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From: dorner@pequod.cso.uiuc.edu (Steve Dorner)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Why do application partitions exist?
Message-ID: <1991Feb7.161131.15262@ux1.cso.uiuc.edu>
Date: 7 Feb 91 16:11:31 GMT
References: <48874@apple.Apple.COM> <1991Feb6.135730.4792@ux1.cso.uiuc.edu> <48914@apple.Apple.COM>
Sender: news@ux1.cso.uiuc.edu (News)
Organization: University of Illinois at U-C
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In article <48914@apple.Apple.COM> stevec@Apple.COM (Steve Christensen) writes:
>Dynamic partition sizing is a nice idea, but what happens to an app when
>memory it thought it had (perhaps checked once at launch time to see if it
>could run at all?)

First, I would suggest you set the minimum so the app has enough to run.

Second, any app that decides at launch how much memory it has is on thin ice
anyway; there are DA's and other unexpected drains on memory.  (Besides, *I*
don't use any Microsoft applications :-))

>suddenly disappears because another app needed it?

I dunno about most people, but I assume ANY call that can allocate memory
might fail, and try to be graceful about it.

And, compare:

  Sorry, but there isn't enough memory to do that; perhaps you should quit
  something else to make room.                                       [OK]

with:

  Sorry, but there isn't enough memory to do that; perhaps you should quit
  this application, change its multifinder partition size, quit some other
  application, and launch this application again.  When you're done working
  with "Mondo Document", you might want to quit again, reset the multifinder
  partition size, and start this application up in a more reasonable size.
                                                                      [OK]

>If the
>min and max you mentioned are fixed at launch time, don't we already have that
>(at least the min part) in the Get Info window?

Actually, you have both the min and the max part; they're just the same;
"You can use as little as 512K of memory, or as much as 512K of memory,
or anything in between."

I'm not really arguing that dynamic sizing could be done (I did stipulate
that the tooth fairy do the programming, you recall), just that it
would be nice.  (Though who'd have thought that the HyperDrive or Switcher
could have been done?)

I was really hoping that the Multifinder temporary memory calls were going
to address this issue.  Unfortunately, they seem to be so "temporary" as to
be practically useless for anything except disk buffers; you really have
to go out of your way to allocate and use them. It would be nice (for example)
if my GrowZone function could move an ordinary handle into temporary space
for a while, and flag it as such, to be moved back later (say, next time
through my event loop).  Unfortunately, I can't use the standard handle
calls on the thing, so every piece of my program has to know whether it's
dealing with a real handle or an mf temp handle; yuck.
--
Steve Dorner, U of Illinois Computing Services Office
Internet: s-dorner@uiuc.edu  UUCP: uunet!uiucuxc!uiuc.edu!s-dorner