On Sun, 5 Sep 1999, Richard Gaskin wrote:
> >> When I launch the app, then look at the "About this computer" window in the
> >> finder, the Mac says the program is allocated for 10.6 MB, though I only
> >> allocated 8000K. Hmm.... it would be cool to hear a simply stated
> >> explanation of why this is, for my own info. Other Mac applications don't
> >> seem to do this, or do they and I never noticed?
> >
> >MetaCard uses Temporary Memory for storing most stack data. Many
> >other apps do similar things (PhotoShop being one of the best known),
> >but since it's one of MacOSs dirty little secrets, few give any
> >indication that they're doing this. One dead givaway is if the app's
> >install documentation says it conflicts with RamDoubler, which uses TM
> >too, and in incompatible ways. MetaCard has a TMEM resource that you
> >can change to force MetaCard to stay in its own heap (partition), but
> >you have to increase the partition size if you do this.
>
> Does MC release temporary memory when it's done with it? I've had
> reports of one of our standalones not release memory (no externals in
> it). If this is not normal for MC I'll get more info together and
> generate a formal bug report.
It does, but allocates in large blocks (32K in 2.2.X) and then breaks
them up into smaller pieces as needed. Only if all those pieces are
freed will the 32K block be freed, so depending on what exactly you're
doing, the total size reported by MacOS may only decrease slightly or
even not at all as you delete stacks or other things that use memory.
It just won't increase any more the next time you do something that
requires reusing that memory.
Regards,
Scott
PS: we've since learned that both ClarisWorks and QuickTime also make
extensive use of this MacOS feature. But you probably won't ever see
this admitted anywhere because there are (obviously obsolete)
recommendations not to do this in the MacOS developer documentation.
This technique would work a *lot* better if everyone did it the same
way (allocated the same block size), but Apple doesn't provide any
guidelines in this area and the other vendors doing it won't even
admit it, let alone cooperate on the development of a standard for it.
> - Richard Gaskin
> Fourth World
> Multimedia Design and Development for Mac, Windows, UNIX, and the Web
> _____________________________________________________________________
> [EMAIL PROTECTED] http://www.FourthWorld.com
> US: 800-288-5825 Int'l: 323-225-3717 Fax: 323-225-0716
>
>
********************************************************
Scott Raney [EMAIL PROTECTED] http://www.metacard.com
MetaCard: You know, there's an easier way to do that...
