实时单核和谐周期分区系统时间窗口分配算法

目前航空电子系统正快速朝着综合模块化方向发展。为了防止同一计算平台上的应用相互干扰，IMA软件普遍采用分区机制。由于时间分区的引入，传统的实时周期任务可调度性分析已经不再适用。为此研究了一类特殊的分区系统--和谐周期分区系统在单处理器下的可调度性。给出了和谐周期分区系统的形式化定义以及系统中任务可调度性的充分必要条件，并基于此提出了一种分区时间窗口分配算法。该算法为每个分区在主时间帧内分配多个时间窗口，并且保证只要和谐周期分区系统在理论上可调度，该算法就一定能生成一个可行的调度表，使得当全局调度器按照此调度表周期地调度分区时，各个分区中的任务不会超时。本文提出的算法可以运用在实际的工程中。

Time windows distribution algorithm for real-time harmonic-period partition system on uniprocessor platform

Recently the avionics system is quickly transferring to integrated modular architecture.To pre-vent the mutual interference between different applications, IMA software usually adopts partition mechanism. Due to the "time partition", the traditional real-time schedulability analytical method is not applicable.This paper researches a class of special partition system, which is called harmonic-period partition system on uni-processor platform.This paper gives the formalized definition of harmonic-period partition system and the nec-essary and sufficient condition of schedulability of tasks in harmonic-period partition system.On this basis, this paper proposes an algorithm, which is called time windows distribution algorithm.This algorithm distrib-utes multiple time windows for each partition in the main time frame.This algorithm must be able to find a fea-sible schedule table for a harmonic-period partition system if this system is schedulable theoretically,and all tasks in partitions will not timeout if the global scheduler schedules partitions according to this schedule table. The algorithm proposed in this paper can be applied to practical engineering.