Subject: Re: PROPOSAL: removal of brk()/sbrk().
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 02/28/2002 05:18:50
>>> What about programs that dump themselves for later restart (like
>>> emacs, TeX etc.)?
>> Sendmail used to do that with its config file,
> Nonsense.  sendmail's fc file was a normal file, read/written like
> any other file, sendmail never did any undump nonsense.

No, but what sendmail did was pretty close in many respects.  (The .fc
file was basically write(fd,&_etext,sbrk(0)-&_etext) - not dump/undump,
but definitely not a clean savefile format, and critically dependent on
the way the VM space was laid out.  The mmap-based malloc mentioned
upthread would have broken it instantly.)

> The fc file was certainly sendmail version specific (it contained
> data which would only work with the same sendmail that produced it),
> but that's a different issue entirely.

Not only version specific, but build specific - if the next build
happens to reorder things in the data segment, or change the size of a
structure, an old fc file could be expected to misbehave horribly.

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