Path: utzoo!utgpu!water!watmath!clyde!att!lzaz!lzsc!mkg
From: mkg@lzsc.ATT.COM (Marsh Gosnell)
Newsgroups: comp.sys.mac.programmer
Subject: Re: INITs
Summary: sysz allocation is "temporary"
Keywords: INIT, sysz, System Heap
Message-ID: <1132@lzsc.ATT.COM>
Date: 12 Jul 88 19:42:01 GMT
References: <278@hodge.UUCP> <13728@apple.Apple.COM>
Organization: AT&T ISL Lincroft NJ USA
Lines: 16

In article <13728@apple.Apple.COM>, palevich@Apple.COM (Jack Palevich) writes:
> If you want to grow the System Heap by a fixed ammount whevever your INIT is
> installed, then you can include a sysz resource in your INIT file.  The
> sysz resource has a longword of data which is the number of bytes your INIT
> needs added to the size of the system heap.

One thing that isn't obvious is that you shouldn't ask for more than you're
going to use right then and there.  When an INIT is loaded it's sysz space
request is checked against the free space in the system heap and the heap size
is adjusted accordingly.

What this means is that you can't use sysz to simply reserve space for
yourself.  If you request a big chunk and don't use it, the next INIT loaded
will reuse the space.  The only way to keep your allocation is to make sure
you're loaded last.
  Marsh Gosnell