WebSVN - shark - Blame - Rev 38 - /shark/trunk/include/modules/rm.h

Rev	Author	Line No.	Line
2	pj	1	/*
		2	* Project: S.Ha.R.K.
		3	*
		4	* Coordinators:
		5	* Giorgio Buttazzo <giorgio@sssup.it>
		6	* Paolo Gai <pj@gandalf.sssup.it>
		7	*
		8	* Authors :
		9	* Paolo Gai <pj@gandalf.sssup.it>
		10	* Massimiliano Giorgi <massy@gandalf.sssup.it>
		11	* Luca Abeni <luca@gandalf.sssup.it>
		12	* (see the web pages for full authors list)
		13	*
		14	* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
		15	*
		16	* http://www.sssup.it
		17	* http://retis.sssup.it
		18	* http://shark.sssup.it
		19	*/
		20
		21
		22	/**
		23	------------
38	pj	24	CVS : $Id: rm.h,v 1.2 2003-01-07 17:12:20 pj Exp $
2	pj	25
		26	File: $File$
38	pj	27	Revision: $Revision: 1.2 $
		28	Last update: $Date: 2003-01-07 17:12:20 $
2	pj	29	------------
		30
		31	This file contains the scheduling module RM (Rate Monotonic)
		32
		33	Title:
		34	RM (Rate Monotonic
		35
		36	Task Models Accepted:
		37	HARD_TASK_MODEL - Hard Tasks (Periodic and Sporadic)
		38	wcet field and mit field must be != 0. They are used to set the wcet
		39	and period of the tasks.
		40	periodicity field can be either PERIODIC or APERIODIC
		41	drel field is ignored
		42
		43	Guest Models Accepted:
		44	JOB_TASK_MODEL - a single guest task activation
		45	Identified by an absolute deadline and a period.
		46	all fieds are used
		47
		48	Description:
		49	This module schedule his tasks following the classic RM scheme.
		50	The task guarantee is based on the factor utilization approach.
		51	The tasks scheduled are periodic and sporadic. The sporadic tasks
		52	are like hard task with periodicity set to APERIODIC; they are guaranteed
		53	as a periodic task with period equal to the minimum interarrival time.
		54	All the task are put in a queue and the scheduling is based on the
		55	deadline value.
		56	NO GUARANTEE is performed on guest tasks. The guarantee must be performed
		57	by the level that inserts guest tasks in the EDF level.
		58
		59	Exceptions raised:
		60	XUNVALID_GUEST
		61	This level doesn't support guests. When a guest operation
		62	is called, the exception is raised.
		63
		64	These exceptions are pclass-dependent...
		65	XDEADLINE_MISS
		66	If a task miss his deadline, the exception is raised.
		67
		68	XWCET_VIOLATION
		69	If a task doesn't end the current cycle before if consume the wcet,
		70	an exception is raised, and the task is put in the RM_WCET_VIOLATED
		71	state. To reactivate it, use RM_task_activate via task_activate or
		72	manage directly the RM data structure. Note that the exception is not
		73	handled properly, an XDEADLINE_MISS exeception will also be raised at
		74	the period end...
		75
		76	XACTIVATION
		77	If a sporadic task is activated with a rate that is greather than the
		78	rate declared in the model, this exception is raised and the task is NOT
		79	activated.
		80	This exception is also raised if we are trying to activate a periodic task
		81	stopped with task_sleep before the deadline in which the task_sleep is
		82	called.
		83
		84	Restrictions & special features:
		85	- This level doesn't manage the main task.
		86	- At init time we can choose if the level have to activate
		87	. the wcet check
		88	(If a task require more time than declared, it is stopped and put in
		89	the state RM_WCET_VIOLATED; a XWCET_VIOLATION exception is raised)
		90	. the task guarantee algorithm
		91	(when all task are created the system will check that the task_set
		92	will not use more than the available bandwidth)
		93	- The level use the priority field.
		94	- A function to return the used bandwidth of a level is provided.
		95
		96	**/
		97
		98	/*
		99	* Copyright (C) 2000 Paolo Gai
		100	*
		101	* This program is free software; you can redistribute it and/or modify
		102	* it under the terms of the GNU General Public License as published by
		103	* the Free Software Foundation; either version 2 of the License, or
		104	* (at your option) any later version.
		105	*
		106	* This program is distributed in the hope that it will be useful,
		107	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		108	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		109	* GNU General Public License for more details.
		110	*
		111	* You should have received a copy of the GNU General Public License
		112	* along with this program; if not, write to the Free Software
		113	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		114	*
		115	*/
		116
		117
		118	#ifndef __RM_H__
		119	#define __RM_H__
		120
		121	#include <ll/ll.h>
		122	#include <kernel/config.h>
		123	#include <sys/types.h>
		124	#include <kernel/types.h>
		125
		126	/+ 1 - ln(2) +/
		127
		128	#ifndef RM_MINFREEBANDWIDTH
		129	#define RM_MINFREEBANDWIDTH 1317922825
		130	#endif
		131
		132
		133
		134	/+ flags... +/
		135	#define RM_DISABLE_ALL 0
		136	#define RM_ENABLE_WCET_CHECK 1 /+ Wcet check enabled +/
		137	#define RM_ENABLE_GUARANTEE 2 /+ Task Guarantee enabled +/
		138	#define RM_ENABLE_ALL 3 /+ All flags enabled +/
		139
		140	#define RM_FAILED_GUARANTEE 8 /*+ used in the module, unsettable
		141	in RM_register_level... +*/
		142
		143
		144	/*+ Registration function:
38	pj	145	int flag Options to be used in this level instance...
2	pj	146
38	pj	147	returns the level number at which the module has been registered.
		148	+*/
		149	LEVEL RM_register_level(int flag);
		150
2	pj	151	/+ Returns the used bandwidth of a level +/
		152	bandwidth_t RM_usedbandwidth(LEVEL l);
		153
		154	#endif

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