refcount.h revision 307266
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2012 by Delphix. All rights reserved. 24 */ 25 26#ifndef _SYS_REFCOUNT_H 27#define _SYS_REFCOUNT_H 28 29#include <sys/cdefs.h> 30#include <sys/types.h> 31#include_next <sys/refcount.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#ifdef ZFS_DEBUG 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 boolean_t rc_tracked; 57 list_t rc_list; 58 list_t rc_removed; 59 uint64_t rc_count; 60 uint64_t rc_removed_count; 61} refcount_t; 62 63/* Note: refcount_t must be initialized with refcount_create[_untracked]() */ 64 65void refcount_create(refcount_t *rc); 66void refcount_create_untracked(refcount_t *rc); 67void refcount_destroy(refcount_t *rc); 68void refcount_destroy_many(refcount_t *rc, uint64_t number); 69int refcount_is_zero(refcount_t *rc); 70int64_t refcount_count(refcount_t *rc); 71int64_t refcount_add(refcount_t *rc, void *holder_tag); 72int64_t refcount_remove(refcount_t *rc, void *holder_tag); 73int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 74int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 75void refcount_transfer(refcount_t *dst, refcount_t *src); 76void refcount_transfer_ownership(refcount_t *, void *, void *); 77 78void refcount_sysinit(void); 79void refcount_fini(void); 80 81#else /* ZFS_DEBUG */ 82 83typedef struct refcount { 84 uint64_t rc_count; 85} refcount_t; 86 87#define refcount_create(rc) ((rc)->rc_count = 0) 88#define refcount_create_untracked(rc) ((rc)->rc_count = 0) 89#define refcount_destroy(rc) ((rc)->rc_count = 0) 90#define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 91#define refcount_is_zero(rc) ((rc)->rc_count == 0) 92#define refcount_count(rc) ((rc)->rc_count) 93#define refcount_add(rc, holder) atomic_inc_64_nv(&(rc)->rc_count) 94#define refcount_remove(rc, holder) atomic_dec_64_nv(&(rc)->rc_count) 95#define refcount_add_many(rc, number, holder) \ 96 atomic_add_64_nv(&(rc)->rc_count, number) 97#define refcount_remove_many(rc, number, holder) \ 98 atomic_add_64_nv(&(rc)->rc_count, -number) 99#define refcount_transfer(dst, src) { \ 100 uint64_t __tmp = (src)->rc_count; \ 101 atomic_add_64(&(src)->rc_count, -__tmp); \ 102 atomic_add_64(&(dst)->rc_count, __tmp); \ 103} 104#define refcount_transfer_ownership(rc, current_holder, new_holder) 105 106#define refcount_sysinit() 107#define refcount_fini() 108 109#endif /* ZFS_DEBUG */ 110 111#ifdef __cplusplus 112} 113#endif 114 115#endif /* _SYS_REFCOUNT_H */ 116