320 lines
7.6 KiB
C
320 lines
7.6 KiB
C
/* $NetBSD: sem.c,v 1.5 2008/11/14 15:49:20 ad Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2003 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Jason R. Thorpe.
|
|
*
|
|
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*/
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__RCSID("$NetBSD: sem.c,v 1.5 2008/11/14 15:49:20 ad Exp $");
|
|
|
|
/*
|
|
* If an application is linked against both librt and libpthread, the
|
|
* libpthread versions must be used. Provide weak aliases to cause
|
|
* this behavior.
|
|
*/
|
|
#define sem_init _librt_sem_init
|
|
#define sem_destroy _librt_sem_destroy
|
|
#define sem_open _librt_sem_open
|
|
#define sem_close _librt_sem_close
|
|
#define sem_unlink _librt_sem_unlink
|
|
#define sem_wait _librt_sem_wait
|
|
#define sem_trywait _librt_sem_trywait
|
|
#define sem_post _librt_sem_post
|
|
#define sem_getvalue _librt_sem_getvalue
|
|
|
|
#define _LIBC
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/ksem.h>
|
|
#include <sys/queue.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <semaphore.h>
|
|
#include <stdarg.h>
|
|
|
|
struct _sem_st {
|
|
unsigned int ksem_magic;
|
|
#define KSEM_MAGIC 0x90af0421U
|
|
|
|
LIST_ENTRY(_sem_st) ksem_list;
|
|
intptr_t ksem_semid; /* 0 -> user (non-shared) */
|
|
sem_t *ksem_identity;
|
|
};
|
|
|
|
static int sem_alloc(unsigned int value, intptr_t semid, sem_t *semp);
|
|
static void sem_free(sem_t sem);
|
|
|
|
static LIST_HEAD(, _sem_st) named_sems = LIST_HEAD_INITIALIZER(&named_sems);
|
|
|
|
#ifdef __weak_alias
|
|
__weak_alias(sem_init,_librt_sem_init)
|
|
__weak_alias(sem_destroy,_librt_sem_destroy)
|
|
__weak_alias(sem_open,_librt_sem_open)
|
|
__weak_alias(sem_close,_librt_sem_close)
|
|
__weak_alias(sem_unlink,_librt_sem_unlink)
|
|
__weak_alias(sem_wait,_librt_sem_wait)
|
|
__weak_alias(sem_trywait,_librt_sem_trywait)
|
|
__weak_alias(sem_post,_librt_sem_post)
|
|
__weak_alias(sem_getvalue,_librt_sem_getvalue)
|
|
#endif
|
|
|
|
static void
|
|
sem_free(sem_t sem)
|
|
{
|
|
|
|
sem->ksem_magic = 0;
|
|
free(sem);
|
|
}
|
|
|
|
static int
|
|
sem_alloc(unsigned int value, intptr_t semid, sem_t *semp)
|
|
{
|
|
sem_t sem;
|
|
|
|
if (value > SEM_VALUE_MAX)
|
|
return (EINVAL);
|
|
|
|
if ((sem = malloc(sizeof(struct _sem_st))) == NULL)
|
|
return (ENOSPC);
|
|
|
|
sem->ksem_magic = KSEM_MAGIC;
|
|
sem->ksem_semid = semid;
|
|
|
|
*semp = sem;
|
|
return (0);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
int
|
|
sem_init(sem_t *sem, int pshared, unsigned int value)
|
|
{
|
|
intptr_t semid;
|
|
int error;
|
|
|
|
if (_ksem_init(value, &semid) == -1)
|
|
return (-1);
|
|
|
|
if ((error = sem_alloc(value, semid, sem)) != 0) {
|
|
_ksem_destroy(semid);
|
|
errno = error;
|
|
return (-1);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
sem_destroy(sem_t *sem)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
|
|
if (_ksem_destroy((*sem)->ksem_semid) == -1)
|
|
return (-1);
|
|
|
|
sem_free(*sem);
|
|
|
|
return (0);
|
|
}
|
|
|
|
sem_t *
|
|
sem_open(const char *name, int oflag, ...)
|
|
{
|
|
sem_t *sem, s;
|
|
intptr_t semid;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
int error;
|
|
va_list ap;
|
|
|
|
mode = 0;
|
|
value = 0;
|
|
|
|
if (oflag & O_CREAT) {
|
|
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(name, oflag, mode, value, &semid) == -1)
|
|
return (SEM_FAILED);
|
|
|
|
/*
|
|
* Search for a duplicate ID, we must return the same sem_t *
|
|
* if we locate one.
|
|
*/
|
|
LIST_FOREACH(s, &named_sems, ksem_list) {
|
|
if (s->ksem_semid == semid)
|
|
return (s->ksem_identity);
|
|
}
|
|
|
|
if ((sem = malloc(sizeof(*sem))) == NULL) {
|
|
error = ENOSPC;
|
|
goto bad;
|
|
}
|
|
if ((error = sem_alloc(value, semid, sem)) != 0)
|
|
goto bad;
|
|
|
|
LIST_INSERT_HEAD(&named_sems, *sem, ksem_list);
|
|
(*sem)->ksem_identity = sem;
|
|
|
|
return (sem);
|
|
|
|
bad:
|
|
_ksem_close(semid);
|
|
if (sem != NULL) {
|
|
if (*sem != NULL)
|
|
sem_free(*sem);
|
|
free(sem);
|
|
}
|
|
errno = error;
|
|
return (SEM_FAILED);
|
|
}
|
|
|
|
int
|
|
sem_close(sem_t *sem)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
|
|
if (_ksem_close((*sem)->ksem_semid) == -1)
|
|
return (-1);
|
|
|
|
LIST_REMOVE((*sem), ksem_list);
|
|
sem_free(*sem);
|
|
free(sem);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
sem_unlink(const char *name)
|
|
{
|
|
|
|
return (_ksem_unlink(name));
|
|
}
|
|
|
|
int
|
|
sem_wait(sem_t *sem)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
|
|
return (_ksem_wait((*sem)->ksem_semid));
|
|
}
|
|
|
|
int
|
|
sem_trywait(sem_t *sem)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
|
|
return (_ksem_trywait((*sem)->ksem_semid));
|
|
}
|
|
|
|
int
|
|
sem_post(sem_t *sem)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
|
|
return (_ksem_post((*sem)->ksem_semid));
|
|
}
|
|
|
|
int
|
|
sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
|
|
{
|
|
|
|
#ifdef ERRORCHECK
|
|
if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) {
|
|
errno = EINVAL;
|
|
return (-1);
|
|
}
|
|
#endif
|
|
return (_ksem_getvalue((*sem)->ksem_semid, sval));
|
|
}
|