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// SPDX-License-Identifier: CDDL-1.0
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2018 by Delphix. All rights reserved.
* Copyright (c) 2016 Actifio, Inc. All rights reserved.
* Copyright (c) 2025, Klara, Inc.
*/
#include <assert.h>
#include <pthread.h>
#include <errno.h>
#include <atomic.h>
#include <sys/rwlock.h>
/*
* =========================================================================
* rwlocks
* =========================================================================
*/
void
rw_init(krwlock_t *rwlp, char *name, int type, void *arg)
{
(void) name, (void) type, (void) arg;
VERIFY0(pthread_rwlock_init(&rwlp->rw_lock, NULL));
rwlp->rw_readers = 0;
rwlp->rw_owner = 0;
}
void
rw_destroy(krwlock_t *rwlp)
{
VERIFY0(pthread_rwlock_destroy(&rwlp->rw_lock));
}
void
rw_enter(krwlock_t *rwlp, krw_t rw)
{
if (rw == RW_READER) {
VERIFY0(pthread_rwlock_rdlock(&rwlp->rw_lock));
atomic_inc_uint(&rwlp->rw_readers);
} else {
VERIFY0(pthread_rwlock_wrlock(&rwlp->rw_lock));
rwlp->rw_owner = pthread_self();
}
}
void
rw_exit(krwlock_t *rwlp)
{
if (RW_READ_HELD(rwlp))
atomic_dec_uint(&rwlp->rw_readers);
else
rwlp->rw_owner = 0;
VERIFY0(pthread_rwlock_unlock(&rwlp->rw_lock));
}
int
rw_tryenter(krwlock_t *rwlp, krw_t rw)
{
int error;
if (rw == RW_READER)
error = pthread_rwlock_tryrdlock(&rwlp->rw_lock);
else
error = pthread_rwlock_trywrlock(&rwlp->rw_lock);
if (error == 0) {
if (rw == RW_READER)
atomic_inc_uint(&rwlp->rw_readers);
else
rwlp->rw_owner = pthread_self();
return (1);
}
VERIFY3S(error, ==, EBUSY);
return (0);
}
int
rw_tryupgrade(krwlock_t *rwlp)
{
(void) rwlp;
return (0);
}
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