Time analysis for fault-tolerant real-time group-based scheduling
Lei Wang, Zhaohui Wu, Wu Xian Ming · 2005
The group-based preemptive scheduling provides a flexible mechanism to define the preemptive relations between tasks. However, this scheduling scheme together with a resource access synchronization protocol and requirements of fault tolerance makes the predication of a real-time system's behaviors more difficult than traditional scheduling scheme. The major contribution of our work is an algorithm to calculate the worst-case response time for tasks under the fault-tolerant group-based preemptive scheduling. We first present the algorithm assuming that no task suffers any error. Then the algorithm is extended to consider a fault model and a primary/alternative fault-tolerant mechanism. Based on the tasks' worst-case response time, the schedulability of a given task set can be determined. Moreover, we also introduce a method to calculate the minimum allowed time between two consecutive faults.