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/*
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/*
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 * Copyright (c) 2009 Jakub Jermar
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 * Copyright (c) 2009 Jakub Jermar
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 * All rights reserved.
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 * All rights reserved.
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 *
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 *
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 * Redistribution and use in source and binary forms, with or without
 5 
 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * modification, are permitted provided that the following conditions
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 * are met:
 7 
 * are met:
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 *
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 *
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 * - Redistributions of source code must retain the above copyright
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *   derived from this software without specific prior written permission.
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 *
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 18 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 25 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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 */
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/** @addtogroup libc
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/** @addtogroup libc
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 * @{
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 * @{
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 */
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 */
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/** @file
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/** @file
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 */
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 */
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 34 
 
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#include <fibril_sync.h>
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#include <fibril_sync.h>
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#include <fibril.h>
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#include <fibril.h>
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#include <async.h>
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#include <async.h>
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#include <adt/list.h>
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#include <adt/list.h>
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#include <futex.h>
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#include <futex.h>
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#include <assert.h>
 40 
#include <assert.h>
41 
 
 41 
 
42 
void fibril_mutex_initialize(fibril_mutex_t *fm)
 42 
void fibril_mutex_initialize(fibril_mutex_t *fm)
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{
 43 
{
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    fm->counter = 1;
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    fm->counter = 1;
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    list_initialize(&fm->waiters);
 45 
    list_initialize(&fm->waiters);
46 
}
 46 
}
47 
 
 47 
 
48 
void fibril_mutex_lock(fibril_mutex_t *fm)
 48 
void fibril_mutex_lock(fibril_mutex_t *fm)
49 
{
 49 
{
50 
    futex_down(&async_futex);
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    futex_down(&async_futex);
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    if (fm->counter-- <= 0) {
 51 
    if (fm->counter-- <= 0) {
52 
        fibril_t *f = (fibril_t *) fibril_get_id();
 52 
        fibril_t *f = (fibril_t *) fibril_get_id();
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        list_append(&f->link, &fm->waiters);
 53 
        list_append(&f->link, &fm->waiters);
54 
        fibril_switch(FIBRIL_TO_MANAGER);
 54 
        fibril_switch(FIBRIL_TO_MANAGER);
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    } else {
 55 
    } else {
56 
        futex_up(&async_futex);
 56 
        futex_up(&async_futex);
57 
    }
 57 
    }
58 
}
 58 
}
59 
 
 59 
 
60 
bool fibril_mutex_trylock(fibril_mutex_t *fm)
 60 
bool fibril_mutex_trylock(fibril_mutex_t *fm)
61 
{
 61 
{
62 
    bool locked = false;
 62 
    bool locked = false;
63 
   
 63 
   
64 
    futex_down(&async_futex);
 64 
    futex_down(&async_futex);
65 
    if (fm->counter > 0) {
 65 
    if (fm->counter > 0) {
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        fm->counter--;
 66 
        fm->counter--;
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        locked = true;
 67 
        locked = true;
68 
    }
 68 
    }
69 
    futex_up(&async_futex);
 69 
    futex_up(&async_futex);
70 
   
 70 
   
71 
    return locked;
 71 
    return locked;
72 
}
 72 
}
73 
 
 73 
 
74 
void fibril_mutex_unlock(fibril_mutex_t *fm)
 74 
void fibril_mutex_unlock(fibril_mutex_t *fm)
75 
{
 75 
{
76 
    futex_down(&async_futex);
 76 
    futex_down(&async_futex);
77 
    assert(fm->counter <= 0);
 77 
    assert(fm->counter <= 0);
78 
    if (fm->counter++ < 0) {
 78 
    if (fm->counter++ < 0) {
79 
        link_t *tmp;
 79 
        link_t *tmp;
80 
        fibril_t *f;
 80 
        fibril_t *f;
81 
   
 81 
   
82 
        assert(!list_empty(&fm->waiters));
 82 
        assert(!list_empty(&fm->waiters));
83 
        tmp = fm->waiters.next;
 83 
        tmp = fm->waiters.next;
84 
        f = list_get_instance(tmp, fibril_t, link);
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        f = list_get_instance(tmp, fibril_t, link);
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        list_remove(&f->link);
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        list_remove(&f->link);
86 
        fibril_add_ready((fid_t) f);
 86 
        fibril_add_ready((fid_t) f);
87 
    }
 87 
    }
88 
    futex_up(&async_futex);
 88 
    futex_up(&async_futex);
89 
}
 89 
}
90 
 
 90 
 
91 
void fibril_rwlock_initialize(fibril_rwlock_t *frw)
 91 
void fibril_rwlock_initialize(fibril_rwlock_t *frw)
92 
{
 92 
{
- 
 
 93 
    frw->writers = 0;
- 
 
 94 
    frw->readers = 0;
93 
    fibril_mutex_initialize(&frw->fm);
 95 
    list_initialize(&frw->waiters);
94 
}
 96 
}
95 
 
 97 
 
96 
void fibril_rwlock_read_lock(fibril_rwlock_t *frw)
 98 
void fibril_rwlock_read_lock(fibril_rwlock_t *frw)
97 
{
 99 
{
98 
    fibril_mutex_lock(&frw->fm);
 100 
    futex_down(&async_futex);
- 
 
 101 
    if (frw->writers) {
- 
 
 102 
        fibril_t *f = (fibril_t *) fibril_get_id();
- 
 
 103 
        f->flags &= ~FIBRIL_WRITER;
- 
 
 104 
        list_append(&f->link, &frw->waiters);
- 
 
 105 
        fibril_switch(FIBRIL_TO_MANAGER);
- 
 
 106 
    } else {
- 
 
 107 
        frw->readers++;
- 
 
 108 
        futex_up(&async_futex);
- 
 
 109 
    }
99 
}
 110 
}
100 
 
 111 
 
101 
void fibril_rwlock_write_lock(fibril_rwlock_t *frw)
 112 
void fibril_rwlock_write_lock(fibril_rwlock_t *frw)
102 
{
 113 
{
- 
 
 114 
    futex_down(&async_futex);
- 
 
 115 
    if (frw->writers || frw->readers) {
- 
 
 116 
        fibril_t *f = (fibril_t *) fibril_get_id();
- 
 
 117 
        f->flags |= FIBRIL_WRITER;
- 
 
 118 
        list_append(&f->link, &frw->waiters);
- 
 
 119 
        fibril_switch(FIBRIL_TO_MANAGER);
- 
 
 120 
    } else {
- 
 
 121 
        frw->writers++;
- 
 
 122 
        futex_up(&async_futex);
- 
 
 123 
    }
- 
 
 124 
}
- 
 
 125 
 
- 
 
 126 
static void _fibril_rwlock_common_unlock(fibril_rwlock_t *frw)
- 
 
 127 
{
- 
 
 128 
    futex_down(&async_futex);
- 
 
 129 
    assert(frw->readers || (frw->writers == 1));
- 
 
 130 
    if (frw->readers) {
- 
 
 131 
        if (--frw->readers)
- 
 
 132 
            goto out;
- 
 
 133 
    } else {
- 
 
 134 
        frw->writers--;
- 
 
 135 
    }
- 
 
 136 
   
- 
 
 137 
    assert(!frw->readers && !frw->writers);
- 
 
 138 
   
- 
 
 139 
    while (!list_empty(&frw->waiters)) {
- 
 
 140 
        link_t *tmp = frw->waiters.next;
- 
 
 141 
        fibril_t *f = list_get_instance(tmp, fibril_t, link);
- 
 
 142 
       
- 
 
 143 
        if (f->flags & FIBRIL_WRITER) {
- 
 
 144 
            if (frw->readers)
- 
 
 145 
                break;
- 
 
 146 
            list_remove(&f->link);
- 
 
 147 
            fibril_add_ready((fid_t) f);
- 
 
 148 
            frw->writers++;
- 
 
 149 
            break;
- 
 
 150 
        } else {
- 
 
 151 
            list_remove(&f->link);
103 
    fibril_mutex_lock(&frw->fm);
 152 
            fibril_add_ready((fid_t) f);
- 
 
 153 
            frw->readers++;
- 
 
 154 
        }
- 
 
 155 
    }
- 
 
 156 
out:
- 
 
 157 
    futex_up(&async_futex);
104 
}
 158 
}
105 
 
 159 
 
106 
void fibril_rwlock_read_unlock(fibril_rwlock_t *frw)
 160 
void fibril_rwlock_read_unlock(fibril_rwlock_t *frw)
107 
{
 161 
{
108 
    fibril_mutex_unlock(&frw->fm);
 162 
    _fibril_rwlock_common_unlock(frw);
109 
}
 163 
}
110 
 
 164 
 
111 
void fibril_rwlock_write_unlock(fibril_rwlock_t *frw)
 165 
void fibril_rwlock_write_unlock(fibril_rwlock_t *frw)
112 
{
 166 
{
113 
    fibril_mutex_unlock(&frw->fm);
 167 
    _fibril_rwlock_common_unlock(frw);
114 
}
 168 
}
115 
 
 169 
 
116 
/** @}
 170 
/** @}
117 
 */
 171 
 */
118 
 
 172