freebsd-skq/sbin/hastd/refcnt.h
pjd 0bf19fd812 - Add support for 'memsync' mode. This is the fastest replication mode that's
why it will now be the default.
- Bump protocol version to 2 and add backward compatibility for version 1.
- Allow to specify hosts by kern.hostid as well (in addition to hostname and
  kern.hostuuid) in configuration file.

Sponsored by:	Panzura
Tested by:	trociny
2013-02-17 21:12:34 +00:00

58 lines
2.0 KiB
C

/*-
* Copyright (c) 2005 John Baldwin <jhb@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, 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. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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 __REFCNT_H__
#define __REFCNT_H__
#include <machine/atomic.h>
#include "pjdlog.h"
static __inline void
refcnt_acquire(volatile unsigned int *count)
{
atomic_add_acq_int(count, 1);
}
static __inline unsigned int
refcnt_release(volatile unsigned int *count)
{
unsigned int old;
/* XXX: Should this have a rel membar? */
old = atomic_fetchadd_int(count, -1);
PJDLOG_ASSERT(old > 0);
return (old - 1);
}
#endif /* ! __REFCNT_H__ */