Edit report at http://bugs.php.net/bug.php?id=48781&edit=1
ID: 48781
Updated by: dmi...@php.net
Reported by: nate at frickenate dot com
Summary: Cyclical garbage collector memory leak
Status: Assigned
Type: Bug
Package: Scripting Engine problem
Operating System: Debian 5.0 kernel 2.6.24-23-xen
PHP Version: 5.3.0
Assigned To: dmitry
New Comment:
Yeah. I confirm the problem. It looks like on each 100,000 iterations
PHP runs GC about 12 times. And on each GC run it looses 2 objects
referenced by $user. I'll try to fix it.
Previous Comments:
------------------------------------------------------------------------
[2010-04-18 02:28:35] j...@php.net
I am unable to duplicate this behaviour using 5.3.2. The code given
below consistently uses 0.65 MB even up to 10 million iterations - I
pasted the output of up to 6 million, with the extended GC reporting
turned on:
<?php
class User {
protected $profile;
public function __construct () {
$this->profile = new UserProfile($this);
}
public function dispose() {
$this->profile->dispose();
$this->profile = null;
}
}
class UserProfile {
private $user;
public function __construct ($user) {
$this->user = $user;
}
public function dispose() {
$this->user = null;
}
}
for ($userid = 1; ; $userid++) {
if(isset($user)) {
$user->dispose();
}
$user = new User;
if ($userid % 100000 == 0)
printf("memory usage after %s users: %s MB.\n",
number_format($userid), number_format(memory_get_usage() / 1024 / 1024,
2));
continue;
}
?>
memory usage after 100,000 users: 0.65 MB.
memory usage after 200,000 users: 0.65 MB.
memory usage after 300,000 users: 0.65 MB.
[snip]
memory usage after 5,700,000 users: 0.65 MB.
memory usage after 5,800,000 users: 0.65 MB.
memory usage after 5,900,000 users: 0.65 MB.
GC Statistics
-------------
Runs: 0
Collected: 0
Root buffer length: 0
Root buffer peak: 9
Possible Remove from Marked
Root Buffered buffer grey
-------- -------- ----------- ------
ZVAL 16 7 7 0
ZOBJ 77999984 11999998 11999998 0
------------------------------------------------------------------------
[2010-01-05 19:31:01] nightstorm at tlen dot pl
I confirm, there is a true memory leak. Consider the following script,
where the references are unmounted manually with an extra dispose()
method:
~~~~
<?php
/*
How to use:
a) run test 1 by running code as-is
b) run test 2 by commenting out test 1, uncomment test 2
c) run test 3 by commenting out test 1 & 2, uncomment test 3
*/
class User {
protected
$profile;
public function __construct () {
$this->profile = new UserProfile($this);
}
public function dispose()
{
$this->profile->dispose();
$this->profile = null;
} // end dispose();
}
class UserProfile {
private
$user;
public function __construct ($user) {
$this->user = $user;
}
public function dispose()
{
$this->user = null;
} // end dispose();
}
for ($userid = 1; ; $userid++) {
if(isset($user))
{
$user->dispose();
}
$user = new User;
if ($userid % 100000 == 0)
printf("memory usage after %s users: %s MB.\n",
number_format($userid), number_format(memory_get_usage() / 1024 / 1024,
2));
continue;
}
~~~~~
In this case the result is still the same (PHP 5.3.1):
~~~~
memory usage after 100,000 users: 0.61 MB.
memory usage after 200,000 users: 0.61 MB.
memory usage after 300,000 users: 0.61 MB.
memory usage after 400,000 users: 0.61 MB.
memory usage after 500,000 users: 0.61 MB.
memory usage after 600,000 users: 0.61 MB.
memory usage after 700,000 users: 0.61 MB.
memory usage after 800,000 users: 0.61 MB.
memory usage after 900,000 users: 0.61 MB.
memory usage after 1,000,000 users: 0.61 MB.
memory usage after 1,100,000 users: 0.61 MB.
memory usage after 1,200,000 users: 0.61 MB.
~~~~
If we enable the garbage collector and remove the dispose() method, the
used memory level begins to increase, and if we call gc_collect_cycles()
after creating a new object, the used memory increases even much faster.
On my PC, it is not able to perform display even a single control
message after 100000 iterations. It stopped after approx. 33000 users:
~~~~
memory usage after 30,000 users: 25.37 MB.
memory usage after 31,000 users: 26.07 MB.
memory usage after 32,000 users: 26.76 MB.
memory usage after 33,000 users: 31.46 MB.
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to
allocate 89 bytes) in /home/me/test/memleak.php on line 17
~~~~
------------------------------------------------------------------------
[2009-12-15 01:00:00] php-bugs at lists dot php dot net
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
------------------------------------------------------------------------
[2009-12-08 15:23:16] nate at frickenate dot com
No change, same problem. Considering this bug hasn't even been looked at
or assigned, no surprise there.
------------------------------------------------------------------------
[2009-12-07 09:12:35] j...@php.net
Please try using this snapshot:
http://snaps.php.net/php5.3-latest.tar.gz
For Windows:
http://windows.php.net/snapshots/
------------------------------------------------------------------------
The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
http://bugs.php.net/bug.php?id=48781
--
Edit this bug report at http://bugs.php.net/bug.php?id=48781&edit=1
