基于Petri网的构件组装模型

Component assembly model based on Petri net

针对形式化语义对构件组装和演化描述能力不足的问题,提出了基于Petri网的构件组装模型.以Petri网系统表示构件的静态组装结构,用网中标识在库所中的流动来模拟构件的动态运行过程;构造了6种具有普遍适应性的构件组装运算,给出了构件Petri网的动态运行规则,并通过案例演示了构件Petri网的演化和组装运算过程.为了支持对构件演化过程中波及效应的量化分析,从可达标识图中抽象出构件影响因子用来描述相关构件耦合度的大小,并用以度量构件系统演化时的影响度.该模型可应用于基于构件的软件系统的体系结构描述及构造过程的演化分析.

The component assembly model based on Petri net was proposed to eliminate the deficiencies of formal semantic definitions in describing both component assembly and component evolution. Petri net system functions were employed to describe the static assembly structures of component. In addition, the migration of component ID flowing throughout Petri net was used to simulate the dynamic operation of component model. Six component assembly architecture and dynamic operation rules for Petri net were constructed, and special cases were given to illustrate both the evolution and operation of component Petri net. To support quantitative analysis of ripple effect during component model evolution, impact factors were abstracted from reachable marking graph of Petri to describe the level of coupling between components and to measure the influence degree of component evolution. This model can be applied to the description of architecture and evolution analysis of assembly process in component-based software system.