ID: 22055
Comment by: matthieu dot aubry at gmail dot com
Reported By: jparneodo at yahoo dot fr
Status: No Feedback
Bug Type: Scripting Engine problem
Operating System: RedHat 7.2
PHP Version: 4.3.1-dev
New Comment:

I also have the same problem using
PHP Version => 5.1.2
Build Date => Nov 2 2006 12:28:13
Server API => Command Line Interface

This bug is really annoying.

I'm working on a project which loads thousands of files parsed into
objects.
I use the technic
$this->myObjectMember->register($this);

which creates cross references.

Calling unset() doesn't change anything, as seen in the examples
provided above.

I would love to see this bug fixed! Thank you.


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

[2005-06-17 16:25:54] apinstein at mac dot com

I have experienced this problem on PHP5 as well... here's a
test script:


echo memory_get_usage() . " (initial)\n";
$t = new test;
echo memory_get_usage() . " (after: \$t = new test();)\n";
unset($t);
echo memory_get_usage() . " (after: unset(\$t);)\n";
echo "done\n";


class test
{
protected $str;
protected $t2;

function __construct()
{
print "construct test\n";
$this->str = str_repeat('1234567890', 1000);
$this->t2 = new test2($this);
}

function __destruct()
{
print "destruct test\n";
}
}
class test2
{
protected $str;
protected $t1;

function __construct($t1)
{
print "construct test2\n";
$this->str = str_repeat('1234567890', 1000);
$this->t1 = $t1;
}

function __destruct()
{
print "destruct test2\n";
unset($this->str);
}
}


And the output of this script:

51416 (initial)
construct test
construct test2
72000 (after: $t = new test();)
72000 (after: unset($t);)
done
destruct test
destruct test2

It's definitely a real problem. Simply removing the cross-
referenced instance vars will remove the problem. However,
as you can see, even explicitly calling unset() still
doesn't release the objects or call destructors until the
script EXITS.

This is a *MAJOR* problem for anyone using OO to process
large amounts of information.

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

[2004-03-01 05:07:55] tom at scl dot co dot uk

Is anyone looking into this?

I've found any method of releasing the objects fails, no just using the
unset() function, if the object just go out of scope they aren't
released, for ezample, if you do something like

function MyFunc() {
$x = new C;
$y = new C;

$x->ref =& $y;
$y->ref =& $x;
}

Then after the function has finished then the memory allocated for the
local variables $x and $y is not freed up.

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

[2004-02-23 11:21:41] tom at scl dot co dot uk

I had this problem with PHP4.3.3. I then found this bug report and
upgraded to PHP5.0.0b4 to try and fix this problem and I still get the
memory leak problem, there is some demo code below, you need to change
/path/to/large/file. I've been using a file which is about 1.5mb and
when PHP is set to stop when it reaches 8mb then it only makes it
through the loop twice.

I'm 1.5 years into a project and I could really do with knowing if this
is going to be fixed anytime soon so I can either wait for the fix or
try and find a work around. Thanks for your time,
Tom

---

<?php
class C {
var $ref;
var $val;

function C() {
$this->val = file('/path/to/large/file');
}
}

while (1) {
$x = new C;
$y = new C;

$x->ref =& $y;
$y->ref =& $x;

unset($y);
unset($x);

echo ".";
}
?>

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

[2003-02-25 02:03:00] [email]sniper@php.net[/email]

No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Open". Thank you.



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

[2003-02-17 04:51:30] [email]derick@php.net[/email]

Test with the php5 snapshot please:

[url]http://snaps.php.net/php5-latest.tar.gz[/url]

It won't be fixed in PHP 4 anyway as it has to do with the way objects
work there.

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

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the rest of the comments, please view the bug report online at
[url]http://bugs.php.net/22055[/url]

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