Re: Generic Formal Parameter for a Task Type

["Pat Rogers" <progers@NOclasswideSPAM.com>]

See RM C.7.1 for package Ada.Task_Identification, specifically function
Is_Terminated.  That may be enough...



"James Rogers" <jimmaureenrogers@worldnet.att.net> wrote in message
news:3AA84FC7.CE523E9D@worldnet.att.net...
> The problem with using a formal limited private type is in the
> need to determine if one of the tasks being monitored has terminated.
>
> The 'Terminated attribute only applies to Task objects, either
> directly, or implicitly through an access to the task object.
>
> A limited private type is too general. It is not viewed within the
> generic as a task type. I know. I tried this first.
>
> The only way to make such a system work is to creat a limited record
> type containing an access to task type. You could then create a
> function taking a parameter of the record type, returning the proper
> response from the 'Terminated attribute.
>
> Although this is easily done, it is not what I wanted. I had hoped
> to be able to create a generic package directly usable with most
> any task type.
>
> This appears to be one problem not solvable in Ada, yet easily
> solved in Java.
>
> I would like to add a generic task type formal parameter to the
> list of improvements for the next version of Ada.
>
> Jim Rogers
> Colorado Springs, Colorado USA
>
> Pat Rogers wrote:
> >
> > "James Rogers" <jimmaureenrogers@worldnet.att.net> wrote in message
> > news:3AA80A68.A2C8B042@worldnet.att.net...
> > > I have looked through "Ada as a Second Language" and the Ada Reference
> > > manual. I cannot find any proper form to pass a task type as a
> > > generic formal parameter.
> > >
> > > Is there a generic formal parameter form for this purpose?
> > >
> > > I wanted to create a generic package I call Task_Governor. This
> > > package would control the number of tasks one could create at once.
> > > The idea is that task resources may be limited. This package would
> > > allow someone to limit the number of tasks to a maximum specified.
> > > An instantiation of the package would monitor the tasks it started
> > > and allow another to be started when one of the tasks terminated.
> > >
> > > My problem is that I cannot figure out how to specify a task type
> > > as a generic formal parameter.
> >
> > There is no generic formal task type; you have to use a limited private
> > formal.
> >
> > ---
> > Patrick Rogers                       Consulting and Training in:
> > http://www.classwide.com        Real-Time/OO Languages
> > progers@classwide.com          Hard Deadline Schedulability Analysis
> > (281)648-3165                          Software Fault Tolerance
>