RE: external subprocedures setting on LR: performance impact?

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Dan
>
> AGs: Joe's suggestion of compiling the top program as
> ACTGRP(*NEW) and all the called modules as
> ACTGRP(*CALLER) is intriguing
(...)
> Is this technique usually not
> used when the end of the application
> execution also marks the end of the job?

There have been many discussions about AGs.  An almost universal consensus
has been that programs at the "top level" use AG(*NEW), and called programs
use AG(*CALLER).  The issue is what constitutes top level, and it seems that
the less unanimous but still pretty popular rule of thumb is that if it's
called from a command line (including SBMJOB, I guess) or from an
application menu, then it's a top level program and thus uses AG(*NEW).  So
in those circumstances where one menu option calls another (for example a
customer inquiry has a function key that calls an A/R inquiry which can also
be called directly from the menu), you will have two AGs: the one for
customer inquiry and the one for A/R inquiry.


> Joe, the file pointers will not be an issue.  Everything in the
> called modules is either chained
> to, or SETLL/READE.

And even if you were using "implied file positioning" it's not an issue that
should impede your progress.  The situation can be easily remedied by doing
a SETLL(*START) in your "pseudo-init" routine.

I applaud your effort.  The idea of a gradual migration to new technology is
the best.  I transitioned from RPG III to RPG IV, then to CALLB, then to
external procedures, and am working towards service programs.  I think
that's a perfectly acceptable transition.  Each step can provide real
benefits:

1. RPG IV allows removal of most indicators and other "old" syntax
2. CALLB allows binding (less pieces) and activation groups
3. External procedures allow multiple entry points into a module
4. Service programs allow easier maintenance, I think... <grin>

Joe