832e8b7f9a
Only warnings that could be fixed without changing the generated object code and without restructuring the source code have been handled. Reviewed by: /sbin/md5
358 lines
7.1 KiB
C
358 lines
7.1 KiB
C
/*
|
|
* Copyright (C) 2000 Jason Evans <jasone@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(s), this list of conditions and the following disclaimer as
|
|
* the first lines of this file unmodified other than the possible
|
|
* addition of one or more copyright notices.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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 "namespace.h"
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <semaphore.h>
|
|
#include <stdarg.h>
|
|
#include <pthread.h>
|
|
#include <sys/queue.h>
|
|
#include <_semaphore.h>
|
|
#include "un-namespace.h"
|
|
|
|
#define _SEM_CHECK_VALIDITY(sem) \
|
|
if ((*(sem))->magic != SEM_MAGIC) { \
|
|
errno = EINVAL; \
|
|
retval = -1; \
|
|
goto RETURN; \
|
|
}
|
|
|
|
static sem_t sem_alloc(unsigned int value, semid_t semid, int system_sem);
|
|
static void sem_free(sem_t sem);
|
|
|
|
static LIST_HEAD(, sem) named_sems = LIST_HEAD_INITIALIZER(&named_sems);
|
|
static pthread_mutex_t named_sems_mtx = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
static void
|
|
sem_free(sem_t sem)
|
|
{
|
|
|
|
_pthread_mutex_destroy(&sem->lock);
|
|
_pthread_cond_destroy(&sem->gtzero);
|
|
sem->magic = 0;
|
|
free(sem);
|
|
}
|
|
|
|
static sem_t
|
|
sem_alloc(unsigned int value, semid_t semid, int system_sem)
|
|
{
|
|
sem_t sem;
|
|
|
|
if (value > SEM_VALUE_MAX) {
|
|
errno = EINVAL;
|
|
return (NULL);
|
|
}
|
|
|
|
sem = (sem_t)malloc(sizeof(struct sem));
|
|
if (sem == NULL) {
|
|
errno = ENOSPC;
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Initialize the semaphore.
|
|
*/
|
|
if (_pthread_mutex_init(&sem->lock, NULL) != 0) {
|
|
free(sem);
|
|
errno = ENOSPC;
|
|
return (NULL);
|
|
}
|
|
|
|
if (_pthread_cond_init(&sem->gtzero, NULL) != 0) {
|
|
_pthread_mutex_destroy(&sem->lock);
|
|
free(sem);
|
|
errno = ENOSPC;
|
|
return (NULL);
|
|
}
|
|
|
|
sem->count = (u_int32_t)value;
|
|
sem->nwaiters = 0;
|
|
sem->magic = SEM_MAGIC;
|
|
sem->semid = semid;
|
|
sem->syssem = system_sem;
|
|
return (sem);
|
|
}
|
|
|
|
int
|
|
sem_init(sem_t *sem, int pshared, unsigned int value)
|
|
{
|
|
int retval, got_system_sem;
|
|
semid_t semid;
|
|
|
|
got_system_sem = 0;
|
|
semid = SEM_USER;
|
|
/*
|
|
* Range check the arguments.
|
|
*/
|
|
if (pshared != 0) {
|
|
retval = ksem_init(&semid, value);
|
|
if (retval == -1)
|
|
goto RETURN;
|
|
got_system_sem = 1;
|
|
}
|
|
|
|
(*sem) = sem_alloc(value, semid, got_system_sem);
|
|
if ((*sem) == NULL)
|
|
retval = -1;
|
|
else
|
|
retval = 0;
|
|
RETURN:
|
|
if (retval != 0 && got_system_sem)
|
|
ksem_destroy(semid);
|
|
return retval;
|
|
}
|
|
|
|
int
|
|
sem_destroy(sem_t *sem)
|
|
{
|
|
int retval;
|
|
|
|
_SEM_CHECK_VALIDITY(sem);
|
|
|
|
_pthread_mutex_lock(&(*sem)->lock);
|
|
/*
|
|
* If this is a system semaphore let the kernel track it otherwise
|
|
* make sure there are no waiters.
|
|
*/
|
|
if ((*sem)->syssem != 0) {
|
|
retval = ksem_destroy((*sem)->semid);
|
|
if (retval == -1) {
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
goto RETURN;
|
|
}
|
|
} else if ((*sem)->nwaiters > 0) {
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
errno = EBUSY;
|
|
retval = -1;
|
|
goto RETURN;
|
|
}
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
|
|
sem_free(*sem);
|
|
|
|
retval = 0;
|
|
RETURN:
|
|
return retval;
|
|
}
|
|
|
|
sem_t *
|
|
sem_open(const char *name, int oflag, ...)
|
|
{
|
|
sem_t *sem;
|
|
sem_t s;
|
|
semid_t semid;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
|
|
mode = 0;
|
|
value = 0;
|
|
|
|
if ((oflag & O_CREAT) != 0) {
|
|
va_list ap;
|
|
|
|
va_start(ap, oflag);
|
|
mode = va_arg(ap, int);
|
|
value = va_arg(ap, unsigned int);
|
|
va_end(ap);
|
|
}
|
|
/*
|
|
* we can be lazy and let the kernel handle the "oflag",
|
|
* we'll just merge duplicate IDs into our list.
|
|
*/
|
|
if (ksem_open(&semid, name, oflag, mode, value) == -1)
|
|
return (SEM_FAILED);
|
|
/*
|
|
* search for a duplicate ID, we must return the same sem_t *
|
|
* if we locate one.
|
|
*/
|
|
_pthread_mutex_lock(&named_sems_mtx);
|
|
LIST_FOREACH(s, &named_sems, entry) {
|
|
if (s->semid == semid) {
|
|
_pthread_mutex_unlock(&named_sems_mtx);
|
|
return (s->backpointer);
|
|
}
|
|
}
|
|
sem = (sem_t *)malloc(sizeof(*sem));
|
|
if (sem == NULL)
|
|
goto err;
|
|
*sem = sem_alloc(value, semid, 1);
|
|
if ((*sem) == NULL)
|
|
goto err;
|
|
LIST_INSERT_HEAD(&named_sems, *sem, entry);
|
|
(*sem)->backpointer = sem;
|
|
_pthread_mutex_unlock(&named_sems_mtx);
|
|
return (sem);
|
|
err:
|
|
_pthread_mutex_unlock(&named_sems_mtx);
|
|
ksem_close(semid);
|
|
if (sem != NULL) {
|
|
if (*sem != NULL)
|
|
sem_free(*sem);
|
|
else
|
|
errno = ENOSPC;
|
|
free(sem);
|
|
} else {
|
|
errno = ENOSPC;
|
|
}
|
|
return (SEM_FAILED);
|
|
}
|
|
|
|
int
|
|
sem_close(sem_t *sem)
|
|
{
|
|
|
|
if ((*sem)->syssem == 0) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
_pthread_mutex_lock(&named_sems_mtx);
|
|
if (ksem_close((*sem)->semid) == -1) {
|
|
_pthread_mutex_unlock(&named_sems_mtx);
|
|
return (-1);
|
|
}
|
|
LIST_REMOVE((*sem), entry);
|
|
_pthread_mutex_unlock(&named_sems_mtx);
|
|
sem_free(*sem);
|
|
free(sem);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
sem_unlink(const char *name)
|
|
{
|
|
|
|
return (ksem_unlink(name));
|
|
}
|
|
|
|
int
|
|
sem_wait(sem_t *sem)
|
|
{
|
|
int retval;
|
|
|
|
_SEM_CHECK_VALIDITY(sem);
|
|
|
|
if ((*sem)->syssem != 0) {
|
|
retval = ksem_wait((*sem)->semid);
|
|
goto RETURN;
|
|
}
|
|
|
|
_pthread_mutex_lock(&(*sem)->lock);
|
|
|
|
while ((*sem)->count == 0) {
|
|
(*sem)->nwaiters++;
|
|
_pthread_cond_wait(&(*sem)->gtzero, &(*sem)->lock);
|
|
(*sem)->nwaiters--;
|
|
}
|
|
(*sem)->count--;
|
|
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
|
|
retval = 0;
|
|
RETURN:
|
|
return retval;
|
|
}
|
|
|
|
int
|
|
sem_trywait(sem_t *sem)
|
|
{
|
|
int retval;
|
|
|
|
_SEM_CHECK_VALIDITY(sem);
|
|
|
|
if ((*sem)->syssem != 0) {
|
|
retval = ksem_trywait((*sem)->semid);
|
|
goto RETURN;
|
|
}
|
|
|
|
_pthread_mutex_lock(&(*sem)->lock);
|
|
|
|
if ((*sem)->count > 0) {
|
|
(*sem)->count--;
|
|
retval = 0;
|
|
} else {
|
|
errno = EAGAIN;
|
|
retval = -1;
|
|
}
|
|
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
|
|
RETURN:
|
|
return retval;
|
|
}
|
|
|
|
int
|
|
sem_post(sem_t *sem)
|
|
{
|
|
int retval;
|
|
|
|
_SEM_CHECK_VALIDITY(sem);
|
|
|
|
if ((*sem)->syssem != 0) {
|
|
retval = ksem_post((*sem)->semid);
|
|
goto RETURN;
|
|
}
|
|
|
|
_pthread_mutex_lock(&(*sem)->lock);
|
|
|
|
(*sem)->count++;
|
|
if ((*sem)->nwaiters > 0)
|
|
_pthread_cond_signal(&(*sem)->gtzero);
|
|
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
|
|
retval = 0;
|
|
RETURN:
|
|
return retval;
|
|
}
|
|
|
|
int
|
|
sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
|
|
{
|
|
int retval;
|
|
|
|
_SEM_CHECK_VALIDITY(sem);
|
|
|
|
if ((*sem)->syssem != 0) {
|
|
retval = ksem_getvalue((*sem)->semid, sval);
|
|
goto RETURN;
|
|
}
|
|
|
|
_pthread_mutex_lock(&(*sem)->lock);
|
|
*sval = (int)(*sem)->count;
|
|
_pthread_mutex_unlock(&(*sem)->lock);
|
|
|
|
retval = 0;
|
|
RETURN:
|
|
return retval;
|
|
}
|