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1113 palkovsky 1
/*
4516 jermar 2
 * Copyright (c) 2009 Jakub Jermar
1113 palkovsky 3
 * All rights reserved.
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 *
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 * 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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 * are met:
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 *
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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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 * - 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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 *   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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 *   derived from this software without specific prior written permission.
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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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 * 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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 * 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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 * 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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 * 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
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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1719 decky 29
/** @addtogroup libc
1653 cejka 30
 * @{
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 */
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/** @file
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 */
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4516 jermar 35
#include <fibril_sync.h>
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#include <fibril.h>
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#include <async.h>
4509 decky 38
#include <adt/list.h>
1392 palkovsky 39
#include <futex.h>
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#include <assert.h>
1113 palkovsky 41
 
4516 jermar 42
void fibril_mutex_initialize(fibril_mutex_t *fm)
1129 palkovsky 43
{
4516 jermar 44
    fm->counter = 1;
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    list_initialize(&fm->waiters);
1129 palkovsky 46
}
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4516 jermar 48
void fibril_mutex_lock(fibril_mutex_t *fm)
1129 palkovsky 49
{
4516 jermar 50
    futex_down(&async_futex);
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    if (fm->counter-- <= 0) {
52
        fibril_t *f = (fibril_t *) fibril_get_id();
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        list_append(&f->link, &fm->waiters);
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        fibril_switch(FIBRIL_TO_MANAGER);
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    } else {
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        futex_up(&async_futex);
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    }
1129 palkovsky 58
}
59
 
4516 jermar 60
bool fibril_mutex_trylock(fibril_mutex_t *fm)
1113 palkovsky 61
{
4516 jermar 62
    bool locked = false;
1392 palkovsky 63
 
4516 jermar 64
    futex_down(&async_futex);
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    if (fm->counter > 0) {
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        fm->counter--;
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        locked = true;
1392 palkovsky 68
    }
4516 jermar 69
    futex_up(&async_futex);
1610 palkovsky 70
 
4516 jermar 71
    return locked;
1113 palkovsky 72
}
73
 
4527 jermar 74
static void _fibril_mutex_unlock_unsafe(fibril_mutex_t *fm)
1113 palkovsky 75
{
4516 jermar 76
    assert(fm->counter <= 0);
77
    if (fm->counter++ < 0) {
78
        link_t *tmp;
79
        fibril_t *f;
80
 
81
        assert(!list_empty(&fm->waiters));
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        tmp = fm->waiters.next;
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        f = list_get_instance(tmp, fibril_t, link);
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        list_remove(&f->link);
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        fibril_add_ready((fid_t) f);
1113 palkovsky 86
    }
4527 jermar 87
}
88
 
89
void fibril_mutex_unlock(fibril_mutex_t *fm)
90
{
91
    futex_down(&async_futex);
92
    _fibril_mutex_unlock_unsafe(fm);
4516 jermar 93
    futex_up(&async_futex);
1392 palkovsky 94
}
95
 
4516 jermar 96
void fibril_rwlock_initialize(fibril_rwlock_t *frw)
1392 palkovsky 97
{
4526 jermar 98
    frw->writers = 0;
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    frw->readers = 0;
100
    list_initialize(&frw->waiters);
1392 palkovsky 101
}
1113 palkovsky 102
 
4516 jermar 103
void fibril_rwlock_read_lock(fibril_rwlock_t *frw)
1392 palkovsky 104
{
4526 jermar 105
    futex_down(&async_futex);
106
    if (frw->writers) {
107
        fibril_t *f = (fibril_t *) fibril_get_id();
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        f->flags &= ~FIBRIL_WRITER;
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        list_append(&f->link, &frw->waiters);
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        fibril_switch(FIBRIL_TO_MANAGER);
111
    } else {
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        frw->readers++;
113
        futex_up(&async_futex);
114
    }
1113 palkovsky 115
}
1392 palkovsky 116
 
4516 jermar 117
void fibril_rwlock_write_lock(fibril_rwlock_t *frw)
1392 palkovsky 118
{
4526 jermar 119
    futex_down(&async_futex);
120
    if (frw->writers || frw->readers) {
121
        fibril_t *f = (fibril_t *) fibril_get_id();
122
        f->flags |= FIBRIL_WRITER;
123
        list_append(&f->link, &frw->waiters);
124
        fibril_switch(FIBRIL_TO_MANAGER);
125
    } else {
126
        frw->writers++;
127
        futex_up(&async_futex);
128
    }
1392 palkovsky 129
}
1427 palkovsky 130
 
4526 jermar 131
static void _fibril_rwlock_common_unlock(fibril_rwlock_t *frw)
132
{
133
    futex_down(&async_futex);
134
    assert(frw->readers || (frw->writers == 1));
135
    if (frw->readers) {
136
        if (--frw->readers)
137
            goto out;
138
    } else {
139
        frw->writers--;
140
    }
141
 
142
    assert(!frw->readers && !frw->writers);
143
 
144
    while (!list_empty(&frw->waiters)) {
145
        link_t *tmp = frw->waiters.next;
146
        fibril_t *f = list_get_instance(tmp, fibril_t, link);
147
 
148
        if (f->flags & FIBRIL_WRITER) {
149
            if (frw->readers)
150
                break;
151
            list_remove(&f->link);
152
            fibril_add_ready((fid_t) f);
153
            frw->writers++;
154
            break;
155
        } else {
156
            list_remove(&f->link);
157
            fibril_add_ready((fid_t) f);
158
            frw->readers++;
159
        }
160
    }
161
out:
162
    futex_up(&async_futex);
163
}
164
 
4516 jermar 165
void fibril_rwlock_read_unlock(fibril_rwlock_t *frw)
1427 palkovsky 166
{
4526 jermar 167
    _fibril_rwlock_common_unlock(frw);
1427 palkovsky 168
}
1610 palkovsky 169
 
4516 jermar 170
void fibril_rwlock_write_unlock(fibril_rwlock_t *frw)
1610 palkovsky 171
{
4526 jermar 172
    _fibril_rwlock_common_unlock(frw);
1610 palkovsky 173
}
174
 
4527 jermar 175
void fibril_condvar_initialize(fibril_condvar_t *fcv)
176
{
177
    list_initialize(&fcv->waiters);
178
}
179
 
180
void fibril_condvar_wait(fibril_condvar_t *fcv, fibril_mutex_t *fm)
181
{
182
    fibril_t *f = (fibril_t *) fibril_get_id();
183
 
184
    futex_down(&async_futex);
185
    list_append(&f->link, &fcv->waiters);
186
    _fibril_mutex_unlock_unsafe(fm);
187
    fibril_switch(FIBRIL_TO_MANAGER);
188
    fibril_mutex_lock(fm);
189
}
190
 
191
static void _fibril_condvar_wakeup_common(fibril_condvar_t *fcv, bool once)
192
{
193
    link_t *tmp;
194
    fibril_t *f;
195
 
196
    futex_down(&async_futex);
197
    while (!list_empty(&fcv->waiters)) {
198
        tmp = fcv->waiters.next;
199
        f = list_get_instance(tmp, fibril_t, link);
4535 jermar 200
        list_remove(&f->link);
4527 jermar 201
        fibril_add_ready((fid_t) f);
202
        if (once)
203
            break;
204
    }
205
    futex_up(&async_futex);
206
}
207
 
208
void fibril_condvar_signal(fibril_condvar_t *fcv)
209
{
210
    _fibril_condvar_wakeup_common(fcv, true);
211
}
212
 
213
void fibril_condvar_broadcast(fibril_condvar_t *fcv)
214
{
215
    _fibril_condvar_wakeup_common(fcv, false);
216
}
217
 
1719 decky 218
/** @}
1653 cejka 219
 */