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/*
* Copyright © 2015 Intel Corporation
*
* 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 (including the next
* paragraph) 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 IGT_LIST_H
#define IGT_LIST_H
#include <stdbool.h>
#include <stddef.h>
/**
* SECTION:igt_list
* @short_description: a list implementation inspired by the kernel
* @title: IGT List
* @include: igt_list.h
*
* This list data structure mimics the one we can find in the kernel. A few
* bonus helpers are provided.
*
* igt_list is a doubly-linked list where an instance of igt_list_head is a
* head sentinel and has to be initialized.
*
* Example usage:
*
* |[<!-- language="C" -->
* struct igt_list_head foo_head;
*
* struct element {
* int foo;
* struct igt_list_head link;
* };
*
* struct element e1, e2, e3;
*
* IGT_INIT_LIST_HEAD(&foo_head);
* igt_list_add(&e1.link, &foo_head); // e1 is the first element
* igt_list_add(&e2.link, &foo_head); // e2 is now the first element
* igt_list_add(&e3.link, &e2.link); // insert e3 after e2
*
* printf("list length: %d\n", igt_list_length(&foo_head));
*
* struct element *iter;
* igt_list_for_each_entry(iter, &foo_head, link) {
* printf(" %d\n", iter->foo);
* }
* ]|
*/
struct igt_list_head {
struct igt_list_head *prev;
struct igt_list_head *next;
};
void IGT_INIT_LIST_HEAD(struct igt_list_head *head);
void igt_list_add(struct igt_list_head *elem, struct igt_list_head *head);
void igt_list_del(struct igt_list_head *elem);
void igt_list_move(struct igt_list_head *elem, struct igt_list_head *list);
void igt_list_move_tail(struct igt_list_head *elem, struct igt_list_head *list);
int igt_list_length(const struct igt_list_head *head);
bool igt_list_empty(const struct igt_list_head *head);
#define igt_container_of(ptr, sample, member) \
(__typeof__(sample))((char *)(ptr) - \
offsetof(__typeof__(*sample), member))
#define igt_list_for_each_entry(pos, head, member) \
for (pos = igt_container_of((head)->next, pos, member); \
&pos->member != (head); \
pos = igt_container_of((pos)->member.next, pos, member))
/**
* igt_list_for_each_safe
*
* Safe against removel of the *current* list element. To achive this it
* requires an extra helper variable `tmp` with the same type as `pos`.
*/
#define igt_list_for_each_entry_safe(pos, tmp, head, member) \
for (pos = igt_container_of((head)->next, pos, member), \
tmp = igt_container_of((pos)->member.next, tmp, member); \
&pos->member != (head); \
pos = tmp, \
tmp = igt_container_of((pos)->member.next, tmp, member))
#define igt_list_for_each_entry_reverse(pos, head, member) \
for (pos = igt_container_of((head)->prev, pos, member); \
&pos->member != (head); \
pos = igt_container_of((pos)->member.prev, pos, member))
/* IGT custom helpers */
/**
* IGT_LIST_HEAD
*
* Instead of having to use `IGT_INIT_LIST_HEAD()` list can be defined using
* this helper, e.g. `static IGT_LIST_HEAD(list);`
*/
#define IGT_LIST_HEAD(name) struct igt_list_head name = { &(name), &(name) }
#define igt_list_add_tail(elem, head) igt_list_add(elem, (head)->prev)
#define igt_list_first_entry(head, type, member) \
igt_container_of((head)->next, (type), member)
#define igt_list_last_entry(head, type, member) \
igt_container_of((head)->prev, (type), member)
#endif /* IGT_LIST_H */
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