back-ldap, libldap_r

["Howard Chu" <hyc@highlandsun.com>]

Something I'd be interested in trying out would be adding some mutexes
libldap to allow multiple threads to submit requests on the same handle. I
could do pretty much the same thing in back-ldap but I think it could be
better done in the library.

Need a mutex for each request and response queue. For results we need to
tweak try_read1msg() and wait4msg() such that it unlocks (optionally yields)
and relocks the response mutex before looping back when it hasn't found the
requested msgid. This way multiple threads can wait on their responses
without too much hassle.

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support