Reactor Design Pattern

Abstract

In object-oriented (OO) applications, objects collaborate through message passing, which results in these objects being coupled and mutually dependent. These dependencies can be reactive, i.e. such that, for example, the state change of one object, requires automatic reaction in all dependent objects. Examples of such reactive dependencies can be found in various software systems, including rich graphical interfaces, spreadsheet systems, animation, robotics, etc. Unlike the reactive paradigm which natively provides abstractions and mechanisms for the management of reactive dependencies, the OO paradigm lacks proper support. Object-oriented applications developers often resort to the use of ad-hoc solutions or design patterns such as the well-known Observer pattern, which are not suitable for managing more complex scenarios. In this paper we offer a novel design pattern (REACTOR), which utilizes a graph data structure to improve the management of reactive dependencies in OO applications.