EDF统一调度硬实时周期任务和偶发任务的可调度性判定算法

现有的硬实时周期任务和非周期任务的混合调度方法都没有保证非周期任务的实时性,所以不适合调度具有强实时要求的偶发任务.通过分析和计算EDF算法调度偶发任务所占用的空闲时间和挪用时间,以及调度后对空闲时间和最大可挪用时间的影响,提出一种采用EDF算法统一调度硬实时周期任务和偶发任务时的可调度性充分判定算法.最后用仿真实验得出了该算法在不同系统负载下的判定准确率和偶发任务的平均响应时间.

Schedulability Test of Scheduling Hard Real-time Period and Sporadic Tasks Unified with EDF Policy

Existing Algorithms hybrid scheduling hard real-time periodic tasks and aperiodic tasks is no guarantee of the deadline of the aperiodic tasks. it is not suitable for scheduling sporadic tasks with hard deadline. Because EDF algorithm with a unified scheduling periodic and sporadic tasks in real-time is optimal. By analyzing and calculating EDF scheduling process of idle time and the maximum time can be stealed, Put forward a schedulability test of unified scheduling periodic and sporadic tasks with EDF policy. Finally, the simulation results obtained the accurately rate of schedulability test and the average response time of sporadic tasks under different load.