Aspect-Oriented Programming with C# and .NET

Almost a year ago, Microsoft has introduced the .NET architecture as a new component-based programming environment, which allows for easy integration of classical distributed programming techniques with Web computing. .NET defines a type system and introduces notions such as component, object, and interface, which are building blocks for distributed multi-language component-based applications. As many other component frameworks, .NET mainly focuses on functional interfaces of components. Nonfunctional aspects of components, such as resource usage (CPU, memory), timing behavior, fault-tolerance, or security requirements are currently not expressed in .NET’s component interfaces. These properties are essential for building reliable distributed applications with predictable behavior even in cases of faults. Within this paper, we discuss the usage of aspectoriented programming techniques in context of the .NET framework. We focus on the fault-tolerance aspect and discuss the expression of non-functional component properties (aspects) as C# custom attributes. Our approach uses reflection to generate replicated objects based on settings of a special “fault-tolerance” attribute for C# components. We have implemented an aspect-weaver for integration of aspect-code and componencode, which uses the mechanisms of the language-neutral .NET type system. Therefore, our approach is not restricted to the C# language but works for any of the .NET programming languages.Introduction and Motivation