Re: RPG Performance question

["Mark S. Waterbury" <mark.s.waterbury@xxxxxxx>]

Hi, David:

In part, this will depend on how your "legacy" applications and their 
menus were designed.  If all originally OPM (*DFTACTGRP), then it is 
likely that you may have had the menus coded to issue RCLRSC upon return 
from lower levels.  This would in effect close all files opened at that 
call level and below.  You might want to reconsider that logic.

Also, some ILE applications are coded so that all top-level programs 
(called directly from menus) use ACTGRP(*NEW), so upon return, all of 
the resources within that new activation group are automatically 
reclaimed.  (This may or may not turn out to be a "good idea", depending 
on how your end-users actually use the applications; if they constantly 
come back to the main menu, this could turn out to be a really "bad 
idea"...)

If a file is already open, then the path-length is somewhat shorter for 
subsequent programs or modules opening the same files, but there is 
still some overhead.  At the machine level, an OPEN costs around 
one-million instructions (more or less).  So, if your application is 
opening many, many files, then closing them, and opening them again, 
this overhead will add up.

It really also depends on how the applications are used.   How often do 
the users return all the way back out to the main menu, and then go down 
a different path?  Or, does the application provide a way to jump 
directly from one part of the application to another (e.g. such as group 
jobs)?

All the best,

Mark S. Waterbury

> David FOXWELL wrote:
> Hi all,
>
> I often notice a significant time lapse when exiting client management applications and returning to a menu. Noticing the difference in the list of files (with wrkjob) that I can see that are open during running of the main rpg code and the empty list on returning to the menu, I was wondering if all the closing of files was at least partially to blame. Files can appear on the list of files open several times. This is because they are declared in several modules bound (by copy) to the same program.Is this something to be avoided, or is the performance cost negligible?
>
> Thanks
>
>