[Info-vax] QIO Writes to a mailbox

[Steve Bainbridge]

On Nov 4, 9:09 pm, "Richard B. Gilbert" <rgilber... at comcast.net>
wrote:
> On 11/4/2011 12:52 PM, Steve Bainbridge wrote:
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> > On Nov 4, 2:46 pm, Steven Schweda<sms.antin... at gmail.com>  wrote:
> >> On Nov 4, 5:04 am, Steve Bainbridge<stephen_bainbri... at yahoo.co.uk>
> >> wrote:
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> >>> I have a very simple question, but when looking at the Alpha internals
> >>> manual and talking to colleagues the answer does not seem so obvious.
> >>> [...]
> >>> Unfortunately the writer does not check or report what value the IOSB
> >>> returns [...]
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> >>     I'm confused.  You _know_ that you're ignoring the IOSB
> >> status, and, rather than fixing that, you're looking at "the
> >> Alpha internals manual"?  Really?
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> >>> Is it QIO or QIOW? [...]
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> >>     Another fair question.
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> >>     Why not start by fixing the obvious problems, and then
> >> move on to the obscure stuff (if necessary)?
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> > Hi,
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> > This code was written several years ago and I've been dumped on to
> > investigate and correct the issue we now very occasionally see. I'm
> > aware of the obvious missing check on the IOSB, but I can't say with
> > any certainty that this is causing the problem.
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> The missing check on the IOSB is almost certainly NOT causing the problem!
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> The missing check is making diagnosis more difficult!
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> I'd suggest designating one of the systems involved as the guinea pig
> and add that missing error check.
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> If the check tells you that there is an error and it correlates with
> your problem, you know what to do!  If the error does not correlate, fix
> it at your convenience and keep looking.
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> If there are more instances of this sort of "lazy coding", fix them too.
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> Good luck.  And if you have a few hundred thousand lines of code of this
> quality, you have my sympathy.
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> <snip>

Richard,

If it was just a couple of hundred thousand lines of code I would
laugh my rocks off, alas it's circa 2-2.5 million lines of code,
written over many years by developers of variable quality...some good,
some certainly bad and some very ugly code.

I realise that I'm going to have make changes and release it in the
hope that it will work - it's just difficult to justify the changes
and it's likely success.

Cheers,
Steve