From: taneli at crasman dot fi
Operating system: Linux
PHP version: 5.1.6
PHP Bug Type: Scripting Engine problem
Bug description: Memory leak when object contains reference to "parent" object
Description:
------------
The example says it the best. Reproducible in both 5.1.6 and 4.4.4 (with
minor changes), all extensions disabled. Definately related to references,
although I'm not sure if the code below is good practice, but I've run into
it on more than one occasion. I think it should be freeing the objects when
they go out of scope, but the reference counting must be broken somehow.
Might be related to #22055, but this one's been around for ages.
Reproduce code:
---------------
<?php {
class A {
var $ba;
function A() {
$this->ba = array();
for ($i = 0; $i < 100; $i++)
$this->ba[] = new B($this);
}
function __destruct() { // never gets called
die("Freeing class A\n");
}
}
class B {
var $a;
function B($a) { // function B(&$a), and:
$this->a = $a; // $this->a =& $a; leaks in php 4.4.4
// remove line above to prevent leak
}
function __destruct() { // never gets called either
die("Freeing class B\n");
}
}
$smu = memory_get_usage();
while (true) {
$ba = array();
for ($i = 0; $i < 100; $i++)
$ba[] = new A();
$emu = memory_get_usage();
echo sprintf("leak %.1f kB\r", ($emu - $smu) / 1024.0);
}
}?>
Expected result:
----------------
No memory leak.
Actual result:
--------------
Rapidly increasing memory leak.
--
Edit bug report at http://bugs.php.net/?id=39328&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=39328&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=39328&r=trysnapshot52
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=39328&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=39328&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=39328&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=39328&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=39328&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=39328&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=39328&r=support
Expected behavior: http://bugs.php.net/fix.php?id=39328&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=39328&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=39328&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=39328&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=39328&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=39328&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=39328&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=39328&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=39328&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=39328&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=39328&r=mysqlcfg
