Reusable executives for hard real-time systems in Ada

Abstract

The component library for both the cyclic and tasking executives has been released for distribution by the Spanish Ministry of Defense. The approximate size for each of the executive subsytems is about 8000 loc. The test code adds up to 50000 loc for each subsystem. In our opinion, the development of reusable executive components has been made possible by such Ada features as tasking (for the tasking executive), packages, generics and low level constructions. These features are unique to Ada and provide a solid base for developing high quality reusable software components. A large effort has been made in order to get a clear design and to provide the user with components that are close to his or her perception of the system to be developed. The abstraction level of the components is significantly higher than that provided by pure Ada.