Quoth Derek Simkowiak on Tue, Jan 07, 2003:
> > > (1) The code that implements the drivers.
> > > (2) An *instance* of the use of one of the drivers, specified in the
> > > configuration file.
>
> The word "instance" carries a lot of baggage to me; it could refer
> too O.O.P.,
What's the difference? In object oriented programming, you have
classes, and you have objects which are instances of those
classes; in Exim config file, you have drivers (such as the
"accept" router) and their instances (such as "localuser" in the
default configuration).
> or server processes,
I call them processes.
> or package installs...
How so?
> if a new user goes
> looking for too much analogy with one of those models he may get lost.
Not at all, I'm afraid.
> Perhaps making is very clear at the beginning that an "instance"
> is just a "particular driver config", and nothing more, that would prevent
> anyone assuming weird stuff like parent/child relationships or spawns (or
> whatever).
They're not different from driver instances in the kernel. You
may have two identical cards, which will be driven by two
instances of the same driver (and the devices will be known to
the kernel as, say, sd0 and sd1, if they're SCSI discs).
> 1. A driver is "configured", not "defined", in the config file. I.e.,
> changes like:
>
> "Within a driver definition, there are [...blah, blah...]"
> "Within a driver configuration, there are [...blah...]"
Not sure. Looks quite like C definition to me.
> 2. Underlying drivers and a particular config thereof are not the same
> thing. I.e.:
>
> "[Section Title] 3.8 Running an individual router"
> "[Section Title] 3.8 Running an individual router config"
>
> "The first router in a configuration is often [...blah...]"
> "The first router config in the configuration file is often [...blah...]"
Definitely not. You don't run a config (come on, this is
confusing), you run a driver, or an instance thereof.
> If you define "instance" clearly up front as "a particular
> configuration of a driver", then the above examples would change as
> follows:
>
> "Within a driver definition, there are [...blah, blah...]"
> "Within an instance, there are [...blah...]"
That's somewhat better.
> "3.8 Running an individual router"
> "3.8 Running a router instance"
This sounds quite awkward, to me.
Vadik.
--
Who needs friends when you can sit alone in your room and drink?
