/************************************************************************** * * Copyright 2006 VMware, Inc., Bismarck, ND. USA. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * **************************************************************************/ /** * \file * List macros heavily inspired by the Linux kernel * list handling. No list looping yet. * * Is not threadsafe, so common operations need to * be protected using an external mutex. */ #ifndef _UTIL_LIST_H_ #define _UTIL_LIST_H_ #include <stdbool.h> #include <stddef.h> #include <assert.h> struct list_head { struct list_head *prev; struct list_head *next; }; static inline void list_inithead(struct list_head *item) { item->prev = item; item->next = item; } static inline void list_add(struct list_head *item, struct list_head *list) { item->prev = list; item->next = list->next; list->next->prev = item; list->next = item; } static inline void list_addtail(struct list_head *item, struct list_head *list) { item->next = list; item->prev = list->prev; list->prev->next = item; list->prev = item; } static inline void list_replace(struct list_head *from, struct list_head *to) { to->prev = from->prev; to->next = from->next; from->next->prev = to; from->prev->next = to; } static inline void list_del(struct list_head *item) { item->prev->next = item->next; item->next->prev = item->prev; item->prev = item->next = NULL; } static inline void list_delinit(struct list_head *item) { item->prev->next = item->next; item->next->prev = item->prev; item->next = item; item->prev = item; } static inline bool list_empty(struct list_head *list) { return list->next == list; } /** * Returns whether the list has exactly one element. */ static inline bool list_is_singular(const struct list_head *list) { return list->next != NULL && list->next->next == list; } static inline unsigned list_length(struct list_head *list) { struct list_head *node; unsigned length = 0; for (node = list->next; node != list; node = node->next) length++; return length; } static inline void list_splice(struct list_head *src, struct list_head *dst) { if (list_empty(src)) return; src->next->prev = dst; src->prev->next = dst->next; dst->next->prev = src->prev; dst->next = src->next; } static inline void list_splicetail(struct list_head *src, struct list_head *dst) { if (list_empty(src)) return; src->prev->next = dst; src->next->prev = dst->prev; dst->prev->next = src->next; dst->prev = src->prev; } static inline void list_validate(struct list_head *list) { struct list_head *node; assert(list->next->prev == list && list->prev->next == list); for (node = list->next; node != list; node = node->next) assert(node->next->prev == node && node->prev->next == node); } #define LIST_INITHEAD(__item) list_inithead(__item) #define LIST_ADD(__item, __list) list_add(__item, __list) #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list) #define LIST_REPLACE(__from, __to) list_replace(__from, __to) #define LIST_DEL(__item) list_del(__item) #define LIST_DELINIT(__item) list_delinit(__item) #define LIST_ENTRY(__type, __item, __field) \ ((__type *)(((char *)(__item)) - offsetof(__type, __field))) #define LIST_IS_EMPTY(__list) \ ((__list)->next == (__list)) /** * Cast from a pointer to a member of a struct back to the containing struct. * * 'sample' MUST be initialized, or else the result is undefined! */ #ifndef container_of #define container_of(ptr, sample, member) \ (void *)((char *)(ptr) \ - ((char *)&(sample)->member - (char *)(sample))) #endif #define list_first_entry(ptr, type, member) \ LIST_ENTRY(type, (ptr)->next, member) #define list_last_entry(ptr, type, member) \ LIST_ENTRY(type, (ptr)->prev, member) #define LIST_FOR_EACH_ENTRY(pos, head, member) \ for (pos = NULL, pos = container_of((head)->next, pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.next, pos, member)) #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \ for (pos = NULL, pos = container_of((head)->next, pos, member), \ storage = container_of(pos->member.next, pos, member); \ &pos->member != (head); \ pos = storage, storage = container_of(storage->member.next, storage, member)) #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \ for (pos = NULL, pos = container_of((head)->prev, pos, member), \ storage = container_of(pos->member.prev, pos, member); \ &pos->member != (head); \ pos = storage, storage = container_of(storage->member.prev, storage, member)) #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \ for (pos = NULL, pos = container_of((start), pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.next, pos, member)) #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \ for (pos = NULL, pos = container_of((start), pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.prev, pos, member)) #define list_for_each_entry(type, pos, head, member) \ for (type *pos = LIST_ENTRY(type, (head)->next, member); \ &pos->member != (head); \ pos = LIST_ENTRY(type, pos->member.next, member)) #define list_for_each_entry_safe(type, pos, head, member) \ for (type *pos = LIST_ENTRY(type, (head)->next, member), \ *__next = LIST_ENTRY(type, pos->member.next, member); \ &pos->member != (head); \ pos = __next, \ __next = LIST_ENTRY(type, __next->member.next, member)) #define list_for_each_entry_rev(type, pos, head, member) \ for (type *pos = LIST_ENTRY(type, (head)->prev, member); \ &pos->member != (head); \ pos = LIST_ENTRY(type, pos->member.prev, member)) #define list_for_each_entry_safe_rev(type, pos, head, member) \ for (type *pos = LIST_ENTRY(type, (head)->prev, member), \ *__prev = LIST_ENTRY(type, pos->member.prev, member); \ &pos->member != (head); \ pos = __prev, \ __prev = LIST_ENTRY(type, __prev->member.prev, member)) #define list_for_each_entry_from(type, pos, start, head, member) \ for (type *pos = LIST_ENTRY(type, (start), member); \ &pos->member != (head); \ pos = LIST_ENTRY(type, pos->member.next, member)) #define list_for_each_entry_from_rev(type, pos, start, head, member) \ for (type *pos = LIST_ENTRY(type, (start), member); \ &pos->member != (head); \ pos = LIST_ENTRY(type, pos->member.prev, member)) #endif /*_UTIL_LIST_H_*/