354 lines
10 KiB
C
354 lines
10 KiB
C
|
/*
|
||
|
|
* Copyright © 2010 Intel Corporation
|
||
|
|
* Copyright © 2010 Francisco Jerez <currojerez@riseup.net>
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* Modified by Ben Skeggs <bskeggs@redhat.com> to match kernel list APIs */
|
||
|
|
|
||
|
|
#ifndef _XORG_LIST_H_
|
||
|
|
#define _XORG_LIST_H_
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @file Classic doubly-link circular list implementation.
|
||
|
|
* For real usage examples of the linked list, see the file test/list.c
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* We need to keep a list of struct foo in the parent struct bar, i.e. what
|
||
|
|
* we want is something like this.
|
||
|
|
*
|
||
|
|
* struct bar {
|
||
|
|
* ...
|
||
|
|
* struct foo *list_of_foos; -----> struct foo {}, struct foo {}, struct foo{}
|
||
|
|
* ...
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* We need one list head in bar and a list element in all list_of_foos (both are of
|
||
|
|
* data type 'struct list_head').
|
||
|
|
*
|
||
|
|
* struct bar {
|
||
|
|
* ...
|
||
|
|
* struct list_head list_of_foos;
|
||
|
|
* ...
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* struct foo {
|
||
|
|
* ...
|
||
|
|
* struct list_head entry;
|
||
|
|
* ...
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* Now we initialize the list head:
|
||
|
|
*
|
||
|
|
* struct bar bar;
|
||
|
|
* ...
|
||
|
|
* INIT_LIST_HEAD(&bar.list_of_foos);
|
||
|
|
*
|
||
|
|
* Then we create the first element and add it to this list:
|
||
|
|
*
|
||
|
|
* struct foo *foo = malloc(...);
|
||
|
|
* ....
|
||
|
|
* list_add(&foo->entry, &bar.list_of_foos);
|
||
|
|
*
|
||
|
|
* Repeat the above for each element you want to add to the list. Deleting
|
||
|
|
* works with the element itself.
|
||
|
|
* list_del(&foo->entry);
|
||
|
|
* free(foo);
|
||
|
|
*
|
||
|
|
* Note: calling list_del(&bar.list_of_foos) will set bar.list_of_foos to an empty
|
||
|
|
* list again.
|
||
|
|
*
|
||
|
|
* Looping through the list requires a 'struct foo' as iterator and the
|
||
|
|
* name of the field the subnodes use.
|
||
|
|
*
|
||
|
|
* struct foo *iterator;
|
||
|
|
* list_for_each_entry(iterator, &bar.list_of_foos, entry) {
|
||
|
|
* if (iterator->something == ...)
|
||
|
|
* ...
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* Note: You must not call list_del() on the iterator if you continue the
|
||
|
|
* loop. You need to run the safe for-each loop instead:
|
||
|
|
*
|
||
|
|
* struct foo *iterator, *next;
|
||
|
|
* list_for_each_entry_safe(iterator, next, &bar.list_of_foos, entry) {
|
||
|
|
* if (...)
|
||
|
|
* list_del(&iterator->entry);
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The linkage struct for list nodes. This struct must be part of your
|
||
|
|
* to-be-linked struct. struct list_head is required for both the head of the
|
||
|
|
* list and for each list node.
|
||
|
|
*
|
||
|
|
* Position and name of the struct list_head field is irrelevant.
|
||
|
|
* There are no requirements that elements of a list are of the same type.
|
||
|
|
* There are no requirements for a list head, any struct list_head can be a list
|
||
|
|
* head.
|
||
|
|
*/
|
||
|
|
struct list_head {
|
||
|
|
struct list_head *next, *prev;
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initialize the list as an empty list.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* INIT_LIST_HEAD(&bar->list_of_foos);
|
||
|
|
*
|
||
|
|
* @param The list to initialized.
|
||
|
|
*/
|
||
|
|
#define LIST_HEAD_INIT(name) { &(name), &(name) }
|
||
|
|
|
||
|
|
#define LIST_HEAD(name) \
|
||
|
|
struct list_head name = LIST_HEAD_INIT(name)
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
INIT_LIST_HEAD(struct list_head *list)
|
||
|
|
{
|
||
|
|
list->next = list->prev = list;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
__list_add(struct list_head *entry,
|
||
|
|
struct list_head *prev, struct list_head *next)
|
||
|
|
{
|
||
|
|
next->prev = entry;
|
||
|
|
entry->next = next;
|
||
|
|
entry->prev = prev;
|
||
|
|
prev->next = entry;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Insert a new element after the given list head. The new element does not
|
||
|
|
* need to be initialised as empty list.
|
||
|
|
* The list changes from:
|
||
|
|
* head → some element → ...
|
||
|
|
* to
|
||
|
|
* head → new element → older element → ...
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo *newfoo = malloc(...);
|
||
|
|
* list_add(&newfoo->entry, &bar->list_of_foos);
|
||
|
|
*
|
||
|
|
* @param entry The new element to prepend to the list.
|
||
|
|
* @param head The existing list.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
list_add(struct list_head *entry, struct list_head *head)
|
||
|
|
{
|
||
|
|
__list_add(entry, head, head->next);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Append a new element to the end of the list given with this list head.
|
||
|
|
*
|
||
|
|
* The list changes from:
|
||
|
|
* head → some element → ... → lastelement
|
||
|
|
* to
|
||
|
|
* head → some element → ... → lastelement → new element
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo *newfoo = malloc(...);
|
||
|
|
* list_add_tail(&newfoo->entry, &bar->list_of_foos);
|
||
|
|
*
|
||
|
|
* @param entry The new element to prepend to the list.
|
||
|
|
* @param head The existing list.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
list_add_tail(struct list_head *entry, struct list_head *head)
|
||
|
|
{
|
||
|
|
__list_add(entry, head->prev, head);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
__list_del(struct list_head *prev, struct list_head *next)
|
||
|
|
{
|
||
|
|
next->prev = prev;
|
||
|
|
prev->next = next;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Remove the element from the list it is in. Using this function will reset
|
||
|
|
* the pointers to/from this element so it is removed from the list. It does
|
||
|
|
* NOT free the element itself or manipulate it otherwise.
|
||
|
|
*
|
||
|
|
* Using list_del on a pure list head (like in the example at the top of
|
||
|
|
* this file) will NOT remove the first element from
|
||
|
|
* the list but rather reset the list as empty list.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* list_del(&foo->entry);
|
||
|
|
*
|
||
|
|
* @param entry The element to remove.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
list_del(struct list_head *entry)
|
||
|
|
{
|
||
|
|
__list_del(entry->prev, entry->next);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
list_del_init(struct list_head *entry)
|
||
|
|
{
|
||
|
|
__list_del(entry->prev, entry->next);
|
||
|
|
INIT_LIST_HEAD(entry);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void list_move_tail(struct list_head *list,
|
||
|
|
struct list_head *head)
|
||
|
|
{
|
||
|
|
__list_del(list->prev, list->next);
|
||
|
|
list_add_tail(list, head);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Check if the list is empty.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* list_empty(&bar->list_of_foos);
|
||
|
|
*
|
||
|
|
* @return True if the list contains one or more elements or False otherwise.
|
||
|
|
*/
|
||
|
|
static inline bool
|
||
|
|
list_empty(struct list_head *head)
|
||
|
|
{
|
||
|
|
return head->next == head;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns a pointer to the container of this list element.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo* f;
|
||
|
|
* f = container_of(&foo->entry, struct foo, entry);
|
||
|
|
* assert(f == foo);
|
||
|
|
*
|
||
|
|
* @param ptr Pointer to the struct list_head.
|
||
|
|
* @param type Data type of the list element.
|
||
|
|
* @param member Member name of the struct list_head field in the list element.
|
||
|
|
* @return A pointer to the data struct containing the list head.
|
||
|
|
*/
|
||
|
|
#ifndef container_of
|
||
|
|
#define container_of(ptr, type, member) \
|
||
|
|
(type *)((char *)(ptr) - (char *) &((type *)0)->member)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Alias of container_of
|
||
|
|
*/
|
||
|
|
#define list_entry(ptr, type, member) \
|
||
|
|
container_of(ptr, type, member)
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieve the first list entry for the given list pointer.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo *first;
|
||
|
|
* first = list_first_entry(&bar->list_of_foos, struct foo, list_of_foos);
|
||
|
|
*
|
||
|
|
* @param ptr The list head
|
||
|
|
* @param type Data type of the list element to retrieve
|
||
|
|
* @param member Member name of the struct list_head field in the list element.
|
||
|
|
* @return A pointer to the first list element.
|
||
|
|
*/
|
||
|
|
#define list_first_entry(ptr, type, member) \
|
||
|
|
list_entry((ptr)->next, type, member)
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieve the last list entry for the given listpointer.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo *first;
|
||
|
|
* first = list_last_entry(&bar->list_of_foos, struct foo, list_of_foos);
|
||
|
|
*
|
||
|
|
* @param ptr The list head
|
||
|
|
* @param type Data type of the list element to retrieve
|
||
|
|
* @param member Member name of the struct list_head field in the list element.
|
||
|
|
* @return A pointer to the last list element.
|
||
|
|
*/
|
||
|
|
#define list_last_entry(ptr, type, member) \
|
||
|
|
list_entry((ptr)->prev, type, member)
|
||
|
|
|
||
|
|
#define __container_of(ptr, sample, member) \
|
||
|
|
(void *)container_of((ptr), typeof(*(sample)), member)
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Loop through the list given by head and set pos to struct in the list.
|
||
|
|
*
|
||
|
|
* Example:
|
||
|
|
* struct foo *iterator;
|
||
|
|
* list_for_each_entry(iterator, &bar->list_of_foos, entry) {
|
||
|
|
* [modify iterator]
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* This macro is not safe for node deletion. Use list_for_each_entry_safe
|
||
|
|
* instead.
|
||
|
|
*
|
||
|
|
* @param pos Iterator variable of the type of the list elements.
|
||
|
|
* @param head List head
|
||
|
|
* @param member Member name of the struct list_head in the list elements.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
#define list_for_each_entry(pos, head, member) \
|
||
|
|
for (pos = __container_of((head)->next, pos, member); \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = __container_of(pos->member.next, pos, member))
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Loop through the list, keeping a backup pointer to the element. This
|
||
|
|
* macro allows for the deletion of a list element while looping through the
|
||
|
|
* list.
|
||
|
|
*
|
||
|
|
* See list_for_each_entry for more details.
|
||
|
|
*/
|
||
|
|
#define list_for_each_entry_safe(pos, tmp, head, member) \
|
||
|
|
for (pos = __container_of((head)->next, pos, member), \
|
||
|
|
tmp = __container_of(pos->member.next, pos, member); \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = tmp, tmp = __container_of(pos->member.next, tmp, member))
|
||
|
|
|
||
|
|
|
||
|
|
#define list_for_each_entry_reverse(pos, head, member) \
|
||
|
|
for (pos = __container_of((head)->prev, pos, member); \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = __container_of(pos->member.prev, pos, member))
|
||
|
|
|
||
|
|
#define list_for_each_entry_continue(pos, head, member) \
|
||
|
|
for (pos = __container_of(pos->member.next, pos, member); \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = __container_of(pos->member.next, pos, member))
|
||
|
|
|
||
|
|
#define list_for_each_entry_continue_reverse(pos, head, member) \
|
||
|
|
for (pos = __container_of(pos->member.prev, pos, member); \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = __container_of(pos->member.prev, pos, member))
|
||
|
|
|
||
|
|
#define list_for_each_entry_from(pos, head, member) \
|
||
|
|
for (; \
|
||
|
|
&pos->member != (head); \
|
||
|
|
pos = __container_of(pos->member.next, pos, member))
|
||
|
|
|
||
|
|
#endif
|