Angelo Corsaro

Design Patterns for RTSJ Application Development

The Real-Time Specification for Java provides a memory model, based on memory areas, which introduces some constraints on objects allocation and references. For this reason, many well-known design patterns cannot be used in a RTSJ environment since their structure violates such constraints. In this context, this paper proposes some new RTSJ design patterns and idioms, as well as a re-interpretation of existing patterns into a RTSJ perspective. Five patterns are presented. Three of them are an adaptation to RTSJ world of well-known design patterns—the singleton, the abstract factory and the leader-follower. The other two are new patterns—the eager exception handler and the memory tunnel—which allow to solve some peculiar problems deriving from the constraints of RTSJ memory model.

Techniques and patterns for safe and efficient real-time middleware

Over 90 percent of all microprocessors are now used for real-time and embedded applications. The behavior of these applications is often constrained by the physical world. It is therefore important to devise higher-level languages and middleware that meet conventional functional requirements, as well as dependably and productively enforce real-time constraints. Real-Time Java is emerging as a safe, real-time environment. In this thesis we use it as our experimentation platform; however, our findings are easily adapted to other similar platforms. This thesis provides the following contributions to the study of safe and efficient real-time middleware. First, it identifies potential bottlenecks and problem with respect to guaranteeing real-time performance in middleware. Second, it presents a series of techniques and patterns that allow the design and implementation of safe, predictable, and highly efficient real-time middleware. Third, it provides a set of architectural and design patterns that application developers can use when designing real-time systems. Finally, it provides a methodology for evaluating the merits and benefits of real-time middleware. Empirical results are presented using that methodology for the techniques presented in this thesis. The methodology helps compare the performance and predictability of general, real-time middleware platforms.

A C++ Native Interface for Interpreted JVMs

This paper describes JuNI++, a C++ native interface for interpreted Java Virtual Machines. While JuNI++ was initially designed in order to integrate the RTSJ implementation jRate with Juice, a virtual machine for small footprint environments, its engineering and performance advantages outlived the initial goal. The main contribution of this paper is to show how a C++ based native interface can fully and efficiently support the Java mapping in interpreted environments without requiring any cooperation from the C++ compiler.

Emerging Technologies for Next-generation GRID [ETNGRID Workshop Final Report]

This paper gives a brief overview of the main concerns addressed during the presentations given by authors at the fourth international workshop on Emerging Technologies for Next-generation GRID (ETNGRID), held at WETICE 2007. A presentation of the main topics dealt with is provided, then a summary of the contribution of each paper presented at the workshop is reported, together with the advances the paper introduced in the field of Grid computing.

ETNGRID Workshop Final Report

This paper gives a brief overview of the main concerns addressed during the presentations given by authors at the fourth international workshop on Emerging Technologies for Next-generation GRID (ETNGRID), held at WETICE 2007. A presentation of the main topics dealt with is pro- vided, then a summary of the contribution of each paper presented at the workshop is reported, together with the ad- vances the paper introduced in the field of Grid computing.

Special Issue: First International Workshop on Emerging Technologies for Next-generation GRID (ETNGRID 2004): Editorials

Next generation e-learning platforms will support cooperative use of geographically distributed educational resources as an aggregated environment, thus enabling a more effective knowledge exchange. Sharing this goal, our research activity addresses the definition and implementation of a service-based infrastructure for content distribution and multimedia streaming. The proposed architecture provides enough flexibility, extensibility, and scalability to cope with the ever-increasing heterogeneity and mobility of edge devices. In this paper, we initially illustrate the general objectives and requirements in the development of an e-learning oriented application for multimedia content discovery, access, and distribution in a virtual community. Architectural considerations have motivated the use of Grid technologies as they provide access to resources and services of different administrative domains in a transparent, seamless, and secure way. The Grid-based architecture has been endowed with a number of services including discovery and streaming of multimedia objects, multimedia content update, quality of service (QoS) management, and support for user authentication and authorization. A multimedia application based on the architecture is described and evaluated on a multi-domain network. Copyright

Introduction to the 3rd Workshop on Adaptive and Reflective Middleware (RM2004)

IntroductionMost of the middleware used and developed today is characterised byits inflexibility in adapting to different targetenvironments and application areas. This lack of adaptabilityusually comes from the fact that middleware is traditionally builtas a single monolithic entity. This inflexibility usually canbe characterised by either the inability to adapt the behaviour ofthe platform, the inability to adapt its structure, or even both.In application domains such as mobile computing, distributedmultimedia, and distributed real-time and embedded (DRE) systems,where resources are both constrained and variable in time, havingthe ability to reconfigure the middleware in order tooptimise the resource usage and/or provide the desired quality ofservice (QoS) becomes a key feature. Applying reflectivetechniques to middleware in order to open up the implementation isone of the ways to provide a greater degree ofconfigurability and dynamic adaptability at the middlewarelevel. In the past few years, researchers have been experimentingwith the use of reflection, component-based softwareengineering, software architecture design patterns and componentframeworks to achieve these goals. Following the success of the past two workshops, the goal ofRM2004 is to continue to provide researchers with a leading edgeview on the state of the art in reflective and adaptivemiddleware and the challenging problems that remain unsolved. Thisworkshop permits researchers from around the world investigatingmiddleware adaptation to interact and share ideas. It will providethe platform to further the application of adaptive middlewaretechniques to a variety of domains, such as medicine, command andcontrol, homeland security, entertainment and commerce. This year, the workshop received more papers than did last yearsworkshop. While this is a good indication of the impact this seriesof workshops has brought to the research community, the number andthe high-quality of these submissions have made our job ofselecting papers especially diffcult and many good papers had to beturned down. We selected 16 papers out of the 28 submissions. Thesepapers generally fall into 4 major categories of the 4 sessions ofthe workshop. Componentization: The component-based softwaredevelopment paradigm has become a popular research topics in recentyears as it helps developers manage the complexity of buildinglarge applications. Topics presented in this session includeextending component-based middleware flexibly through anauthorization component framework, adaptive component-basedmiddleware, and new model-based software development paradigmswhich build on the foundation of component-based software. Managing Cross-cutting Concerns: Managing crosscuttingconcerns is a key issue in building adaptive software systems.Reflective and adaptive middleware technologies adoptdifferent techniques to manage and coordinate thesecross-cutting aspects. Papers in this session discuss theseapproaches, including applying application-specific weaversfor composing and configuring applications, profilingtechniques to provide aspects in Java application, using AOPextensions built in the Lua language to configure CORBAapplications, and interoperability between differentreflective systems. Adaptive Communication Paradigms: Adaptive communicationremains a key aspect and research issue in re- flective andadaptive middleware. In this session, we review adaptive securegroup communication management, run-time adaptation management inmobile and pervasive computing environment, how to addresstight-coupling from non-incremental service development, andconstructing resource- aware MOM applications. Adaptive Services and Applications: This sessioncase-study of applying reflective and adaptive middlewaretechniques. We will discuss topics including safe distributedservice deployment in programmable networks, reviews of pastexperiences and future research directions, adaptive middlewaretechniques for flexible data partitioning in parallelcomputation over space and time domains, and collaborativeadaptation among legacy components. AcknowledgementsThe workshop organizers would like to express our thanks to all theprogram committee members, for their hard work in helping usreviewing the papers. Most importantly, we want to thank all theauthors who submitted their papers to the workshop and those whoparticipating in the workshops.

Workshop on Java Technologies for Real-Time and Embedded Systems (JTRES) PC Co-chairs’ Message

Over 90 percent of all microprocessors are now used for real-time and embedded applications, and the behavior of many of these is constrained by the physical world. Higher-level programming languages and middleware are needed to robustly and productively design, implement and enforce real-time constraints along with functional requirements.

Workshop PC Chairs’ Message JTRES 2003 PC Co-Chairs’ Message

Workshop focus. Over 90 percent of all microprocessors are now used for realtime and embedded applications, and the behavior of many of these applications is constrained by the physical world. Higher-level programming languages and middleware are needed to robustly and productively design, implement, compose, integrate, validate, and enforce real-time constraints along with conventional functional requirements and reusable components.