NetBSD/lib/librefuse/refuse_log.c

101 lines
3.2 KiB
C

/* $NetBSD: refuse_log.c,v 1.2 2022/01/29 00:03:41 tnn Exp $ */
/*
* Copyright (c) 2021 The NetBSD Foundation, Inc.
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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>
#if !defined(lint)
__RCSID("$NetBSD: refuse_log.c,v 1.2 2022/01/29 00:03:41 tnn Exp $");
#endif /* !lint */
#include <assert.h>
#include <fuse_log.h>
#if defined(MULTITHREADED_REFUSE)
# include <pthread.h>
#endif
#include <stdio.h>
static void __printflike(2, 0)
default_log_func(enum fuse_log_level level __attribute__((__unused__)),
const char *fmt, va_list ap) {
/* This function needs to be thread-safe. Calling vfprintf(3)
* should be okay because POSIX mandates locking FILE* objects
* internally. */
vfprintf(stderr, fmt, ap);
}
#if defined(MULTITHREADED_REFUSE)
static pthread_mutex_t log_func_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
static fuse_log_func_t log_func = default_log_func;
void
fuse_set_log_func(fuse_log_func_t func) {
#if defined(MULTITHREADED_REFUSE)
/* What we really need here is merely a memory barrier, but
* locking a mutex is the easiest way to achieve that. */
int rv;
rv = pthread_mutex_lock(&log_func_mutex);
assert(rv == 0);
#endif
if (func)
log_func = func;
else
log_func = default_log_func;
#if defined(MULTITHREADED_REFUSE)
rv = pthread_mutex_unlock(&log_func_mutex);
assert(rv == 0);
#endif
}
void
fuse_log(enum fuse_log_level level, const char *fmt, ...) {
va_list ap;
#if defined(MULTITHREADED_REFUSE)
/* What we really need here is merely a memory barrier, but
* locking a mutex is the easiest way to achieve that. */
int rv;
rv = pthread_mutex_lock(&log_func_mutex);
assert(rv == 0);
#endif
va_start(ap, fmt);
log_func(level, fmt, ap);
va_end(ap);
#if defined(MULTITHREADED_REFUSE)
rv = pthread_mutex_unlock(&log_func_mutex);
assert(rv == 0);
#endif
}