include/wine/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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #ifndef __WINE_SERVER_LIST_H
  22 #define __WINE_SERVER_LIST_H
  23
  24 #include <stddef.h>
  25
  26 struct list
  27 {
  28     struct list *next;
  29     struct list *prev;
  30 };
  31
  32 /* Define a list like so:
  33  *
  34  *   struct gadget
  35  *   {
  36  *       struct list  entry;   <-- doesn't have to be the first item in the struct
  37  *       int          a, b;
  38  *   };
  39  *
  40  *   static struct list global_gadgets = LIST_INIT( global_gadgets );
  41  *
  42  * or
  43  *
  44  *   struct some_global_thing
  45  *   {
  46  *       struct list gadgets;
  47  *   };
  48  *
  49  *   list_init( &some_global_thing->gadgets );
  50  *
  51  * Manipulate it like this:
  52  *
  53  *   list_add_head( &global_gadgets, &new_gadget->entry );
  54  *   list_remove( &new_gadget->entry );
  55  *   list_add_after( &some_random_gadget->entry, &new_gadget->entry );
  56  *
  57  * And to iterate over it:
  58  *
  59  *   struct gadget *gadget;
  60  *   LIST_FOR_EACH_ENTRY( gadget, &global_gadgets, struct gadget, entry )
  61  *   {
  62  *       ...
  63  *   }
  64  *
  65  */
  66
  67 /* add an element after the specified one */
  68 static inline void list_add_after( struct list *elem, struct list *to_add )
  69 {
  70     to_add->next = elem->next;
  71     to_add->prev = elem;
  72     elem->next->prev = to_add;
  73     elem->next = to_add;
  74 }
  75
  76 /* add an element before the specified one */
  77 static inline void list_add_before( struct list *elem, struct list *to_add )
  78 {
  79     to_add->next = elem;
  80     to_add->prev = elem->prev;
  81     elem->prev->next = to_add;
  82     elem->prev = to_add;
  83 }
  84
  85 /* add element at the head of the list */
  86 static inline void list_add_head( struct list *list, struct list *elem )
  87 {
  88     list_add_after( list, elem );
  89 }
  90
  91 /* add element at the tail of the list */
  92 static inline void list_add_tail( struct list *list, struct list *elem )
  93 {
  94     list_add_before( list, elem );
  95 }
  96
  97 /* remove an element from its list */
  98 static inline void list_remove( struct list *elem )
  99 {
 100     elem->next->prev = elem->prev;
 101     elem->prev->next = elem->next;
 102 }
 103
 104 /* get the next element */
 105 static inline struct list *list_next( const struct list *list, const struct list *elem )
 106 {
 107     struct list *ret = elem->next;
 108     if (elem->next == list) ret = NULL;
 109     return ret;
 110 }
 111
 112 /* get the previous element */
 113 static inline struct list *list_prev( const struct list *list, const struct list *elem )
 114 {
 115     struct list *ret = elem->prev;
 116     if (elem->prev == list) ret = NULL;
 117     return ret;
 118 }
 119
 120 /* get the first element */
 121 static inline struct list *list_head( const struct list *list )
 122 {
 123     return list_next( list, list );
 124 }
 125
 126 /* get the last element */
 127 static inline struct list *list_tail( const struct list *list )
 128 {
 129     return list_prev( list, list );
 130 }
 131
 132 /* check if a list is empty */
 133 static inline int list_empty( const struct list *list )
 134 {
 135     return list->next == list;
 136 }
 137
 138 /* initialize a list */
 139 static inline void list_init( struct list *list )
 140 {
 141     list->next = list->prev = list;
 142 }
 143
 144 /* count the elements of a list */
 145 static inline unsigned int list_count( const struct list *list )
 146 {
 147     unsigned count = 0;
 148     const struct list *ptr;
 149     for (ptr = list->next; ptr != list; ptr = ptr->next) count++;
 150     return count;
 151 }
 152
 153 /* move all elements from src to the tail of dst */
 154 static inline void list_move_tail( struct list *dst, struct list *src )
 155 {
 156     if (list_empty(src)) return;
 157
 158     dst->prev->next = src->next;
 159     src->next->prev = dst->prev;
 160     dst->prev = src->prev;
 161     src->prev->next = dst;
 162     list_init(src);
 163 }
 164
 165 /* move all elements from src to the head of dst */
 166 static inline void list_move_head( struct list *dst, struct list *src )
 167 {
 168     if (list_empty(src)) return;
 169
 170     dst->next->prev = src->prev;
 171     src->prev->next = dst->next;
 172     dst->next = src->next;
 173     src->next->prev = dst;
 174     list_init(src);
 175 }
 176
 177 /* iterate through the list */
 178 #define LIST_FOR_EACH(cursor,list) \
 179     for ((cursor) = (list)->next; (cursor) != (list); (cursor) = (cursor)->next)
 180
 181 /* iterate through the list, with safety against removal */
 182 #define LIST_FOR_EACH_SAFE(cursor, cursor2, list) \
 183     for ((cursor) = (list)->next, (cursor2) = (cursor)->next; \
 184          (cursor) != (list); \
 185          (cursor) = (cursor2), (cursor2) = (cursor)->next)
 186
 187 /* iterate through the list using a list entry */
 188 #define LIST_FOR_EACH_ENTRY(elem, list, type, field) \
 189     for ((elem) = LIST_ENTRY((list)->next, type, field); \
 190          &(elem)->field != (list); \
 191          (elem) = LIST_ENTRY((elem)->field.next, type, field))
 192
 193 /* iterate through the list using a list entry, with safety against removal */
 194 #define LIST_FOR_EACH_ENTRY_SAFE(cursor, cursor2, list, type, field) \
 195     for ((cursor) = LIST_ENTRY((list)->next, type, field), \
 196          (cursor2) = LIST_ENTRY((cursor)->field.next, type, field); \
 197          &(cursor)->field != (list); \
 198          (cursor) = (cursor2), \
 199          (cursor2) = LIST_ENTRY((cursor)->field.next, type, field))
 200
 201 /* iterate through the list in reverse order */
 202 #define LIST_FOR_EACH_REV(cursor,list) \
 203     for ((cursor) = (list)->prev; (cursor) != (list); (cursor) = (cursor)->prev)
 204
 205 /* iterate through the list in reverse order, with safety against removal */
 206 #define LIST_FOR_EACH_SAFE_REV(cursor, cursor2, list) \
 207     for ((cursor) = (list)->prev, (cursor2) = (cursor)->prev; \
 208          (cursor) != (list); \
 209          (cursor) = (cursor2), (cursor2) = (cursor)->prev)
 210
 211 /* iterate through the list in reverse order using a list entry */
 212 #define LIST_FOR_EACH_ENTRY_REV(elem, list, type, field) \
 213     for ((elem) = LIST_ENTRY((list)->prev, type, field); \
 214          &(elem)->field != (list); \
 215          (elem) = LIST_ENTRY((elem)->field.prev, type, field))
 216
 217 /* iterate through the list in reverse order using a list entry, with safety against removal */
 218 #define LIST_FOR_EACH_ENTRY_SAFE_REV(cursor, cursor2, list, type, field) \
 219     for ((cursor) = LIST_ENTRY((list)->prev, type, field), \
 220          (cursor2) = LIST_ENTRY((cursor)->field.prev, type, field); \
 221          &(cursor)->field != (list); \
 222          (cursor) = (cursor2), \
 223          (cursor2) = LIST_ENTRY((cursor)->field.prev, type, field))
 224
 225 /* macros for statically initialized lists */
 226 #undef LIST_INIT
 227 #define LIST_INIT(list)  { &(list), &(list) }
 228
 229 /* get pointer to object containing list element */
 230 #undef LIST_ENTRY
 231 #define LIST_ENTRY(elem, type, field) \
 232     ((type *)((char *)(elem) - offsetof(type, field)))
 233
 234 #endif  /* __WINE_SERVER_LIST_H */