WebSVN - shark - Blame - Rev 1618 - /shark/branches/xen/kernel/mutex.c

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	------------
502	giacomo	21	CVS : $Id: mutex.c,v 1.6 2004-03-10 14:51:42 giacomo Exp $
2	pj	22
		23	File: $File$
502	giacomo	24	Revision: $Revision: 1.6 $
		25	Last update: $Date: 2004-03-10 14:51:42 $
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
385	giacomo	84	#include <tracer.h>
		85
2	pj	86	/---------------------------------------------------------------------/
		87	/* Mutexes */
		88	/---------------------------------------------------------------------/
		89
		90
		91	int mutex_init(mutex_t mutex, const mutexattr_t attr)
		92	{
		93	RLEVEL l;
318	giacomo	94	SYS_FLAGS f;
38	pj	95	int result;
2	pj	96
318	giacomo	97	f = kern_fsave();
2	pj	98	mutex->mutexlevel = -1;
		99	mutex->use = 0;
		100
		101	for (l=0; l<res_levels; l++) {
		102	if (resource_table[l]->rtype == MUTEX_RTYPE) {
		103	/* the cast to mutex_resource_des is legal */
		104	mutex_resource_des m = (mutex_resource_des )resource_table[l];
		105
		106	/* can the mutex level manage the mutexattr_t ? */
228	giacomo	107	if ((result = m->init(l, mutex, attr)) >=0) {
318	giacomo	108	kern_frestore(f);
38	pj	109	return result;
228	giacomo	110	}
2	pj	111	}
		112	}
318	giacomo	113	kern_frestore(f);
2	pj	114
38	pj	115	return EINVAL;
2	pj	116	}
		117
		118
		119	int mutex_destroy(mutex_t *mutex)
		120	{
		121	mutex_resource_des *m;
		122
		123	if (mutex->mutexlevel == -1)
		124	return (EINVAL);
		125
		126	if (mutex->use)
		127	return (EBUSY);
		128
		129	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		130
		131	return m->destroy(mutex->mutexlevel, mutex);
		132	}
		133
		134	int mutex_lock(mutex_t *mutex)
		135	{
		136	mutex_resource_des *m;
		137
		138	if (mutex->mutexlevel == -1)
		139	return (EINVAL);
		140
502	giacomo	141	TRACER_LOGEVENT(FTrace_EVT_set_mutex_lock,(unsigned short int)proc_table[exec_shadow].context,(unsigned int)(mutex));
385	giacomo	142
2	pj	143	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		144
		145	return m->lock(mutex->mutexlevel, mutex);
		146	}
		147
		148	int mutex_trylock(mutex_t *mutex)
		149	{
		150	mutex_resource_des *m;
		151
		152	if (mutex->mutexlevel == -1)
		153	return (EINVAL);
		154
		155	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		156
		157	return m->trylock(mutex->mutexlevel, mutex);
		158	}
		159
		160	int mutex_unlock(mutex_t *mutex)
		161	{
		162	mutex_resource_des *m;
		163
		164	if (mutex->mutexlevel == -1)
		165	return (EINVAL);
		166
502	giacomo	167	TRACER_LOGEVENT(FTrace_EVT_set_mutex_unlock,(unsigned short int)proc_table[exec_shadow].context,(unsigned int)(mutex));
385	giacomo	168
2	pj	169	m = (mutex_resource_des *)resource_table[mutex->mutexlevel];
		170
		171	return m->unlock(mutex->mutexlevel, mutex);
		172	}
		173

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