关键词: 软件容错 实时系统 容错调度

Abstract:

The software fault-tolerant module is used to improve the dependability of real-time systems. In order to compare the performance of different backwar d 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 coope rates well with four backward scheduling algorithms, and it can get better scheduling performance than RMF. Simulation results also show that four backw ard 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 appli  cable for software faulttolerant modules.

Key words: （software fault-tolerance, real-time system, fault-tolerant scheduling）