Rev 3186 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
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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 | * |
| 3186 | jermar | 46 | * @param cv Condition variable. |
| 387 | jermar | 47 | */ |
| 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 | |||
| 3186 | jermar | 53 | /** Signal the condition has become true to the first waiting thread by waking |
| 54 | * it up. |
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| 387 | jermar | 55 | * |
| 3186 | jermar | 56 | * @param cv Condition variable. |
| 387 | jermar | 57 | */ |
| 1 | jermar | 58 | void condvar_signal(condvar_t *cv) |
| 59 | { |
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| 60 | waitq_wakeup(&cv->wq, WAKEUP_FIRST); |
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| 61 | } |
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| 62 | |||
| 3186 | jermar | 63 | /** Signal the condition has become true to all waiting threads by waking |
| 64 | * them up. |
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| 387 | jermar | 65 | * |
| 3186 | jermar | 66 | * @param cv Condition variable. |
| 387 | jermar | 67 | */ |
| 1 | jermar | 68 | void condvar_broadcast(condvar_t *cv) |
| 69 | { |
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| 70 | waitq_wakeup(&cv->wq, WAKEUP_ALL); |
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| 71 | } |
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| 72 | |||
| 1375 | jermar | 73 | /** Wait for the condition becoming true. |
| 387 | jermar | 74 | * |
| 3186 | jermar | 75 | * @param cv Condition variable. |
| 76 | * @param mtx Mutex. |
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| 77 | * @param usec Timeout value in microseconds. |
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| 78 | * @param flags Select mode of operation. |
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| 404 | jermar | 79 | * |
| 3186 | jermar | 80 | * For exact description of meaning of possible combinations of usec and flags, |
| 81 | * see comment for waitq_sleep_timeout(). Note that when |
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| 82 | * SYNCH_FLAGS_NON_BLOCKING is specified here, ESYNCH_WOULD_BLOCK is always |
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| 83 | * returned. |
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| 404 | jermar | 84 | * |
| 3186 | jermar | 85 | * @return See comment for waitq_sleep_timeout(). |
| 387 | jermar | 86 | */ |
| 1780 | jermar | 87 | int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, uint32_t usec, int flags) |
| 1 | jermar | 88 | { |
| 89 | int rc; |
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| 1375 | jermar | 90 | ipl_t ipl; |
| 1 | jermar | 91 | |
| 1375 | jermar | 92 | ipl = waitq_sleep_prepare(&cv->wq); |
| 1 | jermar | 93 | mutex_unlock(mtx); |
| 1375 | jermar | 94 | |
| 1416 | jermar | 95 | cv->wq.missed_wakeups = 0; /* Enforce blocking. */ |
| 1502 | jermar | 96 | rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags); |
| 1416 | jermar | 97 | |
| 1 | jermar | 98 | mutex_lock(mtx); |
| 1375 | jermar | 99 | waitq_sleep_finish(&cv->wq, rc, ipl); |
| 100 | |||
| 1 | jermar | 101 | return rc; |
| 102 | } |
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| 1702 | cejka | 103 | |
| 1757 | jermar | 104 | /** @} |
| 1702 | cejka | 105 | */ |