Re: libldap and _r-functions

[Ralf Haferkamp <rhafer@suse.de>]

On Wednesday 25 May 2005 17:35, Kurt D. Zeilenga wrote:
> At 05:47 AM 5/25/2005, Ralf Haferkamp wrote:
> >are there specific reasons that the _r-functions (gethostbyname_r,
> >gethostbyaddr_r, ...) are only used for libldap_r and not libldap?
>
> Yes, there are a number of reasons.
>
> libldap was never designed for use in programs which
> aren't built/linked for use with a threaded program.  Thread
> programs may have problems even where that program serializes
> all calls to the library (because of conflicts between the
> program's and library's use of system (and dependent library)
> calls.  libldap_r was designed for use in threaded programs,
> such as slurpd(8).  While libldap_r does have a number of
> limitations, it is safe when used properly.
>
> The reason we have two libraries is that, on many systems,
> threaded and non-threaded programs are required to
> be compiled/linked differently, and that many of the _r
> functions are only available to programs compiled/linked
> as threaded programs.
Ok, thanks for clarifying that.

> >I have a problem here where nss_ldap (configured to be used for
> >resolving hostnames) deadlocks in a gethostbyname() call in libldap.
> >Building libldap so that it uses gethostbyname_r() fixed that
> > problem for me.
>
> Seems like nss_ldap should have been compiled/linked with
> libldap_r.
But wouldn't I get symbol conflicts then with applications that link 
against "normal" libldap on nss_ldap-enabled systems?

-- 
Ralf