Subversion Repositories HelenOS

Rev

Rev 2787 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1 
/*
2071 jermar 2 
 * Copyright (c) 2001-2004 Jakub Jermar
1 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 
 
1888 jermar 29 
/** @addtogroup sync
1702 cejka 30 
 * @{
31 
 */
32 
/** @file
33 
 */
34 
 
1888 jermar 35 
#ifndef KERN_RWLOCK_H_
36 
#define KERN_RWLOCK_H_
1 jermar 37 
 
38 
#include <arch/types.h>
39 
#include <synch/mutex.h>
40 
#include <synch/synch.h>
623 jermar 41 
#include <synch/spinlock.h>
1 jermar 42 
 
2085 decky 43 
typedef enum {
1 jermar 44 
    RWLOCK_NONE,
45 
    RWLOCK_READER,
46 
    RWLOCK_WRITER
2085 decky 47 
} rwlock_type_t;
1 jermar 48 
 
2085 decky 49 
typedef struct {
623 jermar 50 
    SPINLOCK_DECLARE(lock);
2106 jermar 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. */
4692 svoboda 56 
    size_t readers_in;
2085 decky 57 
} rwlock_t;
1 jermar 58 
 
59 
#define rwlock_write_lock(rwl) \
2106 jermar 60 
    _rwlock_write_lock_timeout((rwl), SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE)
1 jermar 61 
#define rwlock_read_lock(rwl) \
2106 jermar 62 
    _rwlock_read_lock_timeout((rwl), SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE)
1 jermar 63 
#define rwlock_write_trylock(rwl) \
2106 jermar 64 
    _rwlock_write_lock_timeout((rwl), SYNCH_NO_TIMEOUT, \
65 
        SYNCH_FLAGS_NON_BLOCKING)
1 jermar 66 
#define rwlock_read_trylock(rwl) \
2106 jermar 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)
1 jermar 73 
 
74 
extern void rwlock_initialize(rwlock_t *rwl);
75 
extern void rwlock_read_unlock(rwlock_t *rwl);
76 
extern void rwlock_write_unlock(rwlock_t *rwl);
1780 jermar 77 
extern int _rwlock_read_lock_timeout(rwlock_t *rwl, uint32_t usec, int flags);
78 
extern int _rwlock_write_lock_timeout(rwlock_t *rwl, uint32_t usec, int flags);
1 jermar 79 
 
80 
#endif
1502 jermar 81 
 
1888 jermar 82 
/** @}
1702 cejka 83 
 */