[f761f1eb] | 1 | /*
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[df4ed85] | 2 | * Copyright (c) 2001-2004 Jakub Jermar
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[f761f1eb] | 3 | * All rights reserved.
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| 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 |
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[cc73a8a1] | 29 | /** @addtogroup sync
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[b45c443] | 30 | * @{
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| 31 | */
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| 32 |
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[cf26ba9] | 33 | /**
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[b45c443] | 34 | * @file
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[cf26ba9] | 35 | * @brief Condition variables.
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| 36 | */
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| 37 |
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[f761f1eb] | 38 | #include <synch/condvar.h>
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| 39 | #include <synch/mutex.h>
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| 40 | #include <synch/waitq.h>
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[df364582] | 41 | #include <synch/synch.h>
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[c0bc189] | 42 | #include <arch.h>
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[f761f1eb] | 43 |
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[c0bc189] | 44 | /** Initialize condition variable.
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[df364582] | 45 | *
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| 46 | * @param cv Condition variable.
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| 47 | */
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[f761f1eb] | 48 | void condvar_initialize(condvar_t *cv)
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| 49 | {
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| 50 | waitq_initialize(&cv->wq);
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| 51 | }
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| 52 |
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[c0bc189] | 53 | /**
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[df364582] | 54 | * Signal the condition has become true
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| 55 | * to the first waiting thread by waking it up.
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| 56 | *
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[a783ca4] | 57 | * @param cv Condition variable.
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[df364582] | 58 | */
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[f761f1eb] | 59 | void condvar_signal(condvar_t *cv)
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| 60 | {
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| 61 | waitq_wakeup(&cv->wq, WAKEUP_FIRST);
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| 62 | }
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| 63 |
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[c0bc189] | 64 | /**
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[df364582] | 65 | * Signal the condition has become true
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| 66 | * to all waiting threads by waking them up.
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| 67 | *
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[a783ca4] | 68 | * @param cv Condition variable.
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[df364582] | 69 | */
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[f761f1eb] | 70 | void condvar_broadcast(condvar_t *cv)
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| 71 | {
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| 72 | waitq_wakeup(&cv->wq, WAKEUP_ALL);
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| 73 | }
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| 74 |
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[c0bc189] | 75 | /** Wait for the condition becoming true.
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[df364582] | 76 | *
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[a783ca4] | 77 | * @param cv Condition variable.
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| 78 | * @param mtx Mutex.
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| 79 | * @param usec Timeout value in microseconds.
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[116d1ef4] | 80 | * @param flags Select mode of operation.
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[a783ca4] | 81 | *
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[116d1ef4] | 82 | * For exact description of meaning of possible combinations
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| 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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[a783ca4] | 86 | *
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| 87 | * @return See comment for waitq_sleep_timeout().
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[df364582] | 88 | */
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[7f1c620] | 89 | int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, uint32_t usec, int flags)
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[f761f1eb] | 90 | {
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| 91 | int rc;
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[c0bc189] | 92 | ipl_t ipl;
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[f761f1eb] | 93 |
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[c0bc189] | 94 | ipl = waitq_sleep_prepare(&cv->wq);
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[f761f1eb] | 95 | mutex_unlock(mtx);
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[baafe71] | 96 |
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| 97 | cv->wq.missed_wakeups = 0; /* Enforce blocking. */
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[116d1ef4] | 98 | rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
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[c0bc189] | 99 |
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[f761f1eb] | 100 | mutex_lock(mtx);
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[c0bc189] | 101 | waitq_sleep_finish(&cv->wq, rc, ipl);
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| 102 |
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[f761f1eb] | 103 | return rc;
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| 104 | }
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[b45c443] | 105 |
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[cc73a8a1] | 106 | /** @}
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[b45c443] | 107 | */
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