The Ada language has for long provided support for the development of reliable real-time systems, with a model of computation amenable for real-time analysis. To complement the already existent multiprocessor support in the language, an ongoing effort is underway to extend Ada with a fine-grained parallel programming model also suitable for real-time systems. This paper overviews the model which is being proposed, pointing out the main issues still open and road ahead.

Integrating concurrent and object-oriented programming has been an active research topic since the late 1980's. There is a now a plethora of methods for achieving this integration. The majority of approaches have taken a sequential object-oriented language and made it concurrent. A few approaches have taken a concurrent language and made it object-oriented. The most important of this latter class is the Ada 95 language, which is an extension to the object-based concurrent programming language Ada 83. Arguably, Ada 95 does not fully integrate its models of concurrency and object-oriented programming. For example, neither tasks nor protected objects are extensible. This article discusses ways in which protected objects can be made more extensible.