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To: "Jacques A. Vidrine" <nectar@FreeBSD.org>
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From: "Brian F. Feldman" <green@FreeBSD.org>
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Date: Mon, 09 Feb 2004 11:36:34 -0500
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Subject: Re: mostly-reentrant resolver/getaddrinfo(3) 
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"Jacques A. Vidrine" <nectar@FreeBSD.org> wrote:
> > BTW, a slightly more complete patch that has the diffs for
> > /usr/include/resolv.h and also should correctly close the sockets that each
> > thread opens for the resolver can be found here:
> >
> > 	http://green.homeunix.org/~green/mostly_reentrant_resolver.patch
> 
> Cool!
> 
> Use pthread_once for creating keys, not a mutex (referring to
> res_init_mutex/res_keys_inited).
> 
> I prefer to see `_pthread_*' in libc source (rather than `thr_*'), but
> that's just me.

If I try to use pthread_once(3) then I still need to have a variable which 
stores whether the call to pthread_key_create(3) succeeded from the 
pthread_once(3), right?  So at the least, I'd have something like:

static once_t keyonce;
static int keyfailed;
static void
key_allocate(void)
{
	if (thr_keycreate(foo, bar) != 0)
		keyfailed = 1;
}

static void
allocate(void)
{
	if (thr_once(&keyonce, key_allocate) != 0 || keyfailed)
		return (&_res_bogus);
}

It would be so much nicer if pthread_once(once, func, retval) existed, but I 
guess this would probably still work....

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green@FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\