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To: Justin Erenkrantz <jerenkrantz@ebuilt.com>
Cc: dev@apr.apache.org
Subject: Re: [PATCH] Switch to pthread as the default interprocess lock...
References: <20010922122558.B6756@ebuilt.com>
From: Jeff Trawick <trawick@attglobal.net>
Date: 24 Sep 2001 11:34:39 -0400
In-Reply-To: <20010922122558.B6756@ebuilt.com>
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Justin Erenkrantz <jerenkrantz@ebuilt.com> writes:

> I've brought this up before and I'll bring it up again.  =-)
> 
> Ian has seen about a ~60rps improvement using AcceptMutex pthread
> versus fcntl() on Solaris with httpd.  Also, fcntl has scalability 
> issues from what I can tell on Solaris (as described in STATUS) 
> that cause fatal errors in httpd.
>   
> I know that the AIX guys use pthread as well.
> 
> Is there any platform that meets the criteria for our pthread
> interprocess implementation where it is *not* better than fcntl()?

That is the wrong question for deciding whether or not to set the
default to pthread IMHO.

There is empirical evidence (lots of happy 1.3 users) that fcntl is a
good overall choice.  If/when we find that a certain platform should
use a different mechanism, I think we should specify *for that platform
only* to use a different mechanism rather than consider changing the
default on multiple platforms. 

pthread isn't even the best choice across the board on Solaris*.  How
are we going to be able to evaluate whether or not it should be used
on platforms we don't use/test extensively?

*I don't mean to infer that fcntl is the best choice across the board
 on Solaris.  Instead, I mean that certain Solaris configurations
 shouldn't be using pthread.

-- 
Jeff Trawick | trawick@attglobal.net | PGP public key at web site:
       http://www.geocities.com/SiliconValley/Park/9289/
             Born in Roswell... married an alien...