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1 | jermar | 1 | /* |
2071 | jermar | 2 | * Copyright (c) 2001-2004 Jakub Jermar |
1 | jermar | 3 | * All rights reserved. |
4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
1757 | jermar | 29 | /** @addtogroup sync |
1702 | cejka | 30 | * @{ |
31 | */ |
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32 | |||
1264 | jermar | 33 | /** |
1702 | cejka | 34 | * @file |
1264 | jermar | 35 | * @brief Condition variables. |
36 | */ |
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37 | |||
1 | jermar | 38 | #include <synch/condvar.h> |
39 | #include <synch/mutex.h> |
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40 | #include <synch/waitq.h> |
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387 | jermar | 41 | #include <synch/synch.h> |
1375 | jermar | 42 | #include <arch.h> |
1 | jermar | 43 | |
1375 | jermar | 44 | /** Initialize condition variable. |
387 | jermar | 45 | * |
46 | * @param cv Condition variable. |
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47 | */ |
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1 | jermar | 48 | void condvar_initialize(condvar_t *cv) |
49 | { |
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50 | waitq_initialize(&cv->wq); |
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51 | } |
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52 | |||
1375 | jermar | 53 | /** |
387 | jermar | 54 | * Signal the condition has become true |
55 | * to the first waiting thread by waking it up. |
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56 | * |
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404 | jermar | 57 | * @param cv Condition variable. |
387 | jermar | 58 | */ |
1 | jermar | 59 | void condvar_signal(condvar_t *cv) |
60 | { |
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61 | waitq_wakeup(&cv->wq, WAKEUP_FIRST); |
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62 | } |
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63 | |||
1375 | jermar | 64 | /** |
387 | jermar | 65 | * Signal the condition has become true |
66 | * to all waiting threads by waking them up. |
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67 | * |
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404 | jermar | 68 | * @param cv Condition variable. |
387 | jermar | 69 | */ |
1 | jermar | 70 | void condvar_broadcast(condvar_t *cv) |
71 | { |
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72 | waitq_wakeup(&cv->wq, WAKEUP_ALL); |
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73 | } |
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74 | |||
1375 | jermar | 75 | /** Wait for the condition becoming true. |
387 | jermar | 76 | * |
404 | jermar | 77 | * @param cv Condition variable. |
78 | * @param mtx Mutex. |
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79 | * @param usec Timeout value in microseconds. |
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1502 | jermar | 80 | * @param flags Select mode of operation. |
404 | jermar | 81 | * |
1502 | jermar | 82 | * For exact description of meaning of possible combinations |
83 | * of usec and flags, see comment for waitq_sleep_timeout(). |
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84 | * Note that when SYNCH_FLAGS_NON_BLOCKING is specified here, |
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85 | * ESYNCH_WOULD_BLOCK is always returned. |
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404 | jermar | 86 | * |
87 | * @return See comment for waitq_sleep_timeout(). |
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387 | jermar | 88 | */ |
1780 | jermar | 89 | int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, uint32_t usec, int flags) |
1 | jermar | 90 | { |
91 | int rc; |
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1375 | jermar | 92 | ipl_t ipl; |
1 | jermar | 93 | |
1375 | jermar | 94 | ipl = waitq_sleep_prepare(&cv->wq); |
1 | jermar | 95 | mutex_unlock(mtx); |
1375 | jermar | 96 | |
1416 | jermar | 97 | cv->wq.missed_wakeups = 0; /* Enforce blocking. */ |
1502 | jermar | 98 | rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags); |
1416 | jermar | 99 | |
1 | jermar | 100 | mutex_lock(mtx); |
1375 | jermar | 101 | waitq_sleep_finish(&cv->wq, rc, ipl); |
102 | |||
1 | jermar | 103 | return rc; |
104 | } |
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1702 | cejka | 105 | |
1757 | jermar | 106 | /** @} |
1702 | cejka | 107 | */ |