摘要
利用模块化设计的思想 ,首先为分布式数据库系统中各事务的每一种操作 (读锁、写锁、解锁 )构造一个基本的加权 Petri网模型 ,并给出了加权 Petri网共享合成的概念 .然后利用共享合成技术 ,动态地构造各站点的加权 Petri网模型 ,以适应系统的动态变化 .此外 ,本文利用 Petri网的化简技术 ,极大地简化了各站点的 Petri网模型 ,之后利用同步合成技术构造出整个系统的 Petri网模型 ,较好地解决了 Petri网的可达性分析中可能出现的状态 "爆炸 "问题 .
First, a weighted Petri net model for every operation ( share locking, exclusive locking and unlocking) of a transaction in distributed database system was constructed using modular technique in this paper. The definition of sharing synthesis of weighted Petri nets is given in this paper. Second, the paper composes weighted Petri net models for every site using sharing synthesis. It is convenient for dynamically constructing Petri net models in order to fit to dynamic change of system state. Moreover, the paper largely reduces the weighted Petri net model for every site with reduction technique. The Petri net model for overall system is constructed using synchronizing synthesis. It solves the state explosion problem in reachability analysis of Petri nets. Last, a sufficient and necessary condition for judging whether the system is deadlock is given in the paper.
出处
《小型微型计算机系统》
CSCD
北大核心
2004年第5期821-826,共6页
Journal of Chinese Computer Systems
基金
国家"973"重点基础研究发展规划项目(G19980 3 0 60 4)资助
中国科学院计算机科学实验室开放课题项目(SYSKF0 3 0 4)资助
上海市重点基础研究计划资助
关键词
分布式数据库系统
并发控制
死锁检测
PETRI网
共享合成
同步合成
化简
distributed database system
concurrent control
deadlock detection
petri net
sharing composition
synchronizing composition
reduction
