Re: Odd problem passing a data structure to a procedure

["Michael Ryan" <michaelrtr@xxxxxxxxx>]

Any chance there's another procedure out there with the same name?

On 12/1/06, David Gibbs <david@xxxxxxxxxxxx> wrote:
> Folks:
>
> I've got an odd problem that's kind of driving me crazy.
>
> Please keep in mind, this code worked fine the day before yesterday ...
> I have no idea what changed to cause it to stop working.
>
> Basically, I'm getting a MCH3601-pointer not set error when I try to
> assign a character field with options(*varsize) to the substring of a
> standalone field.
>
> Here's the situation ... I've got a generic routine that I used to
> retrieve an entry off a keyed data queue (getClientData).  Since the
> data queue entry is formatted for a data structure, I pass a data
> structure into the routine.
>
> Here's how the data structure is defined in the calling routine ...
>
> D dataQueueEntry...
> D               E DS                  extname(EXTDSPF) qualified inz
>
> (this data structure is 601 bytes long)
>
> And the call to the generic data queue routine is ...
>
> moreEntries = getClientData(pListId: dataQueueEntry);
>
>
> getClientData is is a different module than the caller, but the same
> service program.
>
> Here is the full getClientData Routine ...
>
>      PgetClientData...
>      P                 B                   export
>      D                 PI              N
>      D pListId                       35    value
>      D pData                       2048    options(*varsize)
>      D
>
>      D data            S           2048
>      D dataLength      S              5  0
>      D gotData         S               N
>      D dummySender     S              8
>      D parmLength      S              5  0
>
>       /free
>
>        QRCVDTAQ(CLIENT_REQUEST_DATA_QUEUE:'*LIBL':dataLength:data:
>          *zero:'EQ':%size(pListId):pListId:*zero:dummySender);
>
>        gotData = (dataLength > 0);
>
>        if gotData;
>          pData = %subst(data:1:dataLength);
>        else;
>          pData = *blank;
>        endif;
>
>        return gotData;
>
>       /end-free
>
>      P                 E
>
> When I receive the entry off the data queue, everything is fine ... the
> dataLength is 601 (which is correct for the data queue entry), the data
> field has the data queue entry content.
>
> The problem arises when I try to trim the data field to the datalength
> value (using %subst) and put it into the pData field.  pData, which was
> previously valid, now has an invalid pointer.  The debugger tells me
> this, and the program bombs with the MCH3601 error.
>
> This is driving me crazy ... it worked FINE two days ago.  I can't
> figure out what changed.
>
> I did rename a few procedures ... but the binding source was updated and
> all modules recompiled and the service program recreated.
>
> Can anyone see what is probably quite obvious ... that I'm missing?
>
> Thanks!
>
> david
> --
> This is the RPG programming on the AS400 / iSeries (RPG400-L) mailing list
> To post a message email: RPG400-L@xxxxxxxxxxxx
> To subscribe, unsubscribe, or change list options,
> visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
> or email: RPG400-L-request@xxxxxxxxxxxx
> Before posting, please take a moment to review the archives
> at http://archive.midrange.com/rpg400-l.