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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Robert Watson <rwatson@FreeBSD.org>
References: <86myrlahee.fsf@ds4.des.no> <5647.1199451237@critter.freebsd.dk>
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Date: Sat, 05 Jan 2008 14:50:37 +0100
In-Reply-To: <20080104132310.X77222@fledge.watson.org> (Robert Watson's
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Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, freebsd-current@freebsd.org,
	Jason Evans <jasone@freebsd.org>, Igor Mozolevsky <igor@hybrid-lab.co.uk>
Subject: Re: sbrk(2) broken
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Robert Watson <rwatson@FreeBSD.org> writes:
> Another aspect of the problem is that applications have come to depend
> in malloc(3) returning NULL when memory is getting tight [...]

I don't do that any more.  Unless the program I'm writing is intended to
run for a long time and can gracefully handle an out-of-memory situation
(such as denying client requests until the situation improves), I write
malloc() wrappers which zero the allocated region before returning to
the caller, to force a SIGSEGV and spare the caller from having to check
the return value.

I sometimes also allocate a little bit extra and stick a magic signature
and an allocation length in there so my free() wrapper can check for
bugs and zero the allocated memory before freeing it.  I wouldn't need
any of this if my code only ran on FreeBSD, but most of my $DAYTIME_JOB
code these days runs on Linux first and FreeBSD second.

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no