Re: RPG Service Program vs Include Source for Shared and SQL Calls

Hey Richard;

Thanx for your interest - I just carved this out for you;


Here is the prototype;

///
// Programs and procedures : Load service program procedure as procedure
pointer
//
//
// @param (input) Library where the ILE service program exists or *LIBL
// @param (input) Program name of the ILE service program
// @return procedure pointer or null and wrap it in a MONITOR
//
///
Dcl-PR json_LoadServiceProgramProc pointer(*proc) extproc(*CWIDEN :
'jx_loadServiceProgramProc');
  library        char(10) const;
  program        char(10) const;
  procedure      pointer     value  options(*string);
End-PR;


Example of usages:

dcl-proc callNameAndAge;

   dcl-pr NameAndAge pointer extproc(pNameAndAge);
        name char (10) const;
        text char(200);
        age  packed(5:0);
    end-pr;

    dcl-s text char(200);
    dcl-s age  packed(5:0);
    dcl-s msg  char(50);

    dcl-s pNameAndAge pointer (*PROC) static;

    pNameAndAge = json_loadServiceProgramProc ( '*LIBL' : 'HELOSRVPGM' :
'NAMEAGE');
    if pNameAndAge = *null;
        json_joblog('Could not load program HELOSRVPGM');
        return;
    endif;

    // Now we have an efficient dynamic procedure pointer to the service
program
    // We can call it with the parameters we want,using prototype
    // Note that text and age parameters are passed by reference, so we can
change them
    text = 'Hello world from RPG';
    age  = 55;
    NameAndAge ('Niels': text: age);
    json_joblog ('Called HELOSRVPGM/NAMEAGE returns: "text": ' +
%trim(text) + ', "age": ' + %char(age));

end-proc;


You can find it here - where you also can see how it is implemented;

https://github.com/sitemule/noxDB/blob/master/headers/JSONPARSER.rpgle

Search for: json_LoadServiceProgramProc

This program examples/JSONPGM02B show how to use it:

https://github.com/sitemule/noxDB/blob/master/examples/JSONPGM02B.Call-ILE-service-program-procedure-by-proc-pointer.rpgle




On Sun, Mar 22, 2026 at 4:56 PM Richard Schoen <[email protected]>
wrote:

> Ooh I'll have to check out the dynamic loading in noxDb.
>
> Thanks for reminding me. I hadn't looked at that in a while.
>
> Regards,
> Richard Schoen
> Web: http://www.richardschoen.net
> Email: [email protected]
>
> ----------------------------------------------------------------------
>
> message: 1
> date: Sun, 22 Mar 2026 17:14:12 +0800
> from: Niels Liisberg <[email protected]>
> subject: Re: RPG Service Program vs Include Source for Shared
>         Subprocedures and SQL Calls
>
> Hey Brian,
>
> We did it manually- so each ?breaking? version got its own version
> signature- and it worked fine. The problem occurred when you have hundreds
> of versions- and trying to keep track of each.. with hundreds of exports..
> the binder source exploded..
>
> So we went to a more pragmatic solution: only adding exports to the end -
> and if implementation is challenged- add that to the end and don?t touch
> the original so any client code will work in touched.
>
> .. but that is a convention, and conventions can easy be broken.
>
> That made me implement the dynamic procedure load and we use that in all
> our products and projects
>
> You can find ?the magic? in both noxDb and ILEastic and in our IceBreak.
>
>
> --
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