| 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 |