Schedulability Analysis for Self-Suspending Tasks Under EDF-Like Scheduling

Abstract

Real-time systems involve tasks that may voluntarily suspend their execution as they await specific events or resources. Such self-suspension can introduce further delays and unpredictability in scheduling, making the analysis more challenging. Most current schedulability analysis methods of self-suspending tasks focus on fixed-priority scheduling or tasks with constrained deadlines. This paper proposes two schedulability analysis methods for self-suspending tasks with arbitrary deadlines under earliest-deadline-first-like (EDF-like) scheduling. Both methods are designed for preemptive uniprocessor systems. We first present a jitter-based response time analysis (JRTA) method. JRTA is designed based on a self-suspending response time analysis (SS-RTA) method under earliest-deadline-first (EDF) scheduling. We first convert self-suspensions to release jitters and then present a response time analysis (RTA) method of tasks with release jitters under EDF-like scheduling. To address the complexity of JRTA, we propose an improved schedulability analysis (ISA), a sufficiency blocking-based method. Finally, we provide many simulation experiments under some EDF-like scheduling algorithms. The results verify the effectiveness and efficiency of both proposed methods.