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/*
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 * Copyright (c) 2001-2004 Jakub Jermar
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 * 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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/** @addtogroup sync
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 * @{
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 */
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/**
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 * @file
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 * @brief   Mutexes.
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 */
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#include <synch/mutex.h>
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#include <synch/semaphore.h>
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#include <synch/synch.h>
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#include <debug.h>
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/** Initialize mutex.
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 *
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 * @param mtx       Mutex.
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 * @param type      Type of the mutex.
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 */
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void mutex_initialize(mutex_t *mtx, mutex_type_t type)
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{
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    mtx->type = type;
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    semaphore_initialize(&mtx->sem, 1);
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}
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/** Acquire mutex.
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 *
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 * Timeout mode and non-blocking mode can be requested.
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 *
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 * @param mtx       Mutex.
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 * @param usec      Timeout in microseconds.
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 * @param flags     Specify mode of operation.
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 *
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 * For exact description of possible combinations of
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 * usec and flags, see comment for waitq_sleep_timeout().
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 *
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 * @return      See comment for waitq_sleep_timeout().
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 */
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int _mutex_lock_timeout(mutex_t *mtx, uint32_t usec, int flags)
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{
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    int rc;
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    if (mtx->type == MUTEX_PASSIVE) {
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        rc = _semaphore_down_timeout(&mtx->sem, usec, flags);
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    } else {
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        ASSERT(mtx->type == MUTEX_ACTIVE);
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        ASSERT(usec == SYNCH_NO_TIMEOUT);
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        ASSERT(!(flags & SYNCH_FLAGS_INTERRUPTIBLE));
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        do {
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            rc = semaphore_trydown(&mtx->sem);
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        } while (SYNCH_FAILED(rc) &&
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            !(flags & SYNCH_FLAGS_NON_BLOCKING));
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    }
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    return rc;
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}
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/** Release mutex.
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 *
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 * @param mtx       Mutex.
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 */
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void mutex_unlock(mutex_t *mtx)
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{
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    semaphore_up(&mtx->sem);
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}
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/** @}
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 */