Precise Access Control Support in Object-oriented Systems on a Descriptor Computer

摘要

Object-orientation concept becomes popular in the development of software systems today. The object-orientation concept provides advantages over traditional procedure-oriented languages in important software attributes, such as dynamic binding, inheritance, information hiding and data abstraction. With the features of information hiding and data abstraction, the reliability of software systems can be improved because one software module (object) cannot affect private data and internal implementation of other software modules. Objects may only operate other objects through the interface provided by the target object itself. However, current systems only provide primitive access control support for object-oriented systems. The protection of these systems is often supported on individual page or segment basis. The access control for object-oriented systems is only managed mainly by the software systems. A proposed architecture - HISC (High-level Instruction Computer), provides a precise hardware support in access control for object-oriented systems comparing with conventional hardware systems. This paper briefly describes various hardware protection schemes and the precise access control in HISC.