Bug #61505 [Com]: Wrong destructors order
Edit report at https://bugs.php.net/bug.php?id=61505&edit=1
ID: 61505
Comment by: enelar at develop-project dot ru
Reported by: enelar at develop-project dot ru
Summary: Wrong destructors order
Status: Not a bug
Type: Bug
Package: Class/Object related
Operating System: Ubuntu
PHP Version: 5.3.10
Block user comment: N
Private report: N
New Comment:
--Your case is completly different, as $world and $human do not reference
each other. They're independent objects. $human is NOT part of $world
just
because you named the variables like that. Hence there is no reason to think
that there should be any particular order of destruction.
Yep... Its just example, why i think its wrong..
Call they '$a' and '$b'. Dont think that i am stupid like that, annoying.
I am a '$god', first of all, i created a '$sky', then
'$land_under_the_sky'.
And i want, that last of all will be '$sky', not the
'$land_under_the_sky_when_sky_isnt_exsiting'.
Now its clear?
Previous Comments:
------------------------------------------------------------------------
[2012-03-27 05:34:41] phpmpan at mpan dot pl
Actually in C++ construction and destruction order of global objects is not deterministic too*. If
you believed it is deterministic and based your code behaviour on this belief, you have some broken
code now. Also I know no modern GC language that cares about destruction order of unrelated objects.
This issue is not important in object-oriented environment.
____
* The order is defined only for a single compilation unit.
On application level it is undefined and often leads
to errors in code written by coders unaware of this issue.
------------------------------------------------------------------------
[2012-03-26 20:38:40] enelar at develop-project dot ru
"Destructor order is not guaranteed to be deterministic."
Could you please add that in documentation?
And one more "Destructors in php not like other destructors in the world. Its just
laggy coded duct tape, for OOP label on language. Dont use them in C++ style, its
wrong."
------------------------------------------------------------------------
[2012-03-26 05:31:27] aharvey@php.net
Destructor order is not guaranteed to be deterministic.
------------------------------------------------------------------------
[2012-03-26 03:52:58] phpmpan at mpan dot pl
This is not related to bug36759. 36759 is about destroying referenced object before referencing one
even when circular dependency is not present.
Your case is completly different, as $world and $human do not reference
each other. They're independent objects. $human is NOT part of $world
just because you named the variables like that. Hence there is no reason to think that there should
be any particular order of destruction.
------------------------------------------------------------------------
[2012-03-26 01:07:43] enelar at develop-project dot ru
Description:
------------
followed: https://bugs.php.net/bug.php?id=36759
They told that fixed in 5.2*, but its wrong! Reprodused in 5.3.2
Destructors on allocated objects should be called in reverse order:
$a = new world();
$b = new human();
== Shold be called as:
world->__construct();
human->__construct();
human->__destruct();
world->__destruct();
== Now its calling as:
world->__construct();
human->__construct();
world->__destruct(); // now people, cars and other exists without world. wtf??
human->__destruct();
== Why i think current way its wrong:
When we creating object $b, we expecting that object $a exists. And while
lifetime $b, object $a should be exist. Even $b dying, $a should be exists.
We expect in $a that $b may be not exist, but we should`t check in all methods
of $b 'is $a exist'.
Destructor its not exception and should be executed right.
== Some simular reports:
https://bugs.php.net/bug.php?id=38572
https://bugs.php.net/bug.php?id=29032 (if we
imagine that $SESSION = new
bla_bla(), before our code)
Test script:
---------------
class screen
{
public $screen;
public function __construct()
{
echo "screen construct<br>";
$text->screen = "";
}
public function Write( $text )
{
echo "writed to screen $text<br>";
$this->screen .= $text;
}
public function __destruct()
{
echo "screen destruct<br>";
echo $this->screen;
}
}
$A = new screen();
class dummy
{
public function __constuct()
{
echo "dummy constuct<br>";
}
public function __destuct()
{
echo "dummy destruct<br>";
global $A;
$A->Write("Dummy: I`m dying!<br>");
// or $A->DoVeryImportantActionBeforeDie($bla, $bla1);
}
}
$B = new dummy();
Expected result:
----------------
screen construct
dummy constuct
writed to screen Dummy: I`m dying!
screen destruct
Dummy: I`m dying!
Actual result:
--------------
screen construct
dummy constuct
screen destruct
Fatal error: Call to a member function Write() on a non-object in ...
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=61505&edit=1
Thread (6 messages)