Xref:	news2.mv.net comp.os.msdos.djgpp:852
From:	Erik Max Francis <max AT alcyone DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: malloc/free ends up fragmenting dynamic memory?
Date:	Tue, 06 Feb 1996 07:49:04 -0800
Organization:	&tSftDotIotE
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Message-ID:	<31177870.7944FD77@alcyone.com>
References:	<4f5sm8$2kt AT cardinal1 DOT Stanford DOT EDU>
NNTP-Posting-Host:	newton.alcyone.com
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

John Beale wrote:

> I am guessing that the many malloc/free operations fragments the memory
> store analgous to hard disk filesystem fragmentation with many saves and
> deletes, such that a contiguous memory segment for a large malloc() can no
> longer be found. Is there a malloc_unfragment() command or equivalent?  How
> do other people handle this problem?

With pointer-based allocation, there's no way to defragment memory, since you
can't move a block of memory _and_ update the pointers which happen to be
pointing to (and in) it.

On the Macintosh, a whole new level of abstraction is introduced to deal with
this problem -- the handle (which is a pointer to a pointer).

The solution to this is to either 1. get more memory (not all that unreasonable
of a request these days) or 2. devise a way to not fragment memory in the first
place (this depends entirely on your application).

-- 
Erik Max Francis, &tSftDotIotE. && max AT alcyone DOT darkside DOT com || max AT alcyone DOT com
San Jose, California, U.S.A. && 37 20 07 N 121 53 38 W && the 4th R is respect
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Omnia quia sunt, lumina sunt. && GIGO Omega Psi && http://www.alcyone.com/max/
"Out from his breast/his soul went to seek/the doom of the just." -- _Beowulf_

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