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From: Ted Dennison <dennison@telepath.com>
Subject: Re: 'Read for pointers
Date: 2000/07/31
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In article <uhf99lxx4.fsf@gsfc.nasa.gov>,
  Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov> wrote:
> Ted Dennison <dennison@telepath.com> writes:
>
> >    type Handle is access all Instance;
> > The problem is that Item is an *out* parameter. That means I won't
> > have acces to the pointer's old value inside Read. There's no way I
> > can put the newly read data from the stream into the Instance that
> > Handle currently points to!
>
> But if you are reading from a stream, Handle doesn't yet point to
> anything! So 'Read needs to allocate an Instance, and set Handle to
> that.

Not true. In my case, Handle points to some working user data that the
client is continually saving off using 'Write, but may in certian
situations want to restore using 'Read. It will *always* have a good
(non-null) value when 'Read is called. I don't care about the previous
value referenced by the pointer, but I defintely do care about the
pointer's value itself.

> needs; it should be free'd before the new Instance pointer is
> assigned. So Handle must be a controlled type. My, this is getting fun
> :).

Bleach! When this is happening, its in a realtime program in a
high-priority task running at 60HZ. You want me to needlessly deallocate
then reallocate the same sized memory at 60Hz?

Uhhh...no.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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