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From Graham Leggett <minf...@sharp.fm>
Subject Re: MPMs, COW vs Child Process Spawning
Date Wed, 29 Oct 2008 19:28:13 GMT
Paul Querna wrote:

> One of the things I would like to do on the Simple MPM is unify how 
> child processes are created on win32 and unix.
> 
> On Win32, there is no fork, so roughly speaking what the current winnt 
> MPM creates a new process, and feeds the configuration over a pipe to 
> the new child.
> 
> On Unix, all of the current MPMs use fork, and do not execute a new 
> process, but instead then drop privileges and continue running.
> 
> What I would like to do, is change Unix to use the same pattern as on 
> Windows.

Hmmm.

I think for a large configurations, the copy on write is a significant 
optimisation - you can have large numbers of processes, and a large 
configuration, and get away with it, as practically the configuration is 
only memory resident once.

I think it would be important to still support both, but certainly the 
code to support both shouldn't be at all complex. Perhaps the choice of 
which to choose could be configurable, so that Leopard users could 
choose "config via pipe".

Although the MPM should be simple, it should ideally not be so 
simplified to become simplistic.

Regards,
Graham
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