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From "Paul J. Reder" <rede...@raleigh.ibm.com>
Subject Re: plz vote on tagging current CVS as APACHE_2_0_19
Date Thu, 21 Jun 2001 20:34:44 GMT
rbb@covalent.net wrote:
>                                                             It will
> require locking anytime somebody wants to walk the scoreboard, which means
> that potentially the scoreboard will be run once a request.  Think
> mod_status and/or mod_snmp.

This is just plain not true. The pointer to the worker is placed in the 
conn_rec for direct access. Neither the worker, nor the scoreboard need
to be locked for the worker to be updated during a request. The request
processing knows that the worker pointer is valid for the duration of
the request. The request processing does not care about any other 
workers or processes during update. The status code doesn't care if the
worker data is updated while it is doing a walk.

The locking is only required during the time that a worker or process is
being added or removed from the tree or mod_status is running. And the
locking is only needed to keep those two events out of each others hair.
Mod_status does not happen often, nor does adding/removing workers and
processes.

I am looking forward to seeing the 100 lines of code it takes to make
processes share worker space in the scoreboard.

-- 
Paul J. Reder
-----------------------------------------------------------
"The strength of the Constitution lies entirely in the determination of each
citizen to defend it.  Only if every single citizen feels duty bound to do
his share in this defense are the constitutional rights secure."
-- Albert Einstein

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