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mirror of https://github.com/phpbb/phpbb.git synced 2025-02-25 04:23:38 +01:00
2011-02-12 22:05:51 -05:00

81 lines
1.5 KiB
PHP

<?php
/**
*
* @package phpBB3
* @version $Id$
* @copyright (c) 2010 phpBB Group
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*
*/
/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
exit;
}
/**
* Cron lock class
* @package phpBB3
*/
class phpbb_cron_lock
{
private $cron_id;
public function lock()
{
global $config, $db;
if (!isset($config['cron_lock']))
{
set_config('cron_lock', '0', true);
}
// make sure cron doesn't run multiple times in parallel
if ($config['cron_lock'])
{
// if the other process is running more than an hour already we have to assume it
// aborted without cleaning the lock
$time = explode(' ', $config['cron_lock']);
$time = $time[0];
if ($time + 3600 >= time())
{
return false;
}
}
$this->cron_id = time() . ' ' . unique_id();
$sql = 'UPDATE ' . CONFIG_TABLE . "
SET config_value = '" . $db->sql_escape($this->cron_id) . "'
WHERE config_name = 'cron_lock' AND config_value = '" . $db->sql_escape($config['cron_lock']) . "'";
$db->sql_query($sql);
// another cron process altered the table between script start and UPDATE query so exit
if ($db->sql_affectedrows() != 1)
{
return false;
}
return true;
}
/**
* Releases cron lock.
*
* Attempting to release a cron lock that is already released is harmless.
*/
public function unlock()
{
global $db;
$sql = 'UPDATE ' . CONFIG_TABLE . "
SET config_value = '0'
WHERE config_name = 'cron_lock' AND config_value = '" . $db->sql_escape($this->cron_id) . "'";
$db->sql_query($sql);
}
}