Describes a software architecture which supports incremental system and software integration, hardware and software maintenance, and system evolution and reconfiguration without imposing a significant impact on system performance or availability. The approach utilizes a compact command language for controlling the dynamic integration of new or replacement software and hardware components into a distributed real-time system while that system is operating normally. The approach works with current languages, architectures and applications and does not depend on the availability of redundant processing components. The dynamic integration command language is described using a typical usage scenario, and the results of a prototype implementation effort are discussed, in which real-time dynamic integration commands have been shown to have performance times in the 20-30-/spl mu/s range.>

The STRUCT system utilizes the flexibility of a powerful graphics display system to provide a set of tools for program analysis. These tools allow the analysis of the static program structure and the dynamic execution behaviour of programs within the entire operating system user program environment of the Brown University Graphics System (BUGS). Information is collected and presented in a manner which fully exploits two aspects of this environment. First, the operating system has been developed in a well-structured hierarchical manner following principles laid down by other researchers. Second the programs under analysis have been written in a structured programming language following coding conventions which make available, at the source code level, valuable program control information. This system is currently being used to predict and analyze the performance advantages available through the migration of function between levels of software and between software and firmware within the BUGS.