An analysis of communication and multiprogramming in the Helios operating system

Abstract

This paper analyzes some features of the Helios distributed operating system. The study is made in the framework of the VCP (Virtual Class Processor) project. VCP is a software architecture, which makes the implementation of Concurrent Object-Oriented Languages on multicomputers easier. A VCP prototype is being developed on a Transputer-based multicomputer: the Multicluster-2 by Parsytec. The Helios system has been chosen to implement VCP. The heavy use of message-passing and multiprogramming facilities required by the VCP architecture, has led us to the valuation of the available facilities under Helios. The results of a quantitative analysis are examined: performances of communication at kernel level, the cost of process management, the method invocation elapsed time. A qualitative analysis enables to estimate: the development interface of Helios, the possibilities of message-passing, the questions of communication reliability and the interest of the notion of task.