Abstract
The increasing use of distributed real-time embedded systems in modern application domains introduces new challenges in developing software [1]. These systems present design constraints such as low memory and reduced processing power, while also having to comply with the demands of real-time computing. A research project conducted at the University of Karlsruhe in Germany, has dealt with these issues and developed an Open Systems Architecture Platform for Universal Services (OSA+) [2,3].
OSA+ is a middleware solution for real-time embedded systems, written in Java, which aims to reduce the overhead as much as possible by means of memory footprint and computation time. It is designed in a service oriented microkernel approach, using pluggable services for adapting to hardware and for extending middleware functionality.
The Common Object Request Broker Architecture (CORBA) is the most important standard for distributed applications. It is merely a specification, defining a set of conventions and protocols that must be followed by CORBA implementations, and provides interoperability between objects regardless of programming language or platform. CORBA has been implemented by numerous hardware and software system manufacturers, creating a rich and robust framework that successfully operates across heterogeneous computing platforms.
Our research work focuses on extending the feature of OSA+ middleware by adding a CORBA service. This service extension empowers the OSA+ middleware by giving it the possibility to receive invocations from any CORBA implementation using a predefined interface [4]. The main goal of the service has been to keep the memory footprint to an absolute minimum, while keeping the interoperability of CORBA. The approach for reaching this goal has been to identify which mechanisms from the specification that are needed to provide the middleware API of OSA+ to other CORBA applications. The result is a highly narrowed down CORBA implementation encompassing 15.3KB of compiled classes, which combined with the OSA+ totals at a memory footprint of approximately 59KB. This is extremely low for a complete real-time middleware platform incorporating CORBA interoperability.