From: "A.Appleyard" <A DOT APPLEYARD AT fs2 DOT mt DOT umist DOT ac DOT uk>
Organization: Materials Science Centre
To: DJGPP AT DELORIE DOT COM
Date: Wed, 29 Jan 1997 09:14:46 GMT
Subject: Re: A misfeature re malloc() and new
Message-ID: <BE4B552ED7@fs2.mt.umist.ac.uk>

### Please send a copy of the reply to me at a DOT appleyard AT fs2 DOT mt DOT umist DOT ac DOT uk,
as I had to unsubscribe from djgpp because of excessive email intray overload

  (1) Please where can I read dggpp email group's archives by FTP or WWW?
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  (2) Mark Wodrich <mwodrich AT ct DOT lia DOT net> wrote:-
> You have checked the source, so I bow to your superior knowledge, BUT: How
> can this be? The more I hear about djgpp's malloc, the more I shudder! Is
> this "standard" GNU implementation of malloc/free? It seems horribly
> wasteful.... Perhaps someone should spend a while coding a decent heap
> manager for djgpp? (hacking the source is your only "workaround" as I see
> it...) I understand that malloc is optimised for speed, but a
> half-intelligent heap manager can't be that slow can it ? From the basic 2nd
> year Computer Science I did, a heap is not that big a deal to code. Merging
> freed blocks, and using first fit, best fit, or worst fit was (I thought)
> standard practice. It seems from your post that GNU libc keeps tables of
> blocks for each 2^n size...?

  It is so now under v2, and it was so under v1.
  djgpp's heap needs a garbage collecter. I could write one easily; but it
would need to know the whereabouts of <all> pointers-to-heap that may need to
be updated during the garbage collection. In any software that I write, it is
fairly easy to keep track of pointers-to-heap; but I will need to know the
whereabouts of all pointers-to-heap created by standard library routines.
  Of the functions and subroutines declared by these #includes, which use the
heap?: ctype.h dpmi.h fcntl.h go32.h new.h pc.h setjmp.h std.h string.h
sys/exceptn.h sys/farptr.h sys/stat.h time.h
  The matter which is automatically obeyed before main() is called: does it
use the heap?
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  (3) As a character in a book by James Herriot (vet) once wrote: "It allus [=
always] ends up wi' malloc() at t'finish.". (Mallock was a knacker-man.)
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  (4) > "It is now safe to turn off your computer." - Windows 95
  After struggling with Windows 95 after a lifetime of Windows 3.1 & similar:-
  As to where whoever-it-was got his ideas for Windows 95, I would not be
surprised if I found that he keeps a UFO in his garage.
  Part of the Windows 95 system is called `Chicago'. Perhaps that is why
Windows 95 looks like the result of letting Al Capone run the computer room.