From: modea at hush dot com
Operating system: Windows 2000 Server
PHP version: 4.3.2
PHP Bug Type: COM related
Bug description: Accessing ADO via COM results in rapid memory leak
Description:
------------
When using the COM interface to access MS SQL server via ADO (per client's
stringent requirements), we're finding that the PHP executable's memory
use is increasing very rapidly, quickly resulting in a failure to
instantiate any more COM.
The COM is being called iteratively to load the data 100 rows at a time,
so in some page loads the COM may be loaded and used up to 80 or 90 times.
As each pass completes, the ADO Connection and Recordset objects are
closed, and the local variables are unset().
We're finding that on our larger loads (the 80 to 90 COM loads), our
memory consumption is increasing by as much as 9MB, whereas we'd expect an
increase of nothing more than about 500k. If we swap the ADO with the
mssql_ libraries, the memory increase is as expected.
It takes about 40 such loads before COM fails to start. At that time, the
PHP executable occupies about 290MB of memory.
Reproduce code:
---------------
// simplified. this is called in a loop 80x or more.
$dbc = new COM("ADODB.Connection") or die ("Connection create failure");
$dbostr = "-connection details-";
$dbc->Open($dbostr);
$RSet=$dbc->Execute("querystring");
//code to process rows in RSet
$RSet->close;
$dbc->close;
unset($RSet);
unset($dbc);
Expected result:
----------------
Would expect the memory to be properly cleaned after calling the close
method for both objects and unset'ing the local variables. The final data
returned from this function is the same whether we use mssql_ or ADO, but
with ADO the PHP exe's memory utilization increases much to rapidly.
Actual result:
--------------
Memory increase depends on size of result set. With every 8,000-10,000
rows loaded, we usually lose about 10MB. Once we hit ~290MB, ADO no
longer instantiates, and we error out.
--
Edit bug report at http://bugs.php.net/?id=24442&edit=1
--
Try a CVS snapshot: http://bugs.php.net/fix.php?id=24442&r=trysnapshot
Fixed in CVS: http://bugs.php.net/fix.php?id=24442&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=24442&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=24442&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=24442&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=24442&r=support
Expected behavior: http://bugs.php.net/fix.php?id=24442&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=24442&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=24442&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=24442&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=24442&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=24442&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=24442&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=24442&r=gnused
