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Re: libldap and libldap_r in the same process

Jan Engelhardt wrote:

A given (threaded) program makes use of libldap_r. It now also wants to
make use of, say, libcurl. On certain systems, libcurl happens to be
linked against libldap (not _r).

Eventually, both libldap and libldap_r end up in the process image of my
program, and a symbol like "ldap_init" may point to the function of
either library file. The threaded program may end up unexpectedly been
given the non-threaded functions, depending on how the runtime linker
loaded said libraries and binds the symbols. (I am seeing crashes in a
large program's initialization because of this.)

There is a 7-year old post indicating libldap should get locking/
be replaced by libldap_r.
To date, openldap still consists of the two libraries.
What are the preferred options to go forward here?

* Killing non-threaded libldap in openldap for real
If not,
* Should curl have used -lldap_r instead of -lldap?

Is curl already multithreaded? On Ubuntu curl is built with libldap_r already. If curl is a threaded program then yes, it should use libldap_r.

* Should Linux distributions make libldap and libldap_r be the same thing?

I'm wary of doing that, but I suppose thread support on Linux today is a lot more stable than it was 7-15 years ago.

* Should libldap and libldap_r be augmented by ELF symbol versions?
* All of the above? :)

  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/