1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26#ifndef _SYS_REFCOUNT_H 27#define _SYS_REFCOUNT_H 28 29#pragma ident "%Z%%M% %I% %E% SMI" 30 31#include <sys/inttypes.h> 32#include <sys/list.h> 33#include <sys/zfs_context.h> 34 35#ifdef __cplusplus 36extern "C" { 37#endif 38 39/* 40 * If the reference is held only by the calling function and not any 41 * particular object, use FTAG (which is a string) for the holder_tag. 42 * Otherwise, use the object that holds the reference. 43 */ 44#define FTAG ((char *)__func__) 45 46#if defined(DEBUG) || !defined(_KERNEL) 47typedef struct reference { 48 list_node_t ref_link; 49 void *ref_holder; 50 uint64_t ref_number; 51 uint8_t *ref_removed; 52} reference_t; 53 54typedef struct refcount { 55 kmutex_t rc_mtx; 56 list_t rc_list; 57 list_t rc_removed; 58 int64_t rc_count; 59 int64_t rc_removed_count; 60} refcount_t; 61 62/* Note: refcount_t must be initialized with refcount_create() */ 63 64void refcount_create(refcount_t *rc); 65void refcount_destroy(refcount_t *rc); 66void refcount_destroy_many(refcount_t *rc, uint64_t number); 67int refcount_is_zero(refcount_t *rc); 68int64_t refcount_count(refcount_t *rc); 69int64_t refcount_add(refcount_t *rc, void *holder_tag); 70int64_t refcount_remove(refcount_t *rc, void *holder_tag); 71int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 72int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 73 74void refcount_init(void); 75void refcount_fini(void); 76 77#else /* DEBUG */ 78 79typedef struct refcount { 80 uint64_t rc_count; 81} refcount_t; 82 83#define refcount_create(rc) ((rc)->rc_count = 0) 84#define refcount_destroy(rc) ((rc)->rc_count = 0) 85#define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 86#define refcount_is_zero(rc) ((rc)->rc_count == 0) 87#define refcount_count(rc) ((rc)->rc_count) 88#define refcount_add(rc, holder) atomic_add_64_nv(&(rc)->rc_count, 1) 89#define refcount_remove(rc, holder) atomic_add_64_nv(&(rc)->rc_count, -1) 90#define refcount_add_many(rc, number, holder) \ 91 atomic_add_64_nv(&(rc)->rc_count, number) 92#define refcount_remove_many(rc, number, holder) \ 93 atomic_add_64_nv(&(rc)->rc_count, -number) 94 95#define refcount_init() 96#define refcount_fini() 97 98#endif /* DEBUG */ 99 100#ifdef __cplusplus 101} 102#endif 103 104#endif /* _SYS_REFCOUNT_H */ 105