Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:57817
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain zend.com designates 212.199.177.89 as permitted sender)
To: Dmitry Stogov <dmitry@zend.com>
Date: Mon, 13 Feb 2012 10:56:03 +0200
User-Agent: KMail/1.13.7 (Linux/2.6.37; KDE/4.7.2; i686; ; )
CC: PHP Internals <internals@lists.php.net>, Alex Haiut <alex.h@zend.com>,
	Zeev Suraski <zeev@zend.com>, Eran Ifrah <eran@zend.com>, Lior Kaplan
	<lior.k@zend.com>
References: <201202121409.54891.yoram.b@zend.com> <4F38AE39.8000708@zend.com>
In-Reply-To: <4F38AE39.8000708@zend.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-ID: <201202131056.04017.yoram.b@zend.com>
Subject: Re: restore user opcode handler in PHP
From: yoram.b@zend.com (yoram bar haim)

Hi Dmitry.
the patch does work, in sense of actually restoring the handlers state when 
you call zend_set_user_opcode_handler() with original handler.
the patch does not solve the basic problem of no re-initialization of static 
arrayes on mac.

As for feeling the array with zero's, if we do that, we also need to fill it 
with original opcodes, something like :

static zend_base_user_opcodes = {0,1,2,3,4,....};

and then in php_module_startup :

memset (zend_user_opcode_handlers,0,sizeof(zend_user_opcode_handlers);
memcpy 
(zend_user_opcodes,zend_base_user_opcodes,sizeof(zend_base_user_opcodes);

So basically, every modifiably variable should be initialized as startup and 
not only by static initializer.

On Monday, February 13, 2012 08:31:21 AM Dmitry Stogov wrote:
> Hi Yoram,
> 
> Can we just fill this arrays with zeros on php startup?
> 
> Thanks. Dmitry.
> 
> On 02/12/2012 04:09 PM, yoram bar haim wrote:
> > I first saw this problem while addapting extension to PHP 5.4 but the
> > code is the same in 5.3 :
> > when you call zend_set_user_opcode_handler() it set's a pointer (handler)
> > in zend_user_opcode_handlers and a uint opcode value in
> > zend_user_opcodes to ZEND_USER_OPCODE .
> > 
> > you can call zend_set_user_opcode_handler with the original handler to
> > restore it, but if the original state did not include ZEND_USER_OPCODE
> > you have no way to restore it.
> > 
> > Why restoring ?
> > On mac, static variables are not re-initialized on dlclose()+dlopen().
> > that means that apache reload does not re-create
> > zend_user_opcode_handlers and zend_user_opcodes.
> > if your extension sets user_opcode_handler and is not reloaded in apache
> > reload (because you commented it in php.ini, for example), your handlers
> > array will actually point to non-exist handler.
> > if you will call zend_set_user_opcode_handler() with the original handler
> > at MSHUTDOWN, it will restore the handler but zend_user_opcodes[<opcode]
> > will still be ZEND_USER_OPCODE so you will end up calling a NULL
> > handler.
> > 
> > we should eather allow zend_set_user_opcode_handler to also set the value
> > in zend_user_opcodes[<opcode>] or we should build those arrayes from
> > scratch at php_module_init.
> > 
> > currently an extension tha calls zend_set_user_opcode_handler() will make
> > PHP crash on mac after disabling the extension and apache reload.