1 /************************************************************************** 2 * 3 * Copyright 2006 VMware, Inc., Bismarck, ND. USA. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 17 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 18 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 19 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 20 * USE OR OTHER DEALINGS IN THE SOFTWARE. 21 * 22 * The above copyright notice and this permission notice (including the 23 * next paragraph) shall be included in all copies or substantial portions 24 * of the Software. 25 * 26 **************************************************************************/ 27 28 /** 29 * \file 30 * List macros heavily inspired by the Linux kernel 31 * list handling. No list looping yet. 32 * 33 * Is not threadsafe, so common operations need to 34 * be protected using an external mutex. 35 */ 36 37 #ifndef _UTIL_LIST_H_ 38 #define _UTIL_LIST_H_ 39 40 41 #include <stdbool.h> 42 #include <stddef.h> 43 #include <assert.h> 44 #include "c99_compat.h" 45 46 47 struct list_head 48 { 49 struct list_head *prev; 50 struct list_head *next; 51 }; 52 53 static inline void list_inithead(struct list_head *item) 54 { 55 item->prev = item; 56 item->next = item; 57 } 58 59 static inline void list_add(struct list_head *item, struct list_head *list) 60 { 61 item->prev = list; 62 item->next = list->next; 63 list->next->prev = item; 64 list->next = item; 65 } 66 67 static inline void list_addtail(struct list_head *item, struct list_head *list) 68 { 69 item->next = list; 70 item->prev = list->prev; 71 list->prev->next = item; 72 list->prev = item; 73 } 74 75 static inline bool list_empty(struct list_head *list); 76 77 static inline void list_replace(struct list_head *from, struct list_head *to) 78 { 79 if (list_empty(from)) { 80 list_inithead(to); 81 } else { 82 to->prev = from->prev; 83 to->next = from->next; 84 from->next->prev = to; 85 from->prev->next = to; 86 } 87 } 88 89 static inline void list_del(struct list_head *item) 90 { 91 item->prev->next = item->next; 92 item->next->prev = item->prev; 93 item->prev = item->next = NULL; 94 } 95 96 static inline void list_delinit(struct list_head *item) 97 { 98 item->prev->next = item->next; 99 item->next->prev = item->prev; 100 item->next = item; 101 item->prev = item; 102 } 103 104 static inline bool list_empty(struct list_head *list) 105 { 106 return list->next == list; 107 } 108 109 /** 110 * Returns whether the list has exactly one element. 111 */ 112 static inline bool list_is_singular(const struct list_head *list) 113 { 114 return list->next != NULL && list->next != list && list->next->next == list; 115 } 116 117 static inline unsigned list_length(struct list_head *list) 118 { 119 struct list_head *node; 120 unsigned length = 0; 121 for (node = list->next; node != list; node = node->next) 122 length++; 123 return length; 124 } 125 126 static inline void list_splice(struct list_head *src, struct list_head *dst) 127 { 128 if (list_empty(src)) 129 return; 130 131 src->next->prev = dst; 132 src->prev->next = dst->next; 133 dst->next->prev = src->prev; 134 dst->next = src->next; 135 } 136 137 static inline void list_splicetail(struct list_head *src, struct list_head *dst) 138 { 139 if (list_empty(src)) 140 return; 141 142 src->prev->next = dst; 143 src->next->prev = dst->prev; 144 dst->prev->next = src->next; 145 dst->prev = src->prev; 146 } 147 148 static inline void list_validate(struct list_head *list) 149 { 150 struct list_head *node; 151 assert(list->next->prev == list && list->prev->next == list); 152 for (node = list->next; node != list; node = node->next) 153 assert(node->next->prev == node && node->prev->next == node); 154 } 155 156 #define LIST_INITHEAD(__item) list_inithead(__item) 157 #define LIST_ADD(__item, __list) list_add(__item, __list) 158 #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list) 159 #define LIST_REPLACE(__from, __to) list_replace(__from, __to) 160 #define LIST_DEL(__item) list_del(__item) 161 #define LIST_DELINIT(__item) list_delinit(__item) 162 163 #define LIST_ENTRY(__type, __item, __field) \ 164 ((__type *)(((char *)(__item)) - offsetof(__type, __field))) 165 166 #define LIST_IS_EMPTY(__list) \ 167 ((__list)->next == (__list)) 168 169 /** 170 * Cast from a pointer to a member of a struct back to the containing struct. 171 * 172 * 'sample' MUST be initialized, or else the result is undefined! 173 */ 174 #ifndef container_of 175 #define container_of(ptr, sample, member) \ 176 (void *)((char *)(ptr) \ 177 - ((char *)&(sample)->member - (char *)(sample))) 178 #endif 179 180 #define list_first_entry(ptr, type, member) \ 181 LIST_ENTRY(type, (ptr)->next, member) 182 183 #define list_last_entry(ptr, type, member) \ 184 LIST_ENTRY(type, (ptr)->prev, member) 185 186 187 #define LIST_FOR_EACH_ENTRY(pos, head, member) \ 188 for (pos = NULL, pos = container_of((head)->next, pos, member); \ 189 &pos->member != (head); \ 190 pos = container_of(pos->member.next, pos, member)) 191 192 #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \ 193 for (pos = NULL, pos = container_of((head)->next, pos, member), \ 194 storage = container_of(pos->member.next, pos, member); \ 195 &pos->member != (head); \ 196 pos = storage, storage = container_of(storage->member.next, storage, member)) 197 198 #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \ 199 for (pos = NULL, pos = container_of((head)->prev, pos, member), \ 200 storage = container_of(pos->member.prev, pos, member); \ 201 &pos->member != (head); \ 202 pos = storage, storage = container_of(storage->member.prev, storage, member)) 203 204 #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \ 205 for (pos = NULL, pos = container_of((start), pos, member); \ 206 &pos->member != (head); \ 207 pos = container_of(pos->member.next, pos, member)) 208 209 #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \ 210 for (pos = NULL, pos = container_of((start), pos, member); \ 211 &pos->member != (head); \ 212 pos = container_of(pos->member.prev, pos, member)) 213 214 #define list_for_each_entry(type, pos, head, member) \ 215 for (type *pos = LIST_ENTRY(type, (head)->next, member); \ 216 &pos->member != (head); \ 217 pos = LIST_ENTRY(type, pos->member.next, member)) 218 219 #define list_for_each_entry_safe(type, pos, head, member) \ 220 for (type *pos = LIST_ENTRY(type, (head)->next, member), \ 221 *__next = LIST_ENTRY(type, pos->member.next, member); \ 222 &pos->member != (head); \ 223 pos = __next, \ 224 __next = LIST_ENTRY(type, __next->member.next, member)) 225 226 #define list_for_each_entry_rev(type, pos, head, member) \ 227 for (type *pos = LIST_ENTRY(type, (head)->prev, member); \ 228 &pos->member != (head); \ 229 pos = LIST_ENTRY(type, pos->member.prev, member)) 230 231 #define list_for_each_entry_safe_rev(type, pos, head, member) \ 232 for (type *pos = LIST_ENTRY(type, (head)->prev, member), \ 233 *__prev = LIST_ENTRY(type, pos->member.prev, member); \ 234 &pos->member != (head); \ 235 pos = __prev, \ 236 __prev = LIST_ENTRY(type, __prev->member.prev, member)) 237 238 #define list_for_each_entry_from(type, pos, start, head, member) \ 239 for (type *pos = LIST_ENTRY(type, (start), member); \ 240 &pos->member != (head); \ 241 pos = LIST_ENTRY(type, pos->member.next, member)) 242 243 #define list_for_each_entry_from_rev(type, pos, start, head, member) \ 244 for (type *pos = LIST_ENTRY(type, (start), member); \ 245 &pos->member != (head); \ 246 pos = LIST_ENTRY(type, pos->member.prev, member)) 247 248 #endif /*_UTIL_LIST_H_*/ 249
