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Date: Mon, 27 Sep 2010 17:08:37 -0400
From: Jim Jagielski <jim@jaguNET.com>
To: dev@httpd.apache.org
Subject: Re: memory leak in mod_slotmem_shm
Message-ID: <20100927210837.GA35629@devsys.jaguNET.com>
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User-Agent: Mutt/1.5.20 (2009-06-14)

On Mon, Sep 27, 2010 at 08:03:51PM +0200, Rainer Jung wrote:
> On 27.09.2010 19:19, Stefan Fritsch wrote:
> >On Monday 27 September 2010, Jim Jagielski wrote:
> >>>BTW, it is not that obvious that the shm is supposed to be
> >>>cleaned up  and re-created on graceful restarts. This should be
> >>>documented in the code.
> >>>
> >>>
> >>
> >>That's an interesting point. I always assumed that it should be,
> >>since one use for it would be as a scoreboard-like replacement
> >>(and the pain for the scoreboard is that it's a set size)...
> >>But I can also see reasons for it to NOT be cleaned/recreated...
> >>How best to handle that??
> >
> >If it would be used for e.g. storing mod_proxy_balancer's worker
> >configuration/state, one would want the data to survive a graceful
> >restart, wouldn't one? But from a consumer's perspective, it doesn't
> >matter if this achieved by not destroying the shm segment or by saving
> >the data to disk and reloading it after recreating the shm segment.
> >So it seems to me that the current functionality is enough.
> 
> So if a graceful restart is initiated, will old children working on
> requests still be able to use the old shm segment, i.e. will it be
> destroyed after the last old child dies or earlier?
> 

The cleanup is when the config pool is cleaned up, at which point
there are no more consumers of that pool so we're safe.
-- 
===========================================================================
   Jim Jagielski   [|]   jim@jaguNET.com   [|]   http://www.jaguNET.com/
        "Great is the guilt of an unnecessary war"  ~ John Adams