1d6e636c9SPawel Jakub Dawidek /*- 2d6e636c9SPawel Jakub Dawidek * Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org> 3d6e636c9SPawel Jakub Dawidek * All rights reserved. 4d6e636c9SPawel Jakub Dawidek * 5d6e636c9SPawel Jakub Dawidek * Redistribution and use in source and binary forms, with or without 6d6e636c9SPawel Jakub Dawidek * modification, are permitted provided that the following conditions 7d6e636c9SPawel Jakub Dawidek * are met: 8d6e636c9SPawel Jakub Dawidek * 1. Redistributions of source code must retain the above copyright 9d6e636c9SPawel Jakub Dawidek * notice, this list of conditions and the following disclaimer. 10d6e636c9SPawel Jakub Dawidek * 2. Redistributions in binary form must reproduce the above copyright 11d6e636c9SPawel Jakub Dawidek * notice, this list of conditions and the following disclaimer in the 12d6e636c9SPawel Jakub Dawidek * documentation and/or other materials provided with the distribution. 13d6e636c9SPawel Jakub Dawidek * 3. Neither the name of the author nor the names of any co-contributors 14d6e636c9SPawel Jakub Dawidek * may be used to endorse or promote products derived from this software 15d6e636c9SPawel Jakub Dawidek * without specific prior written permission. 16d6e636c9SPawel Jakub Dawidek * 17d6e636c9SPawel Jakub Dawidek * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18d6e636c9SPawel Jakub Dawidek * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19d6e636c9SPawel Jakub Dawidek * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20d6e636c9SPawel Jakub Dawidek * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21d6e636c9SPawel Jakub Dawidek * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22d6e636c9SPawel Jakub Dawidek * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23d6e636c9SPawel Jakub Dawidek * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24d6e636c9SPawel Jakub Dawidek * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25d6e636c9SPawel Jakub Dawidek * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26d6e636c9SPawel Jakub Dawidek * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27d6e636c9SPawel Jakub Dawidek * SUCH DAMAGE. 28d6e636c9SPawel Jakub Dawidek * 29d6e636c9SPawel Jakub Dawidek * $FreeBSD$ 30d6e636c9SPawel Jakub Dawidek */ 31d6e636c9SPawel Jakub Dawidek 32d6e636c9SPawel Jakub Dawidek #ifndef __REFCNT_H__ 33d6e636c9SPawel Jakub Dawidek #define __REFCNT_H__ 34d6e636c9SPawel Jakub Dawidek 356e87c151SEd Schouten #include <stdatomic.h> 36d6e636c9SPawel Jakub Dawidek 37d6e636c9SPawel Jakub Dawidek #include "pjdlog.h" 38d6e636c9SPawel Jakub Dawidek 396e87c151SEd Schouten typedef atomic_uint refcnt_t; 406e87c151SEd Schouten 41d6e636c9SPawel Jakub Dawidek static __inline void 426e87c151SEd Schouten refcnt_init(refcnt_t *count, unsigned int v) 43d6e636c9SPawel Jakub Dawidek { 44d6e636c9SPawel Jakub Dawidek 456e87c151SEd Schouten atomic_init(count, v); 466e87c151SEd Schouten } 476e87c151SEd Schouten 486e87c151SEd Schouten static __inline void 496e87c151SEd Schouten refcnt_acquire(refcnt_t *count) 506e87c151SEd Schouten { 516e87c151SEd Schouten 526e87c151SEd Schouten atomic_fetch_add_explicit(count, 1, memory_order_acquire); 53d6e636c9SPawel Jakub Dawidek } 54d6e636c9SPawel Jakub Dawidek 55d6e636c9SPawel Jakub Dawidek static __inline unsigned int 566e87c151SEd Schouten refcnt_release(refcnt_t *count) 57d6e636c9SPawel Jakub Dawidek { 58d6e636c9SPawel Jakub Dawidek unsigned int old; 59d6e636c9SPawel Jakub Dawidek 60d6e636c9SPawel Jakub Dawidek /* XXX: Should this have a rel membar? */ 616e87c151SEd Schouten old = atomic_fetch_sub(count, 1); 62d6e636c9SPawel Jakub Dawidek PJDLOG_ASSERT(old > 0); 63d6e636c9SPawel Jakub Dawidek return (old - 1); 64d6e636c9SPawel Jakub Dawidek } 65d6e636c9SPawel Jakub Dawidek 66d6e636c9SPawel Jakub Dawidek #endif /* ! __REFCNT_H__ */ 67