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Date: Mon, 17 Mar 2008 09:50:58 +0200
Message-ID: <06B0D32C7A96544490D18AF653D6BDE5027598F7@il-ex1.zend.net>
Thread-Topic: [PHP-DEV] Patch for opcode caches
Thread-Index: AciGdZLbSu5+pX08TzSwmpYBtrg7UABjYN3A
To: "Xuefer" <xuefer@gmail.com>,
	"Rasmus Lerdorf" <rasmus@lerdorf.com>
Cc: "Marcus Boerger" <helly@php.net>,
	"Stas Malyshev" <stas@zend.com>,
	"Andi Gutmans" <andi@zend.com>,
	<internals@lists.php.net>
Subject: RE: [PHP-DEV] Patch for opcode caches
From: dmitry@zend.com ("Dmitry Stogov")



> -----Original Message-----
> From: Xuefer [mailto:xuefer@gmail.com]=20
> Sent: Saturday, March 15, 2008 11:21 AM
> To: Rasmus Lerdorf
> Cc: Marcus Boerger; Stas Malyshev; Dmitry Stogov; Andi=20
> Gutmans; internals@lists.php.net
> Subject: Re: [PHP-DEV] Patch for opcode caches
>=20
>=20
> >  I don't actually see early binding as being much of a problem, the=20
> > real  problem is when the same class is both early and late=20
> bound.  If=20
> > you  consistently always bind early or always bind late,=20
> opcode caches=20
> > should  be quite happy to let you do that.  But if you mix the two,=20
> > things get  chaotic and the problem becomes intractable.  We went=20
> > through all this  in APC a couple of years ago.  My=20
> initial, somewhat=20
> > naiive attempt at
> i'm not sure why i can't reproduce it years ago with apc=20
> enabled and i reproduce it with a complex script later.
>=20
> a1.php
> class a { function aMethod() { echo __FILE__; } }
> a2.php
> class a { function aMethod() { echo __FILE__; } }
> child.php
> class child extends a { }
>=20
> main1.php which is requested first
> include "a1.php";
> include "child.php";
> $child =3D new child()
> $child->aMethod(); // aMethod() from a1.php, but what if i=20
> update a1.php after child.php is cached?
>=20
> main2.php which is requested later
> include "a2.php";
> include "child.php";
> $child =3D new child();
> $child->aMethod(); // aMethod() from a1.php because of early=20
> binding is done before cache? or from a2.php?
>=20
> with and without opcode cacher, what is echo'ed if you=20
> requests main1 first and main2 later?
>=20
> with the delayed early binding, php behavior exactly the same=20
> with opcode cachers enabled or disabled imho, with delayed=20
> early binding, every class is binded once when there is no=20
> opcode cacher, and opcode cacher can even decide to call bind=20
> api before cache. looks like we can always the delay the=20
> binding unless we want binary back compatbility for 3rd party=20
> modules? correct me if i'm wrong
>=20

Compatibility is not an issue for php-5.3.
We don't need to delay early-binding without opcode caches.
It will do exactly the same as current early binding but slower.

Thanks. Dmitry.