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Date: Thu, 01 Apr 2010 11:38:02 -0700
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Subject: Re: [PHP-DEV] php and multithreading (additional arguments)
From: stas@zend.com (Stanislav Malyshev)

Hi!

>        processing, but then the state syncing of the forked background processing
>        results with the main thread requires a whole new protocol / switching to
>        interprocess communication, which makes such developments unnecessarily
>        hard. Threads exist for a _reason_ not only because they sound cool.

Interesting thing here threads would require (at least if they are 
implemented the way C, etc. threads usually work) whole new protocol of 
synchronization too. Just think about something: do you have shared 
classes/variables/etc.?
If you do, how you control access to them? Hello locks and the whole can 
of worms! Most people that think they can program in threads actually 
are just pushing their luck until some complex interaction leaves their 
app malfunctioning in a bizarre way and them without any means to debug 
it. I mean, you can do it right, but it's usually harder than it looks. 
Share-nothing exists for a reason too :)
If you don't, how it's different from forking except that you need to 
work 10 times as hard to keep engine guts from entangling in two "threads"?

>        2. Without thread support, it is not possible to use multi-core processing
>        paradigms directly from PHP - which means PHP relies on external frameworks for

What kinds of paradigms those are? in 90% of cases I saw if you need 
real multicore involvement in PHP you either doing it in a wrong place 
(i.e. webserver vs. backend) or doing it in a wrong language.
-- 
Stanislav Malyshev, Zend Software Architect
stas@zend.com   http://www.zend.com/
(408)253-8829   MSN: stas@zend.com