source: mainline/kernel/generic/include/synch/rwlock.h@ 86018c1

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 86018c1 was 98000fb, checked in by Martin Decky <martin@…>, 16 years ago

remove redundant index_t and count_t types (which were always quite ambiguous and not actually needed)

  • Property mode set to 100644
File size: 2.9 KB
Line 
1/*
2 * Copyright (c) 2001-2004 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup sync
30 * @{
31 */
32/** @file
33 */
34
35#ifndef KERN_RWLOCK_H_
36#define KERN_RWLOCK_H_
37
38#include <arch/types.h>
39#include <synch/mutex.h>
40#include <synch/synch.h>
41#include <synch/spinlock.h>
42
43typedef enum {
44 RWLOCK_NONE,
45 RWLOCK_READER,
46 RWLOCK_WRITER
47} rwlock_type_t;
48
49typedef struct {
50 SPINLOCK_DECLARE(lock);
51 /**
52 * Mutex for writers, readers can bypass it if readers_in is positive.
53 */
54 mutex_t exclusive;
55 /** Number of readers in critical section. */
56 size_t readers_in;
57} rwlock_t;
58
59#define rwlock_write_lock(rwl) \
60 _rwlock_write_lock_timeout((rwl), SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE)
61#define rwlock_read_lock(rwl) \
62 _rwlock_read_lock_timeout((rwl), SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE)
63#define rwlock_write_trylock(rwl) \
64 _rwlock_write_lock_timeout((rwl), SYNCH_NO_TIMEOUT, \
65 SYNCH_FLAGS_NON_BLOCKING)
66#define rwlock_read_trylock(rwl) \
67 _rwlock_read_lock_timeout((rwl), SYNCH_NO_TIMEOUT, \
68 SYNCH_FLAGS_NON_BLOCKING)
69#define rwlock_write_lock_timeout(rwl, usec) \
70 _rwlock_write_lock_timeout((rwl), (usec), SYNCH_FLAGS_NONE)
71#define rwlock_read_lock_timeout(rwl, usec) \
72 _rwlock_read_lock_timeout((rwl), (usec), SYNCH_FLAGS_NONE)
73
74extern void rwlock_initialize(rwlock_t *rwl);
75extern void rwlock_read_unlock(rwlock_t *rwl);
76extern void rwlock_write_unlock(rwlock_t *rwl);
77extern int _rwlock_read_lock_timeout(rwlock_t *rwl, uint32_t usec, int flags);
78extern int _rwlock_write_lock_timeout(rwlock_t *rwl, uint32_t usec, int flags);
79
80#endif
81
82/** @}
83 */
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