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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _SYS_REFCOUNT_H 28 #define _SYS_REFCOUNT_H 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include <sys/inttypes.h> 33 #include <sys/list.h> 34 #include <sys/zfs_context.h> 35 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 /* 41 * If the reference is held only by the calling function and not any 42 * particular object, use FTAG (which is a string) for the holder_tag. 43 * Otherwise, use the object that holds the reference. 44 */ 45 #define FTAG ((void*)__func__) 46 47 #if defined(DEBUG) || !defined(_KERNEL) 48 typedef struct reference { 49 list_node_t ref_link; 50 void *ref_holder; 51 uint64_t ref_number; 52 uint8_t *ref_removed; 53 } reference_t; 54 55 typedef struct refcount { 56 kmutex_t rc_mtx; 57 list_t rc_list; 58 list_t rc_removed; 59 int64_t rc_count; 60 int64_t rc_removed_count; 61 } refcount_t; 62 63 /* Note: refcount_t should be initialized to zero before use. */ 64 65 void refcount_create(refcount_t *rc); 66 void refcount_destroy(refcount_t *rc); 67 void refcount_destroy_many(refcount_t *rc, uint64_t number); 68 int refcount_is_zero(refcount_t *rc); 69 int64_t refcount_count(refcount_t *rc); 70 int64_t refcount_add(refcount_t *rc, void *holder_tag); 71 int64_t refcount_remove(refcount_t *rc, void *holder_tag); 72 int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 73 int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 74 75 void refcount_init(void); 76 void refcount_fini(void); 77 78 #else /* DEBUG */ 79 80 typedef struct refcount { 81 uint64_t rc_count; 82 } refcount_t; 83 84 #define refcount_create(rc) ((rc)->rc_count = 0) 85 #define refcount_destroy(rc) ((rc)->rc_count = 0) 86 #define refcount_destroy_many(rc, number) ((rc)->rc_count = 0) 87 #define refcount_is_zero(rc) ((rc)->rc_count == 0) 88 #define refcount_count(rc) ((rc)->rc_count) 89 #define refcount_add(rc, holder) atomic_add_64_nv(&(rc)->rc_count, 1) 90 #define refcount_remove(rc, holder) atomic_add_64_nv(&(rc)->rc_count, -1) 91 #define refcount_add_many(rc, number, holder) \ 92 atomic_add_64_nv(&(rc)->rc_count, number) 93 #define refcount_remove_many(rc, number, holder) \ 94 atomic_add_64_nv(&(rc)->rc_count, -number) 95 96 #define refcount_init() 97 #define refcount_fini() 98 99 #endif /* DEBUG */ 100 101 #ifdef __cplusplus 102 } 103 #endif 104 105 #endif /* _SYS_REFCOUNT_H */ 106