From: tstarling
Operating system: Linux
PHP version: master-Git-2012-10-29 (Git)
Package: XML related
Bug Type: Bug
Bug description:Allocation via libxml does not use PHP's per-request allocator
Description:
------------
Allocation via libxml does not use PHP's per-request allocator. So any
memory used by libxml will not be accounted against memory_get_usage() or
memory_limit.
At Wikimedia we use libxml DOM trees to store wikitext parse trees, because
they are more compact in memory than the equivalent pure-PHP data
structures. When these parse trees are cached, the memory requirements can
become excessive, and the memory is typically not returned to the system
after request termination. Using xmlMemSetup() to set hook functions which
use PHP's per-request allocation functions will allow us to more
effectively monitor and limit the use of libxml in production.
I've developed a patch and will submit it to GitHub as a pull request.
Test script:
---------------
$doc = new DOMDocument;
for ( $i = 0; $i < 1000000 ; $i++ ) {
$doc->appendChild($doc->createElement('foo'));
}
print memory_get_usage()."\n";
Expected result:
----------------
312331440 (with debug and ZTS)
Actual result:
--------------
694256
--
Edit bug report at https://bugs.php.net/bug.php?id=63380&edit=1
--
Try a snapshot (PHP 5.4):
https://bugs.php.net/fix.php?id=63380&r=trysnapshot54
Try a snapshot (PHP 5.3):
https://bugs.php.net/fix.php?id=63380&r=trysnapshot53
Try a snapshot (trunk):
https://bugs.php.net/fix.php?id=63380&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=63380&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=63380&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=63380&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=63380&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=63380&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=63380&r=support
Expected behavior: https://bugs.php.net/fix.php?id=63380&r=notwrong
Not enough info:
https://bugs.php.net/fix.php?id=63380&r=notenoughinfo
Submitted twice:
https://bugs.php.net/fix.php?id=63380&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=63380&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=63380&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=63380&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=63380&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=63380&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=63380&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=63380&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=63380&r=mysqlcfg
