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