摘要
随着数字信息技术的发展,嵌入式实时操作系统ERTOS(Embedded Real-Time Operating System)不仅渗透到科学研究、工程技术等领域,而且与人们的生活联系越来越密切。ERTOS最重要的特性是实时性,它需要调度一切可利用的资源去完成实时任务。为正确评价ERTOS的实时性能,必须通过科学、系统的方法对ERTOS的实时性能进行研究,并对其实时性能进行全面、准确的测试。
本文首先研究了ERTOS为实现强实时性,在系统体系结构、任务模式、内存管理和中断管理等方面的实现机制,分析了ERTOS主要的实时性能指标;
其次剖析了嵌入式实时操作系统VxWorks内核,从最底层的数据结构开始,通过数据结构之间的关联关系全面展示了整个内核的构成,并对VxWorks操作系统内核在任务调度、内核抢占、任务间通信、内存管理和中断管理等方面的变化进行了动态的分析,对VxWorks操作系统内核特有的工作延期机制进行了分析。
接着通过对实时性能指标测试方法的研究,本文提出了一种测试实时性能指标的方法,通过使用新方法和Rhealstone方法分别对上下文切换时间和死锁解除时间进行测试,由此说明此方法所测得的数据更准确,更符合ERTOS运行的实际情况。
本文最后通过设计合理的测试用例,对VxWorks操作系统各项实时性能指标进行了详细的测试,获得了大量测试数据。通过对测试数据的分析,进一步验证了本文对VxWorks操作系统实时性能的分析。
With the development of digital information technology, ERTOS(Embedded Real-Time Operating System) not only has involved in the scientific research and engineering domains,but also has many affinities people's life. Real-Time performance is the most important performance of Embedded Operating System. It needs dispatching all available resources to achieve real-time task. In order to correctly evaluate the performance of a real-time Embedded Operating System, we must be scientific, systematic approach to ERTOS study of Real-Time performance and comprehensive Real-Time performance and accurate testing.
Firstly,This article has researched on the Embedded Operating System for hard Real-Time implementation of the system architecture, task-mode, memory management and interrupt management to implement mechanism; this article has analysed the Real-Time performance target.
Secondly this article has analysed the source code of VxWorks kernel depthly and a global dynamic scene of a running VxWorks kernel has been shown. This article has analysed the data structure, discovered the relationship of the data structure and shown the processes of the task rescheduling, the communications, the kernel depriving and the allocation of memory in the Operating System. This article has also analysed the defer work mechanism.
This article has proposed a method to measure Real-Time performance, through the use of new method and Rhealstone method respectively has tested the task switching time and deadlock breaking time, description the measured data of this method has more realistic, more in line with the Real-Time system the actual situation.
Finally, This article has designed some reasonable test case.This article has tested the Real-Time performance indicators on the Operating System of VxWorks, This article obtained lots of test date. This article has analysed of test data, authentication the analysis of the real-time performance on the Operating System of VxWorks for this ariticle.
引文
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