#48541 [Opn->Csd]: spl_autoload_register only registers first closure, then leaks the others
ID: 48541
Updated by: cellog@php.net
Reported By: cellog@php.net
-Status: Open
+Status: Closed
Bug Type: SPL related
PHP Version: 5.3CVS-2009-06-13 (CVS)
-Assigned To:
+Assigned To: cellog
New Comment:
This bug has been fixed in CVS.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
fixed in HEAD and PHP_5_3
Previous Comments:
------------------------------------------------------------------------
[2009-06-13 06:09:09] cellog@php.net
Description:
------------
The test script below does not leak, but if $a were to successfully
load class "foo" (i.e. move the eval() in $b() into $a) it leaks memory
in zend_execute.c on line 723, which is the portion called when the
closure is assigned to $b.
This is caused by 2 separate bugs.
1) php_spl.c line 501 increases the refcount of the closure zval
2) php_spl.c line 511 checks to see if the function name has already
been registered, but treats all closures as if they were
"closure::__invoke" instead of using some unique aspect of each closure.
This then jumps to the end of spl_autoload_register without decreasing
the refcount, and boom, we have a memory leak.
I don't know anything about the closures implementation, so someone who
knows a better way to get a unique function name for a closure needs to
fix this, both the refcount and the only-one-closure-allowed issues.
Also, the memory leak is triggered by an important feature of Pyrus,
and yes, we are registering multiple closures as autoload callbacks to
implement a dynamic plugin system. It works great except for these two
bugs.
Reproduce code:
---------------
<?php
$a = function ($class) {
echo "a called\n";
};
$b = function ($class) {
eval('class ' . $class . '{}');
echo "b called\n";
};
spl_autoload_register($a);
spl_autoload_register($b);
$c = new foo;
Expected result:
----------------
a called
b called
Actual result:
--------------
a called
Fatal error: Class 'foo' not found in
/home/user/workspace/php5/test.php on line 11
Call Stack:
0.0005 345172 1. {main}()
/home/user/workspace/php5/test.php:0
------------------------------------------------------------------------
--
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