确保时态一致性的实时并发控制协议  

Real-Time Concurrency Control Protocol of Guaranteeing Temporal Consistency

作　　者：肖迎元[1,2] 刘云生[3] 

机构地区：[1]天津理工大学计算机科学与技术学院,天津300191 [2]天津市智能计算及软件新技术重点实验室,天津300191 [3]华中科技大学计算机科学与技术学院,湖北武汉430074

出　　处：《电子学报》2008年第11期2102-2106,共5页Acta Electronica Sinica

基　　金：国家自然科学基金(No.6073045);国防预研基金(No.51415030203JW05);天津市自然科学基金(No.08JCYBJC12400);天津市高等学校科技发展基金(No.2006BA16)

摘　　要：实时控制系统通常需要维护大量的时态数据对象,这些时态数据对象是现实世界不断变化的物理环境的逻辑表示.应用事务通过对时态数据对象的访问来产生最终的控制活动.在实际应用中,实时控制系统不仅需要确保事务能在规定的期限内完成,也需要保证事务存取的是时态一致性的数据对象.传统的实时并发控制协议强调事务截止期的满足,而忽略了事务对其所存取数据对象有时态一致性需求.本文首先给出了数据和事务时态一致性的形式化定义,在此基础上,提出了一种新的能确保时态一致性的实时并发控制协议:时态一致性高优先级两段锁协议(TCHP-2PL).为了实现更好的实时性能,我们对TCHP-2PL进行了改进,通过引入相似性概念,提出了TCHP-2PL的改进版本:STCHP-2PL.性能测试结果显示,STCHP-2PL在确保时态一致性的同时仍能保证很好的实时性能.A real-time control system usually requires maintaining a large amount of temporal data objects, which are logic descriptions for the fluctuant physical environment in the real world. These temporal data objects are accessed by application Wansactions to generate the ultimate control actions. In the actual applications,real-time control systems require not only ensuring transactions finished in the specified lime limits, but also guaranteeing temporal consistency of data objects accessed by transactions. The traditional real-time concurrency control protocols stress on meeting transaction deadlines, while ignore the requirement m ternporal consistency of data objects access by transactions. This paper first gives the formal definitions of temporal consistency about data and transaction. On the basis of them, a novel real-time concurrency control protocol called TCHP-2PL （Temporal Consistency High Priority two Phase Lock） is presented, TCHP-2PL can guarantee temporal consistency. In order to obtain the better real-time performance,an enhanced TCHP-2PL called STCHP-2PL is proposed by introducing the concept of similarity.Performance tests show that STCHP-2PL can still ensure the very well real-time performance under circumstances of ensuring temporal consistency.

关 键 词：截止期 时态一致性 实时并发控制 实时控制系统 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]