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 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _SYS_REFCOUNT_H 27 #define _SYS_REFCOUNT_H 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #include <sys/inttypes.h> 32 #include <sys/list.h> 33 #include <sys/zfs_context.h> 34 35 #ifdef __cplusplus 36 extern "C" { 37 #endif 38 39 /* 40 * If the reference is held only by the calling function and not any 41 * particular object, use FTAG (which is a string) for the holder_tag. 42 * Otherwise, use the object that holds the reference. 43 */ 44 #define FTAG ((char *)__func__) 45 46 #if defined(DEBUG) || !defined(_KERNEL) 47 typedef struct reference { 48 list_node_t ref_link; 49 void *ref_holder; 50 uint64_t ref_number; 51 uint8_t *ref_removed; 52 } reference_t; 53 54 typedef struct refcount { 55 kmutex_t rc_mtx; 56 list_t rc_list; 57 list_t rc_removed; 58 int64_t rc_count; 59 int64_t rc_removed_count; 60 } refcount_t; 61 62 /* Note: refcount_t should be initialized to zero before use. */ 63 64 void refcount_create(refcount_t *rc); 65 void refcount_destroy(refcount_t *rc); 66 void refcount_destroy_many(refcount_t *rc, uint64_t number); 67 int refcount_is_zero(refcount_t *rc); 68 int64_t refcount_count(refcount_t *rc); 69 int64_t refcount_add(refcount_t *rc, void *holder_tag); 70 int64_t refcount_remove(refcount_t *rc, void *holder_tag); 71 int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag); 72 int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag); 73 74 void refcount_init(void); 75 void refcount_fini(void); 76 77 #else /* DEBUG */ 78 79 typedef struct refcount { 80 uint64_t rc_count; 81 } refcount_t; 82 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 95 #define refcount_init() 96 #define refcount_fini() 97 98 #endif /* DEBUG */ 99 100 #ifdef __cplusplus 101 } 102 #endif 103 104 #endif /* _SYS_REFCOUNT_H */ 105