基于优先级时间Petri网的实时嵌入式多核系统分析

已有的基于点区间优先级时间Petri网分析实时嵌入式多核系统的工作, 存在以下不足: (1)点区间优先级时间Petri网只考虑每个任务的执行时间是一个固定值的情况, 而更多的实际应用中每个任务的执行时间是在一个区间范围内, 因此不能模拟这些应用; (2)没有实现从任务依赖图到点区间优先级时间Petri网的自动转化, 不便于工程设计人员使用; (3)没有考虑任务间互斥访问共享变量的情况. 为此, 定义了优先级时间Petri网(Pri-TPN)以弥补第1个不足; 定义带有资源分配与优先级的任务依赖图(TDG-RAP)以弥补第3个不足; 给出从TDG-RAP到Pri-TPN的转化规则与算法以弥补第2个不足, 以及基于Pri-TPN分析任务最坏执行时间与系统死锁的算法; 开发工具软件, 方便工程设计人员使用.

Analysis of Real-time Embedded Multi-core System Based on Prioritized Time Petri Net

Existing work on the analysis of real-time embedded multi-core systems using point-interval prioritized time Petri nets has the following limitations. (1) Point-interval prioritized time Petri nets only consider the case where the execution time of each task is a fixed value, but in many practical applications, the execution time of a task is generally within a range so that this kind of model cannot be used to analyze these applications. (2) There is a lack of automatic transformation from task dependency graphs to this point-interval prioritized time Petri nets, and thus it is inconvenient for engineering designers. (3) The case of mutually exclusive access to shared variables has not been considered. To address these issues, this study defines prioritized time Petri nets (Pri-TPN) to overcome the first limitation and introduces a task dependency graph with resource allocation and priority (TDG-RAP) to overcome the third limitation. It develops algorithms based on Pri-TPN for analyzing the worst-case execution time (WCET) and system deadlocks of tasks. Additionally, a tool software is developed to facilitate its use by engineering designers.