Abstract: The paper solved the problem that current popular safeguard scheduling algorithm cannot achieve the safeguard function under the environment of software and hardware failure. It built a new hierarchical real-time scheduling model which describes the safety requirement of safety-critical real-time application from two aspects including function component and safe partition,and designed a three-level safeguard scheduler framework. Based on the model and framework, the paper proposed a new hierarchical safeguard scheduling algorithm ( HSS) which achieves spacial separation effect by distributing function components with different critical degrees to different physical processor clusters,and attains temporal separation effect by activating various partitions running on the same processor in a fixed cycle. Empirical investigations show that the improvements in the safeguard performance and the endurance to different application loads can be achieved by choosing HSS than other similar algorithms.

Key words: Safety critical, Real time, Hierarchical, Scheduling, Algorithm