Bryce, Robert William2024-08-132024-08-1319951995https://hdl.handle.net/1828/17116This thesis describes mechanisms designed and implemented to enhance the overall, and specifically, real-time performance of a distributed object-oriented operating system called Apertos. Apertos employs a meta-hierarchy, defined by the relationship between an object and its supporting environment, which is intended to support various objects with different requirements, such as real-time support and persistence. As such a system grows, satisfying different object requirements via the meta-hierarchy with its related communication overheads becomes orthogonal to achieving real-time response perfor­mance. To address this performance penalty and to improve real-time support, we intro­duce preemptive scheduling and hierarchical scheduling as solutions. Preemptive scheduling improves the stability of the system. Hierarchical scheduling establishes a more flexible system in terms of scheduling, and improves communication performance by a large factor over the original scheme applied.119 pagesAvailable to the World Wide WebThesis