/**************************************************************************
*
* Copyright 2006 VMware, Inc., Bismarck, ND. USA.
* All Rights Reserved.
*
* 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
**************************************************************************/
/**
* \file
* List macros heavily inspired by the Linux kernel
* list handling. No list looping yet.
*
* Is not threadsafe, so common operations need to
* be protected using an external mutex.
*/
#ifndef _UTIL_LIST_H_
#define _UTIL_LIST_H_
#include <stdbool.h>
#include <stddef.h>
#include <assert.h>
#include "c99_compat.h"
#ifdef DEBUG
# define list_assert(cond, msg) assert(cond && msg)
#else
# define list_assert(cond, msg) (
void)(0 && (cond))
#endif
struct list_head
{
struct list_head *prev;
struct list_head *next;
};
static inline void list_inithead(
struct list_head *item)
{
item->prev = item;
item->next = item;
}
static inline void list_add(
struct list_head *item,
struct list_head *list)
{
item->prev = list;
item->next = list->next;
list->next->prev = item;
list->next = item;
}
static inline void list_addtail(
struct list_head *item,
struct list_head *list)
{
item->next = list;
item->prev = list->prev;
list->prev->next = item;
list->prev = item;
}
static inline bool list_is_empty(
const struct list_head *list);
static inline void list_replace(
struct list_head *from,
struct list_head *to)
{
if (list_is_empty(from)) {
list_inithead(to);
}
else {
to->prev = from->prev;
to->next = from->next;
from->next->prev = to;
from->prev->next = to;
}
}
static inline void list_del(
struct list_head *item)
{
item->prev->next = item->next;
item->next->prev = item->prev;
item->prev = item->next = NULL;
}
static inline void list_delinit(
struct list_head *item)
{
item->prev->next = item->next;
item->next->prev = item->prev;
item->next = item;
item->prev = item;
}
static inline bool list_is_empty(
const struct list_head *list)
{
return list->next == list;
}
/**
* Returns whether the list has exactly one element.
*/
static inline bool list_is_singular(
const struct list_head *list)
{
return list->next != NULL && list->next != list && list->next->next == list;
}
static inline unsigned list_length(
const struct list_head *list)
{
struct list_head *node;
unsigned length = 0;
for (node = list->next; node != list; node = node->next)
length++;
return length;
}
static inline void list_splice(
struct list_head *src,
struct list_head *dst)
{
if (list_is_empty(src))
return;
src->next->prev = dst;
src->prev->next = dst->next;
dst->next->prev = src->prev;
dst->next = src->next;
}
static inline void list_splicetail(
struct list_head *src,
struct list_head *dst)
{
if (list_is_empty(src))
return;
src->prev->next = dst;
src->next->prev = dst->prev;
dst->prev->next = src->next;
dst->prev = src->prev;
}
static inline void list_validate(
const struct list_head *list)
{
struct list_head *node;
assert(list->next->prev == list && list->prev->next == list);
for (node = list->next; node != list; node = node->next)
assert(node->next->prev == node && node->prev->next == node);
}
#define LIST_ENTRY(__type, __item, __field) \
((__type *)(((
char *)(__item)) - offsetof(__type, __field)))
/**
* Cast from a pointer to a member of a struct back to the containing struct.
*
* 'sample' MUST be initialized, or else the result is undefined!
*/
#ifndef container_of
#define container_of(ptr, sample, member) \
(
void *)((
char *)(ptr) \
- ((
char *)&(sample)->member - (
char *)(sample)))
#endif
#define list_first_entry(ptr, type, member) \
LIST_ENTRY(type, (ptr)->next, member)
#define list_last_entry(ptr, type, member) \
LIST_ENTRY(type, (ptr)->prev, member)
#define LIST_FOR_EACH_ENTRY(pos, head, member) \
for (pos = NULL, pos = container_of((head)->next, pos, member); \
&pos->member != (head); \
pos = container_of(pos->member.next, pos, member))
#define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \
for (pos = NULL, pos = container_of((head)->next, pos, member), \
storage = container_of(pos->member.next, pos, member); \
&pos->member != (head); \
pos = storage, storage = container_of(storage->member.next, storage, member))
#define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \
for (pos = NULL, pos = container_of((head)->prev, pos, member), \
storage = container_of(pos->member.prev, pos, member); \
&pos->member != (head); \
pos = storage, storage = container_of(storage->member.prev, storage, member))
#define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \
for (pos = NULL, pos = container_of((start), pos, member); \
&pos->member != (head); \
pos = container_of(pos->member.next, pos, member))
#define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \
for (pos = NULL, pos = container_of((start), pos, member); \
&pos->member != (head); \
pos = container_of(pos->member.prev, pos, member))
#define list_for_each_entry(type, pos, head, member) \
for (type *pos = LIST_ENTRY(type, (head)->next, member), \
*__next = LIST_ENTRY(type, pos->member.next, member); \
&pos->member != (head); \
pos = LIST_ENTRY(type, pos->member.next, member), \
list_assert(pos == __next,
"use _safe iterator"), \
__next = LIST_ENTRY(type, __next->member.next, member))
#define list_for_each_entry_safe(type, pos, head, member) \
for (type *pos = LIST_ENTRY(type, (head)->next, member), \
*__next = LIST_ENTRY(type, pos->member.next, member); \
&pos->member != (head); \
pos = __next, \
__next = LIST_ENTRY(type, __next->member.next, member))
#define list_for_each_entry_rev(type, pos, head, member) \
for (type *pos = LIST_ENTRY(type, (head)->prev, member), \
*__prev = LIST_ENTRY(type, pos->member.prev, member); \
&pos->member != (head); \
pos = LIST_ENTRY(type, pos->member.prev, member), \
list_assert(pos == __prev,
"use _safe iterator"), \
__prev = LIST_ENTRY(type, __prev->member.prev, member))
#define list_for_each_entry_safe_rev(type, pos, head, member) \
for (type *pos = LIST_ENTRY(type, (head)->prev, member), \
*__prev = LIST_ENTRY(type, pos->member.prev, member); \
&pos->member != (head); \
pos = __prev, \
__prev = LIST_ENTRY(type, __prev->member.prev, member))
#define list_for_each_entry_from(type, pos, start, head, member) \
for (type *pos = LIST_ENTRY(type, (start), member); \
&pos->member != (head); \
pos = LIST_ENTRY(type, pos->member.next, member))
#define list_for_each_entry_from_rev(type, pos, start, head, member) \
for (type *pos = LIST_ENTRY(type, (start), member); \
&pos->member != (head); \
pos = LIST_ENTRY(type, pos->member.prev, member))
#endif /*_UTIL_LIST_H_*/
