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A Real-Time Object Architecture for Large Scale Distributed Systems

大规模分布式系统的实时对象体系结构

基本信息

批准号：
06452244
负责人：
TOKORO Mario
金额：
$ 4.29万
依托单位：
Faculty of Science and Technology, Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06452244/
关键词：
Distributed System Real-Time Computing Object-Oriented Computing Concurrent process Culculus Scheduling Algorithm DROL DtCCS スケジューリング・アルゴリズム DtCCS 分散実時間オブジェクト実時間ネットワーク・プロトコル並行計算モデル R+P D+CCS 動的スケジューリング MART RtP

项目摘要

As the utility of distributed systems is widely recognized, real-time computing in such distributed environments will play an important role for various applications such as distributed multi-media systems consisting of multiple computers connected by high-speed networks, large scale air traffic control systems where high-speed networks connect neighboring airports, and satellite monitoring systems that have to control multiple remote satellites.Most of previously proposed real-time programming languages has been designed to describe centralized real-time systems. Thus, a great deal of effort has been made to construct statically predictable real-time systems. However, in distributed environments at which we aim, networks are not always reliable. This lack of reliability brings unexpected delay to message transmissions, or causes the loss of messages.Consequently, it makes difficult to analyze timing characteristics of software which communicates with other nodes with a static and unif … More ied method. Moreover, it also becomes difficult to analyze whole of system's behavior from a global view point.Thus, the predictability on which in the category of the centralized real-time systems we have laid stress is meaningless. A new programming paradigm for distributed real-time systems is needed. This dissertation proposes the Distributed Real-time Object model, as a new programming model that can flexibly deal with such unexpected situations. Then, a programming language DROL that is an extension of C++ is designed and Implemented. A distributed real-time object defined in the programming language DROL is an active object which encapsulates timing information and supports two strategies, best service and least suffering.In order to demonstrate the effectiveness of the distributed real-time object model and the design and implementation of the programming language DROL,we describe programming examples of DROL and evaluation results of runtime performance concretely.We also present a process calculus for timed concurrent systems and study its theoretical properties. The calculus is an extension of Milner's CCS by introducing two timed related notion : a tick action and a timeout operator. The operational semantics of the calculus is given by a labelled transition system. It allows to describe not only the functional behavior of concurrent systems but also variant time properties of them, such as quantitative time, timed behavior on the passage of time, and communication delay. It enjoys most of the fundamental framework of CCS almost unchanged. Less

随着分布式系统的实用性得到广泛认可，在这种分布式环境中的实时计算将在各种应用中发挥重要作用，例如由高速网络连接的多台计算机组成的分布式多媒体系统，高速网络连接相邻机场的大规模空中交通管制系统，大多数以前提出的实时程序设计语言都是为了描述集中式实时系统而设计的。因此，大量的努力已经取得了建设静态可预测的实时系统。然而，在我们所瞄准的分布式环境中，网络并不总是可靠的。这种可靠性的缺乏给消息的传输带来了不可预料的延迟，或者造成消息的丢失，从而给分析软件的定时特性带来了困难，这些软件以静态和统一的方式与其他节点通信， ...更多信息 IED方法此外，从全局的角度分析整个系统的行为也变得困难，因此，在集中式实时系统的范畴中，我们所强调的可预测性是没有意义的。一个新的分布式实时系统的编程范式是必要的。本文提出了分布式实时对象模型，作为一种新的编程模型，可以灵活地处理这种突发情况。在此基础上，设计并实现了一种扩展C++的程序设计语言DROL.用DROL语言定义的分布式实时对象是一个主动对象，它封装了定时信息，支持最佳服务和最少痛苦两种策略.为了说明分布式实时对象模型的有效性和DROL语言的设计与实现，具体描述了DROL的编程示例和运行时性能评估结果，提出了时间并发系统的进程演算，并研究了其理论性质。演算是米尔纳的CCS的扩展，通过引入两个时间相关的概念：滴答动作和超时操作符。演算的操作语义是由一个标记的转换系统给出的。它不仅可以描述并发系统的功能行为，还可以描述它们的时间特性，如定量时间，时间流逝的时间行为和通信延迟。它享有CCS的大部分基本框架，几乎没有变化。少