DEC Ada Tasks and multiporcessors

DEC Ada Tasks and multiporcessors

[Mats Weber]

The current DEC Ada on AXP does not support multiprocessors; that is,
tasks in the same program cannot execute on multiple processors.

Will this be possible in a (near) future release of DEC Ada ?

I know GNAT is getting ported to VMS/AXP and will support
multiprocessors. When will this port become available ?

Is GNAT going to be DEC's standard Ada 95 compiler for VMS/AXP ?

Re: DEC Ada Tasks and multiporcessors

[Larry Kilgallen]

In article <dewar.855676306@merv>, dewar@merv.cs.nyu.edu (Robert Dewar) writes:

> We can provide beta test versions of the VMS/AXP compiler to customers
> right now. The compiler is in excellent shape and will be validated
> shortly. The debugging support is not yet complete. 

Will it interface to the regular VMS debugger or will one have
to use the GNAT-specific debugger?

Larry Kilgallen

Re: DEC Ada Tasks and multiporcessors

[Robert Dewar]

Larry asked

<<Will it interface to the regular VMS debugger or will one have
to use the GNAT-specific debugger?>>

Digital decided that they preferred to have GDB be the primary debugger.
This is because they do not want to make the necessary changes to the
regular VMS debugger to fully support Ada 95. However, we chose to use
compatible debugging formats, so in fact the VMS debugger works pretty
well (it just does not understand as much as it should about GNAT),
while GDB will be tailored much more completely for GNAT and Ada 95.

Robert Dewar
Ada Core Technologies

Re: DEC Ada Tasks and multiporcessors

[Larry Kilgallen]

In article <33005327.4E54@elca-matrix.ch>, Mats Weber <Mats.Weber@elca-matrix.ch> writes:
> The current DEC Ada on AXP does not support multiprocessors; that is,
> tasks in the same program cannot execute on multiple processors.
> 
> Will this be possible in a (near) future release of DEC Ada ?

Despite the fact that DEC Ada on VAX uses a private tasking engine:

DEC Ada on Alpha VMS uses the common DECthreads engine also used by
the C-oriented pthreads and the (language-neutral-except-for-Ada ?)
DECthreads interface.  That engine was upgraded for VMS V7 to use
kernel threads but only fully enabled with a VMS patch kit for V7.0
or without any patch kit in V7.1.

At least that was DEC's announced plan.

So at what operating system version are you unable to used multiple
processors from a single Ada program ?  Has DEC departed from their
stated intentions which I listed above ?

(I don't have a multiprocessor system to test these assertions.)

Larry Kilgallen

re: DEC Ada Tasks and multiporcessors

[Charlie McCutcheon]

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Hi, sorry I'm not able to reply to this properly.  I got this as
mail forwarded to me (I'm not on internet enough), I wasn't able
to see this original posting, only replies to it, and now my server
isn't even showing me the replies.  I can however see postings
much older than Feb 11, the date this was posted.  Sigh!

>Article 165128 of comp.os.vms:
>From: Mats Weber <Mats.Weber@elca-matrix.ch>
>Newsgroups: comp.lang.ada,comp.os.vms
>Subject: DEC Ada Tasks and multiporcessors
>Date: Tue, 11 Feb 1997 12:09:38 +0100
>Organization: ELCA Matrix SA
>Lines: 9
>Message-ID: <33005327.4E54@elca-matrix.ch>
>Reply-To: Mats.Weber@elca-matrix.ch
>NNTP-Posting-Host: hlm127.elca-matrix.ch
>Mime-Version: 1.0
>Content-Type: text/plain; charset=us-ascii
>Content-Transfer-Encoding: 7bit
>X-Mailer: Mozilla 3.01 (Macintosh; I; PPC)
>
>The current DEC Ada on AXP does not support multiprocessors; that is,
>tasks in the same program cannot execute on multiple processors.
>
>Will this be possible in a (near) future release of DEC Ada ?

Likely support for this is in OpenVMS Alpha V7.1, which supports
Kernel Threads (see VMS documentation for more information).  DECthreads,
which DEC ada uses to implement Ada tasking on Alpha, gives the kind
of support we need for allowing DEC Ada tasks to run on multiple
processors.

We are in the process of testing DEC Ada on OpenVMS 7.1 to confirm
our general support.  We have run the subset tests which would be
likely to give us problems, and saw no problems.  We did a lot of
this subset testing while the VMS engineering group was developing
Kernel Threads.

>I know GNAT is getting ported to VMS/AXP and will support
>multiprocessors. When will this port become available ?
>
>Is GNAT going to be DEC's standard Ada 95 compiler for VMS/AXP ?

I saw some postings from Robert Dewar who I assume answered this
to your satisfaction.  Gnat is in field test now.

For more help with either topic, you can contact me or the DEC Ada Product
Manager, Cathy Axel (axel@teamlk.dec.enet.com).

Charlie
DEC Ada