摘要
实时系统由于其业务对时间要求的特殊性,使得传统工作流技术难以满足其需求.在传统工作流的基础上,针对实时系统提出了实时工作流的概念,并建立了实时工作流元模型.与传统的工作流相比,主要对工作流的时间约束和异常处理进行了考虑.在活动上扩展了启动时间和执行时间,在工作流过程上扩展了执行时间,在并发活动上扩展了并发时间约束等,此外,元模型中还考虑了活动的超时异常以及应用程序和活动之间的执行关系.为了能够利用实时工作流元模型进行实时工作流建模,通过扩展UML定义了一种实时工作流描述语言,并分别从设计要求、定义技术和profile三个方面对实时工作流描述语言进行了阐述,给出了实时工作流的建模规则.最后结合船舶指控系统的具体实例,对建模方法进行了说明.
Traditional workflow technology can＇t meet the requirements of real-time system because of the particularity of business with temporal factor. Thence the real-time workflow is defined for real-time system in this paper, and the metamodel of real-time workflow is established, expending the metamodel of traditional workflow to support the time constraint and exception in real-time workflow. The extended attributes include the start time and duration in activity model, the duration in workflow process, the concurrent constraint in concurrent activities etc. Besides, the tirneout exception of execution of activities is considered, and the relationships between the application programs and activities executed by them are established in the metamodel. Based on the metamodel, a UML based real-time workflow description language is defined by using profile mechanism, which is extended from UML2.0. The modeling principles are discussed to describe a real time workflow by using this language firstly; and then the UML based extension technology and the profiles of the language are introduced; finally, a specific example of shipborne combat system is given to explain the modeling approach. This work provides a language which is easy to learn, use and understand for workflow designers, and basis for the execution and time analysis of real-time workflow.
出处
《计算机研究与发展》
EI
CSCD
北大核心
2010年第7期1184-1191,共8页
Journal of Computer Research and Development
基金
国家自然科学基金项目(90818017)
国家"九七三"重点基础研究发展计划基金项目(2007CB310803)
