| 1 | // SPDX-FileCopyrightText: 2002 Free Software Foundation, Inc. |
| 2 | // SPDX-FileCopyrightText: 2009 Pierre-Marc Fournier |
| 3 | // SPDX-FileCopyrightText: 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | // |
| 5 | // SPDX-License-Identifier: LGPL-2.1-or-later |
| 6 | |
| 7 | /* |
| 8 | * (originally part of the GNU C Library) |
| 9 | * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
| 10 | */ |
| 11 | |
| 12 | #ifndef _CDS_LIST_H |
| 13 | #define _CDS_LIST_H 1 |
| 14 | |
| 15 | #include <urcu/compiler.h> |
| 16 | |
| 17 | /* |
| 18 | * The definitions of this file are adopted from those which can be |
| 19 | * found in the Linux kernel headers to enable people familiar with the |
| 20 | * latter find their way in these sources as well. |
| 21 | */ |
| 22 | |
| 23 | /* Basic type for the double-link list. */ |
| 24 | struct cds_list_head { |
| 25 | struct cds_list_head *next, *prev; |
| 26 | }; |
| 27 | |
| 28 | /* Define a variable with the head and tail of the list. */ |
| 29 | #define CDS_LIST_HEAD(name) \ |
| 30 | struct cds_list_head name = { &(name), &(name) } |
| 31 | |
| 32 | /* Initialize a new list head. */ |
| 33 | #define CDS_INIT_LIST_HEAD(ptr) \ |
| 34 | (ptr)->next = (ptr)->prev = (ptr) |
| 35 | |
| 36 | #define CDS_LIST_HEAD_INIT(name) { .next = &(name), .prev = &(name) } |
| 37 | |
| 38 | /* Add new element at the head of the list. */ |
| 39 | static inline |
| 40 | void cds_list_add(struct cds_list_head *newp, struct cds_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 | /* Add new element at the tail of the list. */ |
| 49 | static inline |
| 50 | void cds_list_add_tail(struct cds_list_head *newp, struct cds_list_head *head) |
| 51 | { |
| 52 | head->prev->next = newp; |
| 53 | newp->next = head; |
| 54 | newp->prev = head->prev; |
| 55 | head->prev = newp; |
| 56 | } |
| 57 | |
| 58 | /* Remove element from list. */ |
| 59 | static inline |
| 60 | void __cds_list_del(struct cds_list_head *prev, struct cds_list_head *next) |
| 61 | { |
| 62 | next->prev = prev; |
| 63 | prev->next = next; |
| 64 | } |
| 65 | |
| 66 | /* Remove element from list. */ |
| 67 | static inline |
| 68 | void cds_list_del(struct cds_list_head *elem) |
| 69 | { |
| 70 | __cds_list_del(elem->prev, elem->next); |
| 71 | } |
| 72 | |
| 73 | /* Remove element from list, initializing the element's list pointers. */ |
| 74 | static inline |
| 75 | void cds_list_del_init(struct cds_list_head *elem) |
| 76 | { |
| 77 | cds_list_del(elem); |
| 78 | CDS_INIT_LIST_HEAD(elem); |
| 79 | } |
| 80 | |
| 81 | /* Delete from list, add to another list as head. */ |
| 82 | static inline |
| 83 | void cds_list_move(struct cds_list_head *elem, struct cds_list_head *head) |
| 84 | { |
| 85 | __cds_list_del(elem->prev, elem->next); |
| 86 | cds_list_add(elem, head); |
| 87 | } |
| 88 | |
| 89 | /* Replace an old entry. */ |
| 90 | static inline |
| 91 | void cds_list_replace(struct cds_list_head *old, struct cds_list_head *_new) |
| 92 | { |
| 93 | _new->next = old->next; |
| 94 | _new->prev = old->prev; |
| 95 | _new->prev->next = _new; |
| 96 | _new->next->prev = _new; |
| 97 | } |
| 98 | |
| 99 | /* Join two lists. */ |
| 100 | static inline |
| 101 | void cds_list_splice(struct cds_list_head *add, struct cds_list_head *head) |
| 102 | { |
| 103 | /* Do nothing if the list which gets added is empty. */ |
| 104 | if (add != add->next) { |
| 105 | add->next->prev = head; |
| 106 | add->prev->next = head->next; |
| 107 | head->next->prev = add->prev; |
| 108 | head->next = add->next; |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | /* Get typed element from list at a given position. */ |
| 113 | #define cds_list_entry(ptr, type, member) caa_container_of(ptr, type, member) |
| 114 | |
| 115 | |
| 116 | /* Get first entry from a list. */ |
| 117 | #define cds_list_first_entry(ptr, type, member) \ |
| 118 | cds_list_entry((ptr)->next, type, member) |
| 119 | |
| 120 | /* Iterate forward over the elements of the list. */ |
| 121 | #define cds_list_for_each(pos, head) \ |
| 122 | for (pos = (head)->next; (pos) != (head); pos = (pos)->next) |
| 123 | |
| 124 | /* |
| 125 | * Iterate forward over the elements list. The list elements can be |
| 126 | * removed from the list while doing this. |
| 127 | */ |
| 128 | #define cds_list_for_each_safe(pos, p, head) \ |
| 129 | for (pos = (head)->next, p = (pos)->next; \ |
| 130 | (pos) != (head); \ |
| 131 | pos = (p), p = (pos)->next) |
| 132 | |
| 133 | /* Iterate backward over the elements of the list. */ |
| 134 | #define cds_list_for_each_prev(pos, head) \ |
| 135 | for (pos = (head)->prev; (pos) != (head); pos = (pos)->prev) |
| 136 | |
| 137 | /* |
| 138 | * Iterate backwards over the elements list. The list elements can be |
| 139 | * removed from the list while doing this. |
| 140 | */ |
| 141 | #define cds_list_for_each_prev_safe(pos, p, head) \ |
| 142 | for (pos = (head)->prev, p = (pos)->prev; \ |
| 143 | (pos) != (head); \ |
| 144 | pos = (p), p = (pos)->prev) |
| 145 | |
| 146 | #define cds_list_for_each_entry(pos, head, member) \ |
| 147 | for (pos = cds_list_entry((head)->next, __typeof__(*(pos)), member); \ |
| 148 | &(pos)->member != (head); \ |
| 149 | pos = cds_list_entry((pos)->member.next, __typeof__(*(pos)), member)) |
| 150 | |
| 151 | #define cds_list_for_each_entry_reverse(pos, head, member) \ |
| 152 | for (pos = cds_list_entry((head)->prev, __typeof__(*(pos)), member); \ |
| 153 | &(pos)->member != (head); \ |
| 154 | pos = cds_list_entry((pos)->member.prev, __typeof__(*(pos)), member)) |
| 155 | |
| 156 | #define cds_list_for_each_entry_safe(pos, p, head, member) \ |
| 157 | for (pos = cds_list_entry((head)->next, __typeof__(*(pos)), member), \ |
| 158 | p = cds_list_entry((pos)->member.next, __typeof__(*(pos)), member); \ |
| 159 | &(pos)->member != (head); \ |
| 160 | pos = (p), p = cds_list_entry((pos)->member.next, __typeof__(*(pos)), member)) |
| 161 | |
| 162 | /* |
| 163 | * Same as cds_list_for_each_entry_safe, but starts from "pos" which should |
| 164 | * point to an entry within the list. |
| 165 | */ |
| 166 | #define cds_list_for_each_entry_safe_from(pos, p, head, member) \ |
| 167 | for (p = cds_list_entry((pos)->member.next, __typeof__(*(pos)), member); \ |
| 168 | &(pos)->member != (head); \ |
| 169 | pos = (p), p = cds_list_entry((pos)->member.next, __typeof__(*(pos)), member)) |
| 170 | |
| 171 | static inline |
| 172 | int cds_list_empty(struct cds_list_head *head) |
| 173 | { |
| 174 | return head == head->next; |
| 175 | } |
| 176 | |
| 177 | static inline |
| 178 | void cds_list_replace_init(struct cds_list_head *old, |
| 179 | struct cds_list_head *_new) |
| 180 | { |
| 181 | struct cds_list_head *head = old->next; |
| 182 | |
| 183 | cds_list_del(old); |
| 184 | cds_list_add_tail(_new, head); |
| 185 | CDS_INIT_LIST_HEAD(old); |
| 186 | } |
| 187 | |
| 188 | #endif /* _CDS_LIST_H */ |