Fix am_mod_cfg_rec not being reused.(#36)

[oss-aimoto]

Reuse am_mod_cfg_rec.
mellon Sessions are not lost on httpd restart (signal: HUP, USR1).
However, the cache size is not changed.

[simo5]

My httpd internals memories are a bit rusty in places, but are you moving the mutex from allocation on a global memory pool to a per-process pool ?

[oss-aimoto]

The global memory pool is apr_pool_clear() at Gracefull restart. (by reset_process_pconf() in main.c)
s->process->pool is not cleared, the mutex can be reused.
I refer to the code of mod_ssl.

[simo5]

I guess the question is how thi affects the usage of the mutex, does it still remain a global mutex that all processes can reach? Or does this change open up the possibility that different processes will se actually different mutexes and not be coordinated anymore ?

[oss-aimoto]

A global mutex that is reachable by all processes.
s-> process-> pool is also a global pool.

[simo5]

In that case I am ok with this, but I'd like another pair of eyes to take a look.

[thijskh]

@jhrozek Can you take a look perhaps?