diff options
Diffstat (limited to 'lib/libpthread')
| -rw-r--r-- | lib/libpthread/uthread/Makefile.inc | 3 | ||||
| -rw-r--r-- | lib/libpthread/uthread/uthread_sem.c | 247 |
2 files changed, 249 insertions, 1 deletions
diff --git a/lib/libpthread/uthread/Makefile.inc b/lib/libpthread/uthread/Makefile.inc index 597381fc9c1..b9a005b26fe 100644 --- a/lib/libpthread/uthread/Makefile.inc +++ b/lib/libpthread/uthread/Makefile.inc @@ -1,4 +1,4 @@ -# $OpenBSD: Makefile.inc,v 1.12 2001/08/17 22:12:31 pvalchev Exp $ +# $OpenBSD: Makefile.inc,v 1.13 2002/01/18 22:07:27 fgsch Exp $ # $FreeBSD: Makefile.inc,v 1.19 1999/08/28 00:03:19 peter Exp $ # uthread sources @@ -93,6 +93,7 @@ SRCS+= \ uthread_rwlockattr.c \ uthread_select.c \ uthread_self.c \ + uthread_sem.c \ uthread_sendmsg.c \ uthread_sendto.c \ uthread_seterrno.c \ diff --git a/lib/libpthread/uthread/uthread_sem.c b/lib/libpthread/uthread/uthread_sem.c new file mode 100644 index 00000000000..21f7cf86975 --- /dev/null +++ b/lib/libpthread/uthread/uthread_sem.c @@ -0,0 +1,247 @@ +/* $OpenBSD: uthread_sem.c,v 1.1 2002/01/18 22:07:27 fgsch Exp $ */ +/* + * 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: uthread_sem.c,v 1.10 2001/05/18 00:36:05 jasone Exp $ + */ + +#include <stdlib.h> +#include <errno.h> +#include <semaphore.h> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + +#define _SEM_CHECK_VALIDITY(sem) \ + if ((*(sem))->magic != SEM_MAGIC) { \ + errno = EINVAL; \ + retval = -1; \ + goto RETURN; \ + } + +int +sem_init(sem_t *sem, int pshared, unsigned int value) +{ + int retval; + + /* + * Range check the arguments. + */ + if (pshared != 0) { + /* + * The user wants a semaphore that can be shared among + * processes, which this implementation can't do. Sounds like a + * permissions problem to me (yeah right). + */ + errno = EPERM; + retval = -1; + goto RETURN; + } + + if (value > SEM_VALUE_MAX) { + errno = EINVAL; + retval = -1; + goto RETURN; + } + + *sem = (sem_t)malloc(sizeof(struct sem)); + if (*sem == NULL) { + errno = ENOSPC; + retval = -1; + goto RETURN; + } + + /* + * Initialize the semaphore. + */ + if (pthread_mutex_init(&(*sem)->lock, NULL) != 0) { + free(*sem); + errno = ENOSPC; + retval = -1; + goto RETURN; + } + + if (pthread_cond_init(&(*sem)->gtzero, NULL) != 0) { + pthread_mutex_destroy(&(*sem)->lock); + free(*sem); + errno = ENOSPC; + retval = -1; + goto RETURN; + } + + (*sem)->count = (u_int32_t)value; + (*sem)->nwaiters = 0; + (*sem)->magic = SEM_MAGIC; + + retval = 0; + RETURN: + return retval; +} + +int +sem_destroy(sem_t *sem) +{ + int retval; + + _SEM_CHECK_VALIDITY(sem); + + /* Make sure there are no waiters. */ + pthread_mutex_lock(&(*sem)->lock); + if ((*sem)->nwaiters > 0) { + pthread_mutex_unlock(&(*sem)->lock); + errno = EBUSY; + retval = -1; + goto RETURN; + } + pthread_mutex_unlock(&(*sem)->lock); + + pthread_mutex_destroy(&(*sem)->lock); + pthread_cond_destroy(&(*sem)->gtzero); + (*sem)->magic = 0; + + free(*sem); + + retval = 0; + RETURN: + return retval; +} + +sem_t * +sem_open(const char *name, int oflag, ...) +{ + errno = ENOSYS; + return SEM_FAILED; +} + +int +sem_close(sem_t *sem) +{ + errno = ENOSYS; + return -1; +} + +int +sem_unlink(const char *name) +{ + errno = ENOSYS; + return -1; +} + +int +sem_wait(sem_t *sem) +{ + int retval; + + _thread_enter_cancellation_point(); + + _SEM_CHECK_VALIDITY(sem); + + 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: + _thread_leave_cancellation_point(); + return retval; +} + +int +sem_trywait(sem_t *sem) +{ + int retval; + + _SEM_CHECK_VALIDITY(sem); + + 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); + + /* + * sem_post() is required to be safe to call from within signal + * handlers. Thus, we must defer signals. + */ + _thread_kern_sig_defer(); + + pthread_mutex_lock(&(*sem)->lock); + + (*sem)->count++; + if ((*sem)->nwaiters > 0) + pthread_cond_signal(&(*sem)->gtzero); + + pthread_mutex_unlock(&(*sem)->lock); + + _thread_kern_sig_undefer(); + retval = 0; + RETURN: + return retval; +} + +int +sem_getvalue(sem_t *sem, int *sval) +{ + int retval; + + _SEM_CHECK_VALIDITY(sem); + + pthread_mutex_lock(&(*sem)->lock); + *sval = (int)(*sem)->count; + pthread_mutex_unlock(&(*sem)->lock); + + retval = 0; + RETURN: + return retval; +} + +#endif |