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From Ryan Bloom <>
Subject Re: Memory Hog
Date Mon, 11 Oct 1999 12:40:52 GMT

First of all, in the near future I will have nothing to do with whether or
not a particular system uses poll or select for this APR function.  This
is because it will be selectable at APR configuration time.  This has been
a goal for a while, but nobody has had the time to invest in learning
autoconf well enough to do it.  When this is true, I am assuming people
will use whichever method is the better performer on their system.

The general consensus I have heard, is that select is better for densly
populated lists of file descriptors, and poll is better for sparesly
populated lists.  Because Apache tends to have sparesly populated lists,
poll would seem to make sense.  Of course, that requires that the
poll implementation of ap_poll is tuned much better.  :)


On Sun, 10 Oct 1999 wrote:

> Ryan, just a short comment about poll/select. The project that 
> I was working on had a simple rule of portability. Use
> poll() for TLI implementation and use select() for the 
> BSD Socket implementations. This guaranteed maximum portability
> among different Unixes.
> Also there was a general agreement that BSD socket was more 
> efficient than TLI because more performance work was done on
> the BSD by the UC Berkely fellows than the TLI. So this makes
> select() more efficient than poll(). We never measured the performance
> of the two by profiling. It was just an agreement among the engineers.
>    My two cents,
>    ST.

Ryan Bloom
4205 S Miami Blvd	
RTP, NC 27709		It's a beautiful sight to see good dancers 
			doing simple steps.  It's a painful sight to
			see beginners doing complicated patterns.	

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