Re: why not "standardize" the Booch Components? (was Re: is Ada dying?)

[Simon Wright <simon@pushface.org>]

"Pat Rogers" <progers@classwide.com> writes:

> "Marin David Condic" <dont.bother.mcondic.auntie.spam@[acm.org> wrote in
> message news:9q49fc$nh3$1@nh.pace.co.uk...

> > It ought to be noted that something like the Booch components are not going
> > to be suitable for all applications. If they rely on dynamic memory, they
> > may be unsuitable for any sort of realtime work. If they rely on fixed
> > memory, they may not be suitable for very dynamic workstation apps. If they
> > provide both implementations, they may be "too big" and/or offer too many
> > choices to the user. IOW, they cannot be all things to all users and hence
> > it should be clear as to what the intended usage is.
> 
> Yes, that's true, but at least the storage management is an explicit
> part of the abstraction when allocations are involved -- one has to
> specify the pool to instantiate those components.  For predictable
> storage allocation one would use, for example, a fixed-block pool.
> Barnes' book has one, and I show one in my Real-Time Ada course, so
> they aren't hard to get.  Better yet would be to add it to the
> existing BC pool managers already available.  I'll see if Simon is
> open to that.

Absolutely.

I managed to find some pathological allocation patterns with the Pool
that Pat contrbuted to the BCs recently, things like removing every
other element, so as ever one would have to look at the actual
requirement.

The BCs have a middle form (Dynamic) between the two extrmenes
mentioned so far (Bounded & Unbounded), as ever performance varies
with usage (and I think I've not actually implemented the C++
faithfully here; but since this form looks like a poor person's
Storage Pool, perhaps I won't worry too much).

The next release of the BCs will use Storage Pools like

   generic
      Storage : in out System.Storage_Pools.Root_Storage_Pool'Class;
   package BC.Containers.Collections.Unbounded is

so really you can use any storage pool you like.