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/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 36 extern "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 47 typedef 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 54 typedef 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 65 void refcount_create(refcount_t *rc); 66 void refcount_create_untracked(refcount_t *rc); 67 void refcount_create_tracked(refcount_t *rc); 68 void refcount_destroy(refcount_t *rc); 69 void refcount_destroy_many(refcount_t *rc, uint64_t number); 70 int refcount_is_zero(refcount_t *rc); 71 int64_t refcount_count(refcount_t *rc); 72 int64_t refcount_add(refcount_t *rc, void *holder_tag); 73 int64_t refcount_remove(refcount_t *rc, void *holder_tag); 74 int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 75 int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 76 void refcount_transfer(refcount_t *dst, refcount_t *src); 77 void refcount_transfer_ownership(refcount_t *, void *, void *); 78 boolean_t refcount_held(refcount_t *, void *); 79 boolean_t refcount_not_held(refcount_t *, void *); 80 81 void refcount_sysinit(void); 82 void refcount_fini(void); 83 84 #else /* ZFS_DEBUG */ 85 86 typedef struct refcount { 87 uint64_t rc_count; 88 } refcount_t; 89 90 #define refcount_create(rc) ((rc)->rc_count = 0) 91 #define refcount_create_untracked(rc) ((rc)->rc_count = 0) 92 #define refcount_create_tracked(rc) ((rc)->rc_count = 0) 93 #define refcount_destroy(rc) ((rc)->rc_count = 0) 94 #define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 95 #define refcount_is_zero(rc) ((rc)->rc_count == 0) 96 #define refcount_count(rc) ((rc)->rc_count) 97 #define refcount_add(rc, holder) atomic_inc_64_nv(&(rc)->rc_count) 98 #define refcount_remove(rc, holder) atomic_dec_64_nv(&(rc)->rc_count) 99 #define refcount_add_many(rc, number, holder) \ 100 atomic_add_64_nv(&(rc)->rc_count, number) 101 #define refcount_remove_many(rc, number, holder) \ 102 atomic_add_64_nv(&(rc)->rc_count, -number) 103 #define refcount_transfer(dst, src) { \ 104 uint64_t __tmp = (src)->rc_count; \ 105 atomic_add_64(&(src)->rc_count, -__tmp); \ 106 atomic_add_64(&(dst)->rc_count, __tmp); \ 107 } 108 #define refcount_transfer_ownership(rc, current_holder, new_holder) 109 #define refcount_held(rc, holder) ((rc)->rc_count > 0) 110 #define refcount_not_held(rc, holder) (B_TRUE) 111 112 #define refcount_sysinit() 113 #define refcount_fini() 114 115 #endif /* ZFS_DEBUG */ 116 117 #ifdef __cplusplus 118 } 119 #endif 120 121 #endif /* _SYS_REFCOUNT_H */ 122