RE: Large Return values (was Re: Variable Length Field Question)

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Hans Boldt
Sent: Thursday, May 20, 2004 9:28 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Large Return values (was Re: Variable Length Field
Question)

>(BTW, improving the performance of large aggregate return values is a
>future objective.)

Is IBM going to use the method I posted at the beginning of the year on the
rpg yahoogroups list? My idea is to add two new features to RPG. one is to
auto dealloc a pointer returned from a proc.  The 2nd is to let the compiler
know what a return pointer points to.

The point being, that if the compiler knows a proc is returning a pointer to
a varying string:
 d DatabaseRecordToXml...
 d              pr                *   varying options(*AutoDealloc)

then the compiler can generate the code needed to efficiently copy that
return value to the receiver in the calling proc:
  d XmlString    s        9999a  varying
  /free
       XmlString = DatabaseRecordToXmlString( filename: recordDataStruct ) ;

The *AutoDealloc feature would then auto dealloc the return pointer once the
call return is completed.

here is what I had posted:

my suggestion is that a procedure should be able to return a pointer that is
auto dealloc once the call return completes.  and the proc should also be
able to declare what the returned pointer points to, like a varying or null
term string:

 d DatabaseRecordToXml...
 d              pr                *   varying options(*AutoDealloc)

the procedure would then use "alloc" to allocate and build the string.  And
the rpg compiler would auto run the "dealloc" stmt once the return from the
proc call is completed and its return value copied to whereever it is
destined:

  d XmlString    s        9999a  varying
  /free
       XmlString = DatabaseRecordToXmlString( filename: recordDataStruct ) ;
     // rpg compiler auto deallocs the return pointer right here

-Steve Richter