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From: cim2@pyuxv.UUCP (Robert L. Fair)
Newsgroups: comp.sys.ibm.pc
Subject: Fragmentation on DOS - HELP !
Message-ID: <287@pyuxv.UUCP>
Date: Thu, 14-May-87 15:44:13 EDT
Article-I.D.: pyuxv.287
Posted: Thu May 14 15:44:13 1987
Date-Received: Sat, 16-May-87 19:42:38 EDT
Organization: CHC
Lines: 32

Does anyone out there know how DOS handles massive amounts of dynamic
allocation and freeing, in particular memory fragmentation. 

In particular some applications which do this run when the machine is
first turned on, but fail later when the machine has been used for 
a while.

Specifically:
	1. Microsoft C-compiler 4.0 when compiling a VERY large program
	   (output of a 2000 line yacc grammer with several hundred symbols)

	2. Our own product, FORESEE*, when doing large amounts of virtual 
	aggregation (munching around 10 MB of doubles using a virtual
	array via dynamic disk swapping) [FORESEE is written in MS-C.]

	Each time 2. is run it gets malloc failures earlier and earlier
	into the program, implying that memory is getting eaten up
	somehow !

	*FORESEE is a trademark of Bell Communications Research.

	Systems: IBM PC/AT, IBM PC/XT, PC-DOS 3.1, 640K RAM all true blue.

Any suggestions on whether its an MSC problem, DOS problem or a bug (unlikely)
would be much appreciated - reply by mail is fine.

This query is posed as a private individual and has no connection with
Bellcore/CHC or any other person living or dead.

Bob Fair
Bellcore/CHC
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