Re: Service Program Limitations

"RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxxxxxxxx> wrote on 05/23/2019
01:00:03 PM:

----- Message from Mark Waterbury <mark.s.waterbury@xxxxxxxxxxxxx>
on Thu, 23 May 2019 14:37:34 +0000 (UTC) -----

To:

RPG programming on IBM i <rpg400-l@xxxxxxxxxxxxxxxxxx>

Subject:

Re: Service Program Limitations

Hi, Michael,

. . .
. . .
. . .>

That is why, with V6R1, IBM added the *IMMED or *DEFER option to the
BNDSRVPGM parameter on CRTPGM, CRTSRVPGM, UPDPGM and UPDSRVPGM, and
ADDBNDDIRE. -- With the new *DEFER option, the IBM i system will
defer loading "A" until it is actually needed, e.g. when any of its
procedures are actually first called. And, if "A" was created with
the *DEFER option for "B", then "B" would not be loaded and
activated until actually needed, and so on, down the line, as long
as you specified *DEFER for all of them.


There is a slight overhead for the "stubs" generated to handle this,
when *DEFER is specified, but overall, this can be a big "win" when
many of those *SRVPGMs might never actually be needed in any given
job. This is a "Pay me now, or pay me later" trade-off. (Take the
"hit" when the job first starts up, vs. spreading that load across
the entire duration of the job.)


Note that *IMMED is the default, so the system continues to behave
as it always did, unless you take action to specify *DEFER as and
where needed on those binder commands.


Hope that helps,

Mark S. Waterbury

On Thursday, May 23, 2019, 10:26:07 AM EDT,
MichaelQuigley@xxxxxxxxxx <MichaelQuigley@xxxxxxxxxx> wrote:

. . .
. . .
. . .

While there may not be much in the way of an actual limit to the number

of

procedures in a service program, don't all procedures to through
activation when a program with the *SRVPGM bound to it is first called?

In

the past I've experienced a noticeable delay to program startup when a
bound *SRVPGM had several extraneous procedures.

Michael Quigley
Computer Services
The Way International

Thanks Mark. I should have remembered that. I just had the thought and did
my reply. I appreciate your keeping me (and others) straight on this.

Michael Quigley
Computer Services
The Way International