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From Rodent of Unusual Size <Ken.C...@Golux.Com>
Subject Re: some reasons why Apache 2.0 threaded is slower than prefork
Date Thu, 01 Mar 2001 20:42:54 GMT
Cliff Woolley wrote:
> 
> It's the "lock-free operations" part that I've been stumbling over
> so far.

OpenVMS on the VAX dealt with this by using the low bit of the
pointer as a lock.  Blocks were always 64-bit aligned, so it
was free.  They used interlocked instructions that were guaranteed
atomic:  BBSSI (branch on bit set and set, interlocked) and BBCCI.
I do not know how we could use that here, but it was simple and
elegant.. thread, process, and SMP safe.
-- 
#ken    P-)}

Ken Coar                    <http://Golux.Com/coar/>
Apache Software Foundation  <http://www.apache.org/>
"Apache Server for Dummies" <http://Apache-Server.Com/>
"Apache Server Unleashed"   <http://ApacheUnleashed.Com/>

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