Re: [naviserver-devel] How to disable HAVE_GETNAMEINFO ?

[Stephen D. <sd...@gm...>]

On 10/5/05, Zoran Vasiljevic <zv...@ar...> wrote:
> Hi !
>
> I'm confused. Very.
>
> I need to disable the configure  machinery to
> define the HAVE_GETNAMEINFO and HAVE_GETADDRINFO
> for Darwin builds. Reason: those are broken on
> Darwin, and upon that, also MT-unsafe. OTOH,
> the classic gethostbyname/gethostbyaddr are
> working and are protected by critical section
> so I think it is better to use those.
>
> BUT: I do not see a clear way how to influence
> configure NOT to use/define those above !
>
> I COULD just
>
> #ifdef __APPLE
> # undef HAVE_GETADDRINFO
> # undef HAVE_GETNAMEINFO
> #endif
>
> but this is not elegant.
>
> Any ideas?
>
> Zoran
>
>
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Around line 195 of configure.in there's this test:

has_threadsafe_dns=3Dno
AC_CHECK_LIB(socket, getaddrinfo)
AC_CHECK_LIB(socket, getnameinfo)
AC_CHECK_FUNCS(getaddrinfo getnameinfo)
if test "${ac_cv_func_getaddrinfo}" =3D "yes" \
    -a "${ac_cv_func_getnameinfo}" =3D "yes" ; then
    has_threadsafe_dns=3Dyes
fi
if test "${has_threadsafe_dns}" !=3D "yes" ; then
    AC_HAVE_GETHOSTBYNAME_R
    AC_HAVE_GETHOSTBYADDR_R
    if test "${ac_cv_func_gethostbyname_r}" =3D "yes" \
        -a "${ac_cv_func_gethostbyaddr_r}" =3D "yes" ; then
        has_threadsafe_dns=3Dyes
    fi
fi
if test "${has_threadsafe_dns}" !=3D "yes" ; then
  AC_MSG_WARN([dns queries will use non-threadsafe calls which could
result in server instability])
fi


Maybe you could check if $system =3D=3D Darwin after the first check and
set has_threadsafe_dns =3D no.

At least this way all the checking is confined to the configure script
and not scattered throughout the source.

Even better would be to test for the brokenness rather than the
platform.  Not sure what what the bug is or how easy it would be to
check for.  Then when Apple fix this we start using getnameinfo again
automatically.