For that, you should use apr_reslist_t. IIRC, it was written for exactly this purpose. I believe Pier was using it for the now defunct mod_jerry, but I don't think mod_jk picked up on it.One 'ultimate' way to proof how much sense it would make is by using it to do simply/do some clever apache/tomcat connection pooling.
I would also bet that the pooling code for LDAP could take advantage of apr_reslist_t and remove a lot of code. -- justin