Real-time preemptive scheduling of sporadic tasks based on supervisory control of discrete event systems

This paper presents a preemptive scheduling scheme for real-time systems with sporadic tasks based on the supervisory control theory of discrete event systems. In particular, we present a systematic method of computing a schedulable language that includes all achievable sequences that meet the given deadlines of accepted sporadic tasks. A supervisor that achieves the schedulable language corresponds to a scheduler that can secure the deadlines of all accepted tasks. We further show that the schedulable language includes the decisions on whether a scheduler accepts or rejects a newly arrived sporadic task.