Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!husc6!endor!siegel
From: siegel@endor.harvard.edu (Rich Siegel)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Object Pascal and memory management
Message-ID: <1289@husc6.harvard.edu>
Date: 28 Feb 89 16:23:36 GMT
References: <604330910.18716@minster.york.ac.uk>
Sender: news@husc6.harvard.edu
Reply-To: siegel@endor.UUCP (Rich Siegel)
Organization: Symantec/THINK Technologies, Bedford, MA
Lines: 23

In article <604330910.18716@minster.york.ac.uk> alistair@minster.york.ac.uk writes:
>Can anyone out there explain how Object Pascal objects are allocated in memory,

	In Lightspeed Pascal (and probably in MPW Pascal as well), an
OBJECT type is allocated as a handle in the heap; the first word of the handle
is an A5-relative offset to the class info proc, and the rest of the space,
I believe, is for the instance variables.

	It's important that the DECLARATION for an object type be in the
main segment (or in some other segment that won't be unloaded or moved around),
but the implementation of a method can be in any segment, as long as you
don't do anything like unload your caller's segment.

		--Rich



Rich Siegel
Staff Software Developer
THINK Technologies Division, Symantec Corp.
Internet: siegel@endor.harvard.edu
UUCP: ..harvard!endor!siegel
Phone: (617) 275-4800 x305