Kernel structuring for object-oriented operating systems: The apertos approach

Abstract

This paper addresses the issues faced when constructing an operating system and its kernel with object-oriented technology. We first propose object/metaobject separation, a means of constructing an object-oriented operating system and its kernel. This method divides the implementing system facilities and applications into two types: objects and metaobjects. This paper presents the concept of object/metaobject separation and discusses why object/metaobject separation is required in terms of limitations in the micro-kernel and object-oriented technologies. We also discuss an example of using object/metaobject separation as implemented in Apertos. This paper then proposes mechanisms which efficiently implement object/metaobject separation. These are characterized by meta-level context management, and are implemented in the Apertos operating system. Meta-level context management is designed to reduce the overhead of control transfer between an object and its metaspace. Here, metaobjects reflectors, MetaCore, Context, and Activity are introduced to represent the metahierarchy of an object’s execution. Finally, we present the evaluation results of the Apertos implementation, and discuss the relationship with previous work.