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Diffstat (limited to 'include/sys/refcount.h')
| -rw-r--r-- | include/sys/refcount.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/include/sys/refcount.h b/include/sys/refcount.h new file mode 100644 index 000000000..1752c64e3 --- /dev/null +++ b/include/sys/refcount.h @@ -0,0 +1,107 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + */ + +#ifndef _SYS_REFCOUNT_H +#define _SYS_REFCOUNT_H + +#include <sys/inttypes.h> +#include <sys/list.h> +#include <sys/zfs_context.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * If the reference is held only by the calling function and not any + * particular object, use FTAG (which is a string) for the holder_tag. + * Otherwise, use the object that holds the reference. + */ +#define FTAG ((char *)__func__) + +#ifdef ZFS_DEBUG +typedef struct reference { + list_node_t ref_link; + void *ref_holder; + uint64_t ref_number; + uint8_t *ref_removed; +} reference_t; + +typedef struct refcount { + kmutex_t rc_mtx; + list_t rc_list; + list_t rc_removed; + int64_t rc_count; + int64_t rc_removed_count; +} refcount_t; + +/* Note: refcount_t must be initialized with refcount_create() */ + +void refcount_create(refcount_t *rc); +void refcount_destroy(refcount_t *rc); +void refcount_destroy_many(refcount_t *rc, uint64_t number); +int refcount_is_zero(refcount_t *rc); +int64_t refcount_count(refcount_t *rc); +int64_t refcount_add(refcount_t *rc, void *holder_tag); +int64_t refcount_remove(refcount_t *rc, void *holder_tag); +int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); +int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); +void refcount_transfer(refcount_t *dst, refcount_t *src); + +void refcount_init(void); +void refcount_fini(void); + +#else /* ZFS_DEBUG */ + +typedef struct refcount { + uint64_t rc_count; +} refcount_t; + +#define refcount_create(rc) ((rc)->rc_count = 0) +#define refcount_destroy(rc) ((rc)->rc_count = 0) +#define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) +#define refcount_is_zero(rc) ((rc)->rc_count == 0) +#define refcount_count(rc) ((rc)->rc_count) +#define refcount_add(rc, holder) atomic_add_64_nv(&(rc)->rc_count, 1) +#define refcount_remove(rc, holder) atomic_add_64_nv(&(rc)->rc_count, -1) +#define refcount_add_many(rc, number, holder) \ + atomic_add_64_nv(&(rc)->rc_count, number) +#define refcount_remove_many(rc, number, holder) \ + atomic_add_64_nv(&(rc)->rc_count, -number) +#define refcount_transfer(dst, src) { \ + uint64_t __tmp = (src)->rc_count; \ + atomic_add_64(&(src)->rc_count, -__tmp); \ + atomic_add_64(&(dst)->rc_count, __tmp); \ +} + +#define refcount_init() +#define refcount_fini() + +#endif /* ZFS_DEBUG */ + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_REFCOUNT_H */ |