Path: utzoo!attcan!uunet!decwrl!adobe!jholt
From: jholt@adobe.COM (Joe Holt)
Newsgroups: comp.sys.mac.programmer
Subject: Re: ThinkC's handling of CODE resources.
Message-ID: <3806@adobe.UUCP>
Date: 11 Jul 90 16:12:31 GMT
References: <1990Jul10.150057.24765@hod.uit.no>
Reply-To: jholt@adobe.com (Joe Holt)
Organization: Adobe Systems Incorporated, Mountain View, CA
Lines: 15

Code resources are never unlocked unless you explicitly UnloadSeg().  Even
in such a case, as soon as code begins executing in that segment, it is
locked down and stays locked until another UnloadSeg() -- again, explicitly
by you.  It would be disastrous if code segments could move around between
calls with no OS support!

Remember, tho', that unlocked handles may move.  Be careful passing a
dereferenced handle which is unlocked to a routine in another segment.  Even
if that routine doesn't move memory, simply calling it may.  Yikes.

This reminds me of Microsoft Windows 3.0's approach to code segments.  They
*can* move around between calls, but Windows has a daemon which actually
walks the return stack and patches addresses so that they jive.  Zowie.

-- joe