| The primary objective of object-oriented system designs is to partition the subsystem into a set of interconnectable collaborative objects or components. Each object implements an important entity of complete system software. Object-Oriented Design (OOD) and Programming (OOP) can help to partition complex system software into smaller and simpler objects. However, separation of concerns cannot be completely achieved. System aspectual properties, such as synchronization, tracing, and fault tolerance, cannot be captured and localized in both the design and implementation. Codes of these system aspectual properties are scattered among all objects in the system design and implementation. The outcome makes the system software hard to understand, adapt, evolve, and maintain.; Some system aspectual properties in object-oriented operating systems such as synchronization, scheduling, tracing, and fault tolerance crosscut the basic functionality of the system, such as the file system and process management. In every layered system aspectual properties may need to be modified. By separating system aspectual properties and functional components of operating systems in every layer, we can provide a better generic design model of operating systems and better support of comprehension, adaptability, reusability, and expandability. However, such support is difficult to accomplish.; We have developed the Aspect-Oriented Framework (AOF) for supporting the design of adaptable operating systems. A framework represents the reusable and adaptable design and implementation for a family of system software, such as operating systems. The framework, represented as a collective set of collaborative defined as system aspectual properties. An aspect-oriented framework simplifies the system design by expressing it at a better and higher level than that provided by OOD and OOP. Our framework promises comprehension, adaptability, reusability, and expandability of the design and implementation while separating functional components and system aspectual properties from each other in every layer of the system. The framework uses design patterns, which help designers and developers to easily understand and develop the framework. |
