0,0 → 1,68 |
/* |
* Copyright (C) 2001-2004 Jakub Jermar |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
#ifndef __RWLOCK_H__ |
#define __RWLOCK_H__ |
|
#include <arch/types.h> |
#include <typedefs.h> |
#include <synch/mutex.h> |
#include <synch/synch.h> |
|
enum rwlock_type { |
RWLOCK_NONE, |
RWLOCK_READER, |
RWLOCK_WRITER |
}; |
|
struct rwlock { |
spinlock_t lock; |
mutex_t exclusive; /**< Mutex for writers, readers can bypass it if readers_in is positive. */ |
count_t readers_in; /**< Number of readers in critical section. */ |
}; |
|
#define rwlock_write_lock(rwl) \ |
_rwlock_write_lock_timeout((rwl),SYNCH_NO_TIMEOUT,SYNCH_BLOCKING) |
#define rwlock_read_lock(rwl) \ |
_rwlock_read_lock_timeout((rwl),SYNCH_NO_TIMEOUT,SYNCH_BLOCKING) |
#define rwlock_write_trylock(rwl) \ |
_rwlock_write_lock_timeout((rwl),SYNCH_NO_TIMEOUT,SYNCH_NON_BLOCKING) |
#define rwlock_read_trylock(rwl) \ |
_rwlock_read_lock_timeout((rwl),SYNCH_NO_TIMEOUT,SYNCH_NON_BLOCKING) |
#define rwlock_write_lock_timeout(rwl,usec) \ |
_rwlock_write_lock_timeout((rwl),(usec),SYNCH_NON_BLOCKING) |
#define rwlock_read_lock_timeout(rwl,usec) \ |
_rwlock_read_lock_timeout((rwl),(usec),SYNCH_NON_BLOCKING) |
|
extern void rwlock_initialize(rwlock_t *rwl); |
extern void rwlock_read_unlock(rwlock_t *rwl); |
extern void rwlock_write_unlock(rwlock_t *rwl); |
extern int _rwlock_read_lock_timeout(rwlock_t *rwl, __u32 usec, int trylock); |
extern int _rwlock_write_lock_timeout(rwlock_t *rwl, __u32 usec, int trylock); |
|
#endif |