about threaded libpq

Hi,

I'm currently working with bacula developpers in order to improve performance
(mainly for postgresql).

In order for our new code to work, we need to be sure that libpq is threaded.
For 8.2, we can use PQisthreadsafe();. The problem is we cannot force all
users to migrate to 8.2, and that many of them use packaged postgresql
binaries.

Is there another reliable way to determine (at bacula configure time for
instance) that libpq is threaded ? (it also has to be a way/several ways that
works on all platforms, as bacula runs on many unix and win32). We'd like to
do it as well as possible.

Thanks a lot for feedback...

Marc Cousin