/* $NetBSD: sem.c,v 1.7 2012/03/10 19:59:21 joerg 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 . * 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 __RCSID("$NetBSD: sem.c,v 1.7 2012/03/10 19:59:21 joerg 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_timedwait _librt_sem_timedwait #define sem_trywait _librt_sem_trywait #define sem_post _librt_sem_post #define sem_getvalue _librt_sem_getvalue #define _LIBC #include #include #include #include #include #include #include #include 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_timedwait,_librt_sem_timedwait) __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) { int error, save_errno; #ifdef ERRORCHECK if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) { errno = EINVAL; return (-1); } #endif error = _ksem_destroy((*sem)->ksem_semid); save_errno = errno; sem_free(*sem); errno = save_errno; return error; } 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) { int error, save_errno; #ifdef ERRORCHECK if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) { errno = EINVAL; return (-1); } #endif error = _ksem_close((*sem)->ksem_semid); LIST_REMOVE((*sem), ksem_list); save_errno = errno; sem_free(*sem); free(sem); errno = save_errno; return error; } 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_timedwait(sem_t *sem, const struct timespec * __restrict abstime) { #ifdef ERRORCHECK if (sem == NULL || *sem == NULL || (*sem)->ksem_magic != KSEM_MAGIC) { errno = EINVAL; return (-1); } #endif return (_ksem_timedwait((*sem)->ksem_semid, abstime)); } 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)); }