ID:               49501
 User updated by:  romain dot riviere at gmail dot com
 Reported By:      romain dot riviere at gmail dot com
 Status:           Open
 Bug Type:         *General Issues
 Operating System: Gentoo Linux 32bit
 PHP Version:      5.2.10
 New Comment:

The last line of the initial description should have read : PHP
compiled --with-pic.

For the record, the problem appeared in Drupal and was reported as
happening at zend_opcode.c:48. However, since it can obviously be
reproduced with something as simple as a string, I believe it is a more
general memory leak issue.


Previous Comments:
------------------------------------------------------------------------

[2009-09-08 19:04:48] romain dot riviere at gmail dot com

Description:
------------
While trying to diagnose apparently random Out of Memory errors in
various PHP scripts (including Drupal among others), I ended up using
the code pasted below for testing purposes.

Browing the resulting page several times always results in an
ever-increasing VSZ for apache processes (up to 4GB in my case) and
eventually Out of Memory errors way before the script itself actually
reaches the limit. The script was called with size=61 in my case
(memory_limit=64M). On an 8GB system, it might take as many as 30
requests to recreate the bug. With a higher memory limit and value of
the "size" parameter, it will probably happen much sooner.

PHP compiled with 

Reproduce code:
---------------
<?php
ini_set('display_errors',true);
if (isset($_GET['size']) && $_GET['size'] < 200) {
$mb = intval($_GET['size']);
}
else {
        $mb=5;
}
$var = '';
echo 'Memory limit: '.ini_get('memory_limit').'<br>';
for ($i=0; $i<=$mb; $i++) {
        $var.= str_repeat('a',1*1024*1024);
        echo memory_get_usage().'<br>';
}
echo 'String length: '. strlen($var);
?>


Expected result:
----------------
For the first few runs, the script correctly displays the memory usage
and the value is consistent with the memory limit :

Memory limit: 64M
<snip>
String length: 65011712 

Actual result:
--------------
Memory limit: 64M
<snip>
Fatal error: Out of memory (allocated 61341696) at
/var/tmp/portage/dev-lang/php-5.2.10/work/php-5.2.10/ext/standard/string.c:4599
(tried to allocate 1048577 bytes) in /home/acrm/OF-svn/2.0/test.php on
line 14

Subsequent runs : 

Fatal error: Out of memory (allocated 262144) at
/var/tmp/portage/dev-lang/php-5.2.10/work/php-5.2.10/ext/standard/string.c:4599
(tried to allocate 1048577 bytes) in /home/acrm/OF-svn/2.0/test.php on
line 14


------------------------------------------------------------------------


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