/*
* Copyright © 2008, 2010 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.
*/
/**
* \file list.h
* \brief Doubly-linked list abstract container type.
*
* Each doubly-linked list has a sentinel head and tail node. These nodes
* contain no data. The head sentinel can be identified by its \c prev
* pointer being \c NULL. The tail sentinel can be identified by its
* \c next pointer being \c NULL.
*
* A list is empty if either the head sentinel's \c next pointer points to the
* tail sentinel or the tail sentinel's \c prev poiner points to the head
* sentinel.
*
* Instead of tracking two separate \c node structures and a \c list structure
* that points to them, the sentinel nodes are in a single structure. Noting
* that each sentinel node always has one \c NULL pointer, the \c NULL
* pointers occupy the same memory location. In the \c list structure
* contains a the following:
*
* - A \c head pointer that represents the \c next pointer of the
* head sentinel node.
* - A \c tail pointer that represents the \c prev pointer of the head
* sentinel node and the \c next pointer of the tail sentinel node. This
* pointer is \b always \c NULL.
* - A \c tail_prev pointer that represents the \c prev pointer of the
* tail sentinel node.
*
* Therefore, if \c head->next is \c NULL or \c tail_prev->prev is \c NULL,
* the list is empty.
*
* Do note that this means that the list nodes will contain pointers into the
* list structure itself and as a result you may not \c realloc() an \c
* exec_list or any structure in which an \c exec_list is embedded.
*
* To anyone familiar with "exec lists" on the Amiga, this structure should
* be immediately recognizable. See the following link for the original Amiga
* operating system documentation on the subject.
*
* http://www.natami.net/dev/Libraries_Manual_guide/node02D7.html
*
* \author Ian Romanick <ian.d.romanick@intel.com>
*/
#pragma once
#ifndef LIST_CONTAINER_H
#define LIST_CONTAINER_H
#ifndef __cplusplus
#include <stddef.h>
#endif
#include <assert.h>
#include "util/ralloc.h"
struct exec_node {
struct exec_node *next;
struct exec_node *prev;
#ifdef __cplusplus
DECLARE_RALLOC_CXX_OPERATORS(exec_node)
exec_node() : next(NULL), prev(NULL)
{
/* empty */
}
const exec_node *get_next() const;
exec_node *get_next();
const exec_node *get_prev() const;
exec_node *get_prev();
void remove();
/**
* Link a node with itself
*
* This creates a sort of degenerate list that is occasionally useful.
*/
void self_link();
/**
* Insert a node in the list after the current node
*/
void insert_after(exec_node *after);
/**
* Insert a node in the list before the current node
*/
void insert_before(exec_node *before);
/**
* Insert another list in the list before the current node
*/
void insert_before(struct exec_list *before);
/**
* Replace the current node with the given node.
*/
void replace_with(exec_node *replacement);
/**
* Is this the sentinel at the tail of the list?
*/
bool is_tail_sentinel() const;
/**
* Is this the sentinel at the head of the list?
*/
bool is_head_sentinel() const;
#endif
};
static inline void
exec_node_init(struct exec_node *n)
{
n->next = NULL;
n->prev = NULL;
}
static inline const struct exec_node *
exec_node_get_next_const(const struct exec_node *n)
{
return n->next;
}
static inline struct exec_node *
exec_node_get_next(struct exec_node *n)
{
return n->next;
}
static inline const struct exec_node *
exec_node_get_prev_const(const struct exec_node *n)
{
return n->prev;
}
static inline struct exec_node *
exec_node_get_prev(struct exec_node *n)
{
return n->prev;
}
static inline void
exec_node_remove(struct exec_node *n)
{
n->next->prev = n->prev;
n->prev->next = n->next;
n->next = NULL;
n->prev = NULL;
}
static inline void
exec_node_self_link(struct exec_node *n)
{
n->next = n;
n->prev = n;
}
static inline void
exec_node_insert_after(struct exec_node *n, struct exec_node *after)
{
after->next = n->next;
after->prev = n;
n->next->prev = after;
n->next = after;
}
static inline void
exec_node_insert_node_before(struct exec_node *n, struct exec_node *before)
{
before->next = n;
before->prev = n->prev;
n->prev->next = before;
n->prev = before;
}
static inline void
exec_node_replace_with(struct exec_node *n, struct exec_node *replacement)
{
replacement->prev = n->prev;
replacement->next = n->next;
n->prev->next = replacement;
n->next->prev = replacement;
}
static inline bool
exec_node_is_tail_sentinel(const struct exec_node *n)
{
return n->next == NULL;
}
static inline bool
exec_node_is_head_sentinel(const struct exec_node *n)
{
return n->prev == NULL;
}
#ifdef __cplusplus
inline const exec_node *exec_node::get_next() const
{
return exec_node_get_next_const(this);
}
inline exec_node *exec_node::get_next()
{
return exec_node_get_next(this);
}
inline const exec_node *exec_node::get_prev() const
{
return exec_node_get_prev_const(this);
}
inline exec_node *exec_node::get_prev()
{
return exec_node_get_prev(this);
}
inline void exec_node::remove()
{
exec_node_remove(this);
}
inline void exec_node::self_link()
{
exec_node_self_link(this);
}
inline void exec_node::insert_after(exec_node *after)
{
exec_node_insert_after(this, after);
}
inline void exec_node::insert_before(exec_node *before)
{
exec_node_insert_node_before(this, before);
}
inline void exec_node::replace_with(exec_node *replacement)
{
exec_node_replace_with(this, replacement);
}
inline bool exec_node::is_tail_sentinel() const
{
return exec_node_is_tail_sentinel(this);
}
inline bool exec_node::is_head_sentinel() const
{
return exec_node_is_head_sentinel(this);
}
#endif
#ifdef __cplusplus
/* This macro will not work correctly if `t' uses virtual inheritance. If you
* are using virtual inheritance, you deserve a slow and painful death. Enjoy!
*/
#define exec_list_offsetof(t, f, p) \
(((char *) &((t *) p)->f) - ((char *) p))
#else
#define exec_list_offsetof(t, f, p) offsetof(t, f)
#endif
/**
* Get a pointer to the structure containing an exec_node
*
* Given a pointer to an \c exec_node embedded in a structure, get a pointer to
* the containing structure.
*
* \param type Base type of the structure containing the node
* \param node Pointer to the \c exec_node
* \param field Name of the field in \c type that is the embedded \c exec_node
*/
#define exec_node_data(type, node, field) \
((type *) (((char *) node) - exec_list_offsetof(type, field, node)))
#ifdef __cplusplus
struct exec_node;
#endif
struct exec_list {
struct exec_node *head;
struct exec_node *tail;
struct exec_node *tail_pred;
#ifdef __cplusplus
DECLARE_RALLOC_CXX_OPERATORS(exec_list)
exec_list()
{
make_empty();
}
void make_empty();
bool is_empty() const;
const exec_node *get_head() const;
exec_node *get_head();
const exec_node *get_tail() const;
exec_node *get_tail();
unsigned length() const;
void push_head(exec_node *n);
void push_tail(exec_node *n);
void push_degenerate_list_at_head(exec_node *n);
/**
* Remove the first node from a list and return it
*
* \return
* The first node in the list or \c NULL if the list is empty.
*
* \sa exec_list::get_head
*/
exec_node *pop_head();
/**
* Move all of the nodes from this list to the target list
*/
void move_nodes_to(exec_list *target);
/**
* Append all nodes from the source list to the end of the target list
*/
void append_list(exec_list *source);
/**
* Prepend all nodes from the source list to the beginning of the target
* list
*/
void prepend_list(exec_list *source);
#endif
};
static inline void
exec_list_make_empty(struct exec_list *list)
{
list->head = (struct exec_node *) & list->tail;
list->tail = NULL;
list->tail_pred = (struct exec_node *) & list->head;
}
static inline bool
exec_list_is_empty(const struct exec_list *list)
{
/* There are three ways to test whether a list is empty or not.
*
* - Check to see if the \c head points to the \c tail.
* - Check to see if the \c tail_pred points to the \c head.
* - Check to see if the \c head is the sentinel node by test whether its
* \c next pointer is \c NULL.
*
* The first two methods tend to generate better code on modern systems
* because they save a pointer dereference.
*/
return list->head == (struct exec_node *) &list->tail;
}
static inline const struct exec_node *
exec_list_get_head_const(const struct exec_list *list)
{
return !exec_list_is_empty(list) ? list->head : NULL;
}
static inline struct exec_node *
exec_list_get_head(struct exec_list *list)
{
return !exec_list_is_empty(list) ? list->head : NULL;
}
static inline const struct exec_node *
exec_list_get_tail_const(const struct exec_list *list)
{
return !exec_list_is_empty(list) ? list->tail_pred : NULL;
}
static inline struct exec_node *
exec_list_get_tail(struct exec_list *list)
{
return !exec_list_is_empty(list) ? list->tail_pred : NULL;
}
static inline unsigned
exec_list_length(const struct exec_list *list)
{
unsigned size = 0;
struct exec_node *node;
for (node = list->head; node->next != NULL; node = node->next) {
size++;
}
return size;
}
static inline void
exec_list_push_head(struct exec_list *list, struct exec_node *n)
{
n->next = list->head;
n->prev = (struct exec_node *) &list->head;
n->next->prev = n;
list->head = n;
}
static inline void
exec_list_push_tail(struct exec_list *list, struct exec_node *n)
{
n->next = (struct exec_node *) &list->tail;
n->prev = list->tail_pred;
n->prev->next = n;
list->tail_pred = n;
}
static inline void
exec_list_push_degenerate_list_at_head(struct exec_list *list, struct exec_node *n)
{
assert(n->prev->next == n);
n->prev->next = list->head;
list->head->prev = n->prev;
n->prev = (struct exec_node *) &list->head;
list->head = n;
}
static inline struct exec_node *
exec_list_pop_head(struct exec_list *list)
{
struct exec_node *const n = exec_list_get_head(list);
if (n != NULL)
exec_node_remove(n);
return n;
}
static inline void
exec_list_move_nodes_to(struct exec_list *list, struct exec_list *target)
{
if (exec_list_is_empty(list)) {
exec_list_make_empty(target);
} else {
target->head = list->head;
target->tail = NULL;
target->tail_pred = list->tail_pred;
target->head->prev = (struct exec_node *) &target->head;
target->tail_pred->next = (struct exec_node *) &target->tail;
exec_list_make_empty(list);
}
}
static inline void
exec_list_append(struct exec_list *list, struct exec_list *source)
{
if (exec_list_is_empty(source))
return;
/* Link the first node of the source with the last node of the target list.
*/
list->tail_pred->next = source->head;
source->head->prev = list->tail_pred;
/* Make the tail of the source list be the tail of the target list.
*/
list->tail_pred = source->tail_pred;
list->tail_pred->next = (struct exec_node *) &list->tail;
/* Make the source list empty for good measure.
*/
exec_list_make_empty(source);
}
static inline void
exec_list_prepend(struct exec_list *list, struct exec_list *source)
{
exec_list_append(source, list);
exec_list_move_nodes_to(source, list);
}
static inline void
exec_node_insert_list_before(struct exec_node *n, struct exec_list *before)
{
if (exec_list_is_empty(before))
return;
before->tail_pred->next = n;
before->head->prev = n->prev;
n->prev->next = before->head;
n->prev = before->tail_pred;
exec_list_make_empty(before);
}
static inline void
exec_list_validate(const struct exec_list *list)
{
const struct exec_node *node;
assert(list->head->prev == (const struct exec_node *) &list->head);
assert(list->tail == NULL);
assert(list->tail_pred->next == (const struct exec_node *) &list->tail);
/* We could try to use one of the interators below for this but they all
* either require C++ or assume the exec_node is embedded in a structure
* which is not the case for this function.
*/
for (node = list->head; node->next != NULL; node = node->next) {
assert(node->next->prev == node);
assert(node->prev->next == node);
}
}
#ifdef __cplusplus
inline void exec_list::make_empty()
{
exec_list_make_empty(this);
}
inline bool exec_list::is_empty() const
{
return exec_list_is_empty(this);
}
inline const exec_node *exec_list::get_head() const
{
return exec_list_get_head_const(this);
}
inline exec_node *exec_list::get_head()
{
return exec_list_get_head(this);
}
inline const exec_node *exec_list::get_tail() const
{
return exec_list_get_tail_const(this);
}
inline exec_node *exec_list::get_tail()
{
return exec_list_get_tail(this);
}
inline unsigned exec_list::length() const
{
return exec_list_length(this);
}
inline void exec_list::push_head(exec_node *n)
{
exec_list_push_head(this, n);
}
inline void exec_list::push_tail(exec_node *n)
{
exec_list_push_tail(this, n);
}
inline void exec_list::push_degenerate_list_at_head(exec_node *n)
{
exec_list_push_degenerate_list_at_head(this, n);
}
inline exec_node *exec_list::pop_head()
{
return exec_list_pop_head(this);
}
inline void exec_list::move_nodes_to(exec_list *target)
{
exec_list_move_nodes_to(this, target);
}
inline void exec_list::append_list(exec_list *source)
{
exec_list_append(this, source);
}
inline void exec_list::prepend_list(exec_list *source)
{
exec_list_prepend(this, source);
}
inline void exec_node::insert_before(exec_list *before)
{
exec_node_insert_list_before(this, before);
}
#endif
#define foreach_in_list(__type, __inst, __list) \
for (__type *(__inst) = (__type *)(__list)->head; \
!(__inst)->is_tail_sentinel(); \
(__inst) = (__type *)(__inst)->next)
#define foreach_in_list_reverse(__type, __inst, __list) \
for (__type *(__inst) = (__type *)(__list)->tail_pred; \
!(__inst)->is_head_sentinel(); \
(__inst) = (__type *)(__inst)->prev)
/**
* This version is safe even if the current node is removed.
*/
#define foreach_in_list_safe(__type, __node, __list) \
for (__type *__node = (__type *)(__list)->head, \
*__next = (__type *)__node->next; \
__next != NULL; \
__node = __next, __next = (__type *)__next->next)
#define foreach_in_list_reverse_safe(__type, __node, __list) \
for (__type *__node = (__type *)(__list)->tail_pred, \
*__prev = (__type *)__node->prev; \
__prev != NULL; \
__node = __prev, __prev = (__type *)__prev->prev)
#define foreach_in_list_use_after(__type, __inst, __list) \
__type *(__inst); \
for ((__inst) = (__type *)(__list)->head; \
!(__inst)->is_tail_sentinel(); \
(__inst) = (__type *)(__inst)->next)
/**
* Iterate through two lists at once. Stops at the end of the shorter list.
*
* This is safe against either current node being removed or replaced.
*/
#define foreach_two_lists(__node1, __list1, __node2, __list2) \
for (struct exec_node * __node1 = (__list1)->head, \
* __node2 = (__list2)->head, \
* __next1 = __node1->next, \
* __next2 = __node2->next \
; __next1 != NULL && __next2 != NULL \
; __node1 = __next1, \
__node2 = __next2, \
__next1 = __next1->next, \
__next2 = __next2->next)
#define foreach_list_typed(__type, __node, __field, __list) \
for (__type * __node = \
exec_node_data(__type, (__list)->head, __field); \
(__node)->__field.next != NULL; \
(__node) = exec_node_data(__type, (__node)->__field.next, __field))
#define foreach_list_typed_reverse(__type, __node, __field, __list) \
for (__type * __node = \
exec_node_data(__type, (__list)->tail_pred, __field); \
(__node)->__field.prev != NULL; \
(__node) = exec_node_data(__type, (__node)->__field.prev, __field))
#define foreach_list_typed_safe(__type, __node, __field, __list) \
for (__type * __node = \
exec_node_data(__type, (__list)->head, __field), \
* __next = \
exec_node_data(__type, (__node)->__field.next, __field); \
(__node)->__field.next != NULL; \
__node = __next, __next = \
exec_node_data(__type, (__next)->__field.next, __field))
#define foreach_list_typed_safe_reverse(__type, __node, __field, __list) \
for (__type * __node = \
exec_node_data(__type, (__list)->tail_pred, __field), \
* __prev = \
exec_node_data(__type, (__node)->__field.prev, __field); \
(__node)->__field.prev != NULL; \
__node = __prev, __prev = \
exec_node_data(__type, (__prev)->__field.prev, __field))
#endif /* LIST_CONTAINER_H */