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 (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 /* 26 * Generic doubly-linked list implementation 27 */ 28 29 #include <sys/list.h> 30 #include <sys/list_impl.h> 31 #include <sys/types.h> 32 #include <sys/sysmacros.h> 33 #ifdef _KERNEL 34 #include <sys/debug.h> 35 #else 36 #include <assert.h> 37 #define ASSERT(a) assert(a) 38 #endif 39 40 #ifdef lint 41 extern list_node_t *list_d2l(list_t *list, void *obj); 42 #else 43 #define list_d2l(a, obj) ((list_node_t *)(((char *)obj) + (a)->list_offset)) 44 #endif 45 #define list_object(a, node) ((void *)(((char *)node) - (a)->list_offset)) 46 #define list_empty(a) ((a)->list_head.list_next == &(a)->list_head) 47 48 #define list_insert_after_node(list, node, object) { \ 49 list_node_t *lnew = list_d2l(list, object); \ 50 lnew->list_prev = (node); \ 51 lnew->list_next = (node)->list_next; \ 52 (node)->list_next->list_prev = lnew; \ 53 (node)->list_next = lnew; \ 54 } 55 56 #define list_insert_before_node(list, node, object) { \ 57 list_node_t *lnew = list_d2l(list, object); \ 58 lnew->list_next = (node); \ 59 lnew->list_prev = (node)->list_prev; \ 60 (node)->list_prev->list_next = lnew; \ 61 (node)->list_prev = lnew; \ 62 } 63 64 #define list_remove_node(node) \ 65 (node)->list_prev->list_next = (node)->list_next; \ 66 (node)->list_next->list_prev = (node)->list_prev; \ 67 (node)->list_next = (node)->list_prev = NULL 68 69 void 70 list_create(list_t *list, size_t size, size_t offset) 71 { 72 ASSERT(list); 73 ASSERT(size > 0); 74 ASSERT(size >= offset + sizeof (list_node_t)); 75 76 list->list_size = size; 77 list->list_offset = offset; 78 list->list_head.list_next = list->list_head.list_prev = 79 &list->list_head; 80 } 81 82 void 83 list_destroy(list_t *list) 84 { 85 list_node_t *node = &list->list_head; 86 87 ASSERT(list); 88 ASSERT(list->list_head.list_next == node); 89 ASSERT(list->list_head.list_prev == node); 90 91 node->list_next = node->list_prev = NULL; 92 } 93 94 void 95 list_insert_after(list_t *list, void *object, void *nobject) 96 { 97 if (object == NULL) { 98 list_insert_head(list, nobject); 99 } else { 100 list_node_t *lold = list_d2l(list, object); 101 list_insert_after_node(list, lold, nobject); 102 } 103 } 104 105 void 106 list_insert_before(list_t *list, void *object, void *nobject) 107 { 108 if (object == NULL) { 109 list_insert_tail(list, nobject); 110 } else { 111 list_node_t *lold = list_d2l(list, object); 112 list_insert_before_node(list, lold, nobject); 113 } 114 } 115 116 void 117 list_insert_head(list_t *list, void *object) 118 { 119 list_node_t *lold = &list->list_head; 120 list_insert_after_node(list, lold, object); 121 } 122 123 void 124 list_insert_tail(list_t *list, void *object) 125 { 126 list_node_t *lold = &list->list_head; 127 list_insert_before_node(list, lold, object); 128 } 129 130 void 131 list_remove(list_t *list, void *object) 132 { 133 list_node_t *lold = list_d2l(list, object); 134 ASSERT(!list_empty(list)); 135 ASSERT(lold->list_next != NULL); 136 list_remove_node(lold); 137 } 138 139 void * 140 list_remove_head(list_t *list) 141 { 142 list_node_t *head = list->list_head.list_next; 143 if (head == &list->list_head) 144 return (NULL); 145 list_remove_node(head); 146 return (list_object(list, head)); 147 } 148 149 void * 150 list_remove_tail(list_t *list) 151 { 152 list_node_t *tail = list->list_head.list_prev; 153 if (tail == &list->list_head) 154 return (NULL); 155 list_remove_node(tail); 156 return (list_object(list, tail)); 157 } 158 159 void * 160 list_head(list_t *list) 161 { 162 if (list_empty(list)) 163 return (NULL); 164 return (list_object(list, list->list_head.list_next)); 165 } 166 167 void * 168 list_tail(list_t *list) 169 { 170 if (list_empty(list)) 171 return (NULL); 172 return (list_object(list, list->list_head.list_prev)); 173 } 174 175 void * 176 list_next(list_t *list, void *object) 177 { 178 list_node_t *node = list_d2l(list, object); 179 180 if (node->list_next != &list->list_head) 181 return (list_object(list, node->list_next)); 182 183 return (NULL); 184 } 185 186 void * 187 list_prev(list_t *list, void *object) 188 { 189 list_node_t *node = list_d2l(list, object); 190 191 if (node->list_prev != &list->list_head) 192 return (list_object(list, node->list_prev)); 193 194 return (NULL); 195 } 196 197 /* 198 * Insert src list after dst list. Empty src list thereafter. 199 */ 200 void 201 list_move_tail(list_t *dst, list_t *src) 202 { 203 list_node_t *dstnode = &dst->list_head; 204 list_node_t *srcnode = &src->list_head; 205 206 ASSERT(dst->list_size == src->list_size); 207 ASSERT(dst->list_offset == src->list_offset); 208 209 if (list_empty(src)) 210 return; 211 212 dstnode->list_prev->list_next = srcnode->list_next; 213 srcnode->list_next->list_prev = dstnode->list_prev; 214 dstnode->list_prev = srcnode->list_prev; 215 srcnode->list_prev->list_next = dstnode; 216 217 /* empty src list */ 218 srcnode->list_next = srcnode->list_prev = srcnode; 219 } 220 221 void 222 list_link_replace(list_node_t *lold, list_node_t *lnew) 223 { 224 ASSERT(list_link_active(lold)); 225 ASSERT(!list_link_active(lnew)); 226 227 lnew->list_next = lold->list_next; 228 lnew->list_prev = lold->list_prev; 229 lold->list_prev->list_next = lnew; 230 lold->list_next->list_prev = lnew; 231 lold->list_next = lold->list_prev = NULL; 232 } 233 234 void 235 list_link_init(list_node_t *link) 236 { 237 link->list_next = NULL; 238 link->list_prev = NULL; 239 } 240 241 int 242 list_link_active(list_node_t *link) 243 { 244 return (link->list_next != NULL); 245 } 246 247 int 248 list_is_empty(list_t *list) 249 { 250 return (list_empty(list)); 251 } 252