process_shared/ext/libpsem/psem_posix.c

131 lines
3.4 KiB
C

/*
* A type which wraps a semaphore
*
* semaphore.c
*
* Copyright (c) 2006-2008, R Oudkerk
*
* 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.
*
* 3. Neither the name of author nor the names of any contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 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.
*/
/*
* Modifications Copyright (c) 2011, Patrick Mahoney
*/
#include <errno.h>
#include <fcntl.h> /* For O_* constants */
#include <sys/stat.h> /* For mode constants */
#include <semaphore.h>
#include <stdlib.h> /* malloc, free */
#include <math.h> /* floorf */
#include <time.h> /* timespec */
#include "psem.h"
#include "psem_posix.h"
psem_t *
psem_alloc(void) {
return (psem_t *) malloc(sizeof(psem_t));
}
void
psem_free(psem_t *psem) {
free(psem);
}
#define errcheck_val(expr, errval, err) \
do { \
if ((expr) == (errval)) { \
error_new((err), E_SOURCE_SYSTEM, errno); \
return ERROR; \
} \
return OK; \
} while (0)
#define errcheck(expr, err) errcheck_val((expr), -1, (err))
int
psem_open(psem_t *psem, const char *name, unsigned int value, error_t **err)
{
errcheck_val(psem->sem = sem_open(name, O_CREAT | O_EXCL, 0600, value),
SEM_FAILED,
err);
}
int
psem_close(psem_t *psem, error_t **err)
{
errcheck(sem_close(psem->sem), err);
}
int
psem_unlink(const char *name, error_t **err)
{
errcheck(sem_unlink(name), err);
}
int
psem_post(psem_t *psem, error_t **err)
{
errcheck(sem_post(psem->sem), err);
}
int
psem_wait(psem_t *psem, error_t **err)
{
errcheck(sem_wait(psem->sem), err);
}
int
psem_trywait(psem_t *psem, error_t **err)
{
errcheck(sem_trywait(psem->sem), err);
}
int
psem_timedwait(psem_t *psem, float timeout_s, error_t **err)
{
struct timespec abs_timeout;
abs_timeout.tv_sec = floorf(timeout_s);
abs_timeout.tv_nsec =
floorf((timeout_s - abs_timeout.tv_sec) * (1000 * 1000 * 1000));
errcheck(sem_timedwait(psem->sem, &abs_timeout), err);
}
int
psem_getvalue(psem_t *psem, int *sval, error_t **err)
{
errcheck(sem_getvalue(psem->sem, sval), err);
}