| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2002 Free Software Foundation, Inc. |
| 5 | * This file is part of the GNU C Library. |
| 6 | * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
| 7 | */ |
| 8 | |
| 9 | #ifndef _BT_LIST_H |
| 10 | #define _BT_LIST_H 1 |
| 11 | |
| 12 | /* The definitions of this file are adopted from those which can be |
| 13 | found in the Linux kernel headers to enable people familiar with |
| 14 | the latter find their way in these sources as well. */ |
| 15 | |
| 16 | #ifdef __cplusplus |
| 17 | extern "C" { |
| 18 | #endif |
| 19 | |
| 20 | /* Basic type for the double-link list. */ |
| 21 | struct bt_list_head |
| 22 | { |
| 23 | struct bt_list_head *next; |
| 24 | struct bt_list_head *prev; |
| 25 | }; |
| 26 | |
| 27 | |
| 28 | /* Define a variable with the head and tail of the list. */ |
| 29 | #define BT_LIST_HEAD(name) \ |
| 30 | struct bt_list_head name = { &(name), &(name) } |
| 31 | |
| 32 | /* Initialize a new list head. */ |
| 33 | #define BT_INIT_LIST_HEAD(ptr) \ |
| 34 | (ptr)->next = (ptr)->prev = (ptr) |
| 35 | |
| 36 | #define BT_LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) } |
| 37 | |
| 38 | /* Add new element at the head of the list. */ |
| 39 | static inline void |
| 40 | bt_list_add (struct bt_list_head *newp, struct bt_list_head *head) |
| 41 | { |
| 42 | head->next->prev = newp; |
| 43 | newp->next = head->next; |
| 44 | newp->prev = head; |
| 45 | head->next = newp; |
| 46 | } |
| 47 | |
| 48 | |
| 49 | /* Add new element at the tail of the list. */ |
| 50 | static inline void |
| 51 | bt_list_add_tail (struct bt_list_head *newp, struct bt_list_head *head) |
| 52 | { |
| 53 | head->prev->next = newp; |
| 54 | newp->next = head; |
| 55 | newp->prev = head->prev; |
| 56 | head->prev = newp; |
| 57 | } |
| 58 | |
| 59 | |
| 60 | /* Remove element from list. */ |
| 61 | static inline void |
| 62 | __bt_list_del (struct bt_list_head *prev, struct bt_list_head *next) |
| 63 | { |
| 64 | next->prev = prev; |
| 65 | prev->next = next; |
| 66 | } |
| 67 | |
| 68 | /* Remove element from list. */ |
| 69 | static inline void |
| 70 | bt_list_del (struct bt_list_head *elem) |
| 71 | { |
| 72 | __bt_list_del (elem->prev, elem->next); |
| 73 | } |
| 74 | |
| 75 | /* delete from list, add to another list as head */ |
| 76 | static inline void |
| 77 | bt_list_move (struct bt_list_head *elem, struct bt_list_head *head) |
| 78 | { |
| 79 | __bt_list_del (elem->prev, elem->next); |
| 80 | bt_list_add (elem, head); |
| 81 | } |
| 82 | |
| 83 | /* replace an old entry. |
| 84 | */ |
| 85 | static inline void |
| 86 | bt_list_replace(struct bt_list_head *old, struct bt_list_head *_new) |
| 87 | { |
| 88 | _new->next = old->next; |
| 89 | _new->prev = old->prev; |
| 90 | _new->prev->next = _new; |
| 91 | _new->next->prev = _new; |
| 92 | } |
| 93 | |
| 94 | /* Join two lists. */ |
| 95 | static inline void |
| 96 | bt_list_splice (struct bt_list_head *add, struct bt_list_head *head) |
| 97 | { |
| 98 | /* Do nothing if the list which gets added is empty. */ |
| 99 | if (add != add->next) |
| 100 | { |
| 101 | add->next->prev = head; |
| 102 | add->prev->next = head->next; |
| 103 | head->next->prev = add->prev; |
| 104 | head->next = add->next; |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | |
| 109 | /* Get typed element from list at a given position. */ |
| 110 | #define bt_list_entry(ptr, type, member) \ |
| 111 | ((type *) ((char *) (ptr) - (uintptr_t) (&((type *) 0)->member))) |
| 112 | |
| 113 | |
| 114 | |
| 115 | /* Iterate forward over the elements of the list. */ |
| 116 | #define bt_list_for_each(pos, head) \ |
| 117 | for (pos = (head)->next; pos != (head); pos = pos->next) |
| 118 | |
| 119 | |
| 120 | /* Iterate forward over the elements of the list. */ |
| 121 | #define bt_list_for_each_prev(pos, head) \ |
| 122 | for (pos = (head)->prev; pos != (head); pos = pos->prev) |
| 123 | |
| 124 | |
| 125 | /* Iterate backwards over the elements list. The list elements can be |
| 126 | removed from the list while doing this. */ |
| 127 | #define bt_list_for_each_prev_safe(pos, p, head) \ |
| 128 | for (pos = (head)->prev, p = pos->prev; \ |
| 129 | pos != (head); \ |
| 130 | pos = p, p = pos->prev) |
| 131 | |
| 132 | #define bt_list_for_each_entry(pos, head, member) \ |
| 133 | for (pos = bt_list_entry((head)->next, __typeof__(*pos), member); \ |
| 134 | &pos->member != (head); \ |
| 135 | pos = bt_list_entry(pos->member.next, __typeof__(*pos), member)) |
| 136 | |
| 137 | #define bt_list_for_each_entry_reverse(pos, head, member) \ |
| 138 | for (pos = bt_list_entry((head)->prev, __typeof__(*pos), member); \ |
| 139 | &pos->member != (head); \ |
| 140 | pos = bt_list_entry(pos->member.prev, __typeof__(*pos), member)) |
| 141 | |
| 142 | #define bt_list_for_each_entry_safe(pos, p, head, member) \ |
| 143 | for (pos = bt_list_entry((head)->next, __typeof__(*pos), member), \ |
| 144 | p = bt_list_entry(pos->member.next, __typeof__(*pos), member); \ |
| 145 | &pos->member != (head); \ |
| 146 | pos = p, p = bt_list_entry(pos->member.next, __typeof__(*pos), member)) |
| 147 | |
| 148 | static inline int bt_list_empty(struct bt_list_head *head) |
| 149 | { |
| 150 | return head == head->next; |
| 151 | } |
| 152 | |
| 153 | static inline void bt_list_replace_init(struct bt_list_head *old, |
| 154 | struct bt_list_head *_new) |
| 155 | { |
| 156 | struct bt_list_head *head = old->next; |
| 157 | bt_list_del(old); |
| 158 | bt_list_add_tail(_new, head); |
| 159 | BT_INIT_LIST_HEAD(old); |
| 160 | } |
| 161 | |
| 162 | #ifdef __cplusplus |
| 163 | } |
| 164 | #endif |
| 165 | |
| 166 | #endif /* _BT_LIST_H */ |