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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org>
* Copyright (c) 2020 The FreeBSD Foundation
*
* Portions of this software were developed by Mark Johnston under
* sponsorship from the FreeBSD Foundation.
*
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef __SYS_BLOCKCOUNT_H__
#define __SYS_BLOCKCOUNT_H__
#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/_blockcount.h>
struct lock_object;
int _blockcount_sleep(blockcount_t *bc, struct lock_object *, const char *wmesg,
int prio);
void _blockcount_wakeup(blockcount_t *bc, u_int old);
static __inline void
blockcount_init(blockcount_t *bc)
{
atomic_store_int(&bc->__count, 0);
}
static __inline void
blockcount_acquire(blockcount_t *bc, u_int n)
{
#ifdef INVARIANTS
u_int old;
old = atomic_fetchadd_int(&bc->__count, n);
KASSERT(old + n > old, ("%s: counter overflow %p", __func__, bc));
#else
atomic_add_int(&bc->__count, n);
#endif
}
static __inline void
blockcount_release(blockcount_t *bc, u_int n)
{
u_int old;
atomic_thread_fence_rel();
old = atomic_fetchadd_int(&bc->__count, -n);
KASSERT(old >= n, ("%s: counter underflow %p", __func__, bc));
if (_BLOCKCOUNT_COUNT(old) == n && _BLOCKCOUNT_WAITERS(old))
_blockcount_wakeup(bc, old);
}
static __inline void
_blockcount_wait(blockcount_t *bc, struct lock_object *lo, const char *wmesg,
int prio)
{
KASSERT((prio & ~PRIMASK) == 0, ("%s: invalid prio %x", __func__, prio));
while (_blockcount_sleep(bc, lo, wmesg, prio) == EAGAIN)
;
}
#define blockcount_sleep(bc, lo, wmesg, prio) \
_blockcount_sleep((bc), (struct lock_object *)(lo), (wmesg), (prio))
#define blockcount_wait(bc, lo, wmesg, prio) \
_blockcount_wait((bc), (struct lock_object *)(lo), (wmesg), (prio))
#endif /* _KERNEL */
#endif /* !__SYS_BLOCKCOUNT_H__ */
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