Qs on the post_config hook, restarts

[Mikhail T.]

Hello!

Various sources suggest, the hook can be called several times -- could 
someone summarize those times for the record?

For example, it appears, that upon start-up the hook is called once to 
"check the syntax" and then again -- for real. Mod-developers can check 
by recording previous invocations with apr_pool_userdata_set() 
(although, really, there should be some other mechanism).

Ok. Now, what about the "graceful restarts"? The hook is called again, 
understandably, but only once, right?

Now, when should a module free() its malloc()-ed memory and do other 
clean-up between restarts? It would seem, that the same process (the 
master httpd) is doing the dlopen() of the module upon every restart and 
thus its memory-use should be continuously growing...

My module, at least, is using some external libraries, so I can't rely 
on the apr_pools for clean-ups. How do I know, when to free-up the 
resources I've allocated?

Thanks!

   -mi