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, 2015 by Delphix. All rights reserved. 24 */ 25 26 #ifndef _SYS_REFCOUNT_H 27 #define _SYS_REFCOUNT_H 28 29 #include <sys/inttypes.h> 30 #include <sys/list.h> 31 #include <sys/zfs_context.h> 32 33 #ifdef __cplusplus 34 extern "C" { 35 #endif 36 37 /* 38 * If the reference is held only by the calling function and not any 39 * particular object, use FTAG (which is a string) for the holder_tag. 40 * Otherwise, use the object that holds the reference. 41 */ 42 #define FTAG ((char *)(uintptr_t)__func__) 43 44 #ifdef ZFS_DEBUG 45 typedef struct reference { 46 list_node_t ref_link; 47 void *ref_holder; 48 uint64_t ref_number; 49 uint8_t *ref_removed; 50 } reference_t; 51 52 typedef struct refcount { 53 kmutex_t rc_mtx; 54 boolean_t rc_tracked; 55 list_t rc_list; 56 list_t rc_removed; 57 uint64_t rc_count; 58 uint64_t rc_removed_count; 59 } zfs_refcount_t; 60 61 /* 62 * Note: zfs_refcount_t must be initialized with 63 * refcount_create[_untracked]() 64 */ 65 66 void zfs_refcount_create(zfs_refcount_t *); 67 void zfs_refcount_create_untracked(zfs_refcount_t *); 68 void zfs_refcount_create_tracked(zfs_refcount_t *); 69 void zfs_refcount_destroy(zfs_refcount_t *); 70 void zfs_refcount_destroy_many(zfs_refcount_t *, uint64_t); 71 int zfs_refcount_is_zero(zfs_refcount_t *); 72 int64_t zfs_refcount_count(zfs_refcount_t *); 73 int64_t zfs_refcount_add(zfs_refcount_t *, void *); 74 int64_t zfs_refcount_remove(zfs_refcount_t *, void *); 75 int64_t zfs_refcount_add_many(zfs_refcount_t *, uint64_t, void *); 76 int64_t zfs_refcount_remove_many(zfs_refcount_t *, uint64_t, void *); 77 void zfs_refcount_transfer(zfs_refcount_t *, zfs_refcount_t *); 78 void zfs_refcount_transfer_ownership(zfs_refcount_t *, void *, void *); 79 void zfs_refcount_transfer_ownership_many(zfs_refcount_t *, uint64_t, 80 void *, void *); 81 boolean_t zfs_refcount_held(zfs_refcount_t *, void *); 82 boolean_t zfs_refcount_not_held(zfs_refcount_t *, void *); 83 84 void zfs_refcount_init(void); 85 void zfs_refcount_fini(void); 86 87 #else /* ZFS_DEBUG */ 88 89 typedef struct refcount { 90 uint64_t rc_count; 91 } zfs_refcount_t; 92 93 #define zfs_refcount_create(rc) ((rc)->rc_count = 0) 94 #define zfs_refcount_create_untracked(rc) ((rc)->rc_count = 0) 95 #define zfs_refcount_create_tracked(rc) ((rc)->rc_count = 0) 96 #define zfs_refcount_destroy(rc) ((rc)->rc_count = 0) 97 #define zfs_refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 98 #define zfs_refcount_is_zero(rc) ((rc)->rc_count == 0) 99 #define zfs_refcount_count(rc) ((rc)->rc_count) 100 #define zfs_refcount_add(rc, holder) atomic_inc_64_nv(&(rc)->rc_count) 101 #define zfs_refcount_remove(rc, holder) atomic_dec_64_nv(&(rc)->rc_count) 102 #define zfs_refcount_add_many(rc, number, holder) \ 103 atomic_add_64_nv(&(rc)->rc_count, number) 104 #define zfs_refcount_remove_many(rc, number, holder) \ 105 atomic_add_64_nv(&(rc)->rc_count, -number) 106 #define zfs_refcount_transfer(dst, src) { \ 107 uint64_t __tmp = (src)->rc_count; \ 108 atomic_add_64(&(src)->rc_count, -__tmp); \ 109 atomic_add_64(&(dst)->rc_count, __tmp); \ 110 } 111 #define zfs_refcount_transfer_ownership(rc, current_holder, new_holder) (void)0 112 #define zfs_refcount_transfer_ownership_many(rc, nr, ch, nh) ((void)0) 113 #define zfs_refcount_held(rc, holder) ((rc)->rc_count > 0) 114 #define zfs_refcount_not_held(rc, holder) (B_TRUE) 115 116 #define zfs_refcount_init() 117 #define zfs_refcount_fini() 118 119 #endif /* ZFS_DEBUG */ 120 121 #ifdef __cplusplus 122 } 123 #endif 124 125 #endif /* _SYS_REFCOUNT_H */ 126