the using of the programming language

Especificação e implementação de uma linguagem para transformação de modelos MOF em repositórios dMOF

This work presents the specification and the implementation of a language of Transformations in definite Models specification MOF (Meta Object Facility) of OMG (Object Management Group). The specification uses a boarding based on rules ECA (Event-Condition-Action) and was made on the basis of a set of scenes of use previously defined. The Parser Responsible parser for guaranteeing that the syntactic structure of the language is correct was constructed with the tool JavaCC (Java Compiler Compiler) and the description of the syntax of the language was made with EBNF (Extended Backus-Naur Form). The implementation is divided in three parts: the creation of the interpretative program properly said in Java, the creation of an executor of the actions specified in the language and its integration with the type of considered repository (generated for tool DSTC dMOF). A final prototype was developed and tested in the scenes previously defined

JCML - Java Card Modeling Language: Definição e Implementação

Formal methods should be used to specify and verify on-card software in Java Card applications. Furthermore, Java Card programming style requires runtime verification of all input conditions for all on-card methods, where the main goal is to preserve the data in the card. Design by contract, and in particular, the JML language, are an option for this kind of development and verification, as runtime verification is part of the Design by contract method implemented by JML. However, JML and its currently available tools for runtime verification were not designed with Java Card limitations in mind and are not Java Card compliant. In this thesis, we analyze how much of this situation is really intrinsic of Java Card limitations and how much is just a matter of a complete re-design of JML and its tools. We propose the requirements for a new language which is Java Card compliant and indicate the lines on which a compiler for this language should be built. JCML strips from JML non-Java Card aspects such as concurrency and unsupported types. This would not be enough, however, without a great effort in optimization of the verification code generated by its compiler, as this verification code must run on the card. The JCML compiler, although being much more restricted than the one for JML, is able to generate Java Card compliant verification code for some lightweight specifications. As conclusion, we present a Java Card compliant variant of JML, JCML (Java Card Modeling Language), with a preliminary version of its compiler

BSmart: desenvolvimento rigoroso de aplicações Java Card com base no método formal B

Java Card technology allows the development and execution of small applications embedded in smart cards. A Java Card application is composed of an external card client and of an application in the card that implements the services available to the client by means of an Application Programming Interface (API). Usually, these applications manipulate and store important information, such as cash and confidential data of their owners. Thus, it is necessary to adopt rigor on developing a smart card application to improve its quality and trustworthiness. The use of formal methods on the development of these applications is a way to reach these quality requirements. The B method is one of the many formal methods for system specification. The development in B starts with the functional specification of the system, continues with the application of some optional refinements to the specification and, from the last level of refinement, it is possible to generate code for some programming language. The B formalism has a good tool support and its application to Java Card is adequate since the specification and development of APIs is one of the major applications of B. The BSmart method proposed here aims to promote the rigorous development of Java Card applications up to the generation of its code, based on the refinement of its formal specification described in the B notation. This development is supported by the BSmart tool, that is composed of some programs that automate each stage of the method; and by a library of B modules and Java Card classes that model primitive types, essential Java Card API classes and reusable data structures

JCircus 2.0: Uma extensão da ferramenta de tradução de Circus para Java

This dissertation aims at extending the JCircus tool, a translator of formal specifications into code that receives a Circus specification as input, and translates the specification into Java code. Circus is a formal language whose syntax is based on Z s and CSP s syntax. JCircus generated code uses JCSP, which is a Java API that implements CSP primitives. As JCSP does not implement all CSP s primitives, the translation strategy from Circus to Java is not trivial. Some CSP primitives, like parallelism, external choice, communication and multi-synchronization are partially implemented. As an aditional scope, this dissertation will also develop a tool for testing JCSP programs, called JCSPUnit, which will also be included in JCircus new version. The extended version of JCircus will be called JCircus 2.0.

Java-XSC : módulo complexo e complexo intervalar

This work aims to develop modules that will increase the computational power of the Java-XSC library, and XSC an acronym for "Language Extensions for Scientific Computation . This library is actually an extension of the Java programming language that has standard functions and routines elementary mathematics useful interval. in this study two modules were added to the library, namely, the modulus of complex numbers and complex numbers of module interval which together with the modules original numerical applications that are designed to allow, for example in the engineering field, can be used in devices running Java programs

Interface gráfica no contexto de teoria dos jogos sob a forma de Java Apples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atribuição de turmas para professores via Beam Search em Java

In the universities, before the start of each school year, is held the distribution of classes among available teachers. Therefore, it is necessary to consider the maximum workweek for each teacher and their preferences for each discipline, to prevent a teacher to give lessons in two separate locations at the same time and to avoid some teachers to become overloaded while others with large clearance. This process, manually performed, is time consuming and does not allow the visualization of other combinations of assignment of teachers to classes, besides being liable to error. This work aims to develop a decision support tool for the problem of assigning teachers to classes in college. The project encompasses the development of a computer program using the concepts of object orientation and a tree search algorithm of a combinatorial nature called Beam Search. The programming language used is Java and the program has a graphical interface for entering and manipulating data of the problem. Once obtained the schedule data of classes and teachers is possible, by means of the tool, perform various simulations and manual adjustments to achieve the final result. It is an efficient method of class scheduling, considering the speed of task execution and the fact that it generates only feasible results

JCML: A specification language for the runtime verification of Java Card programs

COSTA, Umberto Souza; MOREIRA, Anamaria Martins; MUSICANTE, Matin A.; SOUZA NETO, Plácido A. JCML: A specification language for the runtime verification of Java Card programs. Science of Computer Programming. [S.l]: [s.n], 2010.

JCML: A specification language for the runtime verification of Java Card programs

COSTA, Umberto Souza; MOREIRA, Anamaria Martins; MUSICANTE, Matin A.; SOUZA NETO, Plácido A. JCML: A specification language for the runtime verification of Java Card programs. Science of Computer Programming. [S.l]: [s.n], 2010.