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 */ 24 25 #ifndef _SYS_REFCOUNT_H 26 #define _SYS_REFCOUNT_H 27 28 #include <sys/inttypes.h> 29 #include <sys/list.h> 30 #include <sys/zfs_context.h> 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 /* 37 * If the reference is held only by the calling function and not any 38 * particular object, use FTAG (which is a string) for the holder_tag. 39 * Otherwise, use the object that holds the reference. 40 */ 41 #define FTAG ((char *)__func__) 42 43 #if defined(DEBUG) || !defined(_KERNEL) 44 typedef struct reference { 45 list_node_t ref_link; 46 void *ref_holder; 47 uint64_t ref_number; 48 uint8_t *ref_removed; 49 } reference_t; 50 51 typedef struct refcount { 52 kmutex_t rc_mtx; 53 list_t rc_list; 54 list_t rc_removed; 55 int64_t rc_count; 56 int64_t rc_removed_count; 57 } refcount_t; 58 59 /* Note: refcount_t must be initialized with refcount_create() */ 60 61 void refcount_create(refcount_t *rc); 62 void refcount_destroy(refcount_t *rc); 63 void refcount_destroy_many(refcount_t *rc, uint64_t number); 64 int refcount_is_zero(refcount_t *rc); 65 int64_t refcount_count(refcount_t *rc); 66 int64_t refcount_add(refcount_t *rc, void *holder_tag); 67 int64_t refcount_remove(refcount_t *rc, void *holder_tag); 68 int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 69 int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 70 71 void refcount_init(void); 72 void refcount_fini(void); 73 74 #else /* DEBUG */ 75 76 typedef struct refcount { 77 uint64_t rc_count; 78 } refcount_t; 79 80 #define refcount_create(rc) ((rc)->rc_count = 0) 81 #define refcount_destroy(rc) ((rc)->rc_count = 0) 82 #define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 83 #define refcount_is_zero(rc) ((rc)->rc_count == 0) 84 #define refcount_count(rc) ((rc)->rc_count) 85 #define refcount_add(rc, holder) atomic_add_64_nv(&(rc)->rc_count, 1) 86 #define refcount_remove(rc, holder) atomic_add_64_nv(&(rc)->rc_count, -1) 87 #define refcount_add_many(rc, number, holder) \ 88 atomic_add_64_nv(&(rc)->rc_count, number) 89 #define refcount_remove_many(rc, number, holder) \ 90 atomic_add_64_nv(&(rc)->rc_count, -number) 91 #define refcount_transfer(dst, src) { \ 92 uint64_t __tmp = (src)->rc_count; \ 93 atomic_add_64(&(src)->rc_count, -__tmp); \ 94 atomic_add_64(&(dst)->rc_count, __tmp); \ 95 } 96 97 #define refcount_init() 98 #define refcount_fini() 99 100 #endif /* DEBUG */ 101 102 #ifdef __cplusplus 103 } 104 #endif 105 106 #endif /* _SYS_REFCOUNT_H */ 107