[PHP-BUG] Bug #60982 [NEW]: GC not called prior to memory exhausted error
From: Operating system: Linux PHP version: 5.4.0RC7 Package: Scripting Engine problem Bug Type: Bug Bug description:GC not called prior to memory exhausted error Description: This affects all versions of PHP. In a script that is about to run out of memory, gc_collect_cycles() should be called as this can sometimes prevent the script from running out of memory. Example: I have a non-blocking server I wrote in PHP. If there are several thousand connections, the script will run out of memory. However, if the exact same script with the exact same load (using apache benchmark) is run while calling gc_collect_cycles() every half second, there are no out-of-memory issues. Test script: --- The source code for PHP will reveal that garbage collection is not run as a last ditch effort to continue execution within the memory constraints specified by the user. Expected result: I expect PHP to run garbage collection when memory is nearly exhausted to prevent a memory error. Actual result: -- PHP will exhaust memory even when it is not necessary for it to exhaust memory. -- Edit bug report at https://bugs.php.net/bug.php?id=60982&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=60982&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=60982&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=60982&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=60982&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=60982&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=60982&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=60982&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=60982&r=needscript Try newer version: https://bugs.php.net/fix.php?id=60982&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=60982&r=support Expected behavior: https://bugs.php.net/fix.php?id=60982&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=60982&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=60982&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=60982&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=60982&r=php4 Daylight Savings:https://bugs.php.net/fix.php?id=60982&r=dst IIS Stability: https://bugs.php.net/fix.php?id=60982&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=60982&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=60982&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=60982&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=60982&r=mysqlcfg
[PHP-BUG] Bug #60983 [NEW]: Memory is not properly freed
From:
Operating system: all
PHP version: 5.4.0RC7
Package: Scripting Engine problem
Bug Type: Bug
Bug description:Memory is not properly freed
Description:
Memory is not being freed properly. In a short loop several megabytes are
lost that should not be lost. Attached is a test script to demonstrate what
I mean.
Test script:
---
$mem1 = memory_get_usage(true);
echo "MEM1: " . $mem1 . "\n";
class A {
public $class;
}
$c1 = $c2 = null;
for ($i = 0; $i < 2; $i++) {
$c1 = new A();
$c2 = new A();
$c1->class = array($c1, $c2);
$c2->class = array($c1, $c2);
}
unset($c1); unset($c2);
gc_collect_cycles();
$mem2 = memory_get_usage(true);
echo "MEM2: " . $mem2 . "\n";
echo "DIFF: " . ($mem2 - $mem1) . "\n";
Expected result:
I expect the memory difference to be 0. In this case it is several
megabytes.
Actual result:
--
MEM1: 4980736
MEM2: 7340032
DIFF: 2359296
The DIFF should be 0.
--
Edit bug report at https://bugs.php.net/bug.php?id=60983&edit=1
--
Try a snapshot (PHP 5.4):
https://bugs.php.net/fix.php?id=60983&r=trysnapshot54
Try a snapshot (PHP 5.3):
https://bugs.php.net/fix.php?id=60983&r=trysnapshot53
Try a snapshot (trunk):
https://bugs.php.net/fix.php?id=60983&r=trysnapshottrunk
Fixed in SVN:
https://bugs.php.net/fix.php?id=60983&r=fixed
Fixed in SVN and need be documented:
https://bugs.php.net/fix.php?id=60983&r=needdocs
Fixed in release:
https://bugs.php.net/fix.php?id=60983&r=alreadyfixed
Need backtrace:
https://bugs.php.net/fix.php?id=60983&r=needtrace
Need Reproduce Script:
https://bugs.php.net/fix.php?id=60983&r=needscript
Try newer version:
https://bugs.php.net/fix.php?id=60983&r=oldversion
Not developer issue:
https://bugs.php.net/fix.php?id=60983&r=support
Expected behavior:
https://bugs.php.net/fix.php?id=60983&r=notwrong
Not enough info:
https://bugs.php.net/fix.php?id=60983&r=notenoughinfo
Submitted twice:
https://bugs.php.net/fix.php?id=60983&r=submittedtwice
register_globals:
https://bugs.php.net/fix.php?id=60983&r=globals
PHP 4 support discontinued:
https://bugs.php.net/fix.php?id=60983&r=php4
Daylight Savings:https://bugs.php.net/fix.php?id=60983&r=dst
IIS Stability:
https://bugs.php.net/fix.php?id=60983&r=isapi
Install GNU Sed:
https://bugs.php.net/fix.php?id=60983&r=gnused
Floating point limitations:
https://bugs.php.net/fix.php?id=60983&r=float
No Zend Extensions:
https://bugs.php.net/fix.php?id=60983&r=nozend
MySQL Configuration Error:
https://bugs.php.net/fix.php?id=60983&r=mysqlcfg
Req #60024 [Com]: Do not keep last element treated by foreach referenced
Edit report at https://bugs.php.net/bug.php?id=60024&edit=1 ID: 60024 Comment by: DeveloperGuy2008 at yahoo dot com Reported by:chealer at gmail dot com Summary:Do not keep last element treated by foreach referenced Status: Open Type: Feature/Change Request Package:Scripting Engine problem PHP Version:5.3.8 Block user comment: N Private report: N New Comment: Please fix this. It creates a lot of hard to debug bugs. Previous Comments: [2011-10-09 21:09:19] chealer at gmail dot com Description: As explained on http://ca.php.net/manual/en/control-structures.foreach.php : Warning Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset(). In my opinion, PHP shouldn't keep the last element referenced by default, but at least, please provide a syntax which will not keep it. The current situations causes bugs like https://bugs.php.net/bug.php?id=49386 -- Edit this bug report at https://bugs.php.net/bug.php?id=60024&edit=1
Bug #60983 [Com]: Memory is not properly freed
Edit report at https://bugs.php.net/bug.php?id=60983&edit=1
ID: 60983
Comment by: DeveloperGuy2008 at yahoo dot com
Reported by:developerguy2008 at yahoo dot com
Summary:Memory is not properly freed
Status: Not a bug
Type: Bug
Package:Scripting Engine problem
Operating System: all
PHP Version:5.4.0RC7
Block user comment: N
Private report: N
New Comment:
Do you know any references where I may read about the object_store? Is there a
to shrink it (like a compile time flag) when it is does not need to be large?
It seems like the ideal result would be to shrink the object store. In this
example it is only a few megabytes but in other cases it could be several
hundred megabytes that essentially lost forever (at least to other processes).
Previous Comments:
[2012-02-06 07:46:59] larue...@php.net
the reason for there is mem diff is that, the EG(objects_store) could only be
grow but could not be shrunk.
if you tweak your test into:
$mem1 = memory_get_usage(true);
echo "MEM1: " . $mem1 . "\n";
class A {
public $class;
}
$c1 = $c2 = null;
for ($i = 0; $i < 2; $i++) {
$c1 = new A();
$c2 = new A();
$c1->class = array($c1, $c2);
$c2->class = array($c1, $c2);
gc_collect_cycles();
}
unset($c1); unset($c2);
$mem2 = memory_get_usage(true);
echo "MEM2: " . $mem2 . "\n";
echo "DIFF: " . ($mem2 - $mem1) . "\n";
you may understand my point
----------------
[2012-02-06 00:43:46] developerguy2008 at yahoo dot com
Description:
Memory is not being freed properly. In a short loop several megabytes are lost
that should not be lost. Attached is a test script to demonstrate what I mean.
Test script:
---
$mem1 = memory_get_usage(true);
echo "MEM1: " . $mem1 . "\n";
class A {
public $class;
}
$c1 = $c2 = null;
for ($i = 0; $i < 2; $i++) {
$c1 = new A();
$c2 = new A();
$c1->class = array($c1, $c2);
$c2->class = array($c1, $c2);
}
unset($c1); unset($c2);
gc_collect_cycles();
$mem2 = memory_get_usage(true);
echo "MEM2: " . $mem2 . "\n";
echo "DIFF: " . ($mem2 - $mem1) . "\n";
Expected result:
I expect the memory difference to be 0. In this case it is several megabytes.
Actual result:
--
MEM1: 4980736
MEM2: 7340032
DIFF: 2359296
The DIFF should be 0.
--
Edit this bug report at https://bugs.php.net/bug.php?id=60983&edit=1
