/* * 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; boolean_t rc_tracked; 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[_untracked]() */ void refcount_create(refcount_t *rc); void refcount_create_untracked(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_create_untracked(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 */