Composite objects: real-time programming with CORBA

The Common Object Request Broker Architecture (CORBA) is a successful, standardized system integration framework based on distributed object technologies. An ongoing effort concerns extensions to CORBA to incorporate real-time computing needs. Although the use of objects in real-time computing is straightforward, the technical challenge lies in the replacement of static real-time computing infrastructures with a flexible real-time computing infrastructure, in which distributed real-time client and server objects can be created and connected as needed at run-time. We propose the concept of "composite objects" for the integration of real-time and non-real-time computing into a single object-based framework. In the paper, we present a methodology for creating objects which interface to CORBA without violating real-time assumptions. We present a example scenario which integrates a real-time computing architecture and CORBA components via composite objects. Finally, we discuss implementation-related issues based on our experiences with composite objects.