freebsd-skq/lib/libstdthreads/mtx.c
ed 6f5f2f5fd7 Add libstdthreads.
This library implements the C11 threads interface on top of the pthreads
library.  As discussed on the lists, the preferred way to implement
this, is as a separate library.

It is unlikely that these functions will be used a lot in the future. It
would have been easier if the C11 working group standardized (a subset
of) pthreads and clock_nanosleep(). Having it as a separate library
allows the embedded people to omit it from their system.

Discussed on:	arch@, threads@
2011-12-26 21:51:53 +00:00

117 lines
2.7 KiB
C

/*-
* Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <pthread.h>
#include "threads.h"
void
mtx_destroy(mtx_t *mtx)
{
(void)pthread_mutex_destroy(mtx);
}
int
mtx_init(mtx_t *mtx, int type)
{
pthread_mutexattr_t attr;
int mt;
switch (type) {
case mtx_plain:
case mtx_timed:
mt = PTHREAD_MUTEX_NORMAL;
break;
case mtx_plain | mtx_recursive:
case mtx_timed | mtx_recursive:
mt = PTHREAD_MUTEX_RECURSIVE;
break;
default:
return (thrd_error);
}
if (pthread_mutexattr_init(&attr) != 0)
return (thrd_error);
if (pthread_mutexattr_settype(&attr, mt) != 0)
return (thrd_error);
if (pthread_mutex_init(mtx, &attr) != 0)
return (thrd_error);
return (thrd_success);
}
int
mtx_lock(mtx_t *mtx)
{
if (pthread_mutex_lock(mtx) != 0)
return (thrd_error);
return (thrd_success);
}
int
mtx_timedlock(mtx_t *restrict mtx, const struct timespec *restrict ts)
{
switch (pthread_mutex_timedlock(mtx, ts)) {
case 0:
return (thrd_success);
case ETIMEDOUT:
return (thrd_timedout);
default:
return (thrd_error);
}
}
int
mtx_trylock(mtx_t *mtx)
{
switch (pthread_mutex_lock(mtx)) {
case 0:
return (thrd_success);
case EBUSY:
return (thrd_busy);
default:
return (thrd_error);
}
}
int
mtx_unlock(mtx_t *mtx)
{
if (pthread_mutex_unlock(mtx) != 0)
return (thrd_error);
return (thrd_success);
}