------------------------------------------------------------------------------ ------------------------------------------------------------------------------ -- 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 systems; use systems; with ada.tags; use ada.tags; with text_io; use text_io; with Debug; use Debug; package body Scheduler.Dynamic_Priority.Edf is procedure Initialize (A_Scheduler : in out Edf_Scheduler) is begin Reset (A_Scheduler); A_Scheduler.parameters.scheduler_type := Earliest_Deadline_First_Protocol; end Initialize; function Copy (A_Scheduler : in Edf_Scheduler) return Generic_Scheduler_Ptr is Ptr : Edf_Scheduler_Ptr; begin Ptr := new Edf_Scheduler; Ptr.parameters := A_Scheduler.parameters; Ptr.Previously_Elected := A_Scheduler.Previously_Elected; return Generic_Scheduler_Ptr (Ptr); end Copy; procedure Do_Election (My_Scheduler : in out Edf_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 Smallest_Deadline : Natural := Natural'Last; I : Tasks_Range := 0; is_ready : boolean := false; previous_task_can_be_run : boolean :=false; begin Put_Debug("Call Do_Election: EDF"); loop if (Si.Tcbs (I).Tsk.cpu_name = Processor_Name) then Dynamic_Priority_Tcb_ptr (Si.Tcbs (i)).Dynamic_Deadline := Si.Tcbs (i).wake_up_time + Si.Tcbs (i).Tsk.deadline; end if; if not Si.Tcbs (i).already_run_at_current_time then if (Si.Tcbs (I).Tsk.cpu_name = Processor_Name) then if Check_Core_Assignment(my_scheduler, Si.Tcbs (I)) then if (Si.Tcbs (I).Wake_Up_Time <= Current_Time) and (Si.Tcbs (I).Rest_Of_Capacity /= 0) then if With_Resources then Check_Resource (My_Scheduler, Si, Result, Current_Time, Si.Tcbs (I), is_ready, Event_To_Generate); else is_ready:=true; end if; if is_ready then Check_jitter(Si.Tcbs (I), Current_Time, Si.Tcbs(I).is_jitter_ready ); if (With_jitters = False) or (Si.Tcbs (I).is_jitter_ready) then if (With_Offsets = False) or Check_Offset (Si.Tcbs (I), Current_Time) then if (With_Precedencies = False) or Check_Precedencies (Si, My_Dependencies, Current_Time, Si.Tcbs (I)) then if i = my_scheduler.previously_elected then previous_task_can_be_run:=true; end if; if (Dynamic_Priority_Tcb_Ptr (Si.Tcbs (I)).Dynamic_Deadline < Smallest_Deadline) then Smallest_Deadline := Dynamic_Priority_Tcb_Ptr (Si.Tcbs (I)).Dynamic_Deadline; Elected := I; end if; end if; end if; end if; end if; end if; end if; end if; end if; I := I + 1; exit when Si.Tcbs (I) = null; end loop; if Smallest_Deadline = Natural'Last then No_Task := True; else No_Task := False; end if; -- By default, as task are sorted in the set according to their name -- when we have two tasks with the same absolute deadline, we choose the first one -- in the task set, i.e. the task with the smallest name. -- This strategy can be useful has it provides a simple mean to introduce a -- tie break as a kind of fixed priority. -- However, it may introduce an extra preemption. -- If we want to reduce preemption number as much as possible, in this case -- we select the previous task ... in this task can be run again ! -- if with_minimize_preemption and previous_task_can_be_run then if Dynamic_Priority_Tcb_ptr (Si.Tcbs (my_scheduler.previously_elected)).Dynamic_Deadline = Smallest_Deadline then elected := my_scheduler.previously_elected; Put_Debug("Call Do_Election: EDF : Minimize preemption"); end if; end if; Put_Debug("Call Do_Election: EDF : Elected : " & Elected'Img); end Do_Election; end Scheduler.Dynamic_Priority.Edf;