RE: threading in rpg. was RPG and Web.. (was Using OO conceptsinRPG)

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Tom Daly
Sent: Thursday, May 22, 2003 11:08 AM
To: 'RPG programming on the AS400 / iSeries'
Subject: RE: threading in rpg. was RPG and Web.. (was Using OO
conceptsinRPG)

Barbara Morris wrote:
 |  But it's not as simple as putting a mutex around each
 |  access to a global structure.  The global static structures
 |  are interrelated, so each RPG procedure would pretty much
 |  be a critical section.
 |
 |  That's the basis of RPG's existing (since V4R4 I think)
 |  THREAD(*SERIALIZE) support that controls access to the
 |  procedures in a module so that only one thread is in a
 |  module at any one time.  This protects the static storage
 |  in the module, making the module thread-safe assuming it
 |  isn't doing anything thread-unsafe.


>Would having only one procedure in each module be a strategy?

Doesnt sound like it would.  It looks like RPG modules have a lot more
"initialize the statics" startup overhead that the more modular languages
like C do not have.  So a lot of modules would mean a lot of startup
overhead. And of course that single procedure could still only be called one
at a time by all the threads.

-Steve