Beispiel #1
0
Scheduler_Void_or_thread _Scheduler_EDF_Unblock(
  const Scheduler_Control *scheduler,
  Thread_Control          *the_thread
)
{
  Scheduler_EDF_Context *context;
  Scheduler_EDF_Node    *node;
  Priority_Control       priority;
  bool                   prepend_it;

  context = _Scheduler_EDF_Get_context( scheduler );
  node = _Scheduler_EDF_Thread_get_node( the_thread );
  priority = _Scheduler_Node_get_priority( &node->Base, &prepend_it );
  (void) prepend_it;

  node->current_priority = priority;
  _Scheduler_EDF_Enqueue( context, node, priority );

  /*
   *  If the thread that was unblocked is more important than the heir,
   *  then we have a new heir.  This may or may not result in a
   *  context switch.
   *
   *  Normal case:
   *    If the current thread is preemptible, then we need to do
   *    a context switch.
   *  Pseudo-ISR case:
   *    Even if the thread isn't preemptible, if the new heir is
   *    a pseudo-ISR system task, we need to do a context switch.
   */
  if ( priority < _Thread_Heir->current_priority ) {
    _Scheduler_Update_heir(
      the_thread,
      priority == ( SCHEDULER_EDF_PRIO_MSB | PRIORITY_PSEUDO_ISR )
    );
  }

  SCHEDULER_RETURN_VOID_OR_NULL;
}
Beispiel #2
0
void _Scheduler_CBS_Unblock(
  Scheduler_Control *scheduler,
  Thread_Control    *the_thread
)
{
  Scheduler_CBS_Per_thread *sched_info;
  Scheduler_CBS_Server *serv_info;
  Priority_Control new_priority;

  _Scheduler_EDF_Enqueue( scheduler, the_thread );
  /* TODO: flash critical section? */

  sched_info = (Scheduler_CBS_Per_thread *) the_thread->scheduler_info;
  serv_info = (Scheduler_CBS_Server *) sched_info->cbs_server;

  /*
   * Late unblock rule for deadline-driven tasks. The remaining time to
   * deadline must be sufficient to serve the remaining computation time
   * without increased utilization of this task. It might cause a deadline
   * miss of another task.
   */
  if (serv_info) {
    time_t deadline = serv_info->parameters.deadline;
    time_t budget = serv_info->parameters.budget;
    time_t deadline_left = the_thread->cpu_time_budget;
    time_t budget_left = the_thread->real_priority -
                           _Watchdog_Ticks_since_boot;

    if ( deadline*budget_left > budget*deadline_left ) {
      /* Put late unblocked task to background until the end of period. */
      new_priority = the_thread->Start.initial_priority;
      if ( the_thread->real_priority != new_priority )
        the_thread->real_priority = new_priority;
      if ( the_thread->current_priority != new_priority )
        _Thread_Change_priority(the_thread, new_priority, true);
    }
  }

  /*
   *  If the thread that was unblocked is more important than the heir,
   *  then we have a new heir.  This may or may not result in a
   *  context switch.
   *
   *  Normal case:
   *    If the current thread is preemptible, then we need to do
   *    a context switch.
   *  Pseudo-ISR case:
   *    Even if the thread isn't preemptible, if the new heir is
   *    a pseudo-ISR system task, we need to do a context switch.
   */
  if (
    _Scheduler_Is_priority_higher_than(
       scheduler,
       the_thread->current_priority,
       _Thread_Heir->current_priority
    )
  ) {
    _Thread_Heir = the_thread;
    if ( _Thread_Executing->is_preemptible ||
         the_thread->current_priority == 0 )
      _Thread_Dispatch_necessary = true;
  }
}
void _Scheduler_EDF_Enqueue_first(
  Thread_Control    *the_thread
)
{
  _Scheduler_EDF_Enqueue(the_thread);
}