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/*
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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: rr.h,v 1.1 2005-02-25 10:45:58 pj Exp $
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 File:        $File$
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 Revision:    $Revision: 1.1 $
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 Last update: $Date: 2005-02-25 10:45:58 $
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 ------------
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 This file contains the scheduling module RR (Round Robin)
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 Title:
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   RR (Round Robin)
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 Task Models Accepted:
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   NRT_TASK_MODEL - Non-Realtime Tasks
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     weight field is ignored
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     slice  field is used to set the slice of a task, if it is !=0
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     activation field is ignored
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     policy field is ignored
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     inherit field is ignored
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 Description:
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   This module schedule his tasks following the classic round-robin
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   scheme. The default timeslice is given at registration time and is a
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   a per-task specification. The default timeslice is used if the slice
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   field in the NRT_TASK_MODEL is 0.
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   The module always SKIP instances, either if SAVE_ARRIVALS is set!!!
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   There is another module, RR2, thar remember activations...
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 Exceptions raised:
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   XUNVALID_GUEST
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     This level doesn't support guests. When a guest operation
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     is called, the exception is raised.
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 Restrictions & special features:
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   - if specified, it creates at init time a task,
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     called "Main", attached to the function __init__().
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   - There must be only one module in the system that creates a task
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     attached to the function __init__().
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   - The level tries to guarantee that a task uses a "full" timeslice
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     before going to the queue tail. "full" means that a task can execute
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     a maximum time of slice+sys_tick due to the approx. done by
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     the Virtual Machine. If a task execute more time than the slice,
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     the next time it execute less...
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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 __RR_H__
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#define __RR_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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#include "ll/sys/cdefs.h"
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__BEGIN_DECLS
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extern TASK __init__(void *arg);
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/*+ Const: +*/
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#define RR_MINIMUM_SLICE      1000 /*+ Minimum Timeslice +*/
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#define RR_MAXIMUM_SLICE    500000 /*+ Maximum Timeslice +*/
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#define RR_MAIN_YES              1 /*+ The level creates the main +*/
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#define RR_MAIN_NO               0 /*+ The level does'nt create the main +*/
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/*+ Registration function:
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    TIME slice                the slice for the Round Robin queue
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    int createmain            1 if the level creates the main task 0 otherwise
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    struct multiboot_info *mb used if createmain specified  
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    returns the level number at which the module has been registered.
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+*/
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LEVEL RR_register_level(TIME slice,
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                       int createmain,
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                       struct multiboot_info *mb);
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__END_DECLS
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#endif