Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!sun-barr!rutgers!cbmvax!peter
From: peter@cbmvax.commodore.com (Peter Cherna)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Memory fragging
Message-ID: <21884@cbmvax.commodore.com>
Date: 24 May 91 14:56:45 GMT
References: <1991May21.195251.16477@zorch.SF-Bay.ORG> <21795@cbmvax.commodore.com> <886@dvncnms.Devoncnms.Unisys.COM>
Reply-To: peter@cbmvax.commodore.com (Peter Cherna)
Organization: Commodore-Amiga, Inc.  West Chester, PA.
Lines: 38

In article <886@dvncnms.Devoncnms.Unisys.COM> efb@dvncnms.Devoncnms.Unisys.COM (Edward Bacon) writes:
>How about lists of Gadgets?  Here is what I do:
>One routine uses AllocRemember() for the gadget, text and image memory.
>It calls FreeRemember(TRUE) or FreeRemember(FALSE),

AllocRemember() does:

	AllocMem( a little header )
	AllocMem( the block you want )

and then puts tracking information into the little header.  FreeRemember(TRUE)
disposes of the headers and the blocks.  FreeRemember(FALSE) blows away
all the little headers, and leaves you with a memory map that looks like


     *----*----*----*----*----*----*----*----*----*----

Where * = free and - = allocated.

Sorta looks like Swiss cheese, or the barn in Black Sunday.

Theoretically, the worst thing you can do is allocate a bunch of blocks
and free every second block.  Sounds a lot like FreeRemember(FALSE).

It would be better to hang on the the little blocks and use FreeRemember(TRUE)
at the end of your program.

It would be _even_ better if Intuition used a memory-pool manager from
which to draw the Remember-headers.  It would be _even_even_ better
if Intuition itself stopped using FreeRemember(FALSE) itself, but
that's another topic.

     Peter
--
Peter Cherna, Operating Systems Development Group, Commodore-Amiga, Inc.
{uunet|rutgers}!cbmvax!peter    peter@cbmvax.commodore.com
My opinions do not necessarily represent the opinions of my employer.
"If all you have is a hammer, everything looks like a nail."