/* * Linux klist like system *  * Copyright (c) 2016-2017 Fabrice Bellard * * 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, sublicense, 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 above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * 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 NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS 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. */#ifndef LIST_H#define LIST_H #ifndef NULL#include <stddef.h>#endif struct list_head {    struct list_head *prev;    struct list_head *next;}; #define LIST_HEAD_INIT(el) { &(el), &(el) } /* return the pointer of type 'type *' containing 'el' as field 'member' */#define list_entry(el, type, member) \    ((type *)((uint8_t *)(el) - offsetof(type, member))) static inline void init_list_head(struct list_head *head){    head->prev = head;    head->next = head;} /* insert 'el' between 'prev' and 'next' */static inline void __list_add(struct list_head *el,                               struct list_head *prev, struct list_head *next){    prev->next = el;    el->prev = prev;    el->next = next;    next->prev = el;} /* add 'el' at the head of the list 'head' (= after element head) */static inline void list_add(struct list_head *el, struct list_head *head){    __list_add(el, head, head->next);} /* add 'el' at the end of the list 'head' (= before element head) */static inline void list_add_tail(struct list_head *el, struct list_head *head){    __list_add(el, head->prev, head);} static inline void list_del(struct list_head *el){    struct list_head *prev, *next;    prev = el->prev;    next = el->next;    prev->next = next;    next->prev = prev;    el->prev = NULL; /* fail safe */    el->next = NULL; /* fail safe */} static inline int list_empty(struct list_head *el){    return el->next == el;} #define list_for_each(el, head) \  for(el = (head)->next; el != (head); el = el->next) #define list_for_each_safe(el, el1, head)                \    for(el = (head)->next, el1 = el->next; el != (head); \        el = el1, el1 = el->next) #define list_for_each_prev(el, head) \  for(el = (head)->prev; el != (head); el = el->prev) #define list_for_each_prev_safe(el, el1, head)           \    for(el = (head)->prev, el1 = el->prev; el != (head); \        el = el1, el1 = el->prev) #endif /* LIST_H */