关于实时系统的几个主要的研究内容

进来阅读关于实时调度、实时系统建模与验证等方面的文章，但总感觉对于实时系统缺乏那种宏观上的、本质上的洞悉和把握，分析原因，可能是由于对实时系统的主要研究方向缺乏了解所致。为了使自己"活的明白一点"，在此把"real-time systems"一书中的相关描述做一摘抄和记录,同时把在一些文章看到的主要研究问题页罗列到这儿，等到有了足够的材料时对其进行总结，整理出一个完善的脉络。

(1) The field of real-time computing is espesially rich in research problems because all problems in computer architecture, fault-tolerant computing, and operating systems are also problems in real-time computing, with the added complexity that real-time constrains must be met.

(2) A real-time computer must be more reliable than its individual hardware and software componets.

(3) It is important that the task execution time be predictable to allow the diesgner to figure out if all critical tasks will meet their deadlines.

(4)Since the consequences of failure are more severe in real-time systems than in therir general-purpose counterparts,such systems need to be specified more carefully and their performance better validated;that is, we need specification languages and perormance measures that is capable of expressing timing requirements. We require, among other things, meas by which to predict the executiong times of programs;to model the reliability of software and of hardware;to assign tasks to processors and schedule them so that deadlines are met;and to develop mechanisms by which the system can quickly recover from the failure of an individual componet.