Implementing CIFO using Ada 95 and POSIX

Abstract

Many people are interested in reducing the cost of development for military systems through reuse of existing software. One of the issues associated with supporting reuse of software is the need to support application interfaces. With the upgrade of the Ada programming language, many vendor's existing interfaces may change or become obsolete. In order to support legacy software as it is moved from Ada 83 to Ada 95, it is necessary to have a way to replace the application interfaces with a minimal impact on the legacy software.This paper describes a study to evaluate the possibility of supporting legacy software based on the Texas Instruments F-16 Modular Mission Computer Ada Compilation System (MACS) on a different target, using the features of Ada[?] and POSIX to implement the MACS-specific Application Programmer Interface (API). The majority of the MACS API was based on the Association for Computing Machinery (ACM) Ada Run- Time Environment Working Group (ARTEWG) Catalogue of Interface Features and Options (CIFO)[?]. The organization of this paper follows the same organization as the CIFO. The author assumes that the available Ada 95 compiler supports the Systems Programming and Real-Time annexes. The following CIFO entries were not implemented in the MACS:• Two Stage Task Suspension• Blackboards• Broadcasts• Mutuall Exclusive Access to Shared Data• Memory Management (though Ada 95 defines a similar package)