WebSVN - shark - Blame - Rev 3 - /shark/trunk/include/modules/ss.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	------------
		24	CVS : $Id: ss.h,v 1.1.1.1 2002-03-29 14:12:51 pj Exp $
		25
		26	File: $File$
		27	Revision: $Revision: 1.1.1.1 $
		28	Last update: $Date: 2002-03-29 14:12:51 $
		29	------------
		30
		31	This file contains the aperiodic server SS (Sporadic Server)
		32
		33	Title:
		34	SS (Sporadic Server)
		35
		36	Task Models Accepted:
		37	SOFT_TASK_MODEL - Soft Tasks
		38	wcet field is ignored
		39	met field is ignored
		40	period field is ignored
		41	periodicity field can be only APERIODIC
		42	arrivals field can be either SAVE or SKIP
		43
		44	Description:
		45	This module schedule his tasks following the Sporadic Server scheme.
		46	The scheme is slightly modified respect to classic SS. The server
		47	becomes active at arrival time of a task must be served.
		48
		49	All the tasks are put in a FIFO (FCFS) queue and at a time only the first
		50	task in the queue is put in the upper level.
		51
		52	The module remembers pending activations when calling task_sleep...
		53
		54	Exceptions raised:
		55	XUNVALID_GUEST
		56	This level doesn't support guests. When a guest operation
		57	is called, the exception is raised.
		58	XUNVALID_SS_REPLENISH
		59	Indicates an anomalous replenishment situation:
		60	. replenish time fires and no amounts are set
		61	. replenish amount posted when server is not active
		62	. no more space to post a replenish amount
		63
		64	Restrictions & special features:
		65	- This level doesn't manage the main task.
		66	- At init time we have to specify:
		67	. The Capacity and the period used by the server
		68	- The level don't use the priority field.
		69	- if an aperiodic task calls a task_delay when owning a mutex implemented
		70	with shadows, the delay may have no effect, so don't use delay when
		71	using a mutex!!!
		72	- On calling task_delay and task_sleep the replenish amount is posted.
		73	This because replenish time may fires when task is sleeping (server
		74	is not active).
		75	- A function to return the used bandwidth of the level is provided.
		76	- A function to return the avail server capacity is provided.
		77
		78	**/
		79
		80	/*
		81	* Copyright (C) 2000 Paolo Gai
		82	*
		83	* This program is free software; you can redistribute it and/or modify
		84	* it under the terms of the GNU General Public License as published by
		85	* the Free Software Foundation; either version 2 of the License, or
		86	* (at your option) any later version.
		87	*
		88	* This program is distributed in the hope that it will be useful,
		89	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		90	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		91	* GNU General Public License for more details.
		92	*
		93	* You should have received a copy of the GNU General Public License
		94	* along with this program; if not, write to the Free Software
		95	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		96	*
		97	*/
		98
		99
		100	#ifndef __SS_H__
		101	#define __SS_H__
		102
		103	#include <kernel/config.h>
		104	#include <kernel/types.h>
		105	#include <sys/types.h>
		106	#include <modules/codes.h>
		107
		108	/+ 1 - ln(2) +/
		109	#ifndef RM_MINFREEBANDWIDTH
		110	#define RM_MINFREEBANDWIDTH 1317922825
		111	#endif
		112
		113	/+ Max size of replenish queue +/
		114	#define SS_MAX_REPLENISH MAX_EVENT
		115
		116	/+ flags... +/
		117	#define SS_DISABLE_ALL 0
		118	#define SS_ENABLE_BACKGROUND 1 /+ Background scheduling enabled +/
		119	#define SS_ENABLE_GUARANTEE_EDF 2 /+ Task Guarantee enabled +/
		120	#define SS_ENABLE_ALL_EDF 3 /+ guarantee+background enabled +/
		121
		122	#define SS_ENABLE_GUARANTEE_RM 4 /+ Task Guarantee enabled +/
		123	#define SS_ENABLE_ALL_RM 5 /+ guarantee+background enabled +/
		124
		125	/+ internal flags +/
		126	#define SS_BACKGROUND 8 /*+ this flag is set when scheduling
		127	in background +*/
		128	#define SS_BACKGROUND_BLOCK 16 /*+ this flag is set when we want to
		129	blocks the background scheduling +*/
		130
		131	/+ internal switches +/
		132	typedef enum {
		133	SS_SERVER_NOTACTIVE, /+ SS is not active +/
		134	SS_SERVER_ACTIVE /+ SS is active +/
		135	} ss_status;
		136
		137	/+ internal functions +/
		138
		139	/+ Used to store replenishment events +/
		140	/* Now we use static allocated array. In this way, no more then
		141	SS_MAX_REPLENISH replenishments can be posted.
		142	typedef struct {
		143	struct timespec rtime;
		144	int ramount;
		145	replenishq *next;
		146	} replenishq;
		147	*/
		148
		149	/*+ Registration function:
		150	bandwidth_t b Max bandwidth used by the SS
		151	int flags Options to be used in this level instance...
		152	LEVEL master The level that must be used as master level
		153	int Cs Server capacity
		154	int per Server period +*/
		155	void SS_register_level(int flags, LEVEL master, int Cs, int per);
		156
		157	/+ Returns the used bandwidth of a level +/
		158	bandwidth_t SS_usedbandwidth(LEVEL l);
		159
		160	/+ Returns tha available capacity +/
		161	int SS_availCs(LEVEL l);
		162
		163	#endif

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