Response Time Analysis for Hybrid Task Sets under Fixed Priority Scheduling

Quan Zhou, Jihua Huang, Jianjun Li, Zhi Li

Abstract: The task set in some real-time systems consists of adaptive variable-rate (AVR) tasks and time-triggered tasks. AVR tasks generate instances when the rotating source rotates to some special angles. Time-triggered tasks generate jobs irregularly under the constraint of minimum release time interval. Response time analysis (RTA) is an effective method to test the schedulability of tasks. The consideration on angular phase is conducive to improve the accuracy of RTAs. To the best of our knowledge, there is only one RTA method that considers angular phases and supports hybrid tasks. However, this method is incorrect since it may misjudge some unschedulable task sets as schedulable task sets. In this work, we propose the first correct RTA method that considers angular phases. The theoretical analysis proves the correctness of our method.