source: mainline/src/synch/mutex.c@ a783ca4

/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <synch/mutex.h>
#include <synch/semaphore.h>
#include <synch/synch.h>

/** Initialize mutex
 *
 * Initialize mutex.
 *
 * @param mtx Mutex.
 */
void mutex_initialize(mutex_t *mtx)
{
        semaphore_initialize(&mtx->sem, 1);
}

/** Acquire mutex
 *
 * Acquire mutex.
 * Timeout mode and non-blocking mode can be requested.
 *
 * @param mtx Mutex.
 * @param usec Timeout in microseconds.
 * @param trylock Switches between blocking and non-blocking mode.
 *
 * For exact description of possible combinations of
 * 'usec' and 'trylock', see comment for waitq_sleep_timeout().
 *
 * @return See comment for waitq_sleep_timeout().
 */
int _mutex_lock_timeout(mutex_t *mtx, __u32 usec, int trylock)
{
        return _semaphore_down_timeout(&mtx->sem, usec, trylock);
}

/** Release mutex
 *
 * Release mutex.
 *
 * @param mtx Mutex.
 */
void mutex_unlock(mutex_t *mtx)
{
        semaphore_up(&mtx->sem);
}