Studies on a Dynamic Scheduling Method in Distributed Real-Time System

在这个财政年度。本文提出了一种预运行调度方法，并通过对该方法和其它方法的仿真结果，讨论了该方法的有效性。在此基础上，提出了一种基于资源预留的动态调度方法，并讨论了其在实时事务调度中的应用。主要研究结果如下：1.一种具有端到端定时约束的分布式实时系统调度算法在本研究中，我们提出了一种适用于具有各种定时约束（如端到端定时约束和抖动约束）的分布式实时系统的调度算法。该算法具有调度网络和满足各种约束条件的处理机的能力，适用于不需要实时通信设施的网络系统。仿真研究表明，该算法在获得较高成功率的同时，具有很高的效率.一种基于资源预留的实时同步协议和调度方法本文提出了一种基于时间戳排序的实时事务动态同步协议和调度方法。首先，在这项研究中。提出了一种基于时间戳排序和优先级的动态事务调度方法。该方法可以减少事务的截止日期错过。最后，在本研究中，所提出的方法和其他方法的仿真结果和所提出的方法的效率进行了讨论。

In this fiscal year. we have developed a pre-runtime scheduling method and discussed its effectiveness based on simulation results of it and other methods. Furthermore, we have developed a dynamic scheduling method based on the resource reservation and discussed its applications to the scheduling of real-time transactions. These results are summarized as follows :1. A scheduling algorithm for distributed real-time systems with end-to-end timing constraintsIn this research, we have developed a scheduling algorithm for distributed real-time systems with various timing constraints such as end-to-end timing constraints and jitter constraints. The proposed algorithm has capability to schedule networks as well as processors satisfying various constraints and is applicable to the systems with networks which need not have real-time commimication facilities. Simulation study shows that the proposed algorithm is very efficient while achieving high success ratio.2. A real-time synchronization protocol and scheduling method based on the resource reservationIn this research, we have developed a dynamic synchronization protocol and scheduling method based on time-stamp ordering for real-time transactions. First, in this research. the synchronization protocol which prevents transaction abortions by reservation of shared resources is developed, Next, in this research, the dynamic transaction scheduling method based on timestamp ordering and priority is developed. This method makes it possible to decrease the deadline miss of transactions. Finally, in this research, simulation results of proposed and other methods are presented and efficiency of proposed methods are discussed.