1 common.inc backdrop_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.


core/includes/common.inc, line 6255
Common functions that many Backdrop modules will need to reference.


function backdrop_cron_run() {
  // Allow execution to continue even if the request gets canceled.

  // Prevent session information from being saved while cron is running.
  $original_session_saving = backdrop_save_session();

  // Force the current user to anonymous to ensure consistent permissions on
  // cron runs.
  $original_user = $GLOBALS['user'];
  $GLOBALS['user'] = backdrop_anonymous_user();

  // Try to allocate enough time to run all the hook_cron implementations.

  $return = FALSE;
  // Grab the defined cron queues.
  $queues = module_invoke_all('cron_queue_info');
  backdrop_alter('cron_queue_info', $queues);

  // Try to acquire cron lock.
  if (!lock_acquire('cron', 240.0)) {
    // 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) {

    // 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.
    state_set('cron_last', REQUEST_TIME);
    watchdog('cron', 'Cron run completed.', array(), WATCHDOG_NOTICE);

    // Release cron lock.

    // 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.
    $callback = $info['worker callback'];
    $end = time() + (isset($info['time']) ? $info['time'] : 15);
    $queue = BackdropQueue::get($queue_name);
    while (time() < $end && ($item = $queue->claimItem())) {
      try {
        call_user_func($callback, $item->data);
      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;

  return $return;