Re: AW: CallP Versus Program 'CALL'

Rpglist,

As Scott says, it's about more than just performance.

If the processing in your hypothetical 'procedure' will never need to be
used by any other program/procedure, then you may as well create an
internal procedure (i.e. a subprocedure coded in the same module as the
CALLP) and use CALLP (either explicitly or implicitly by just naming the
procedure). This is fast, and the code is right there in the same source
member where it's called.

If the processing might be called by another program/procedure, then you'll
have to define it as either an external procedure (in a service program or
in a module which you bind to the calling program) or as a program. If you
define it as a procedure, it's still fast. If you define it as a program,
it's slower (although, as others have said, possibly not noticeably slower).

There's not much good reason to define it as a program, unless you might
want to call it from older RPGIII or OPM COBOL or OPM CL programs.

If in doubt, define it as an external procedure in a service program. It
might be a bit more hassle and a high learning curve if you've not done
much ILE stuff before, but it's a good thing to go through.

Rory


On Sun, Feb 10, 2013 at 7:48 PM, Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>wrote:

Right... but sometimes discussion threads change meaning over time, and
this one had meandered off into a discussion about when typing "CALLP"
was required, so I commented on that offshoot of the discussion.

CALLP is a very versatile tool. It can call *PGMs, like the ancient
CALL opcode can. When it does that, performance is the same as CALL
would be.

CALLP can also call ILE procedures/subprocedures. In this case, it
perfroms better than CALL, but equivalent to the (horrible) CALLB opcode.

CALLP can also call Java Methods. IF you're worried about performance,
I would avoid this option.

So, anyway, I think you can see that your question just isn't as simple
as you phrased it.




On 2/10/2013 10:58 AM, Rpglist wrote:

Thanks Scott I suppose I should have worded my post a little better
in the beginning. What I was trying to determine was I'd it faster
to use a procedure either externally or internally defined versus
coding it as a program and using the CALL 'program name'

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