Tolerance to Multiple Transient Faults for Aperiodic Tasks in Hard Real-Time Systems

ÐReal-time systems are being increasingly used in several applications which are time-critical in nature. Fault tolerance is an essential requirement of such systems, due to the catastrophic consequences of not tolerating faults. In this paper, we study a scheme that guarantees the timely recovery from multiple faults within hard real-time constraints in uniprocessor systems. Assuming earliestdeadline-first scheduling (EDF) for aperiodic preemptive tasks, we develop a necessary and sufficient feasibility-check algorithm for fault-tolerant scheduling with complexity O…n2 k†, where n is the number of tasks to be scheduled and k is the maximum number of faults to be tolerated. Index TermsÐReal-time scheduling, earliest-deadline first, fault-tolerant schedules, fault recovery.