// Must be called with lock held.

template <class ACE_SELECT_REACTOR_TOKEN> int
ACE_Select_Reactor_T<ACE_SELECT_REACTOR_TOKEN>::wait_for_multiple_events
  (ACE_Select_Reactor_Handle_Set &dispatch_set,
   ACE_Time_Value *max_wait_time)
{
  ACE_TRACE ("ACE_Select_Reactor_T::wait_for_multiple_events");
  ACE_Time_Value timer_buf (0);
  ACE_Time_Value *this_timeout = 0;

  int number_of_active_handles = this->any_ready (dispatch_set);

  // If there are any bits enabled in the <ready_set_> then we'll
  // handle those first, otherwise we'll block in <select>.

  if (number_of_active_handles == 0)
    {
      do
        {
          if (this->timer_queue_ == 0)
            return 0;

          this_timeout =
            this->timer_queue_->calculate_timeout (max_wait_time,
                                                   &timer_buf);
#ifdef ACE_WIN32
          // This arg is ignored on Windows and causes pointer
          // truncation warnings on 64-bit compiles.
          int const width = 0;
#else
          int const width = this->handler_rep_.max_handlep1 ();
#endif  /* ACE_WIN32 */

          dispatch_set.rd_mask_ = this->wait_set_.rd_mask_;
          dispatch_set.wr_mask_ = this->wait_set_.wr_mask_;
          dispatch_set.ex_mask_ = this->wait_set_.ex_mask_;
          number_of_active_handles = ACE_OS::select (width,
                                                     dispatch_set.rd_mask_,
                                                     dispatch_set.wr_mask_,
                                                     dispatch_set.ex_mask_,
                                                     this_timeout);
        }
      while (number_of_active_handles == -1 && this->handle_error () > 0);

      if (number_of_active_handles > 0)
        {
#if !defined (ACE_WIN32)
          // Resynchronize the fd_sets so their "max" is set properly.
          dispatch_set.rd_mask_.sync (this->handler_rep_.max_handlep1 ());
          dispatch_set.wr_mask_.sync (this->handler_rep_.max_handlep1 ());
          dispatch_set.ex_mask_.sync (this->handler_rep_.max_handlep1 ());
#endif /* ACE_WIN32 */
        }
      else if (number_of_active_handles == -1)
        {
          // Normally, select() will reset the bits in dispatch_set
          // so that only those filed descriptors that are ready will
          // have bits set.  However, when an error occurs, the bit
          // set remains as it was when the select call was first made.
          // Thus, we now have a dispatch_set that has every file
          // descriptor that was originally waited for, which is not
          // correct.  We must clear all the bit sets because we
          // have no idea if any of the file descriptors is ready.
          //
          // NOTE: We dont have a test case to reproduce this
          // problem. But pleae dont ignore this and remove it off.
          dispatch_set.rd_mask_.reset ();
          dispatch_set.wr_mask_.reset ();
          dispatch_set.ex_mask_.reset ();
        }
    }

  // Return the number of events to dispatch.
  return number_of_active_handles;
}

template <class ACE_SELECT_REACTOR_TOKEN> int
ACE_Select_Reactor_T<ACE_SELECT_REACTOR_TOKEN>::dispatch
  (int active_handle_count,
   ACE_Select_Reactor_Handle_Set &dispatch_set)
{
  ACE_TRACE ("ACE_Select_Reactor_T::dispatch");

  int io_handlers_dispatched = 0;
  int other_handlers_dispatched = 0;
  int signal_occurred = 0;
  // The following do/while loop keeps dispatching as long as there
  // are still active handles.  Note that the only way we should ever
  // iterate more than once through this loop is if signals occur
  // while we're dispatching other handlers.

  do
    {
      // We expect that the loop will decrease the number of active
      // handles in each iteration.  If it does not, then something is
      // inconsistent in the state of the Reactor and we should avoid
      // the loop.  Please read the comments on bug 2540 for more
      // details.
      int initial_handle_count = active_handle_count;

      // Note that we keep track of changes to our state.  If any of
      // the dispatch_*() methods below return -1 it means that the
      // <wait_set_> state has changed as the result of an
      // <ACE_Event_Handler> being dispatched.  This means that we
      // need to bail out and rerun the select() loop since our
      // existing notion of handles in <dispatch_set> may no longer be
      // correct.
      //
      // In the beginning, our state starts out unchanged.  After
      // every iteration (i.e., due to signals), our state starts out
      // unchanged again.

      this->state_changed_ = false;

      // Perform the Template Method for dispatching all the handlers.

      // First check for interrupts.
      if (active_handle_count == -1)
        {
          // Bail out -- we got here since <select> was interrupted.
          if (ACE_Sig_Handler::sig_pending () != 0)
            {
              ACE_Sig_Handler::sig_pending (0);

              // If any HANDLES in the <ready_set_> are activated as a
              // result of signals they should be dispatched since
              // they may be time critical...
              active_handle_count = this->any_ready (dispatch_set);

              // Record the fact that the Reactor has dispatched a
              // handle_signal() method.  We need this to return the
              // appropriate count below.
              signal_occurred = 1;
            }
          else
            return -1;
        }

      // Handle timers early since they may have higher latency
      // constraints than I/O handlers.  Ideally, the order of
      // dispatching should be a strategy...
      else if (this->dispatch_timer_handlers (other_handlers_dispatched) == -1)
        // State has changed or timer queue has failed, exit loop.
        break;

      // Check to see if there are no more I/O handles left to
      // dispatch AFTER we've handled the timers...
      else if (active_handle_count == 0)
        return io_handlers_dispatched
          + other_handlers_dispatched
          + signal_occurred;

      // Next dispatch the notification handlers (if there are any to
      // dispatch).  These are required to handle multi-threads that
      // are trying to update the <Reactor>.

      else if (this->dispatch_notification_handlers
               (dispatch_set,
                active_handle_count,
                other_handlers_dispatched) == -1)
        // State has changed or a serious failure has occured, so exit
        // loop.
        break;

      // Finally, dispatch the I/O handlers.
      else if (this->dispatch_io_handlers
               (dispatch_set,
                active_handle_count,
                io_handlers_dispatched) == -1)
        // State has changed, so exit loop.
        break;

      // if state changed, we need to re-eval active_handle_count,
      // so we will not end with an endless loop
      if (initial_handle_count == active_handle_count
          || this->state_changed_)
      {
        active_handle_count = this->any_ready (dispatch_set);
      }
    }
  while (active_handle_count > 0);

  return io_handlers_dispatched + other_handlers_dispatched + signal_occurred;
}