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.
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.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
25 #ifndef _SYS_REFCOUNT_H
26 #define _SYS_REFCOUNT_H
28 #include <sys/cdefs.h>
29 #include <sys/types.h>
30 #include_next <sys/refcount.h>
32 #include <sys/zfs_context.h>
39 * If the reference is held only by the calling function and not any
40 * particular object, use FTAG (which is a string) for the holder_tag.
41 * Otherwise, use the object that holds the reference.
43 #define FTAG ((char *)__func__)
46 typedef struct reference {
53 typedef struct refcount {
58 int64_t rc_removed_count;
61 /* Note: refcount_t must be initialized with refcount_create() */
63 void refcount_create(refcount_t *rc);
64 void refcount_destroy(refcount_t *rc);
65 void refcount_destroy_many(refcount_t *rc, uint64_t number);
66 int refcount_is_zero(refcount_t *rc);
67 int64_t refcount_count(refcount_t *rc);
68 int64_t refcount_add(refcount_t *rc, void *holder_tag);
69 int64_t refcount_remove(refcount_t *rc, void *holder_tag);
70 int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag);
71 int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag);
72 void refcount_transfer(refcount_t *dst, refcount_t *src);
74 void refcount_sysinit(void);
75 void refcount_fini(void);
79 typedef struct refcount {
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 #define refcount_transfer(dst, src) { \
95 uint64_t __tmp = (src)->rc_count; \
96 atomic_add_64(&(src)->rc_count, -__tmp); \
97 atomic_add_64(&(dst)->rc_count, __tmp); \
100 #define refcount_sysinit()
101 #define refcount_fini()
103 #endif /* ZFS_DEBUG */
109 #endif /* _SYS_REFCOUNT_H */