Date: Fri, 20 Feb 2004 19:48:31 -0500 From: "Brian F. Feldman" <green@FreeBSD.org> To: Daniel Eischen <eischen@vigrid.com> Cc: current@FreeBSD.org Subject: Re: Testers wanted: reentrant resolver Message-ID: <200402210048.i1L0mVGW014390@green.homeunix.org> In-Reply-To: Message from Daniel Eischen <eischen@vigrid.com> <Pine.GSO.4.10.10402201927260.12256-100000@pcnet5.pcnet.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Daniel Eischen <eischen@vigrid.com> wrote: > On Fri, 20 Feb 2004, Brian F. Feldman wrote: > > > Daniel Eischen <eischen@vigrid.com> wrote: > > > Ugh, can you put h_errno inside the per-thread res stuff. > > > We shouldn't need to have to add special hooks in the > > > threads libraries for this. > > > > Please explain what you're saying further. On correctly-threaded operating > > systems, h_errno is just like errno -- and I made it act EXACTLY as errno > > acts, and is per-thread storage for everything but the first thread. It's > > absolutely necessary if we want to return the correct errors; even if > > everything else in the world is totally reentrant, if h_errno isn't, the > > wrong errors can be returned! What "special hooks" do you mean? There's no > > way to not change probably hundreds of lines of code without actually doing > > the work to make h_errno thread-safe. It's the only proper thing to do. > > The implementation of __h_errno() need not depend on something > special stuffed in struct pthread. Use thread-local storage > (pthread_getspecific()) like you did for the res_send_private > stuff. Especially since these interfaces should be deprecated > in favor of what looks to be BIND 8.2.2 interfaces (according > to the Solaris man pages). Other APIs have the option of failing. __h_errno() does not have the option of failing, so what do I do if pthread_key_create() fails? Also, if malloc() fails each time pthread_getspecific() returns NULL for the thread? -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200402210048.i1L0mVGW014390>