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1658 giacomo 1
/*
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 * Project: S.Ha.R.K.
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 *
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 * Coordinators:
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 *   Giorgio Buttazzo    <giorgio@sssup.it>
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *
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 * Authors     :
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *   Massimiliano Giorgi <massy@gandalf.sssup.it>
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 *   Luca Abeni          <luca@gandalf.sssup.it>
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 *   (see the web pages for full authors list)
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 *
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 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
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 *
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 * http://www.sssup.it
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 * http://retis.sssup.it
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 * http://shark.sssup.it
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 */
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/**
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 ------------
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 CVS :        $Id: slsh.h,v 1.1 2004-06-01 11:42:47 giacomo Exp $
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 File:        $File$
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 Revision:    $Revision: 1.1 $
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 Last update: $Date: 2004-06-01 11:42:47 $
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 ------------
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  Author: Tomas Lennvall, Date: Feb 2000.
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 This file contains the scheduling module for Slot shifting.
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 Title:
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   Slot Shifting
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 Task Models Accepted:
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   STATIC_TASK_MODEL - Periodic Hard tasks that are scheduled by
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     an off-line scheduler, so that all guarantees regarding precedence, mutex
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     deadline violation is taken care of. The tasks are in an executione schedule,
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     that is the order in when they become ready. They have the following fields:
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     est (earliest start time), wcet and absolute deadline.
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   HARD_TASK_MODEL - Hard Tasks (Hard aperiodic requests)
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     wcet field and drel field must be != 0. They are used to set the wcet
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     and deadline of the tasks.
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     periodicity field must be APERIODIC
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     mit field is ignored.
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  SOFT_TASK_MODEL - Soft Tasks (Unspecified tasks)
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    wcet field must be != 0. periodicity filed must be APERIODIC
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    period and met filed is ignored.
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 Guest Models Accepted:
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    NONE - Slot shifting handles all tasks by itself (at this moment).  
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 Description:
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   This module schedules the offline scheduled tasks according to the slot-
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   shifting paradigm, dividing time into slots of a fixed length and assigning
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   tasks to execute in those slots. Slot-shifting also keeps track of the free
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   bandwidth in the schedule by using disjoint intervals and sc (spare capacity).
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   Each interval has a sc nr that represents the free bandwidth in that interval,
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   the sc can be used by hard aperiodic tasks, static tasks from later interval or
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   soft aperiodic tasks. Hard aperiodic tasks are guaranteed an incorporated in
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   the schedule by reduction of sc before they execute. No guarantee is
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   performed on the soft aperiodic tasks, they are run when no other task wants
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   to execute and sc is available.    
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 Description:
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  This module implements the Slot shifting algorithm, by Gerhard Fohler. Slot shifting
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  schedules off-line scheduled tasks and also handles hard aperiodic requests by the
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  guarantee alorithm. Slot shifting can also handle soft aperiodic tasks,
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  called unspecified. That is tasks without a deadline.
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 Exceptions raised:
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   These exceptions are pclass-dependent...
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   XDEADLINE_MISS
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     If a task miss his deadline, the exception is raised.
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   XWCET_VIOLATION
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     If a task doesn't end the current cycle before if consume the wcet,
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     an exception is raised, and the task is put in the EDF_WCET_VIOLATED
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     state. To reactivate it, use EDF_task_activate via task_activate or
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     manage directly the EDF data structure. Note that the exception is not
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     handled properly, an XDEADLINE_MISS exeeption will also be raised at
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     the period end...
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 Restrictions & special features:
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   - This level doesn't manage the main task.
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   - At init time we can choose if the level have to activate
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     . the wcet check
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       (If a task require more time than declared, it is stopped and put in
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        the state EDF_WCET_VIOLATED; a XWCET_VIOLATION exception is raised)
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     . the task guarantee algorithm
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       (when all task are created the system will check that the task_set
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        will not use more than the available bandwidth)
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   - The level use the priority and timespec_priority fields.
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   - A function to return the used bandwidth of a level is provided.
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   - The guest tasks don't provide the guest_endcycle function
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**/
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/*
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 * Copyright (C) 2000 Paolo Gai
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
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#ifndef __SLSH_H__
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#define __SLSH_H__
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#include <ll/ll.h>
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#include <kernel/config.h>
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#include <sys/types.h>
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#include <kernel/types.h>
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#define STATIC_PCLASS       0x0500
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#define SLSH_LEVELNAME          "Slot Shifting"
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#define SLSH_LEVEL_CODE         5
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#define SLSH_LEVEL_VERSION      1
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/* -----------------------------------------------------------------------
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   STATIC_TASK_MODEL: offline scheduled Tasks
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   ----------------------------------------------------------------------- */
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/* Offline-scheduled tasks are hard periodic tasks that have been
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    scheduled before runtime. All guarantees are made by the off-
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    line scheduler so the tasks are already guaranteed.
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*/
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typedef struct {
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        TASK_MODEL t;
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        TIME est;
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        TIME wcet;
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        TIME dabs;
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        int interval;   /* used in slot shifting */
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} STATIC_TASK_MODEL;
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#define static_task_default_model(m)                             \
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                        task_default_model((m).t,STATIC_PCLASS), \
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                        (m).est         = -1,                   \
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                        (m).dabs        = 0,                   \
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                        (m).wcet        = 0,                   \
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                        (m).interval    = -1;
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#define static_task_def_level(m,l)    task_def_level((m).t,l)
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#define static_task_def_arg(m,a)      task_def_arg((m).t,a)
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#define static_task_def_stack(m,s)    task_def_stack((m).t,s)
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#define static_task_def_group(m,g)    task_def_group((m).t,g)
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#define static_task_def_usemath(m)    task_def_usemath((m).t)
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#define static_task_def_system(m)     task_def_system((m).t)
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#define static_task_def_nokill(m)     task_def_nokill((m).t)
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#define static_task_def_ctrl_jet(m)   task_def_ctrl_jet((m).t)
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#define static_task_def_est(m,p)      (m).est = (p)
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#define static_task_def_dabs(m,d)     (m).dabs = (d)
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#define static_task_def_wcet(m,w)     (m).wcet = (w)
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#define static_task_def_interval(m,i) (m).interval = (i)
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#define static_task_def_trace(m)      task_def_trace((m).t)
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#define static_task_def_notrace(m)    task_def_notrace((m).t)
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/*#define min(a, b) ((a) < (b) ? (a) : (b))*/
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#define TIME2TIMESPEC(T, TS)                    \
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(                                                               \
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 ((TS).tv_sec = ((T)/1000000)),                 \
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 ((TS).tv_nsec = (((T)%1000000) * 1000)),       \
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 (TS)                                                           \
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)
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/* define the interval struct */
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typedef struct {
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        int start;      /* start of interval */
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        int end;        /* end of interval */
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        int length; /* Length of interval */
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        int maxt;       /* maximum execution time in interval */
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        int sc; /* spare capacity in interval */
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} SLSH_interval;
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/*+ Registration function: */
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LEVEL SLSH_register_level();
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void SLSH_set_interval(LEVEL l, int start, int end, int maxt);
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void SLSH_set_variables(LEVEL l, TIME length);
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#endif
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