Misconceptions about real-time computing: a serious problem fornext-generation systems

The author defines real-time computing and states and dispels the most common misconceptions about it. He discusses the fundamental technical issues of real-time computing. He examines specification and verification, scheduling theory, operating systems, programming languages and design methodology, distributed databases, artificial intelligence, fault tolerance, architectures, and communication     

A fussy-logic control language for embedded controllers

Microcontrollers are being used in many commercial and consumer products to introduce a higher level of intelligence. There exist an opportunity and need to develop high-level languages to be used specifically in industrial product development. A recent trend in such embedded applications is the use of fuzzy-logic control. An ongoing project in the Industrial Research Laboratory at the University of Florida investigates the various aspects of microcontroller architectures, operating systems and languages. This report summarizes our progress in developing a fuzzy-logic control language for microcontrollers.     

Configuration and dynamic reconfiguration of components using the coordination paradigm

One of the most promising approaches in developing component-based (possibly distributed) systems is that of coordination models and languages. Coordination programming enjoys a number of advantages such as the ability to express different software architectures and abstract interaction protocols, support for multi-linguality, reusability and programming-in-the-large, etc. Configuration programming is another promising approach in developing large scale, component-based systems, with the increasing need for supporting the dynamic evolution of components. In this paper we explore and exploit the relationship between the notions of coordination and (dynamic) configuration and we illustrate the potential of control- or event-driven coordination languages to be used as languages for expressing dynamically reconfigurable software architectures. We argue that control-driven coordination has similar goals and aims with the notion of dynamic configuration and we illustrate how the former can achieve the functionality required by the latter.     

An event-based architecture definition language

This paper discusses general requirements for architecture definition languages, and describes the syntax and semantics of the subset of the Rapide language that is designed to satisfy these requirements. Rapide is a concurrent event-based simulation language for defining and simulating the behavior of system architectures. Rapide is intended for modelling the architectures of concurrent and distributed systems, both hardware and software in order to represent the behavior of distributed systems in as much detail as possible. Rapide is designed to make the greatest possible use of event-based modelling by producing causal event simulations. When a Rapide model is executed it produces a simulation that shows not only the events that make up the model's behavior, and their timestamps, but also which events caused other events, and which events happened independently. The architecture definition features of Rapide are described: event patterns, interfaces, architectures and event pattern mappings. The use of these features to build causal event models of both static and dynamic architectures is illustrated by a series of simple examples from both software and hardware. Also we give a detailed example of the use of event pattern mappings to define the relationship between two architectures at different levels of abstraction. Finally, we discuss briefly how Rapide is related to other event-based languages     

双重软件体系结构描述框架XYZ/ADL

体系结构设计在软件开发过程中扮演着重要角色.工程中常用图形语言为软件体系结构建模,它们有直观、半形式化的优点;但是语义不够精确,难以对它们表示的模型进行分析,在这方面,形式化方法可与之互补.但在工程使用中仅用形式化语言建模又不太现实,所以如何结合二者之长以提高软件的可靠性已成为工业界和学术界共同关心的问题.提出了双重软件体系结构描述框架XYZ/ADL:支持工程中软件体系结构的基本概念,前端用一般的体系结构框图作为结构描述,用UML活动图、状态图作为抽象行为表示;后端用既可表示系统动态语义又可表示系统静态语义的时序逻辑语言XYZ/E作为一致的语义基础.前端的图形语言便于软件工程师的交流和使用,后端的形式语言是进一步的形式化分析验证的基础.     

Architectures within the ESPRIT SPAN project

An overview is given of the SPAN project, which pooled the resources of numerous researchers in several countries to integrate symbolic and numeric computing on parallel systems. The resulting Kernel System architectures provided a central model for which two programming languages and two parallel-system architectures were developed. The Kernel System architecture, Parle high-level procedural language, Virtual Machine Code, Sprint processor architecture, and DICE distributed memory architecture are examined