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Subject: Re: [PHP-DEV] php and multithreading (additional arguments)
From: stas@zend.com (Stanislav Malyshev)

Hi!

> Eve Online in Stackless Python
> fmspy.org <http://fmspy.org> with stackless python
> etc.

I don't know how python does it but PHP has a lot of global context, and 
sharing this global context between threads, whatever they are (OS 
threads, user-space threads, etc.) would be massively complex thing tp 
manage either for the engine or for the user.

>     And something like GIL feels like a reasonable compromise to me.

GIL would mean dreams about multicore stuff are just dreams, but beyond 
that even with GIL, what do you do if you checked for class_exists and 
it didn't exist, and you're about to load it when other thread loads it 
before? Etc., etc. You'd have to spend a lot of time thinking about 
stuff like that in your code. The fact that GIL protects you from 
C-level context changes doesn't mean it'd protect you from PHP-level 
context changes, like some code using some data structure and other code 
changing it (on C level it'd be ok - no memory corruption, etc. - but on 
PHP level it might totally break your code).
It's not to say it can't be done, but I didn't see yet coherent proposal 
for any threads implementation that had also good use cases.

> I think PHP is the last from the major scripting languages on the market
> without some kind of thread support.
> (Cannot find a good comparsion, but Ruby, Python, Perl does some)

And "keeping up with Joneses" is not a good use case.
-- 
Stanislav Malyshev, Zend Software Architect
stas@zend.com   http://www.zend.com/
(408)253-8829   MSN: stas@zend.com