連續性媒體磁碟排程法之研究

• Main Authors: Shu-Ting Liao, 廖淑婷
• Other Authors: Chien-I Lee
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/42383097748429096514

碩士 === 臺南師範學院 === 資訊教育研究所 === 87 === In order to meet the time constrains of multimedia system, it is necessary to avoid delay in process of disk services. To schedule the time critical tasks validly will help to guarantee the quality of services. Therefore, it is very important to apply an efficiency disk scheduling approach for multimedia system. In general, the disk seek time is the largest factor of the transfer delay, and most algorithms were proposed to minimize the seek cost of disk. In this thesis, we will propose an efficiency disk scheduling strategy for continuous media which can reduce the excessive disk-seek time in order to obtain the optimal service time. In this strategy, we consider the correlation between deadlines and storage locations of each request for disk accesses. Without disobey the deadline constrains, we try to perfetch the requests with later deadlines on the current disk-scan direction, where those later requests will soon be retrieved for display. From the mathematical analysis, we will prove that the validity of our new proposed strategy, and from the simulation analysis, we will find that our new proposed strategy have best performance than the other disk scheduling strategies. Moreover, by considering the multiple disk drivers for the requirements of storage space and transfer bandwidth of continuous media, we will extend our strategy. From the simulation results, we will also find that our method has best performance than others. Finally, we simulate streams with different bandwidth and dynamic consumer rate to adapt to the practical requirement of user. From the experiment results, we will find that under such cases, our new proposed strategy still has the better performance for continuous media storage server.