【作者】 张雷；

【导师】 刘日升；

【作者基本信息】 大连理工大学 ， 计算机应用技术， 2002， 硕士

【摘要】 许多类型的应用程序都可以从弹性的，开放的中间件中获益。CORBA就是一种用于简化分布式应用程序和服务开发的对象请求代理(ORB)的中间件标准。CORBA的应用经验表明CORBA非常适合传统RPC样式的应用程序。但是，传统CORBA实现中性能优化和服务质量特性的缺乏使得CORBA不适合于高性能和实时应用程序。 当前关于实时CORBA的工作包括脱机调度(Offiine Scheduling)，硬实时(Hard Real-Time)基于的单一速率(Rate Monotonic—RM)调度和在线调度(Online Scheduling)，最佳优化实时系统基于的最早截止期限优先(Earliest Deadline First—EDF)算法。前者以运行时调度的弹性为代价提供服务质量的保证，而后者提供了补充。 在这篇论文中，通过对CORBA基本概念的介绍和体系结构的分析，并结合实时应用所面临的问题指出了传统CORBA在实时应用上的不足，以及实时CORBA对传统CORBA的扩展和实时CORBA的体系结构。在此基础上，本文详细分析了实时CORBA的调度服务，提出了一种调度原则的模型，该原则同时具有单一速率(RM)调度和最早截止期限优先(EDF)两种算法的优点，那就是：服务质量的保证和运行时调度的弹性。最后，对该调度原则模型的进一步工作进行了展望。更多还原

【Abstract】 Many types of applications can benefit from flexible and open middleware. CORBA is an emerging middleware standard for Object Request Brokers (ORBs) that simplifies the development of distributed applications and services. Experience with CORBA demonstrates that it is suitable for traditional RFC-style applications. However, the lack of performance optimizations and quality of service (QoS) features in conventional CORBA implementations make them unsuitable for high performance and real-time applications.Current work on real-time CORBA includes an off-line scheduled, hard real-time system based on rate-monotonic scheduling and an on-line scheduled, best-effort real-time system based on the earliest-deadline-first algorithm. The former provides QoS guarantees at the expense of run-time scheduling flexibility while the latter provides the complement.In this paper, it points out the shortages of conventional CORBA on the field of real time, the extensions of real time CORBA made to the conventional CORBA and the framework of real time CORBA by the introduce of CORBA basic concepts and the analysis of its framework as with the problems what real time applications faced. Based on all of above, this thesis expatiates the scheduling service of real time CORBA on detail and proposes a scheduling service model which provides the advantages of both, that is, QoS guarantees and run-time scheduling flexibility. Finally, some challenges for the future work are presented.更多还原