Re: Ada and Unix--Blocked Tasks

[ae@sei.cmu.edu (Arthur Evans)]

Mike Feldman (mfeldman@june.cs.washington.edu) suggests that Ada tasks
might be mapped onto OS processes.

It's a good idea if it can be done.  However, Ada's semantics permits
tasks to share data, and doing so pretty much requires that tasks have
access to shared parts of main memory.  If the OS does not provide this
feature, then this approach fails.  A few OSs, such as Multics, provide
this feature.  I do not believe that Unix does.

The Ada 9X Requirements in Chapter 8 (Distributed Processing) address
the possibility of parts of Ada programs executing on different
processing systems.  Thus it seems likely that 9X will permit this
approach, if the program is structured appropriately.

Art Evans
Ada Consultant
412-963-0839