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/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   Massimiliano Giorgi <massy@gandalf.sssup.it>

 *   Luca Abeni          <luca@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/**

 ------------

 CVS :        $Id: rm.h,v 1.1.1.1 2002-03-29 14:12:51 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.1.1.1 $

 Last update: $Date: 2002-03-29 14:12:51 $

 ------------

 This file contains the scheduling module RM (Rate Monotonic)

 Title:

   RM (Rate Monotonic

 Task Models Accepted:

   HARD_TASK_MODEL - Hard Tasks (Periodic and Sporadic)

     wcet field and mit field must be != 0. They are used to set the wcet

       and period of the tasks.

     periodicity field can be either PERIODIC or APERIODIC

     drel field is ignored

 Guest Models Accepted:

   JOB_TASK_MODEL - a single guest task activation

     Identified by an absolute deadline and a period.

     all fieds are used

 Description:

   This module schedule his tasks following the classic RM scheme.

   The task guarantee is based on the factor utilization approach.

   The tasks scheduled are periodic and sporadic. The sporadic tasks

   are like hard task with periodicity set to APERIODIC; they are guaranteed

   as a periodic task with period equal to the minimum interarrival time.

   All the task are put in a queue and the scheduling is based on the

   deadline value.

   NO GUARANTEE is performed on guest tasks. The guarantee must be performed

   by the level that inserts guest tasks in the EDF level.

 Exceptions raised:

   XUNVALID_GUEST

     This level doesn't support guests. When a guest operation

     is called, the exception is raised.

   These exceptions are pclass-dependent...

   XDEADLINE_MISS

     If a task miss his deadline, the exception is raised.

   XWCET_VIOLATION

     If a task doesn't end the current cycle before if consume the wcet,

     an exception is raised, and the task is put in the RM_WCET_VIOLATED

     state. To reactivate it, use RM_task_activate via task_activate or

     manage directly the RM data structure. Note that the exception is not

     handled properly, an XDEADLINE_MISS exeception will also be raised at

     the period end...

   XACTIVATION

     If a sporadic task is activated with a rate that is greather than the

     rate declared in the model, this exception is raised and the task is NOT

     activated.

     This exception is also raised if we are trying to activate a periodic task

     stopped with task_sleep before the deadline in which the task_sleep is

     called.

 Restrictions & special features:

   - This level doesn't manage the main task.

   - At init time we can choose if the level have to activate

     . the wcet check

       (If a task require more time than declared, it is stopped and put in

        the state RM_WCET_VIOLATED; a XWCET_VIOLATION exception is raised)

     . the task guarantee algorithm

       (when all task are created the system will check that the task_set

        will not use more than the available bandwidth)

   - The level use the priority field.

   - A function to return the used bandwidth of a level is provided.

**/

/*

 * Copyright (C) 2000 Paolo Gai

 *

 * 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

 *

 */

#ifndef __RM_H__

#define __RM_H__

#include <ll/ll.h>

#include <kernel/config.h>

#include <sys/types.h>

#include <kernel/types.h>

#include <modules/codes.h>

/*+ 1 - ln(2) +*/

#ifndef RM_MINFREEBANDWIDTH

#define RM_MINFREEBANDWIDTH 1317922825

#endif

/*+ flags... +*/

#define RM_DISABLE_ALL           0

#define RM_ENABLE_WCET_CHECK     1  /*+ Wcet check enabled     +*/

#define RM_ENABLE_GUARANTEE      2  /*+ Task Guarantee enabled +*/

#define RM_ENABLE_ALL            3  /*+ All flags enabled      +*/

#define RM_FAILED_GUARANTEE      8  /*+ used in the module, unsettable

                                         in RM_register_level... +*/

/*+ Registration function:

    int flag     Options to be used in this level instance... +*/

void RM_register_level(int flag);

/*+ Returns the used bandwidth of a level +*/

bandwidth_t RM_usedbandwidth(LEVEL l);

#endif