cron.php

<?php
// This file is part of Moodle - https://moodle.org
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * NOTICE OF COPYRIGHT
 *
 *                      Online Judge for Moodle
 *        https://github.com/hit-moodle/moodle-local_onlinejudge
 *
 * Copyright (C) 2009 onwards
 *                      Sun Zhigang  http://sunner.cn
 *                      Andrew Naguib <andrew at fci helwan edu eg>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details:
 *
 *          http://www.gnu.org/copyleft/gpl.html
 */

/**
 * Online Judge cron job
 *
 * @package   local_onlinejudge
 * @copyright 2011 Sun Zhigang (http://sunner.cn)
 * @author    Sun Zhigang
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die();

require_once('judgelib.php');

mtrace('Starting online judge cron');
// Nofity admin if judged is not running
$a = new stdClass();
$a->count = $DB->count_records('onlinejudge_tasks', array('status' => ONLINEJUDGE_STATUS_PENDING));
if ($a->count > 0) {
    $oldestunjudged = $DB->get_records('onlinejudge_tasks', array('status' => ONLINEJUDGE_STATUS_PENDING), 'submittime ASC', 'submittime', 0, 1);
    $pendingperiod = time() - reset($oldestunjudged)->submittime;
    $a->period = format_time($pendingperiod);

    // if there is at least one task has been keeping unjudged in queue for more than 5 mins
    if ($pendingperiod > 5 * 60) {
        mtrace("    Found $a->count long time pending tasks.");

        if ($users = get_users_from_config(get_config('local_onlinejudge', 'judgedcrashnotify'), 'moodle/site:config')) {
            $admin = get_admin();
            foreach ($users as $user) {
                $eventdata = new stdClass();
                $eventdata->component = 'local_onlinejudge';
                $eventdata->name = 'judgedcrashed';
                $eventdata->userfrom = $admin;
                $eventdata->userto = $user;
                $eventdata->subject = get_string('judgednotifysubject', 'local_onlinejudge', $a);
                $eventdata->fullmessage = get_string('judgednotifybody', 'local_onlinejudge', $a);
                $eventdata->fullmessageformat = FORMAT_PLAIN;
                $eventdata->fullmessagehtml = '';
                $eventdata->smallmessage = '';
                $eventdata->notification = 1;
                message_send($eventdata);
                mtrace('    Sent notification to ' . fullname($user));
            }
        }
    }
}

mtrace('Finished online judge cron');