server/list.h

   1 /*
   2  * Linked lists support
   3  *
   4  * Copyright (C) 2002 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #ifndef __WINE_SERVER_LIST_H
  22 #define __WINE_SERVER_LIST_H
  23
  24 struct list
  25 {
  26     struct list *next;
  27     struct list *prev;
  28 };
  29
  30 /* add element at the head of the list */
  31 inline static void list_add_head( struct list *list, struct list *elem )
  32 {
  33     elem->next = list->next;
  34     elem->prev = list;
  35     list->next->prev = elem;
  36     list->next = elem;
  37 }
  38
  39 /* add element at the tail of the list */
  40 inline static void list_add_tail( struct list *list, struct list *elem )
  41 {
  42     elem->next = list;
  43     elem->prev = list->prev;
  44     list->prev->next = elem;
  45     list->prev = elem;
  46 }
  47
  48 /* remove an element from its list */
  49 inline static void list_remove( struct list *elem )
  50 {
  51     elem->next->prev = elem->prev;
  52     elem->prev->next = elem->next;
  53 }
  54
  55 /* get the next element */
  56 inline static struct list *list_next( struct list *list, struct list *elem )
  57 {
  58     struct list *ret = elem->next;
  59     if (elem->next == list) ret = NULL;
  60     return ret;
  61 }
  62
  63 /* get the previous element */
  64 inline static struct list *list_prev( struct list *list, struct list *elem )
  65 {
  66     struct list *ret = elem->prev;
  67     if (elem->prev == list) ret = NULL;
  68     return ret;
  69 }
  70
  71 /* get the first element */
  72 inline static struct list *list_head( struct list *list )
  73 {
  74     return list_next( list, list );
  75 }
  76
  77 /* get the last element */
  78 inline static struct list *list_tail( struct list *list )
  79 {
  80     return list_prev( list, list );
  81 }
  82
  83 /* check if a list is empty */
  84 inline static int list_empty( struct list *list )
  85 {
  86     return list->next == list;
  87 }
  88
  89 /* initialize a list */
  90 inline static void list_init( struct list *list )
  91 {
  92     list->next = list->prev = list;
  93 }
  94
  95 /* iterate through the list */
  96 #define LIST_FOR_EACH(cursor,list) \
  97     for ((cursor) = (list)->next; (cursor) != (list); (cursor) = (cursor)->next)
  98
  99 /* macros for statically initialized lists */
 100 #define LIST_INIT(list)  { &(list), &(list) }
 101
 102 /* get pointer to object containing list element */
 103 #define LIST_ENTRY(elem, type, field) \
 104     ((type *)((char *)(elem) - (unsigned int)(&((type *)0)->field)))
 105
 106 #endif  /* __WINE_SERVER_LIST_H */