#18800 [NEW]: PHP crashes on cleaning up COM objects
| From: | mlorenz at novadys dot de | Date: | Thu, 08 Aug 2002 09:45:19 +0000 |
| Subject: | #18800 [NEW]: PHP crashes on cleaning up COM objects | ||
| Groups: | php.bugs | ||
| Request: | Send a blank email to php-bugs+get-16243@lists.php.net to get a copy of this message | ||
From: mlorenz@novadys.de
Operating system: Windows2000 Professional
PHP version: 4.2.2
PHP Bug Type: COM related
Bug description: PHP crashes on cleaning up COM objects
It seems that php has a problem cleaning up COM object references. I wrote
a litte COM server and the following script that demonstrates the
problem.
<?php
$myA = new COM("PHPTest.A.1") or die("Cannot create A");
$myB = $myA->GetB();
// myA creates a B object and returns a pointer to it.
// It does not store the pointer itself.
$myA->Release();
$myC = new COM("PHPTest.C.1") or die("Cannot create C");
$myC->B = $myB;
// myC stores the pointer to the B object and AddRefs it.
// It releases the pointer on destruction.
$myC->Release();
$myB->Release();
?>
After executing the script PHP crashes on cleanup.
I did a little debugging and found the following.
There is a function php_COM_release in ext/com/COM.c
that is called on every ...->Release call.
During execution of the script all objects are deleted
as expected. A look at the watch window shows me a
structure called 'obj' that contains a field named 'resourceindex' the
values are
1 for the A object
3 for the C object
2 for the B object
After destroying these objects the COM server is going down as expected
because there are no more living objects.
When PHP is cleaning up, it crashes in the same function
trying to realease an object with the 'resourceindex' 4.
Here is the call stack:
php_COM_release(comval_ * 0x00dbd1f8, void * * * 0x00da2ad0) line 231 + 17
bytes
php_COM_destruct(comval_ * 0x00dbd1f8, void * * * 0x00da2ad0) line 363 +
13 bytes
php_comval_destructor(_zend_rsrc_list_entry * 0x00dbd3b0, void * * *
0x00da2ad0) line 373 + 15 bytes
list_entry_destructor(void * 0x00dbd3b0) line 177 + 16 bytes
zend_hash_apply_deleter(_hashtable * 0x00da8a34, bucket * 0x00dbd340) line
596 + 15 bytes
zend_hash_graceful_reverse_destroy(_hashtable * 0x00da8a34) line 662 + 13
bytes
zend_destroy_rsrc_list(_hashtable * 0x00da8a34, void * * * 0x00da2ad0)
line 233 + 9 bytes
shutdown_executor(void * * * 0x00da2ad0) line 196 + 30 bytes
zend_deactivate(void * * * 0x00da2ad0) line 596 + 9 bytes
php_request_shutdown(void * 0x00000000) line 787 + 9 bytes
main(int 0x00000002, char * * 0x00da25d0) line 827 + 8 bytes
mainCRTStartup() line 338 + 17 bytes
KERNEL32! 77e87d08()
The line where the crash happens is:
hr = C_DISPATCH_VT(obj)->Release(C_DISPATCH(obj));
Best regards
Michael
--
Edit bug report at http://bugs.php.net/?id=18800&edit=1
--
Fixed in CVS: http://bugs.php.net/fix.php?id=18800&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=18800&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=18800&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=18800&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=18800&r=support
Expected behavior: http://bugs.php.net/fix.php?id=18800&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=18800&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=18800&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=18800&r=globals