- * If one of these functions return a negative value via \a t->ret the
- * (optional) event_handler gets called (it may also be called in case another
- * event happened). In many cases the only possible event is an error or an eof
- * condition and the event handler simply unregisters the task from the
- * scheduler.
+ * If one of these functions sets \a t->error to a negative value, the
+ * task gets unregistered automatically.