------------------------------------------------------------------------------ ------------------------------------------------------------------------------ -- 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) 2002-2023, Frank Singhoff, Alain Plantec, Jerome Legrand, -- Hai Nam Tran, Stephane Rubini -- -- The Cheddar project was started in 2002 by -- Frank Singhoff, Lab-STICC UMR 6285, 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 README.md -- -- 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 : -- $Rev$ -- $Date$ -- $Author: singhoff $ ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ with unbounded_strings; use unbounded_strings; with translate; use translate; package body scheduler.round_robin is procedure initialize (a_tcb : in out rr_tcb) is begin a_tcb.task_quantum := 0; end initialize; function build_tcb (my_scheduler : in round_robin_scheduler; a_task : generic_task_ptr) return tcb_ptr is a_tcb : rr_tcb_ptr; begin a_tcb := new rr_tcb; initialize (tcb (a_tcb.all), a_task); initialize (a_tcb.all); return tcb_ptr (a_tcb); end build_tcb; procedure initialize (a_scheduler : in out round_robin_scheduler) is begin reset (a_scheduler); a_scheduler.parameters.scheduler_type := round_robin_protocol; end initialize; function copy (a_scheduler : in round_robin_scheduler) return generic_scheduler_ptr is ptr : round_robin_scheduler_ptr; begin ptr := new round_robin_scheduler; ptr.parameters := a_scheduler.parameters; ptr.previously_elected := a_scheduler.previously_elected; return generic_scheduler_ptr (ptr); end copy; procedure put (my_scheduler : in round_robin_scheduler) is begin put (generic_scheduler (my_scheduler)); end put; procedure check_before_scheduling (my_scheduler : in round_robin_scheduler; my_tasks : in tasks_set; processor_name : in Unbounded_String) is begin null; end check_before_scheduling; procedure do_election (my_scheduler : in out round_robin_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; core_name : in Unbounded_String; options : in scheduling_option; event_to_generate : in time_unit_event_type_boolean_table; elected : in out tasks_range; no_task : in out Boolean) is -- find the ready task which is directly after the task "Elected" -- i : tasks_range := 0; has_a_ready_task : Boolean := False; first_task : tasks_range := 0; is_ready : Boolean := False; begin -- Before switching to the next task, first check that -- the task quantum is not exceeded. If the current task -- can be run .... chose it -- if (my_scheduler.parameters.quantum > 0) and (rr_tcb_ptr (si.tcbs (my_scheduler.previously_elected)).task_quantum /= 0) and (si.tcbs (my_scheduler.previously_elected).wake_up_time <= current_time) and (si.tcbs (my_scheduler.previously_elected).rest_of_capacity /= 0) and ((options.with_offsets = False) or check_offset (si.tcbs (i), current_time)) and ((options.with_precedencies = False) or check_precedencies (si, current_time, si.tcbs (my_scheduler.previously_elected))) then no_task := False; elected := my_scheduler.previously_elected; rr_tcb_ptr (si.tcbs (my_scheduler.previously_elected)).task_quantum := rr_tcb_ptr (si.tcbs (my_scheduler.previously_elected)) .task_quantum - 1; else -- Look for the next task -- if si.tcbs (my_scheduler.previously_elected + 1) = null then first_task := 0; else first_task := my_scheduler.previously_elected + 1; end if; i := first_task; loop 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 check_jitter (si.tcbs (i), current_time, si.tcbs (i).is_jitter_ready); if (options.with_jitters = False) or (si.tcbs (i).is_jitter_ready) then if (options.with_offsets = False) or check_offset (si.tcbs (i), current_time) then if (options.with_precedencies = False) or check_precedencies (si, current_time, si.tcbs (i)) then if options.with_resources then check_resource (my_scheduler, si, result, current_time, si.tcbs (i), is_ready, event_to_generate); if is_ready then elected := i; has_a_ready_task := True; if (my_scheduler.parameters.quantum > 0) then rr_tcb_ptr (si.tcbs (i)) .task_quantum := my_scheduler.parameters.quantum - 1; end if; exit; end if; end if; end if; end if; end if; end if; end if; end if; end if; i := i + 1; if si.tcbs (i) = null then i := 0; end if; exit when i = first_task; end loop; if has_a_ready_task then no_task := False; else no_task := True; end if; end if; end do_election; procedure specific_scheduler_initialization (my_scheduler : in out round_robin_scheduler; si : in out scheduling_information; processor_name : in Unbounded_String; address_space_name : in Unbounded_String; my_tasks : in out tasks_set; my_schedulers : in scheduler_table; my_resources : in out resources_set; my_buffers : in out buffers_set; my_messages : in messages_set; msg : in out Unbounded_String) is begin null; end specific_scheduler_initialization; procedure compute_activation_time (my_scheduler : in round_robin_scheduler; si : in out scheduling_information; elected : in tasks_range; value : in out Natural) is begin raise invalid_scheduler; end compute_activation_time; end scheduler.round_robin;