RE: Procedure returning a pointer, and debugging

Larry,

Your input lead me to the answer.
I didn't have the pointer in the subprocedure defined as static, which
is ok... But the problem I had is that I didn't have the data structure
(which is what the pointer was pointing to) defined as Static.  So, I
put the Static keyword on it and it works great.

Thanks,

Kurt Anderson
Application Developer
Highsmith Inc

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Larry Ducie
Sent: Wednesday, January 11, 2006 4:26 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Procedure returning a pointer, and debugging

D'oh!
 
<snip>
Is the pointer defined as static..?
</snip>
 
Obviously, I meant: Is the pointer NOT defined as static..?
 
I must learn how to switch off this predictive-text keyboard!  ;-)
 
Larry Ducie
 

-----Original Message-----
From: Larry Ducie [mailto:Larry_Ducie@xxxxxxxxxxx]
Sent: 11 January 2006 22:19
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Procedure returning a pointer, and debugging


Hi Kurt,
 
Is the pointer you are passing back defined within the procedure you are
calling..? Is the pointer defined as static..?
 
If so you will have trouble because when the procedure returns the
pointer
will be destroyed. The OS may use up the memory allocated to it for
something else at any point, but when this occurs is indeterminate. So,
a
quick return may well result in data still untouched (and the chain
succeeding) , but if a long time elapses (like when debugging) the OS
may
well allocate the storage to something else and "corrupt" your data. It
may
be better to pass your pointer in as an input-output variable and let
the
procedure write data to that. This way, your data will still exist prior
and
after the call. This is how standard IBM APIs usually work.
 
I believe that, even though the pointer is passed back by value you are
simply setting your pointer to point to the same address as the pointer
defined in your procedure (which no longer exists).
 
HTH
 
Larry Ducie