WebSVN - shark - Blame - Rev 39 - /shark/tags/rel_0

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	* (see the web pages for full authors list)
		11	*
		12	* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
		13	*
		14	* http://www.sssup.it
		15	* http://retis.sssup.it
		16	* http://shark.sssup.it
		17	*/
		18
		19	/**
		20	------------
38	pj	21	CVS : $Id: mutex.c,v 1.2 2003-01-07 17:07:49 pj Exp $
2	pj	22
		23	File: $File$
38	pj	24	Revision: $Revision: 1.2 $
		25	Last update: $Date: 2003-01-07 17:07:49 $
2	pj	26	------------
		27
		28	This file contains the mutex and condition variables handling functions.
		29
		30
		31	The mutex init function try to find a resource level with
		32	rtype = MUTEX_RTYPE that can accept a mutex of the type of that
		33	contained in mutexattr_t.
		34
		35	when found, it simply calls the level mutex init function.
		36
		37	Note that a mutex attribute must be specificated, whereas the
		38	pthread_mutex_init accepts a pthread_mutexattr equal to NULL!!!
		39
		40
		41	returns an integer of value:
		42
		43	EAGAIN The system lacked the necessarty resources to initialize another mutex
		44	ENOMEM Insufficient memory exist to initialize the mutex
		45	EPERM The caller does not have the privilege to perform the operation
		46	EBUSY An init on a non-destroyed mutex is called
		47	EINVAL the value specified by attr parameter is invalid
		48	(no resource module found to handle the rtype...)
		49
		50
		51	The others functions simply call the module-dependent functions...
		52
		53	**/
		54
		55	/*
		56	* Copyright (C) 2000 Paolo Gai
		57	*
		58	* This program is free software; you can redistribute it and/or modify
		59	* it under the terms of the GNU General Public License as published by
		60	* the Free Software Foundation; either version 2 of the License, or
		61	* (at your option) any later version.
		62	*
		63	* This program is distributed in the hope that it will be useful,
		64	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		65	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		66	* GNU General Public License for more details.
		67	*
		68	* You should have received a copy of the GNU General Public License
		69	* along with this program; if not, write to the Free Software
		70	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		71	*
		72	*/
		73
		74
		75
		76	#include <kernel/const.h>
		77	#include <sys/types.h>
		78	#include <kernel/model.h>
		79	#include <kernel/descr.h>
		80	#include <kernel/var.h>
		81	#include <kernel/func.h>
		82	#include <errno.h>
		83
		84	/---------------------------------------------------------------------/
		85	/* Mutexes */
		86	/---------------------------------------------------------------------/
		87
		88
		89	int mutex_init(mutex_t mutex, const mutexattr_t attr)
		90	{
		91	RLEVEL l;
38	pj	92	int result;
2	pj	93
		94	kern_cli();
		95	mutex->mutexlevel = -1;
		96	mutex->use = 0;
		97
		98	for (l=0; l<res_levels; l++) {
		99	if (resource_table[l]->rtype == MUTEX_RTYPE) {
		100	/* the cast to mutex_resource_des is legal */
		101	mutex_resource_des m = (mutex_resource_des )resource_table[l];
		102
		103	/* can the mutex level manage the mutexattr_t ? */
38	pj	104	if ((result = m->init(l, mutex, attr)) >=0)
		105	return result;
2	pj	106	}
		107	}
		108	kern_sti();
		109
38	pj	110	return EINVAL;
2	pj	111	}
		112
		113
		114	int mutex_destroy(mutex_t *mutex)
		115	{
		116	mutex_resource_des *m;
		117
		118	if (mutex->mutexlevel == -1)
		119	return (EINVAL);
		120
		121	if (mutex->use)
		122	return (EBUSY);
		123
		124	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		125
		126	return m->destroy(mutex->mutexlevel, mutex);
		127	}
		128
		129	int mutex_lock(mutex_t *mutex)
		130	{
		131	mutex_resource_des *m;
		132
		133	if (mutex->mutexlevel == -1)
		134	return (EINVAL);
		135
		136	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		137
		138	return m->lock(mutex->mutexlevel, mutex);
		139	}
		140
		141	int mutex_trylock(mutex_t *mutex)
		142	{
		143	mutex_resource_des *m;
		144
		145	if (mutex->mutexlevel == -1)
		146	return (EINVAL);
		147
		148	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		149
		150	return m->trylock(mutex->mutexlevel, mutex);
		151	}
		152
		153	int mutex_unlock(mutex_t *mutex)
		154	{
		155	mutex_resource_des *m;
		156
		157	if (mutex->mutexlevel == -1)
		158	return (EINVAL);
		159
		160	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		161
		162	return m->unlock(mutex->mutexlevel, mutex);
		163	}
		164

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(root)/shark/tags/rel_0_3/kernel/mutex.c - Rev 39