软件容错模型中反向与正向调度算法研究  

On the Backward Scheduling Algorithms and the Forward Scheduling Algorithms in Software Fault-Tolerant Modules

作　　者：刘东[1] 张春元[1] 

机构地区：[1]国防科技大学计算机学院,湖南长沙410073

出　　处：《计算机工程与科学》2007年第9期101-105,共5页Computer Engineering & Science

基　　金：国家安全重大基础研究项目(5131202-3)

摘　　要：为了保证实时系统在发生任务失效时仍旧能够正常地工作,通常采用软件容错模型来提高实时系统的容错能力。本文分析了软件容错模型中的BCE容错调度算法,针对该算法中的反向调度和正向调度两个过程,给出了RMB、DMB、FDMB、EDFB四种反向调度算法和RMF、EDFF两种正向调度算法,并指出了反向调度和正向调度相互协调的特性。将各种算法在BCE算法中进行模拟,结果表明,EDFF正向调度算法能够与四种反向调度算法更好地协调,从而获得比RMF正向调度算法更高的调度性能;模拟结果还表明,四种反向调度算法在BCE算法中的性能相近。最后,本文得出了RMB(或DMB)反向调度算法与EDFF正向调度算法的组合较适用于软件容错模型的结论。The software fault-tolerant module is used to improve the dependability of real-time systems. In order to compare the performance of different backward scheduling algorithms and forward scheduling algorithms in software fault-tolerant modules, the BCE algorithm and its processes of backward scheduling and forward scheduling are analyzed. Two backward scheduling algorithms, RMF and EDFF, and four forward scheduling algorithms, RMB, DMB, FDMB and EDFB, are studied. Through simulation, different scheduling algorithms are compared. Simulation results show that the EDFF forward scheduling algorithm cooperates well with four backward scheduling algorithms, and it can get better scheduling performance than RMF. Simulation results also show that four backward scheduling algorithms have a similar effect on the BCE algorithm. The conclusion is made that the combination of EDFF and RMB, or DMB, is more applicable for software faulttolerant modules.

关 键 词：软件容错 实时系统 容错调度 

分 类 号：TP316.2[自动化与计算机技术—计算机软件与理论]