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Date: Tue, 25 Mar 2003 10:37:59 +0100
To: Zeev Suraski <zeev@zend.com>
Cc: internals@lists.php.net
Message-ID: <20030325103759.I31290@wp-sa.pl>
Reply-To: wmeler@wp-sa.pl
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In-Reply-To: <5.1.0.14.2.20030324214937.04581cf0@localhost>; from zeev@zend.com on Mon, Mar 24, 2003 at 09:59:36PM -0800
Subject: Re: [PHP-DEV] ZTS performance
From: wmeler@wp-sa.pl (Wojtek Meler)

On Mon, Mar 24, 2003 at 09:59:36PM -0800, Zeev Suraski wrote:
> If __thread is any similar to Tls under Windows (which would be my guess), 
> then we can't use it directly.  We're already using pthread_setspecific so 
> we're extremely quick with fetches as it is.  As I said, I also doubt very 
> much that our performance penalty is solely due to fetches, but mostly 
> based on other issues, which __thread will not alter in any way.  You're 
> more than encouraged to try and implement a __thread based solution in 
> place of the pthread_setspecific solution and see if it makes any 
> difference.  If it does, we can investigate further in that direction and 
> see if it's usable.

I suppose that __thread is similar to __declspec( thread ). I really don't
know what is faster - using 

__thread / __declspec(thread) struct {..} thread_globals;

and accesing it in code by 

thread_globals.variable

which probably relay on CPU's MMU (depends on compiler and libc) is probably 
faster than

(((type) (*((void ***) tsrm_ls))[TSRM_UNSHUFFLE_RSRC_ID(id)])->element)

which cannot be well optimized because id is global variable and could change
between function calls.
I won't argue - you have more experience. I'll try to implement TSRM macros,
but I don't have time now. I'll do it in July (if it won't be implemented yet).

Regards,
Wojtek