Categorization of Implicit Invocation Systems

Development and maintenance of implicit invocation systems is not as well understood and supported as the development of explicit invocation systems. The situation is aggravated in systems that allow the composition of functionality developed by different organizations, potentially using different programming languages and methodologies. In this document, we categorize the various ways in which implicit invocation systems can define, bind to, announce, subscribe, and deliver events. We also categorize the architectures and topologies of implicit invocation systems. The purpose of the categorization is to increase the understanding of the type of requirements that these systems impose on software development practices. As the categories are introduced, documented representative invocation systems are discussed in order to illustrate the types of systems that fall under each given category. Our categorization applies to systems as varied as active databases, aspect-oriented applications, and distributed heterogeneous event-based systems.