基于path RTL的弱硬实时系统

Novel Weakly Hard Real-time System Based on Path RTL

弱硬实时系统是实时系统中的一个重要研究领域.经典弱硬实时系统以任务流中任务满足或错过的个数来约束系统性能,存在着无法准确表达系统实时特性的不足,以及弱硬实时的可靠性无法证明的缺陷.通过提出弹性截止期的概念,定义基于path RTL的弱硬实时系统,有效解决了经典弱硬实时系统可靠性无法证明的难题;实现了弱硬实时系统的约束由时间特性来表达的目标;对于新兴出现的弱硬实时应用提供了完整的解决方案;同时也对经典弱硬实时系统提出了规约算法,以充分利用经典弱硬实时系统在约束规范、调度算法等方面已有研究成果.通过比较,path RTL弱硬实时系统在系统完整性、系统可靠性和应用领域等方面,比经典弱硬实时系统具有优势.

Weakly hard real-time system has become increasingly important in the research of real-time system.However,classic weakly hard real-time system fails to show its advantage of real-time performance with the constraint by the number of tasks meeting or missing the deadline and has an obvious defect that the reliability of it can not be proved.With the concept of ＂flexible deadline＂,this paper puts forward a novel weakly hard real-time system based on path RTL,which can efficiently solve the problem that the reliability of classic weakly real-time system can not be proved,and implement the constraint of weakly hard real-time with time-depended arguments.The novel weakly hard real-time also provides solutions for the newly emerged applications of weakly hard real-time systems.Moreover,a procedure is proposed to term the classic weakly hard real-time system so as to make the best of its existing research achievements in constraint specification and scheduling algorithm.The result shows that as compared with classic weakly real-time system,the new weakly hard real-time system based on path RTL has a better performance in system integrity,reliability and application fields.