时间分区的设计与实现

为了满足新一代航空电子系统高度综合化、模块化的要求,在高安全实时操作系统中引入了分区（Partition）的概念。分区是运行于一个处理机模块上的一个或多个应用程序（或子系统）,这些应用程序在时间和空间上彼此隔离,互不影响。分区操作系统根据预先定义的主时间框架内的时间窗口调度相应的分区,在分区的时间窗口内,每个分区按照分区内自己的调度策略调度分区内的进程。分区内的进程有周期进程和非周期进程两种类型,每个进程具有截止期属性,周期进程除了截止期还存在周期属性,当进程发生截止期超时或周期超时,操作系统需进行相应的超时处理。本文着重讨论符合ARINC653要求的时间分区的一种设计及实现方法,包括分区时间调度,进程截止期管理,周期进程调度,以及时间事件管理。

Design and Implementation of Time Partitioning

In order to satisfy Integrated Modular Avionics,partition is issued in high safe real-time O/S.Partition is one or more applications（sub-systems）running on a core module,which are separated in time and space and not affected each other.Partition O/S dispatches partitions according to Major Frame（MAF） configured by system,a partition dispatches processes belonging to partition according to certain scheduling capabilities.Process has periodic process and aperiodic process,every process has deadline attribute.Periodic process has period attribute besides deadline.When deadline or period timeout happen,the O/S must deal with timeouts.The paper introduces time partitioning mechanism which satisfies ARINC653,it refers to time partitioned scheduler,process deadline management,periodic process schedule and time event.