Gnass: a Gnat-based allocation and scheduling system

The Ada 95 programming language is designed for programming large systems and for concurrent programming. However, it does not provide facilities in the areas of processor allocation to tasks while its support for flexible task scheduling is limited. In this paper we describe some experiments, resulting in Gnass, in which we extend Ada facilities for real-time multiprocessor applications. As environment we took the Gnat implementation on Solaris (the GNU NYU Ada Translator, Gnat), this primarily because of its availability. Two features offered by Gnass are discussed in this paper, namely control over processor allocation, and scheduling based on timing requirements.