Transactions & Orphan MySQL connections

[eluser]jonsolo11[/eluser]
Hi,

I'm running CI (w/PHP 5 & MySQL 5) on an internal development server. When my DB stopped working, I noticed there were ~40 connections from my CI username, all asleep, and some had been open for 10+ hours.

After a little work, I isolated the bug:

Normally in PHP, if I start a transaction and then there's a PHP error, PHP rolls back the transaction and closes the connection before dying.

CI's error handler, however, does not properly close the connection - and furthermore, the transaction is still open, so all the tables are locked.

This code (inside a Model) will throw a PHP Fatal Error and leave a hanging connection:

Code:

$this->db->query("start transaction");
not_a_function();

This code (again in a Model) will die() and clean up after itself properly:

Code:

$this->db->query("start transaction");
die();

This code (in plain PHP, outside of CI) will throw a Fatal Error, but will clean up:

Code:

$conn = mysql_connect("localhost", $user, $password);
mysql_query("start transaction");
not_a_function();

This code will die(), and will clean up also:

Code:

$conn = mysql_connect("localhost", $user, $password);
mysql_query("start transaction");
die();

This is a serious problem: it renders CI transaction-unsafe. It's not too problematic on a debug server, but it could be disastrous on a production server, as it could instantly lock up my database.