针对严格实时的航空电子分区调度问题,建立了操作系统采用轮转调度策略,分区里采用动态优先级调度策略的双层任务调度模型.针对可调度性分析问题,利用轮转调度周期和分区任务执行系数作为关键参数,在任务时间需求函数的基础上,计算系统消耗时间,得出了系统可调度性的判定定理;同时考察存在释放抖动的时候可调度情况,提出了可调度性的计算边界;通过考察任务周期和轮转调度长度的关系,得出了分区可调度情况下任务负载的理论上限.针对分区设计问题,通过考察关键时刻点,给出了分区调度关键参数的解析模型,在此基础上提出了分区可设计的判定定理,最后给出实例进行具体说明.
To solve the real-time partition schedule problem in the integrated modular avionics, a two-level hierarchical schedule model was proposed in which the operation system adopts round-robin scheduling strategy and each individual partition adopts dynamic priority scheduling strategy. For the schedulablity analysis problem, the system consume time was calculated based on the task demand bound function by using roundrobin time and partition task performance rate as the key parameters. From the calculated system consume time, the partition schedulable judging condition was obtained. The schedulablity calculation bound was also developed by observing the task each implementation with the releasing jitter. Through studying the relationship between the round length and the task periods, the maximum task load upper limit utilization were developed under the condition that the partition was schedulable. For the partition design problem, the partition scheduling key parameters analytical model was established. Then the partition designable judging condition was got. Finally, a practice example was given.