------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Cheddar is a GNU GPL real-time scheduling analysis tool.
-- This program provides services to automatically check schedulability and
-- other performance criteria of real-time architecture models.
--
-- Copyright (C) 2002-2016, Frank Singhoff, Alain Plantec, Jerome Legrand
--
-- The Cheddar project was started in 2002 by 
-- Frank Singhoff, Lab-STICC UMR 6285 laboratory, Université de Bretagne Occidentale
-- 
-- Cheddar has been published in the "Agence de Protection des Programmes/France" in 2008. 
-- Since 2008, Ellidiss technologies also contributes to the development of 
-- Cheddar and provides industrial support.
--
-- The full list of contributors and sponsors can be found in AUTHORS.txt and SPONSORS.txt
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to the Free Software
-- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--
--
-- Contact : cheddar@listes.univ-brest.fr
--           
------------------------------------------------------------------------------
-- Last update : 
--    $Rev: 1249 $
--    $Date: 2014-08-28 07:02:15 +0200 (Fri, 28 Aug 2014) $
--    $Author: singhoff $
------------------------------------------------------------------------------
------------------------------------------------------------------------------

with Xml_Tag;                use Xml_Tag;
with double_util;            use double_util;
with Translate;              use Translate;
with unbounded_strings;      use unbounded_strings;
with Text_IO;                use Text_IO;
with Ada.Exceptions;         use Ada.Exceptions;
with GNAT.Current_Exception; use GNAT.Current_Exception;

package body Scheduler.Fixed_Priority.aperiodic_server.polling is

   procedure Initialize
     (A_Scheduler : in out polling_aperiodic_server_Scheduler)
   is
   begin
      Reset (A_Scheduler);
      A_Scheduler.parameters.scheduler_type :=
        hierarchical_polling_aperiodic_server_protocol;
   end Initialize;

   function Copy
     (A_Scheduler : in polling_aperiodic_server_Scheduler)
      return        Generic_Scheduler_Ptr
   is
      Ptr : polling_aperiodic_server_Scheduler_Ptr;

   begin

      Ptr := new polling_aperiodic_server_Scheduler;

      Ptr.parameters         := A_Scheduler.parameters;
      Ptr.Previously_Elected := A_Scheduler.Previously_Elected;
      Ptr.Used_Resource      := A_Scheduler.Used_Resource;

      return Generic_Scheduler_Ptr (Ptr);

   end Copy;
   
   procedure Do_Election
     (My_Scheduler       : in out polling_aperiodic_server_Scheduler;
      Si                 : in out Scheduling_Information;
      Result             : in out Scheduling_Sequence_Ptr;
      Msg                : in out Unbounded_String;
      Current_Time       : in Natural;
      Processor_Name     : in Unbounded_String;
      Address_Space_Name : in Unbounded_String;
      My_Dependencies    : in Tasks_Dependencies_Ptr;
      With_Offsets       : in Boolean;
      With_Precedencies  : in Boolean;
      With_Resources     : in Boolean;
      With_jitters     : in Boolean;
      With_minimize_preemption     : in Boolean;
      Event_To_Generate  : in Time_Unit_Event_Type_Boolean_Table;
      Elected            : in out Tasks_Range;
      No_Task            : in out Boolean)
   is

   begin

      Do_Election
        (aperiodic_server_Scheduler (My_Scheduler),
         Si,
         Result,
         Msg,
         Current_Time,
         Processor_Name,
         Address_Space_Name,
         My_Dependencies,
         With_Offsets,
         With_Precedencies,
         With_Resources,
        with_jitters,
        with_minimize_preemption,
         Event_To_Generate,
         Elected,
         No_Task);
		 
		-- Election : if Current_Time is within the server awake time limits
		-- we check if there are any aperiodic tasks to run
		-- if not the server falls back to sleep
		-- and only the periodic tasks are serviced until the next 
		-- server's awakening time
		--
		No_Task := True;
		if (Current_Time >= My_Scheduler.current_server_wake_time) and
			(Current_Time < My_Scheduler.current_server_wake_time + 
			My_Scheduler.parameters.capacity)
		then
			if (My_Scheduler.aperiodic_Highest_Priority /= Natural'First) and
				(My_Scheduler.parameters.priority > 
				Priority_Range(My_Scheduler.periodic_Highest_Priority))
			then
				No_Task := False;
				Elected := My_Scheduler.aperiodic_Elected;
			else 
				My_Scheduler.current_server_wake_time :=
					My_Scheduler.current_server_wake_time + My_Scheduler.parameters.period;
				if My_Scheduler.periodic_Highest_Priority /= Natural'First then
					No_Task := False;
					Elected := My_Scheduler.periodic_Elected;
				end if;
			end if;
		else
			if My_Scheduler.periodic_Highest_Priority /= Natural'First then
				No_Task := False;
				Elected := My_Scheduler.periodic_Elected;
			end if;
		end if;
		
		-- If the server exhausted all its capacity
		-- it goes back to sleep
		--
		if Current_Time = My_Scheduler.current_server_wake_time + 
			My_Scheduler.parameters.capacity
		then
			My_Scheduler.current_server_wake_time :=
				My_Scheduler.current_server_wake_time + My_Scheduler.parameters.period;
		end if;

   end Do_Election;

end Scheduler.Fixed_Priority.aperiodic_server.polling;