Re: Question about service programs

On 31/07/2008, at 10:42 PM, Adam Glauser wrote:

I think that David might have the right idea, but not asking quite the
right question. To simplify David's case, lets suppose we have PGM0,
consisting of modules MOD_0 and MOD_UTIL. We also have PGM1, consisting
of MOD_1 and MOD_UTIL.

If I now run PGM0 which calls PGM1, wouldn't there essentially be two
copies of the code for MOD_UTIL in memory?

In that case there are two copies of the same code because you have "bound by copy" but there are also two different programs loaded. You'll have the same effect if you bind a module into a service program and also into a program object. If both the program and the service program are invoked then you'll have two copies of the "code" active but that's a stupid approach. The only case I can think of where it makes sense to bind the same module(s) into multiple objects is for security routines.

However, that's not what he asked. He said "50 people using the same interactive program that weighs 40MB". That is one program used by 50 users. In that case only one copy of the program code no matter who loaded it first nor whether the users are running in different main storage pools.

I think this must be the
case, since if I change MOD_UTIL and rebind PGM0 but don't rebind PGM1,
PGM1 will still use the "old" version of the MOD_UTIL code.

That's true but again, not what he asked.

Regards,
Simon Coulter.
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