xf_list.h

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/*
 * xf_list.h
 *
 *  Created on: 2013-8-29
 *      Author: bt
 */
 
#ifndef __XF_LIST_H__
#define __XF_LIST_H__
 
/* ==================== [Includes] ========================================== */
 
#include "xf_predef.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* ==================== [Defines] =========================================== */
 
#if !defined(XF_LIST_POISON1)
#   define XF_LIST_POISON1              0x00100100
#endif
#if !defined(XF_LIST_POISON2)
#   define XF_LIST_POISON2              0x00200200
#endif
 
/* ==================== [Typedefs] ========================================== */
 
struct xf_list_head {
    struct xf_list_head *next, *prev;
};
typedef struct xf_list_head xf_list_t;
 
/*
 * Simple doubly linked list implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole lists rather than single entries, as
 * sometimes we already know the next/prev entries and we can
 * generate better code by using them directly rather than
 * using the generic single-entry routines.
 */
//static define
#define XF_LIST_HEAD_INIT(name) { &(name), &(name) }
 
#define XF_LIST_HEAD(name) \
    xf_list_t name = XF_LIST_HEAD_INIT(name)
 
/* ==================== [Global Prototypes] ================================= */
 
static inline void xf_list_init(xf_list_t *list)
{
    list->next = list;
    list->prev = list;
}
 
/*
 * Insert a new_node entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
 
static inline void __xf_list_add(xf_list_t *new_node, xf_list_t *prev, xf_list_t *next)
{
    next->prev      = new_node;
    new_node->next  = next;
    new_node->prev  = prev;
    prev->next      = new_node;
}
 
/*
 * list_add - add a new_node entry
 * @new_node: new_node entry to be added
 * @head: list head to add it after
 *
 * Insert a new_node entry after the specified head.
 * This is good for implementing stacks.
 */
 
static inline void xf_list_add(xf_list_t *new_node, xf_list_t *head)
{
    __xf_list_add(new_node, head, head->next);
}
 
/*
 * list_add_tail - add a new_node entry
 * @new_node: new_node entry to be added
 * @head: list head to add it before
 *
 * Insert a new_node entry before the specified head.
 * This is useful for implementing queues.
 */
 
static inline void xf_list_add_tail(xf_list_t *new_node, xf_list_t *head)
{
    __xf_list_add(new_node, head->prev, head);
}
 
/*
 * list_del - deletes entry from list.
 * @entry: the element to delete from the list.
 * Note: list_empty() on entry does not return true after this, the entry is
 * in an undefined state.
 */
 
static inline void __xf_list_del(xf_list_t *prev, xf_list_t *next)
{
    next->prev = prev;
    prev->next = next;
}
 
/*
 * list_del - deletes entry from list.
 * @entry: the element to delete from the list.
 * Note: list_empty() on entry does not return true after this, the entry is
 * in an undefined state.
 */
 
static inline void __xf_list_del_entry(xf_list_t *entry)
{
    __xf_list_del(entry->prev, entry->next);
}
 
static inline void xf_list_del(xf_list_t *entry)
{
    __xf_list_del(entry->prev, entry->next);
    entry->next = (xf_list_t *)XF_LIST_POISON1;
    entry->prev = (xf_list_t *)XF_LIST_POISON2;
}
 
/*
 * list_replace - replace old entry by new_node one
 * @old : the element to be replaced
 * @new_node : the new_node element to insert
 *
 * If @old was empty, it will be overwritten.
 */
 
static inline void xf_list_replace(xf_list_t *old, xf_list_t *new_node)
{
    new_node->next          = old->next;
    new_node->next->prev    = new_node;
    new_node->prev          = old->prev;
    new_node->prev->next    = new_node;
}
 
static inline void xf_list_replace_init(xf_list_t *old, xf_list_t *new_node)
{
    xf_list_replace(old, new_node);
    xf_list_init(old);
}
 
/*
 * list_del_init - deletes entry from list and reinitialize it.
 * @entry: the element to delete from the list.
 */
 
static inline void xf_list_del_init(xf_list_t *entry)
{
    __xf_list_del_entry(entry);
    xf_list_init(entry);
}
 
/*
 * list_move - delete from one list and add as another's head
 * @list: the entry to move
 * @head: the head that will precede our entry
 */
 
static inline void xf_list_move(xf_list_t *list, xf_list_t *head)
{
    __xf_list_del_entry(list);
    xf_list_add(list, head);
}
 
/*
 * list_move_tail - delete from one list and add as another's tail
 * @list: the entry to move
 * @head: the head that will follow our entry
 */
 
static inline void xf_list_move_tail(xf_list_t *list, xf_list_t *head)
{
    __xf_list_del_entry(list);
    xf_list_add_tail(list, head);
}
 
/*
 * list_is_last - tests whether @list is the last entry in list @head
 * @list: the entry to test
 * @head: the head of the list
 */
 
static inline int xf_list_is_last(const xf_list_t *list, const xf_list_t *head)
{
    return list->next == head;
}
 
/*
 * list_empty - tests whether a list is empty
 * @head: the list to test.
 */
 
static inline int xf_list_empty(const xf_list_t *head)
{
    return head->next == head;
}
 
/*
 * xf_list_empty_careful - tests whether a list is empty and not being modified
 * @head: the list to test
 *
 * Description:
 * tests whether a list is empty _and_ checks that no other CPU might be
 * in the process of modifying either member (next or prev)
 *
 * NOTE: using xf_list_empty_careful() without synchronization
 * can only be safe if the only activity that can happen
 * to the list entry is xf_list_del_init(). Eg. it cannot be used
 * if another CPU could re-xf_list_add() it.
 */
 
static inline int xf_list_empty_careful(const xf_list_t *head)
{
    xf_list_t *next = head->next;
    return (next == head) && (next == head->prev);
}
 
/*
 * list_rotate_left - rotate the list to the left
 * @head: the head of the list
 */
 
static inline void xf_list_rotate_left(xf_list_t *head)
{
    xf_list_t *first;
 
    if (!xf_list_empty(head)) {
        first = head->next;
        xf_list_move_tail(first, head);
    }
}
 
/*
 * list_is_singular - tests whether a list has just one entry.
 * @head: the list to test.
 */
 
static inline int xf_list_is_singular(const xf_list_t *head)
{
    return !xf_list_empty(head) && (head->next == head->prev);
}
 
static inline void __xf_list_cut_position(
    xf_list_t *list, xf_list_t *head, xf_list_t *entry)
{
    xf_list_t *new_node_first   = entry->next;
    list->next                  = head->next;
    list->next->prev            = list;
    list->prev                  = entry;
    entry->next                 = list;
    head->next                  = new_node_first;
    new_node_first->prev        = head;
}
 
/*
 * xf_list_cut_position - cut a list into two
 * @list: a new_node list to add all removed entries
 * @head: a list with entries
 * @entry: an entry within head, could be the head itself
 *  and if so we won't cut the list
 *
 * This helper moves the initial part of @head, up to and
 * including @entry, from @head to @list. You should
 * pass on @entry an element you know is on @head. @list
 * should be an empty list or a list you do not care about
 * losing its data.
 *
 */
 
static inline void xf_list_cut_position(
    xf_list_t *list, xf_list_t *head, xf_list_t *entry)
{
    if (xf_list_empty(head)) {
        return;
    }
    if (xf_list_is_singular(head)
            && (head->next != entry && head != entry)) {
        return;
    }
    if (entry == head) {
        xf_list_init(list);
    } else {
        __xf_list_cut_position(list, head, entry);
    }
}
 
static inline void __xf_list_splice(
    const xf_list_t *list, xf_list_t *prev, xf_list_t *next)
{
    xf_list_t *first = list->next;
    xf_list_t *last = list->prev;
 
    first->prev = prev;
    prev->next = first;
 
    last->next = next;
    next->prev = last;
}
 
/*
 * xf_list_splice - join two lists, this is designed for stacks
 * @list: the new_node list to add.
 * @head: the place to add it in the first list.
 */
 
static inline void xf_list_splice(
    const xf_list_t *list, xf_list_t *head)
{
    if (!xf_list_empty(list)) {
        __xf_list_splice(list, head, head->next);
    }
}
 
/*
 * xf_list_splice_tail - join two lists, each list being a queue
 * @list: the new_node list to add.
 * @head: the place to add it in the first list.
 */
 
static inline void xf_list_splice_tail(xf_list_t *list, xf_list_t *head)
{
    if (!xf_list_empty(list)) {
        __xf_list_splice(list, head->prev, head);
    }
}
 
/*
 * xf_list_splice_init - join two lists and reinitialise the emptied list.
 * @list: the new_node list to add.
 * @head: the place to add it in the first list.
 *
 * The list at @list is reinitialised
 */
 
static inline void xf_list_splice_init(xf_list_t *list, xf_list_t *head)
{
    if (!xf_list_empty(list)) {
        __xf_list_splice(list, head, head->next);
        xf_list_init(list);
    }
}
 
/*
 * xf_list_splice_tail_init - join two lists and reinitialise the emptied list
 * @list: the new_node list to add.
 * @head: the place to add it in the first list.
 *
 * Each of the lists is a queue.
 * The list at @list is reinitialised
 */
 
static inline void xf_list_splice_tail_init(xf_list_t *list, xf_list_t *head)
{
    if (!xf_list_empty(list)) {
        __xf_list_splice(list, head->prev, head);
        xf_list_init(list);
    }
}
 
/* ==================== [Macros] ============================================ */
 
/*
 * list_entry - get the struct for this entry
 * @ptr:    the &struct list_head pointer.
 * @type:   the type of the struct this is embedded in.
 * @member: the name of the list_struct within the struct.
 */
 
#define xf_list_entry(ptr, type, member) \
    xf_container_of(ptr, type, member)
 
/*
 * list_first_entry - get the first element from a list
 * @ptr:    the list head to take the element from.
 * @type:   the type of the struct this is embedded in.
 * @member: the name of the list_struct within the struct.
 *
 * Note, that list is expected to be not empty.
 */
 
#define xf_list_first_entry(ptr, type, member) \
    xf_list_entry((ptr)->next, type, member)
 
/*
 * list_for_each    -   iterate over a list
 * @pos:    the &struct list_head to use as a loop cursor.
 * @head:   the head for your list.
 */
 
#define xf_list_for_each(pos, head) \
    for ((pos) = (head)->next; (pos) != (head); (pos) = (pos)->next)
 
/*
 * __list_for_each  -   iterate over a list
 * @pos:    the &struct list_head to use as a loop cursor.
 * @head:   the head for your list.
 *
 * This variant doesn't differ from list_for_each() any more.
 * We don't do prefetching in either case.
 */
 
#define __xf_list_for_each(pos, head) \
    for ((pos) = (head)->next; (pos) != (head); (pos) = (pos)->next)
 
/*
 * list_for_each_prev   -   iterate over a list backwards
 * @pos:    the &struct list_head to use as a loop cursor.
 * @head:   the head for your list.
 */
 
#define xf_list_for_each_prev(pos, head) \
    for ((pos) = (head)->prev; (pos) != (head); (pos) = (pos)->prev)
 
/*
 * list_for_each_safe - iterate over a list safe against removal of list entry
 * @pos:    the &struct list_head to use as a loop cursor.
 * @n:      another &struct list_head to use as temporary storage
 * @head:   the head for your list.
 */
 
#define xf_list_for_each_safe(pos, n, head) \
    for ((pos) = (head)->next, (n) = (pos)->next; (pos) != (head); \
         (pos) = (n), (n) = (pos)->next)
 
/*
 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
 * @pos:    the &struct list_head to use as a loop cursor.
 * @n:      another &struct list_head to use as temporary storage
 * @head:   the head for your list.
 */
 
#define xf_list_for_each_prev_safe(pos, n, head) \
    for ((pos) = (head)->prev, (n) = (pos)->prev; \
         (pos) != (head); \
         (pos) = (n), (n) = (pos)->prev)
 
/*
 * list_for_each_entry  -   iterate over list of given type
 * @pos:    the type * to use as a loop cursor.
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 */
 
#define xf_list_for_each_entry(pos, head, type, member) \
    for ((pos) = xf_list_entry((head)->next, type, member); \
         &(pos)->member != (head); \
         (pos) = xf_list_entry((pos)->member.next, type, member))
 
/*
 * list_for_each_entry_reverse - iterate backwards over list of given type.
 * @pos:    the type * to use as a loop cursor.
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 */
 
#define xf_list_for_each_entry_reverse(pos, head, type, member) \
    for ((pos) = xf_list_entry((head)->prev, type, member); \
         &(pos)->member != (head); \
         (pos) = xf_list_entry((pos)->member.prev, type, member))
 
/*
 * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
 * @pos:    the type * to use as a start point
 * @head:   the head of the list
 * @member: the name of the list_struct within the struct.
 *
 * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
 */
 
#define xf_list_prepare_entry(pos, head, type, member) \
    ((pos) ? : xf_list_entry(head, type, member))
 
/*
 * list_for_each_entry_continue - continue iteration over list of given type
 * @pos:    the type * to use as a loop cursor.
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Continue to iterate over list of given type, continuing after
 * the current position.
 */
 
#define xf_list_for_each_entry_continue(pos, head, type, member) \
    for ((pos) = xf_list_entry((pos)->member.next, type, member); \
         &(pos)->member != (head); \
         (pos) = xf_list_entry((pos)->member.next, type, member))
 
/*
 * list_for_each_entry_continue_reverse - iterate backwards from the given point
 * @pos:    the type * to use as a loop cursor.
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Start to iterate over list of given type backwards, continuing after
 * the current position.
 */
 
#define xf_list_for_each_entry_continue_reverse(pos, head, type, member) \
    for ((pos) = xf_list_entry((pos)->member.prev, type, member); \
         &(pos)->member != (head); \
         (pos) = xf_list_entry((pos)->member.prev, type, member))
 
/*
 * list_for_each_entry_from - iterate over list of given type from the current point
 * @pos:    the type * to use as a loop cursor.
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Iterate over list of given type, continuing from current position.
 */
 
#define xf_list_for_each_entry_from(pos, head, type, member) \
    for (; &(pos)->member != (head); \
         (pos) = xf_list_entry((pos)->member.next, type, member))
 
/*
 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 * @pos:    the type * to use as a loop cursor.
 * @n:      another type * to use as temporary storage
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 */
 
#define xf_list_for_each_entry_safe(pos, n, head, type, member) \
    for ((pos) = xf_list_entry((head)->next, type, member), \
         (n) = xf_list_entry((pos)->member.next, type, member); \
         &(pos)->member != (head); \
         (pos) = (n), (n) = xf_list_entry(n->member.next, type, member))
 
/*
 * list_for_each_entry_safe_continue - continue list iteration safe against removal
 * @pos:    the type * to use as a loop cursor.
 * @n:      another type * to use as temporary storage
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Iterate over list of given type, continuing after current point,
 * safe against removal of list entry.
 */
 
#define xf_list_for_each_entry_safe_continue(pos, n, head, type, member) \
    for ((pos) = xf_list_entry((pos)->member.next, type, member), \
         (n) = xf_list_entry((pos)->member.next, type, member); \
         &(pos)->member != (head); \
         (pos) = (n), (n) = xf_list_entry((n)->member.next, type, member))
 
/*
 * list_for_each_entry_safe_from - iterate over list from current point safe against removal
 * @pos:    the type * to use as a loop cursor.
 * @n:      another type * to use as temporary storage
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Iterate over list of given type from current point, safe against
 * removal of list entry.
 */
 
#define xf_list_for_each_entry_safe_from(pos, n, head, type, member) \
    for ((n) = xf_list_entry((pos)->member.next, type, member); \
         &(pos)->member != (head); \
         (pos) = (n), (n) = xf_list_entry((n)->member.next, type, member))
 
/*
 * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
 * @pos:    the type * to use as a loop cursor.
 * @n:      another type * to use as temporary storage
 * @head:   the head for your list.
 * @member: the name of the list_struct within the struct.
 *
 * Iterate backwards over list of given type, safe against removal
 * of list entry.
 */
 
#define xf_list_for_each_entry_safe_reverse(pos, n, head, type, member) \
    for ((pos) = xf_list_entry((head)->prev, type, member), \
         (n) = xf_list_entry((pos)->member.prev, type, member); \
         &(pos)->member != (head); \
         (pos) = (n), (n) = xf_list_entry((n)->member.prev, type, member))
 
/*
 * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
 * @pos:    the loop cursor used in the list_for_each_entry_safe loop
 * @n:      temporary storage used in list_for_each_entry_safe
 * @member: the name of the list_struct within the struct.
 *
 * list_safe_reset_next is not safe to use in general if the list may be
 * modified concurrently (eg. the lock is dropped in the loop body). An
 * exception to this is if the cursor element (pos) is pinned in the list,
 * and list_safe_reset_next is called after re-taking the lock and before
 * completing the current iteration of the loop body.
 */
 
#define xf_list_safe_reset_next(pos, n, type, member) \
    (n) = xf_list_entry((pos)->member.next, type, member)
 
#ifdef __cplusplus
} /*extern "C"*/
#endif
 
#endif /* __XF_LIST_H__ */