What's next for Ada?

2014-07-04

While the dust settles around the introduction of Ada 2012, it's interesting to see that people are looking forward to what the next version of Ada might bring.

At the Ada Europe conference last week, a number of presentations looked at areas that are not currently in the Ada language, which might be worthy candidates for including in the future. Given our own interests in embedded, real-time systems, we naturally focus upon the ones relevant to this area.

Owing to the unavailability of one of the speakers at the conference, Tucker Taft of AdaCore stepped in at the last minute to give a presentation on providing support for multicore and manycore systems through programming language features. The features Tucker discussed were drawn primarily from his ParaSail programming language, his presentation also included a discussion of how the features could be incorporated to the Ada programming language. This topic was also discussed in a paper by Luis Miguel Pinho (CISTER, Polytechnic Institute of Porto), Brad Moore (General Dynamics) and Stephen Michell (Maurya Software Inc).

Luis Miguel Pinho also appeared as the author of a paper on a runtime verification framework (together with co-authors Andre Pedro and David Pereira also from CISTER and Jorge Pinto from Universidade do Minho). This proposes an extension to the contracts concept introduced in Ada 2012. From these extended contracts, the framework could synthesise runtime monitors to ensure that the desired real-time properties are preserved.

Finally, Prof Alan Burns from University of York (and Rapita's own former chairman) discussed how the deadline-floor inheritance protocol (DFP) could be incorporated into Ada. DFP has been proposed as a resource sharing protocol for Earliest-Deadline First (EDF) scheduling. When EDF was introduced into Ada 2005, the Stack Resource Policy (SRP) was specified for sharing resources among EDF tasks. SRP is a complex protocol and has had a number of difficulties with its specification and implementation. DFP is simpler to understand and more efficient to implement, which keeping all the useful properties of SRP. Consequently, the 16th International Real-Time Ada Workshop agreed the recommendation that SRP should be deprecated and replaced by DFP for single processor systems.