GNAT/RTEMS

Steve steved94 at attbi.com
Fri Jan 24 13:50:29 UTC 2003


----- Original Message -----
From: "Joel Sherrill" <joel.sherrill at OARcorp.com>
To: <Mark.Hann at scisys.co.uk>
Cc: <rtems-users at OARcorp.com>
Sent: Tuesday, January 21, 2003 6:38 AM
Subject: Re: GNAT/RTEMS
[snip]
> I have seen people run into is having non-Ada tasks call Ada routines
> when the task is not at a valid Ada priority.  [Remember Ada's 32
> priorities
> are mapped onto a range of POSIX threads priorities so it is possible
> for
> a POSIX thread to have priorities above and below valid Ada task
> priorities.]
> This can violate the priority ceiling on some of the Ada run-time
> mutexes.

I don't understand why Ada's 32 priorities are mapped to a range of POSIX
thread priorities.  Is this something special about the GNAT implementation?

The only thing I see in the LRM about priorities is in D.1.26 indiciating
that System.Priority shall include at least 30 values.

Steve
(The Duck)

[snip]
>
> --
> Joel Sherrill, Ph.D.             Director of Research & Development
> joel at OARcorp.com                 On-Line Applications Research
> Ask me about RTEMS: a free RTOS  Huntsville AL 35805
> Support Available                (256) 722-9985
>





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