主页期刊介绍编委会编辑部服务介绍道德声明在线审稿编委办公编辑办公English
2018-2019年专刊出版计划 微信服务介绍 最新一期:2019年第6期
     
在线出版
各期目录
纸质出版
分辑系列
论文检索
论文排行
综述文章
专刊文章
美文分享
各期封面
E-mail Alerts
RSS
旧版入口
中国科学院软件研究所
  
投稿指南 问题解答 下载区 收费标准 在线投稿
刘步权,王怀民,姚益平.RTI中乐观推进机制的实现.软件学报,2004,15(3):338-347
RTI中乐观推进机制的实现
Implementation of Optimistic Advancing Mechanism in RTI
投稿时间:2003-11-07  修订日期:2003-11-07
DOI:
中文关键词:  并行离散事件仿真  高层体系结构  时间管理  乐观推进机制  零保存
英文关键词:parallel discrete event simulation  high level architecture  time management  optimistic advancing mechanism  zero-saving
基金项目:Supported by the National High-Tech Research and Development Plan of China under Grant No.2001AA115127(国家高技术研究发展计划(863));the National Grand Fundamental Research 973 Program of China under Grant No.G1999032703(国家重点基础研究发展规划(973))
作者单位
刘步权 国防科学技术大学,计算机学院,湖南,长沙,410073 
王怀民 国防科学技术大学,计算机学院,湖南,长沙,410073 
姚益平 国防科学技术大学,计算机学院,湖南,长沙,410073 
摘要点击次数: 3123
全文下载次数: 2833
中文摘要:
      正确理解乐观推进机制的基本原理,并按照高层体系结构HLA(high level architecture)规范实现RTI(runtime infrastructure)中的乐观推进服务一直是分布式仿真领域关注的难点问题.介绍了并行离散事件仿真PDES(parallel discrete event simulation)和HLA中的乐观推进机制,并指出了它们之间的重要差异,例如PDES中的虚拟时间(virtual time)可以回卷(roll back),回卷发生在进程中;而HLA中的逻辑时间不能够回卷,但乐观盟员在不影响保守盟员推进的情况下可以回卷自己调度事件的时间,回卷发生在盟员内而不是RTI内.另外,提出了在实现乐观推进服务时,不需要RTI作任何保存操作的"零保存"技术,并成功地将该技术应用到RTI软件StarLink中."零保存"技术通过在消息句柄类型RTI::MessageRetractionHandle定义中增加两个变量,一个表示TSO(time stamp order)消息的时标,另一个表示所有接收该消息的盟员(RTI::MessageRetractionHandle为IEEE1516.1定义的数据类型),RTI将具有此类型的消息句柄返回给发送TSO消息的盟员保存,当发送盟员再次使用消息句柄撤消(retract)消息时,RTI从消息句柄中就可以知道并通知接收盟员撤消消息.对于理解和开发RTI中的乐观推进服务具有重要的现实意义.
英文摘要:
      In distributed modeling and simulation area, it is intractable to comprehend the fundamental principles of optimistic advancing mechanism and implement the optimistic advancing services in RTI (runtime infrastructure) according to HLA (high level architecture) specifications. This paper introduces two different optimistic advancing mechanisms in PDES (parallel discrete event simulation) and HLA, and reveals some important differences between them. For example, the virtual time can be rolled back in PDES, the logical time can not be rolled back in HLA, and an optimistic federate can only roll back its message-scheduling time and must ensure that its rollback won’t influence the advancing of conservative federates. Rollback occurs in a logical process in PDES, but it can only occur in a federate rather than RTI in HLA. In addition, a new implementation mechanism called Zero-Saving is proposed in this paper. With this mechanism, a RTI does not need to save any execution states when optimistic advancing services are implemented. This mechanism has successfully been applied to a RTI named StarLink. The Zero-Saving mechanism adds two new variables into the message retraction handle type RTI::MessageRetraction Handle which is a data type defined by IEEE 1516.1. One variable represents the time stamp of the sent TSO (time stamp order) message, and the other is used to save all federates which receive the message. When a TSO message is sent to RTI, RTI returns the sending federate a message retraction handle with all message-received federates. So RTI knows which federates should be notified to retract the received messages whenever the sending federate uses a message retraction handle to ask RTI to retract a TSO message. The fundamental principles and implementation of optimistic advancing services introduced in this paper are useful for RTI developers.
HTML  下载PDF全文  查看/发表评论  下载PDF阅读器
 

京公网安备 11040202500064号

主办单位:中国科学院软件研究所 中国计算机学会
编辑部电话:+86-10-62562563 E-mail: jos@iscas.ac.cn
Copyright 中国科学院软件研究所《软件学报》版权所有 All Rights Reserved
本刊全文数据库版权所有,未经许可,不得转载,本刊保留追究法律责任的权利