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From: barrett@jhunix.HCF.JHU.EDU (Dan Barrett)
Newsgroups: comp.sys.amiga.programmer
Subject: How fast/slow is memory DEallocation?
Message-ID: <8504@jhunix.HCF.JHU.EDU>
Date: 31 May 91 03:48:39 GMT
Organization: The Johns Hopkins University - HCF
Lines: 30


	I wrote a program that uses a LARGE data structure with thousands of
pointers, and I'm now porting it to my Amiga 1000 (stock 68000).  I have
noticed that my data structure is being deallocated extremely slowly ---
almost excruciatingly so.

	The structure is a binary search tree in which every node contains
three linked lists and ANOTHER binary search tree (which contains 3 lists
and another tree, etc, recursively to any level).  When the structure has a
thousand nodes or so, and I deallocate it, it takes several minutes!
Building the structure took much less time, and there was more computation
going on then!

	At first, I thought the problem might be Manx's malloc()/free()
functions, so I switched to AllocMem/FreeMem.  This sped things up a bit,
but not much.

	I have a feeling that this is a system-dependent issue and not an
error in my code.  The program already runs on 3 other CPU's, and
deallocation is lightning fast.  I am using Manx 5.0d.

	Any suggestions?

                                                        Dan

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