1238106Sdes/*- 2238106Sdes * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3238106Sdes * 4238106Sdes * Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org> 5238106Sdes * 6238106Sdes * Redistribution and use in source and binary forms, with or without 7238106Sdes * modification, are permitted provided that the following conditions 8238106Sdes * are met: 9238106Sdes * 1. Redistributions of source code must retain the above copyright 10238106Sdes * notice, this list of conditions and the following disclaimer. 11238106Sdes * 2. Redistributions in binary form must reproduce the above copyright 12238106Sdes * notice, this list of conditions and the following disclaimer in the 13238106Sdes * documentation and/or other materials provided with the distribution. 14238106Sdes * 15238106Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16238106Sdes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17238106Sdes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18238106Sdes * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19238106Sdes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20238106Sdes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21238106Sdes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22238106Sdes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23238106Sdes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24238106Sdes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25238106Sdes * SUCH DAMAGE. 26238106Sdes * 27238106Sdes * $FreeBSD: stable/11/sbin/hastd/refcnt.h 367457 2020-11-07 18:10:59Z dim $ 28238106Sdes */ 29238106Sdes 30238106Sdes#ifndef __REFCNT_H__ 31238106Sdes#define __REFCNT_H__ 32238106Sdes 33238106Sdes#include <machine/atomic.h> 34238106Sdes 35238106Sdes#include "pjdlog.h" 36238106Sdes 37238106Sdestypedef unsigned int refcnt_t; 38238106Sdes 39238106Sdesstatic __inline void 40238106Sdesrefcnt_init(refcnt_t *count, unsigned int v) 41238106Sdes{ 42238106Sdes 43238106Sdes *count = v; 44238106Sdes} 45238106Sdes 46238106Sdesstatic __inline void 47249141Sdesrefcnt_acquire(refcnt_t *count) 48249141Sdes{ 49249141Sdes 50238106Sdes atomic_add_acq_int(count, 1); 51238106Sdes} 52238106Sdes 53238106Sdesstatic __inline unsigned int 54238106Sdesrefcnt_release(refcnt_t *count) 55238106Sdes{ 56238106Sdes unsigned int old; 57238106Sdes 58238106Sdes /* XXX: Should this have a rel membar? */ 59238106Sdes old = atomic_fetchadd_int(count, -1); 60238106Sdes PJDLOG_ASSERT(old > 0); 61238106Sdes return (old - 1); 62238106Sdes} 63238106Sdes 64238106Sdes#endif /* ! __REFCNT_H__ */ 65238106Sdes