层次化动态实时调度框架的设计与实现.pdfVIP

———————————— 作者简介：胡家义(1989－)，男，硕士研究生，主研方向：嵌入式操作系统；张 激，研究员；刘 玲，副教授 收稿日期：2013-07-12 回 期修 日 ：2013-09-17 E-mail：hujiayi he29@163.com 层次化动态实时调度框架的设计与实现 胡家义 1，张 激 1，刘 玲 2 (1. 中国电子科技集团公司第三十二研究所，上海 200233；2. 南京大学计算机软件新技术国家重点实验室，南京 210023) 摘 要：现有嵌入式系统具有应用场景多变、实时性要求严格、上层应用复杂、鲁棒性较强等特点，在嵌入式操作系统层面对系 统防危性要求较高。时间隔离机制是提高系统防危性的重要组成部分，为此，提出一种将层次化动态实时调度框架作为时间隔离 的实现策略。引入任务同质性的概念进行任务分划，将产生的任务集作为层次框架的基础，证明多层次框架下实时任务的可调度 性条件，设计调度算法结构并实现调度算法的动态切换。仿真结果和理论分析表明，该调度框架在保证上下文切换时间复杂度稳 定的前提下，可提高系统防危性并动态应对系统负载的变化。 关键词：时间隔离；任务同质性；层次框架；动态切换；可调度性；时间复杂度 Design and Realization of Hierarchical Dynamic Real-time Scheduling Framework HU Jia-yi 1 , ZHANG Ji 1 , LIU Ling 2 (1. The 32nd Research Institute of China Electronics Technology Group Corporation, Shanghai 200233, China; 2. State Key Laboratory for Novel Software Technology, Nanjing University, Nanjing 210023, China) 【Abstract】The development of embedded systems is facing new trends including variousness of usage scenarios, strict requirement for real-time feature, complexity of upper applications and assurance of strong robustness, demanding the advance of system safety by means of promoting embedded operating systems. Temporal isolation mechanism is an important part to improve the safety of system, proposing a hierarchical dynamic real-time scheduling framework to be the implementation of temporal isolation. This paper uses the homogeneity of task to generate task sets, which can be the basis of hierarchical framework for task partitioning; testifies the schedulable condition of the framework, designs the structure of scheduling algorithm and realizes the dynamic switching of scheduling algorithm. The simulation result and theoretical analysis indicate that the issued framework can improve the safety of system and dynamically adjust to the variation of system load while guaranteeing the stability of time complexity of contex