ap_register_cleanup — register a cleanup function
void ap_register_cleanup(pool *p, void *data, void (*plain_cleanup)(void *), void (*child_cleanup)(void *))
Registers a pair of functions to be called when the pool is
destroyed. Pools can be destroyed for two reasons: first, because the
server has finished with that pool, in which case it destroys it and
calls the plain_cleanup function, or second,
because the server has forked and is preparing to
exec some other program, in which case the
child_cleanup function is called. In either case,
data is passed as the only argument to the cleanup
function. If either of these cleanups is not required, use
ap_null_cleanup.