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Bug #36672 Function Call in IF ( ) with empty code block causes memory leak
Submitted: 2006-03-09 16:01 UTC Modified: 2006-03-17 01:00 UTC
Votes:3
Avg. Score:3.7 ± 0.9
Reproduced:3 of 3 (100.0%)
Same Version:1 (33.3%)
Same OS:1 (33.3%)
From: treehousetim at gmail dot com Assigned:
Status: No Feedback Package: Scripting Engine problem
PHP Version: 5.1.2 OS: Windows
Private report: No CVE-ID: None
View Developer Edit
 [2006-03-09 16:01 UTC] treehousetim at gmail dot com 
Description:
------------
Empty if that calls a function that returns a value causes php to consume huge amounts of memory (at least under windows)

This was tested using CLI

Reproduce code:
---------------
function testIt()
{
return true;
}

for ( $ix = 0; $ix < 200000; $ix++ )
{
    echo "Jere is the Memory King $ix" . NL;

    if ( testIt() )
    {
    }
}




Expected result:
----------------
php's memory usage to remain somewhat stable.

Actual result:
--------------
php's memory usage goes up at the rate of about one meg per second while this script is running.

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2006-03-09 20:44 UTC] mike@php.net 
Please try using this CVS snapshot:

  http://snaps.php.net/php5.1-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.1-win32-latest.zip

Not reproducible on Linux.
 [2006-03-17 01:00 UTC] php-bugs at lists dot php dot net 
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
 [2009-09-28 06:57 UTC] intersect at gmail dot com 
Exists on 5.2.4 on Linux.
Reproduce with the following code:

$ cat TestMem.php
<?php
$counter=0;

echo "Loop that does something..\n";
for($c=0;$c<1000000;$c++) {
	if(MyFunc()) {
		echo ".";
	}
}

echo "\nLoop that does nothing..\n";
$counter=0;
for($c=0;$c<1000000;$c++) {
	if(MyFunc()) {
	}
}

function MyFunc() {
	global $counter;
	if(($counter % 100000) === 0) {
		echo "$counter:" . memory_get_usage() . "\n";
	}
	$counter++;
	return(false);
}

?>


Results:
$ php TestMem.php 
Loop that does something..
0:58216
100000:58216
200000:58256
300000:58256
400000:58256
500000:58256
600000:58256
700000:58256
800000:58256
900000:58256

Loop that does nothing..
0:58256
100000:4058244
200000:8058244
300000:12058244
400000:16058244
500000:20058244
600000:24058244
700000:28058244
800000:32058244
900000:36058244

Note that memory leak results are identical if a 'slightly' non-empty loop (ie: if($blah) { 1; } ) is included instead.

Leigh.
 
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