Edit report at https://bugs.php.net/bug.php?id=62684&edit=1
ID: 62684
User updated by: jerico dot dev at gmail dot com
Reported by: jerico dot dev at gmail dot com
Summary: PHP/DOMDocument: unset() does not release resources
-Status: Open
+Status: Closed
Type: Bug
Package: Performance problem
Operating System: Linux
PHP Version: 5.3.15
Block user comment: N
Private report: N
New Comment:
I could track this down to a memory leak unrelated to DOMDocument. I'm still
far from isolating the problem. But it's not what I thought. Sorry for the
noise.
Previous Comments:
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[2012-07-28 18:54:39] jerico dot dev at gmail dot com
The link is not meant as a reproduction script but points to the actual source
code + solutions I've tried. I tried a long time to better isolate the problem
but I couldn't reproduce it in a smaller setting.
I appreciate any hint how I could go about further isolating the problem. I
currently only rely on memory_get_usage() and xdebug_debug_zval(). Is there
anything more I could do to identify what actually causes the problem? Does PHP
provide some internal debugging messages that might indicate why unset() could
not release the memory?
Here's what I already tried out:
* I checked that the reference count of $dom is exactly one immediately before
the call to unset(): xdebug_debug_zval('dom') reports: dom: (refcount=1,
is_ref=0)=class DOMDocument { }.
* I tried gc_enable() + gc_collect_cycles().
* I tried the solution proposed in
http://stackoverflow.com/questions/8379829/domdocument-php-memory-leak
* I tried calling $dom->__destruct() before unset() but this will result in an
error as DOMDocument apparently does not have a destructor.
* I recursively removed all nodes in the DOM before I unset the variable. It
did not make the least difference.
* I tried setting the variable to null before re-using it: $dom = null
None of these showed any effect. I'm simply out of ideas how to simulate the
problem in a way that makes it easier for you to reproduce it.
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[2012-07-28 18:30:42] ras...@php.net
Sorry, a 1126-line reproduce script? I doubt any of us are going to read
through
that. Please simplify to a 10-15 line example that shows the problem you are
having.
------------------------------------------------------------------------
[2012-07-28 18:01:01] jerico dot dev at gmail dot com
Description:
------------
A complete problem description + sample code can be found here:
http://stackoverflow.com/questions/11703164/php-domdocument-unset-does-not-release-resources
Test script:
---------------
https://github.com/jerico-dev/ojs/blob/abc2af0f66c11664b7e917201fd707aa3307a1e0/plugins/generic/lucene/classes/SolrWebService.inc.php#L296
Expected result:
----------------
I expect unset() to release the memory resources that were used for the object.
Actual result:
--------------
unset() only releases a tiny amount of the resources actually used. See the
debug output in
http://stackoverflow.com/questions/11703164/php-domdocument-unset-does-not-release-resources
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Edit this bug report at https://bugs.php.net/bug.php?id=62684&edit=1
