#20240 [Com]: order of destructor calls
| From: | thekid at thekid dot de | Date: | Fri, 18 Apr 2003 22:49:30 +0000 |
| Subject: | #20240 [Com]: order of destructor calls | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-37875@lists.php.net to get a copy of this message | ||
ID: 20240
Comment by: thekid at thekid dot de
Reported By: vincent dot planchenault at atempo dot com
Status: Open
Bug Type: Zend Engine 2 problem
Operating System: Linux
PHP Version: 5.0.0-dev
New Comment:
Running this script with current PHP5 gives me:
2
3
3
I guess this can be marked as fixed then?
Previous Comments:
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[2002-12-10 14:07:39] tad at tadland dot net
There appears to be a bigger problem. Consider the following code:
<?php
class test
{
var $member;
function test() {
$this->member = 1;
register_shutdown_function(array($this, 'destructor'));
}
function destructor() {
print $this->member;
}
function add() {
$this->member += 1;
print $this->member."<br>\n";
}
}
$t = new test();
$t->add();
$t->add();
?>
One might expect this code to output
2
3
3
But instead, one gets
2
3
1
So, it appears that a copy of the object is being made by
register_shutdown_function().
Tad
------------------------------------------------------------------------
[2002-11-04 03:47:39] vincent dot planchenault at atempo dot com
Using this small PHP code :
<?php
class Referenced
{
private $m_references=0;
function __construct()
{
}
function ref()
{
$this->m_references++;
}
function unref()
{
$this->m_references--;
}
function __destruct()
{
echo 'in Referenced Destructor...<br>';
echo "references = ".$this->m_references."<br>";
echo 'out of Referenced Destructor<br>';
}
}
class Referencer
{
private $m_ref;
function __construct($t)
{
$this->m_ref = $t;
$t->ref();
}
function __destruct()
{
echo "in Referencer Destructor...<br>";
$this->m_ref->unref();
echo "out of Referencer Destructor<br>";
}
}
$t = new Referenced();
echo 'instanciating first Referencer object...<br>';
$a = new Referencer($t);
echo 'instanciating second Referencer object...<br>';
$b = new Referencer($t);
echo 'deleting first Referencer object...<br>';
unset($a);
echo '<b>terminating</b><br>';
?>
I expected PHP to call unref() on Referenced object for the second
Referencer instance in the Referencer destructor, and then let
Referenced object be freed. This simulated output correspond to this
expectation :
instanciating first Referencer object...
instanciating second Referencer object...
deleting first Referencer object...
in Referencer Destructor...
out of Referencer Destructor
terminating
in Referencer Destructor
out of Referencer Destructor
in Referenced Destructor...
references = 0
out of Referenced Destructor...
PHP gave me this output :
instanciating first Referencer object...
instanciating second Referencer object...
deleting first Referencer object...
in Referencer Destructor...
out of Referencer Destructor
terminating
in Referenced Destructor...
references = 1
out of Referenced Destructor
in Referencer Destructor...
Fatal error: Trying to access invalid object in <blablabla>/test.php on
line 42
It seems that object instances are freed BEFORE the call of the object
destructor; I think object variables have to be freed after the
destructor call...
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=20240&edit=1