Re: Code review for thread safeness

[Ken Raeburn]

Oh, how annoying.  In going back over some old email messages in my 
way-too-full mailbox, I just noticed these replies to my message that 
I'd never read!  I apologize for not replying before.

On Mar 9, 2005, at 11:23, Andreas Rottmann wrote:
> Marius Vollmer <address@hidden> writes:
> > Ken Raeburn <address@hidden> writes:
> > > If at all possible, this code should be switched to use get*by*_r, or
> > > in the gethostby* cases, perhaps getaddrinfo and getnameinfo.
> > Yes, definitely.  Could you help with that?
> FWIW, I just stole some code from GNet (http://www.gnetlibrary.org)
> for another project. You might want to have a glance at how they do
> this stuff, since it seems there are different flavours of
> gethostbyname_r (glibc, HPUX, Solaris). The relevant code is in
> inetaddr.c and configure.ac (detection). GNet is LGPL-licenced BTW.

I've spent some time dealing with getaddrinfo/gethostbyname_r/etc for 
work, and found this to be a rather annoying morass to dive into.  
There are at least three variants of gethostbyname_r among the systems 
I'm supporting, and some (even modern systems like NetBSD and Mac OS X) 
don't have it at all; almost all of the systems have getaddrinfo, 
though different implementations have different minor bugs.  I've also 
gone through writing code to determine which flavors of which routines 
are available, and implementing a wrapper to deal with all the 
variants.

In the long term, I think getaddrinfo is what we want to be using.  But 
for the short term, hacking up the gethostby* routines to use the _r 
versions when they're available shouldn't be that hard.  I'll look into 
it.

(Oh, eww, we've got 'gethostent' support too.  Bleah.  Well, glibc at 
least seems to have a gethostent_r...)

Ken