------------------------------------------------------------------------------ ------------------------------------------------------------------------------ -- 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; package scheduler.fixed_priority is type fixed_priority_scheduler is abstract new generic_scheduler with private; type fixed_priority_scheduler_ptr is access all fixed_priority_scheduler'class; type fixed_priority_tcb is new tcb with record -- With fixed priority, task priority may change due to resource accesses -- This attribute stores the current task priorities taking care of resource accesses current_priority : priority_range; -- Store if a task is allowed to run because of its resource access requirement, i.e. does -- the task would be blocked now due to lock resources ?? is_resource_ready : Boolean; end record; type fixed_priority_tcb_ptr is access all fixed_priority_tcb'class; procedure initialize (a_tcb : in out fixed_priority_tcb); ---------------------------------------- type fixed_priority_resource is new shared_resource with record priority_ceiling : priority_range; end record; type fixed_priority_resource_ptr is access all fixed_priority_resource'class; -------------------------------------------------------------------------------------------------------------------------------------------- -- This text is a summary of the blocking and priority inheritance implemented in this package -------------------------------------------------------------------------------------------------------------------------------------------- -- Protocol | Conditions to allocate | action when requesting | action on allocate | action on release -- | | task is blocked on | | -- | | allocation request | | -------------------------------------------------------------------------------------------------------------------------------------------- -- no_protocol | resource.state>0 | | resource.state-- | resource.state++ -------------------------------------------------------------------------------------------------------------------------------------------- -- PIP | | task in critical section | | task leaving -- | | inherits requesting task | | resource -- | | priority | | gets its initial priority -- | resource.state>0 | | resource.state-- | resource.state++ -------------------------------------------------------------------------------------------------------------------------------------------- -- IPCP | resource.state>0 | | resource.state-- | resource.state++ -- | | | | -- | | | requestion task priority = max (static priority, -- | | | ceiling priority of all allocated resources) -------------------------------------------------------------------------------------------------------------------------------------------- -- PCP | resource.state>0 AND | task in critical section | | task leaving -- | priority of requesting task is | inherits requesting task | | resource -- | greater than all priority ceiling| priority | | gets its initial priority -- | of resource that are allocated | | | -- | by other tasks | | | -- | | | resource.state-- | resource.state++ -------------------------------------------------------------------------------------------------------------------------------------------- -- PPCP | resource.state>0 AND | task in critical section | | task leaving -- | priority of requesting task is | inherits requesting task | | resource -- | greater than all priority ceiling| priority | | gets its initial priority -- | of resources that are allocated | | | -- | by other tasks from the same pool| | | -- | (ie sharing resources either | | | -- | directly or indirectly wih the | | | -- | requesting task) | | resource.state-- | resource.state++ -------------------------------------------------------------------------------------------------------------------------------------------- function build_resource (my_scheduler : in fixed_priority_scheduler; a_resource : generic_resource_ptr) return shared_resource_ptr; function build_tcb (my_scheduler : in fixed_priority_scheduler; a_task : generic_task_ptr) return tcb_ptr; procedure do_election (my_scheduler : in out fixed_priority_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); procedure check_resource (my_scheduler : in out fixed_priority_scheduler; si : in out scheduling_information; result : in out scheduling_sequence_ptr; current_time : in Natural; a_tcb : in tcb_ptr; is_ready : out Boolean; event_to_generate : in time_unit_event_type_boolean_table); procedure allocate_resource (my_scheduler : in out fixed_priority_scheduler; si : in out scheduling_information; result : in out scheduling_sequence_ptr; current_time : in Natural; a_tcb : tcb_ptr; event_to_generate : in time_unit_event_type_boolean_table); procedure release_resource (my_scheduler : in out fixed_priority_scheduler; si : in out scheduling_information; result : in out scheduling_sequence_ptr; current_time : in Natural; a_tcb : tcb_ptr; event_to_generate : in time_unit_event_type_boolean_table); procedure specific_scheduler_initialization (my_scheduler : in out fixed_priority_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); procedure compute_ceiling_of_resources (my_scheduler : in out fixed_priority_scheduler; si : in out scheduling_information; processor_name : in Unbounded_String; address_space_name : in Unbounded_String; my_tasks : in out tasks_set; my_resources : in out resources_set); procedure dispatched_change_current_priority (my_scheduler : in out fixed_priority_scheduler; a_tcb : in fixed_priority_tcb_ptr; new_priority : priority_range); procedure change_current_priority (my_scheduler : in out fixed_priority_scheduler'class; a_tcb : in fixed_priority_tcb_ptr; new_priority : priority_range); procedure produce_running_task_event (my_scheduler : in fixed_priority_scheduler; a_task : in tcb_ptr; options : in scheduling_option; si : in scheduling_information; an_event : out time_unit_event_ptr); function export_xml_event_running_task (my_scheduler : in fixed_priority_scheduler; an_event : in time_unit_event_ptr) return Unbounded_String; private type fixed_priority_scheduler is abstract new generic_scheduler with record used_resource : Boolean := False; end record; end scheduler.fixed_priority;