Bug #51648 [Com]: Memory leak in infinite loop
Edit report at http://bugs.php.net/bug.php?id=51648&edit=1
ID: 51648
Comment by: crrodriguez at opensuse dot org
Reported by: shooreek at gmail dot com
Summary: Memory leak in infinite loop
Status: Open
Type: Bug
Package: SQLite related
Operating System: WinXP SP3
PHP Version: 5.3.2
New Comment:
Cannot reproduce in linux, tell us if you have 3rd party extensions
installed as
well if you have modified php.ini.
maybe Pierre can check this one out..
Previous Comments:
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[2010-05-07 13:19:50] shooreek at gmail dot com
Pakage changed to SQLite related
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[2010-05-04 11:48:26] shooreek at gmail dot com
cbandy, you are right: with UPDATE or SELECT queries mem usage remains
constant. But with INSERT queries mem usage grows up. I discovered some
way to free this memory: you should unlink SQLite DB file and create new
one, because $db->close() is _not_ enough! May be there are another ways
to do it, but I do not know about their existence. May be someone
knows?
I think it real bug and it should be fixed. So, it is SQLite extension
related bug.
There is no such problem in Mysqli.
P.S. I first post I wrote that Mysqli have the same problem as SQLite.
My fault. The problem was in multiple calls mysqli_init() function. With
SELECT, UPDATE, INSERT or UPDATE commands Mysqli do not have memory
leaks. If memory leaks related with multiple mysqli_init() calls is a
bug, I can report it in separate. Just let me know.
Thank you for your attention.
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[2010-05-02 16:24:23] cbandy at jbandy dot com
Inserting an infinite number of rows could easily lead to mem usage
within SQLite (not PHP).
By executing only UPDATE in the loop, DB size should stay constant. Then
results should show PHP-SQLite execution leaks.
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[2010-04-24 18:43:44] felipe@php.net
I can't reproduce it on Linux.
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[2010-04-23 16:01:33] shooreek at gmail dot com
Description:
------------
Run PHP script with infinite loop from command line. Call each loop
database function from extension (I tested SQLite and Mysqli). Open task
manager. You will see that memory use is growing up, while PHP function
memory_get_usege() reports that memory usage is constant. The memory
usage may grow up to 1,5Gb or even more (depends on script code size),
even if memory_limit is set to 8Mb.
How is this possible?!
Test script:
---------------
<?php
$dbfile = 'mysqlitedb.db';
if(file_exists($dbfile)) unlink($dbfile);
$db = new SQLite3($dbfile);
$db->exec('CREATE TABLE foo (id INTEGER, bar varchar(30))');
$db->exec("INSERT INTO foo (id, bar) VALUES (1, 'This is a test')");
$i=0;
while(1)
{
$i++;
$db->exec("INSERT INTO foo (id, bar) VALUES ($i, 'This is a test')");
$db->exec("UPDATE foo SET bar='This is memory leak' WHERE id=$i");
echo "$i ".memory_get_usage()." ".memory_get_usage(true)."\r";
}
?>
Expected result:
----------------
Constant memory usage.
Actual result:
--------------
Memory usage grown up (script output):
iteration, memory_get_usage(), memory_get_usage(true), memory usage(from
taskmgr), virtual memory usage(from taskmgr)
2131 330384 524288 - 1068Kb 5356Kb
4661 330384 524288 - 1148Kb 5440Kb
10974 330384 524288 - 1336Kb 5652Kb
24985 330384 524288 - 1824Kb 6140Kb
43894 330384 524288 - 2516Kb 6828Kb
As you can see, memory usage is not constant. Why?!
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