The Research And Implementation Of Realtime Task Scheduling In FOMS System

The core of realtime scheduling studing is to explore how to allocate resource reasonably under certain time limit, in order to make the optimal policy available. Specific to the timing series character of Flight operation and management system (FOMS), this article studies on the task scheduling inside it.In this paper, we try to use the existing scheduling algorithms to solve the problem about time restriction of tasks in the FOMS, and then implement a simulative FOMS with the lower miss ratio and the shorter first response time. Our works include three parts. In the first, we analyse the feature of tasks in the FOMS and choose candidate algorithms from a serials of Real-Time scheduling algorithms based on EDF. Next, we compare the different aspects of candidate algorithms by experiments. Finally, we select the EDF and the BEDF algorithms as the core of the task scheduling. In the second part, we integrate the EDF and the BEDF into our FOMS according to the requirement of these algorithms and the structure of FOMS. Then we design a simulated FOMS that can automatically switch its tasks scheduling algorithm according to the system load. This simulated FOMS is validated by simulation experiment. In the third part, we use Java programming language to implement all modules of the simulated FOMS.There are two emphasises in this paper: we selectively use some performance parameters for evaluating the Real-Time scheduling algorithms based on the restrictions of the deadline and the response time of tasks in the FOMS, these parameters represent various peformance of the algorithms; the other creation is designing and implementing an simulated FOMS with the advantage of Real-Time algorithms in existence.