function drupal_cron_run

Executes a cron run when called.

Do not call this function from a test. Use $this->cronRun() instead.

Return value

bool TRUE if cron ran successfully and FALSE if cron is already running.

File

includes/common.inc, line 5513

Code

function drupal_cron_run() {
    // Allow execution to continue even if the request gets canceled.
    @ignore_user_abort(TRUE);
    // Prevent session information from being saved while cron is running.
    $original_session_saving = drupal_save_session();
    drupal_save_session(FALSE);
    // Force the current user to anonymous to ensure consistent permissions on
    // cron runs.
    $original_user = $GLOBALS['user'];
    $GLOBALS['user'] = drupal_anonymous_user();
    // Try to allocate enough time to run all the hook_cron implementations.
    drupal_set_time_limit(240);
    $return = FALSE;
    // Grab the defined cron queues.
    $queues = module_invoke_all('cron_queue_info');
    drupal_alter('cron_queue_info', $queues);
    // Try to acquire cron lock.
    $cron_lock_expiration_timeout = variable_get('cron_lock_expiration_timeout', 900.0);
    if (!lock_acquire('cron', $cron_lock_expiration_timeout)) {
        // Cron is still running normally.
        watchdog('cron', 'Attempting to re-run cron while it is already running.', array(), WATCHDOG_WARNING);
    }
    else {
        // Make sure every queue exists. There is no harm in trying to recreate an
        // existing queue.
        foreach ($queues as $queue_name => $info) {
            DrupalQueue::get($queue_name)->createQueue();
        }
        // Iterate through the modules calling their cron handlers (if any):
        foreach (module_implements('cron') as $module) {
            // Do not let an exception thrown by one module disturb another.
            try {
                module_invoke($module, 'cron');
            } catch (Exception $e) {
                watchdog_exception('cron', $e);
            }
        }
        // Record cron time.
        variable_set('cron_last', REQUEST_TIME);
        watchdog('cron', 'Cron run completed.', array(), WATCHDOG_NOTICE);
        // Release cron lock.
        lock_release('cron');
        // Return TRUE so other functions can check if it did run successfully
        $return = TRUE;
    }
    foreach ($queues as $queue_name => $info) {
        if (!empty($info['skip on cron'])) {
            // Do not run if queue wants to skip.
            continue;
        }
        $callback = $info['worker callback'];
        $end = time() + (isset($info['time']) ? $info['time'] : 15);
        $queue = DrupalQueue::get($queue_name);
        while (time() < $end && ($item = $queue->claimItem())) {
            try {
                call_user_func($callback, $item->data);
                $queue->deleteItem($item);
            } catch (Exception $e) {
                // In case of exception log it and leave the item in the queue
                // to be processed again later.
                watchdog_exception('cron', $e);
            }
        }
    }
    // Restore the user.
    $GLOBALS['user'] = $original_user;
    drupal_save_session($original_session_saving);
    return $return;
}