1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef _LIST_H_
18#define _LIST_H_
19
20#include <stdbool.h>
21
22struct link_t
23{
24    struct link_t *prev, *next;
25} typedef link_t;
26
27#define list_iterate(list, cur_link, tmp_link)                  \
28    for ((cur_link) = (list)->next,                             \
29            (tmp_link) = (cur_link) ? (cur_link)->next : NULL;  \
30         (cur_link) != NULL && (cur_link) != (list);            \
31         (cur_link) = (tmp_link), (tmp_link) = (cur_link)->next)
32
33#define DECLARE_LIST(list) \
34    link_t list = { .prev = &list, .next = &list }
35
36static inline void list_init(struct link_t *list)
37{
38    list->prev = list->next = list;
39}
40
41static inline void list_add_tail(struct link_t *list, struct link_t *item)
42{
43    if (!list->next)
44        list_init(list);
45
46    item->prev = list->prev;
47    item->next = list;
48    list->prev->next = item;
49    list->prev = item;
50}
51
52static inline void list_delete(struct link_t *item)
53{
54    item->prev->next = item->next;
55    item->next->prev = item->prev;
56    item->next = item->prev = item;
57}
58
59static inline bool list_is_empty(struct link_t *list)
60{
61    return !list->next || list->next == list;
62}
63
64#endif
65
66