include/linux/lists.h

   1 /*
   2  * lists.h:  Simple list macros for Linux
   3  */
   4
   5 #define DLNODE(ptype)                                           \
   6         struct {                                                \
   7                 ptype * dl_prev;                                \
   8                 ptype * dl_next;                                \
   9         }
  10
  11 #define DNODE_SINGLE(node) {(node),(node)}
  12 #define DNODE_NULL {0,0}
  13
  14 #define DLIST_INIT(listnam)                                     \
  15         (listnam).dl_prev = &(listnam);                         \
  16         (listnam).dl_next = &(listnam);
  17
  18 #define DLIST_NEXT(listnam)     listnam.dl_next
  19 #define DLIST_PREV(listnam)     listnam.dl_prev
  20
  21 #define DLIST_INSERT_AFTER(node, new, listnam)  do {            \
  22         (new)->listnam.dl_prev = (node);                        \
  23         (new)->listnam.dl_next = (node)->listnam.dl_next;       \
  24         (node)->listnam.dl_next->listnam.dl_prev = (new);       \
  25         (node)->listnam.dl_next = (new);                        \
  26         } while (0)
  27
  28 #define DLIST_INSERT_BEFORE(node, new, listnam) do {            \
  29         (new)->listnam.dl_next = (node);                        \
  30         (new)->listnam.dl_prev = (node)->listnam.dl_prev;       \
  31         (node)->listnam.dl_prev->listnam.dl_next = (new);       \
  32         (node)->listnam.dl_prev = (new);                        \
  33         } while (0)
  34
  35 #define DLIST_DELETE(node, listnam)     do {            \
  36         node->listnam.dl_prev->listnam.dl_next =                \
  37                 node->listnam.dl_next;                          \
  38         node->listnam.dl_next->listnam.dl_prev =                \
  39                 node->listnam.dl_prev;                          \
  40         } while (0)
  41
  42 /*
  43  * queue-style operations, which have a head and tail
  44  */
  45
  46 #define QUEUE_INIT(head, listnam, ptype)                                \
  47         (head)->listnam.dl_prev = (head)->listnam.dl_next = (ptype)(head);
  48
  49 #define QUEUE_FIRST(head, listnam) (head)->DLIST_NEXT(listnam)
  50 #define QUEUE_LAST(head, listnam) (head)->DLIST_PREV(listnam)
  51 #define QUEUE_IS_EMPTY(head, listnam) \
  52         ((QUEUE_FIRST(head, listnam) == QUEUE_LAST(head, listnam)) && \
  53          ((u_long)QUEUE_FIRST(head, listnam) == (u_long)head))
  54
  55 #define QUEUE_ENTER(head, new, listnam, ptype) do {             \
  56         (new)->listnam.dl_prev = (ptype)(head);                 \
  57         (new)->listnam.dl_next = (head)->listnam.dl_next;       \
  58         (head)->listnam.dl_next->listnam.dl_prev = (new);       \
  59         (head)->listnam.dl_next = (new);                        \
  60         } while (0)
  61
  62 #define QUEUE_REMOVE(head, node, listnam) DLIST_DELETE(node, listnam)