Edit report at https://bugs.php.net/bug.php?id=62111&edit=1
ID: 62111
Updated by: uw@php.net
Reported by: hosiplan at gmail dot com
Summary: MySQL PDO memory leaks, when used own result row
class
Status: Open
Type: Bug
Package: PDO related
Operating System: Linux
PHP Version: 5.4.4RC1
Block user comment: N
Private report: N
New Comment:
There is no leak with MySQL. Memory usage increases, that's it.
==6216== LEAK SUMMARY:
==6216== definitely lost: 0 bytes in 0 blocks
==6216== indirectly lost: 0 bytes in 0 blocks
==6216== possibly lost: 0 bytes in 0 blocks
==6216== still reachable: 54 bytes in 2 blocks
==6216== suppressed: 0 bytes in 0 blocks
==6216== Rerun with --leak-check=full to see details of leaked memory
Previous Comments:
------------------------------------------------------------------------
[2012-06-11 13:48:11] juzna dot cz at gmail dot com
The same causes PHP to crash completely on Windows 32bit with MSSQL server (using
sqlsrv driver). I guess the root cause will be related.
------------------------------------------------------------------------
[2012-05-22 20:39:55] juzna dot cz at gmail dot com
Leaks with mysql, no leaks with sqlite.
No need to fetchAll(); execute() is enough to get leaks
------------------------------------------------------------------------
[2012-05-22 20:12:17] hosiplan at gmail dot com
affected version
------------------------------------------------------------------------
[2012-05-22 20:10:33] hosiplan at gmail dot com
Sorry, I've coppied wrong code
Test script:
---------------
$db = new PDO('mysql:host=127.0.0.1;dbname=information_schema', 'root',
'password');
class DbRow { public function __construct($stt = NULL) { } }
$begin = memory_get_usage();
for ($i=0; $i < 10 ;$i++) {
$stt = $db->prepare("SELECT * FROM COLLATIONS");
$stt->setFetchMode(PDO::FETCH_CLASS, 'DbRow', array($stt));
$stt->execute();
$rows = $stt->fetchAll();
echo number_format((memory_get_usage() - $begin) / 1000000, 2, '.', '
'), " MB\n";
}
------------------------------------------------------------------------
[2012-05-22 20:05:25] hosiplan at gmail dot com
Description:
------------
When PDO is told to use my row class and pass PDOStatement into it, it creates
cyclic reference, that prevents GC from deleting the row data, when not required
anymore.
Test script:
---------------
$db = new PDO('mysql:host=127.0.0.1;dbname=information_schema', 'root',
'password');
class DbRow { public function __construct($stt = NULL) { } }
$begin = memory_get_usage();
for ($i=0; $i < 10 ;$i++) {
$stt = $db->prepare("SELECT * FROM COLLATIONS");
$stt->setFetchMode(PDO::FETCH_CLASS, 'DbRow');
$stt->execute();
$rows = $stt->fetchAll();
echo number_format((memory_get_usage() - $begin) / 1000000, 2, '.', ' '),
" MB\n";
}
Expected result:
----------------
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
0.05 MB
Actual result:
--------------
0.00 MB
0.05 MB
0.10 MB
0.14 MB
0.19 MB
0.24 MB
0.29 MB
0.34 MB
0.38 MB
0.43 MB
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=62111&edit=1