一种非周期软实时系统的缓冲设计方法

A Design Method for Buffer of Aperiodic Soft Real-Time System

研究了任务的到达时间和执行时间均不确定的非周期软实时系统,采用排队论的分析方法,非周期软实时系统被看成是典型的随机离散事件动态系统,并被模型化为一个M/M/1/H混合制排队系统,讨论了抛弃率、截止时间错过率和平均截止时间超过量等三种性能指标,并在此基础上进行了缓冲容量的最优设计。性能分析表明缓冲设计方法能有效地改善系统的性能。

In this paper we research the aperiodic soft real-time system in which the arrival time and the execution time of tasks are uncertain. According to the queuing theory, a aperiodic soft real-time system is a typical stochastic discrete event dynamic system and is usually considered as an M/M/1/H mixed queuing system. After a discussion of three performance metrics including rejection ratio, deadline miss ratio, and average deadline excess amount, we propose a design method for optimal buffer capacity based on these metrics. Lastly, the performance analysis shows that our method can improve the system＇s performance.