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From: nebel@wam.umd.edu (Chris D. Nebel)
Newsgroups: comp.sys.mac.programmer
Subject: Why do application partitions exist?
Message-ID: <1991Feb5.182501.4325@wam.umd.edu>
Date: 5 Feb 91 18:25:01 GMT
Sender: usenet@wam.umd.edu (USENET Posting)
Organization: University of Maryland at College Park
Lines: 22

I got to wondering about this one late one night: why does Multifinder have
this business of application partitions?  Why couldn't it have been written
so that all applications simply share one big heap zone?  This would have
a number of advantages: users don't have to know anything about partition
sizes, you don't have wasted memory because of apps only using small portions
of their partition, having enough contiguous free memory to run a program
becomes much less of a problem, and programmers don't have to worry about
special Multifinder temporary memory.

The only problem I could think of was that the system has to know who created
which blocks, so it can know what to throw away when a program quits
("unexpectedly" or otherwise).  It seems to me, though, that this would be
fairly easy to do, and it wouldn't break anything that didn't use fake handles
or rely on the format of block headers, which they shouldn't have been doing
anyway.

Since this scheme is obviously :) so much better and is trivial :) :) to
implement, why wasn't it done?  Am I missing something obvious?


Chris Nebel
nebel@wam.umd.edu