+ /**
+ * Optional; ping any running queue handler daemons with a notification
+ * such as announcing a new site to handle or requesting clean shutdown.
+ * This avoids having to restart all the daemons manually to update configs
+ * and such.
+ *
+ * Called from scripts/queuectl.php controller utility.
+ *
+ * @param string $event event key
+ * @param string $param optional parameter to append to key
+ * @return boolean success
+ */
+ public function sendControlSignal($event, $param='')
+ {
+ throw new Exception(get_class($this) . " does not support control signals.");
+ }
+