CAJ | 학술논문

针对混合任务实时调度的需求和现有混合任务实时调度算法的局限性,提出了一种长释放时间间隔优先的混合任务实时调度算法LRIF,该算法采用固定优先级和动态优先级相结合的调度策略,根据非周期性软实时任务作业到达流分布,将一定比例的软实时任务作业当作硬实时作业调度,除了可对周期性硬实时任务提供调度保证外,同时还可确保非周期性软实时任务的可调度率.还提出了LRIF调度算法的可调度性分析方法,并讨论了LRIF调度算法的实现方法.测试结果表明:LRIF调度算法具有更好的调度性能,可有效调度由周期性硬实时任务和非周期性软实时任务构成的混合实时系统.
침대혼합임무실시조도적수구화현유혼합임무실시조도산법적국한성,제출료일충장석방시간간격우선적혼합임무실시조도산법LRIF,해산법채용고정우선급화동태우선급상결합적조도책략,근거비주기성연실시임무작업도체류분포,장일정비례적연실시임무작업당작경실시작업조도,제료가대주기성경실시임무제공조도보증외,동시환가학보비주기성연실시임무적가조도솔.환제출료LRIF조도산법적가조도성분석방법,병토론료LRIF조도산법적실현방법.측시결과표명:LRIF조도산법구유경호적조도성능,가유효조도유주기성경실시임무화비주기성연실시임무구성적혼합실시계통.
To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first (LRIF) real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic priority to assign priorities for tasks. By assigning higher priorities to the aperiodic soft real-time jobs with longer release intervals, it guarantees the executions for periodic hard real-time tasks and further probabilistically guarantees the executions for aperiodic soft real-time tasks. The schedulability test approach for the LRIF algorithm is presented. The implementation issues of the LRIF algorithm are also discussed. Simulation result shows that LRIF obtains better schedulable performance than the maximum urgency first (MUF)algorithm, the earliest deadline first (EDF) algorithm and EDF for hybrid tasks. LRIF has great capability to schedule both periodic hard real-time and aperiodic soft real-time tasks.