Edit report at http://bugs.php.net/bug.php?id=36759&edit=1
ID: 36759
Comment by: tstarling at wikimedia dot org
Reported by: alexander dot v at zend dot com
Summary: Objects destructors are invoked in wrong order when
script is finished
Status: Assigned
Type: Bug
Package: Scripting Engine problem
Operating System: all
PHP Version: 5CVS-2006-03-16 (snap)
Assigned To: dmitry
Block user comment: N
Private report: N
New Comment:
r216213 fixes that one test case, but it seems like the actual complaint
here is that objects stored in member variables are destroyed before the
objects that reference them. I can see three problems with r216213. Two
of them mean that this bug is not fixed, and the third causes another
bug.
1. It assumes that all objects which hold references to other objects
will be in the global symbol table. For objects that aren't in the
global symbol table, it fails. For example if you take the test case and
replace this:
$y = new Bar();
$x = new Foo($y);
with this:
function foo() {
static $x, $y;
$y = new Bar();
$x = new Foo($y);
}
foo();
then the destructors are called in the wrong order.
2. It only deletes objects which have a reference count of 1. When a
zval is referred to by two symbol table entries, both symbol table
entries point to the same zval, and both have a reference count of 2, so
neither is deleted. So if you replace the same part of the test case
with:
$y = new Bar();
$x = new Foo($y);
$z = $x;
then the destructors are called in the wrong order.
3. It deletes variables, instead of just calling __destruct() on them as
expected. This was a hack to reuse the reference-counting code in
zval_ptr_dtor(). It's unnecessary and causes several user-visible side
effects, such as bug #54157.
Previous Comments:
------------------------------------------------------------------------
[2011-03-21 01:35:02] s...@php.net
According to Tim Starling, still happens, details to follow soon.
------------------------------------------------------------------------
[2006-07-12 08:57:50] dmi...@php.net
Fixed in CVS HEAD and PHP_5_2.
------------------------------------------------------------------------
[2006-03-16 15:12:50] dmi...@php.net
Reproduce code:
---------------
<?php
class Foo {
private $bar;
function __construct($bar) {
$this->bar = $bar;
}
function __destruct() {
echo __METHOD__,"\n";
unset($this->bar);
}
}
class Bar {
function __destruct() {
echo __METHOD__,"\n";
unset($this->bar);
}
}
$y = new Bar();
$x = new Foo($y);
?>
Expected result:
----------------
Foo::__destruct
Bar::__destruct
Actual result:
--------------
Bar::__destruct
Foo::__destruct
------------------------------------------------------------------------
[2006-03-16 15:02:04] alexander dot v at zend dot com
Description:
------------
Object destructors are invoked in an arbitrarily order.
Objects from a global_symbol_table should be destructed first.
Reproduce code:
---------------
too large and not deterministic
Expected result:
----------------
none
Actual result:
--------------
none
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=36759&edit=1
