Re: A question about multi-module SRVPGM

[Tom Liotta <qsrvbas@xxxxxxxxxxxx>]

Mark S. Waterbury wrote:

> Consider this scenario:
>
>    service program A references (invokes procedures within) service 
> programs B and C
[snip many references]
>    service program G references service programs W, X, Y and Z
>
> As soon as service program A is activated (because the first ILE *PGM 
> that references it was CALLed (activated), the following occurs:
>
>    A is activated
[snip many activations]
>                            Z is activated
>                  H  is activated
[snip]
> Does this "make sense"?

It makes sense, but seems to leave a potentially important element 
unexplored.

At the end of the activation sequence above, we find Z & H being 
activated because A was activated at the top and the reference chain 
got started.

However, what if Z & H were already activated by a different job?

That is, if service programs are comprised of modules that are used 
_in common_ by various programs in various jobs, how many 
activations are likely? You showed examples of E & F previously 
activated higher in the reference chain in the same job, but how 
about multiple jobs?

Compare a nightly dedicated batch subsystem with a single-threaded 
job queue to multiple server jobs with some number of reuses. The 
batch processing might fully resolve a reference chain for every new 
job. The multiple server jobs might only rarely activate a new 
service program. No?

...unless I misunderstand it entirely.

How much does it matter under varying circumstances? How can anyone 
determine if it's significant at all?

So, yes, it makes sense. But does it matter?

Tom Liotta

>  > David FOXWELL wrote:
> > I'm starting to hesitate before posting my question.
> >
> > When you say only one copy of the service program code will be loaded 
> > into memory, would that mean the whole code for all the functions it 
> > may have, even if the calling program only used on of those functions?