[Info-vax] QIO Writes to a mailbox

[abrsvc]

On Nov 4, 6:13 am, gartm... at nonsense.immunbio.mpg.de (Christoph
Gartmann) wrote:
> In article <e519cbe4-54bc-480c-8b07-267b9f90e... at q13g2000vbd.googlegroups.com>, Steve Bainbridge <stephen_bainbri... at yahoo.co.uk> writes:
>
> >We have some old code that issues a QIO WRITEVBLK to a mailbox - the
> >return code from the QIO is normal. Another process reads the mailbox
> >and never gets the message - this only happens very rarely.
> >Unfortunately the writer does not check or report what value the IOSB
> >returns and I need to try and understand why these messages are
> >getting lost. I can't reproduce this on our test systems and I can't
> >easily install updated diagnostic code onto these production systems.
>
> >The question I have is when is the data pointed to by P1 (in the QIO
> >call) actually copied ? It is always done within the QIO routine or is
> >it just scheduled to be done in the QIO call ? Can I re-use the buffer
> >pointed to by P1 immediately after the call to the QIO ?
>
> Is it QIO or QIOW? The former is asynchronous, that is, the program continues
> and doesn't wait for the function to complete. This would explain your
> problems.
>
> Regards,
>    Christoph Gartmann
>
> --
>  Max-Planck-Institut fuer      Phone   : +49-761-5108-464   Fax: -80464
>  Immunbiologie und Epigenetik
>  Postfach 1169                 Internet: gartmann at immunbio dot mpg dot de
>  D-79011  Freiburg, Germany
>                http://www.immunbio.mpg.de/home/menue.html

What would be helpful here is more info.  In the general sense, the
procedures described should work.  However, there are too many
questions about how the code is written. It is easy to write code at
this level that will appear to work properly, yet be incorrect.
Please provide environment information (hardware, software versions,
programming language etc.) and perhaps a snippet of the code involved.

Thanks,
Dan

DansABRservices @ yahoo . com

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