G. S. Alijani und Horst F. Wedde
Enhanced Reliability for Scheduling Critical Tasks in Hard Real-Time Systems
2nd International Conference on Computing and Information, Ottawa, 1991-05
Hard real-time systems are characterized by the execution of tasks under strict time constraints. The importance of meeting a task execution deadline makes the scheduling scheme a central issue for the correctness and reliability of such systems. While reliability is one of the objectives, it cannot be guaranteed that any system be free from faults during its operational lifetime. Thus, in systems performing critical activities, measures that provide fault tolerance should be included [2]. This paper focuses on the design and evaluation of a highly reliable integrated system which consists of local and global task schedulers. Our approach to error detection and recovery problems is to utilize safety times associated with the scheduled tasks and combine local and global recovery techniques. This approach supports system level error detection and recovery for the local scheduler and affected tasks. The performance of the system in terms of the number of recovered tasks is evaluated and the results are presented.