TP7/exo1/list.h

   1 #ifndef __LIST_H
   2 #define __LIST_H
   3
   4 /* This file is from Linux Kernel (include/linux/list.h)
   5  * and modified by simply removing hardware prefetching of list items.
   6  * Here by copyright, credits attributed to wherever they belong.
   7  * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu)
   8  */
   9
  10 /*
  11  * Simple doubly linked list implementation.
  12  *
  13  * Some of the internal functions ("__xxx") are useful when
  14  * manipulating whole lists rather than single entries, as
  15  * sometimes we already know the next/prev entries and we can
  16  * generate better code by using them directly rather than
  17  * using the generic single-entry routines.
  18  */
  19
  20 struct list_head {
  21         struct list_head *next, *prev;
  22 };
  23
  24 #define typeof __typeof__
  25
  26 #define LIST_HEAD_INIT(name) { &(name), &(name) }
  27
  28 #define LIST_HEAD(name) \
  29         struct list_head name = LIST_HEAD_INIT(name)
  30
  31 #define INIT_LIST_HEAD(ptr) do { \
  32         (ptr)->next = (ptr); (ptr)->prev = (ptr); \
  33 } while (0)
  34
  35 /*
  36  * Insert a new entry between two known consecutive entries.
  37  *
  38  * This is only for internal list manipulation where we know
  39  * the prev/next entries already!
  40  */
  41 static inline void __list_add(struct list_head *new,
  42                               struct list_head *prev,
  43                               struct list_head *next)
  44 {
  45         next->prev = new;
  46         new->next = next;
  47         new->prev = prev;
  48         prev->next = new;
  49 }
  50
  51 /**
  52  * list_add - add a new entry
  53  * @new: new entry to be added
  54  * @head: list head to add it after
  55  *
  56  * Insert a new entry after the specified head.
  57  * This is good for implementing stacks.
  58  */
  59 static inline void list_add(struct list_head *new, struct list_head *head)
  60 {
  61         __list_add(new, head, head->next);
  62 }
  63
  64 /**
  65  * list_add_tail - add a new entry
  66  * @new: new entry to be added
  67  * @head: list head to add it before
  68  *
  69  * Insert a new entry before the specified head.
  70  * This is useful for implementing queues.
  71  */
  72 static inline void list_add_tail(struct list_head *new, struct list_head *head)
  73 {
  74         __list_add(new, head->prev, head);
  75 }
  76
  77 /*
  78  * Delete a list entry by making the prev/next entries
  79  * point to each other.
  80  *
  81  * This is only for internal list manipulation where we know
  82  * the prev/next entries already!
  83  */
  84 static inline void __list_del(struct list_head *prev, struct list_head *next)
  85 {
  86         next->prev = prev;
  87         prev->next = next;
  88 }
  89
  90 /**
  91  * list_del - deletes entry from list.
  92  * @entry: the element to delete from the list.
  93  * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
  94  */
  95 static inline void list_del(struct list_head *entry)
  96 {
  97         __list_del(entry->prev, entry->next);
  98         entry->next = (void *) 0;
  99         entry->prev = (void *) 0;
 100 }
 101
 102 /**
 103  * list_del_init - deletes entry from list and reinitialize it.
 104  * @entry: the element to delete from the list.
 105  */
 106 static inline void list_del_init(struct list_head *entry)
 107 {
 108         __list_del(entry->prev, entry->next);
 109         INIT_LIST_HEAD(entry);
 110 }
 111
 112 /**
 113  * list_move - delete from one list and add as another's head
 114  * @list: the entry to move
 115  * @head: the head that will precede our entry
 116  */
 117 static inline void list_move(struct list_head *list, struct list_head *head)
 118 {
 119         __list_del(list->prev, list->next);
 120         list_add(list, head);
 121 }
 122
 123 /**
 124  * list_move_tail - delete from one list and add as another's tail
 125  * @list: the entry to move
 126  * @head: the head that will follow our entry
 127  */
 128 static inline void list_move_tail(struct list_head *list,
 129                                   struct list_head *head)
 130 {
 131         __list_del(list->prev, list->next);
 132         list_add_tail(list, head);
 133 }
 134
 135 /**
 136  * list_empty - tests whether a list is empty
 137  * @head: the list to test.
 138  */
 139 static inline int list_empty(struct list_head *head)
 140 {
 141         return head->next == head;
 142 }
 143
 144 static inline void __list_splice(struct list_head *list,
 145                                  struct list_head *head)
 146 {
 147         struct list_head *first = list->next;
 148         struct list_head *last = list->prev;
 149         struct list_head *at = head->next;
 150
 151         first->prev = head;
 152         head->next = first;
 153
 154         last->next = at;
 155         at->prev = last;
 156 }
 157
 158 /**
 159  * list_splice - join two lists
 160  * @list: the new list to add.
 161  * @head: the place to add it in the first list.
 162  */
 163 static inline void list_splice(struct list_head *list, struct list_head *head)
 164 {
 165         if (!list_empty(list))
 166                 __list_splice(list, head);
 167 }
 168
 169 /**
 170  * list_splice_init - join two lists and reinitialise the emptied list.
 171  * @list: the new list to add.
 172  * @head: the place to add it in the first list.
 173  *
 174  * The list at @list is reinitialised
 175  */
 176 static inline void list_splice_init(struct list_head *list,
 177                                     struct list_head *head)
 178 {
 179         if (!list_empty(list)) {
 180                 __list_splice(list, head);
 181                 INIT_LIST_HEAD(list);
 182         }
 183 }
 184
 185 /**
 186  * list_entry - get the struct for this entry
 187  * @ptr:        the &struct list_head pointer.
 188  * @type:       the type of the struct this is embedded in.
 189  * @member:     the name of the list_struct within the struct.
 190  */
 191 #define list_entry(ptr, type, member) \
 192         ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
 193
 194 /**
 195  * list_for_each        -       iterate over a list
 196  * @pos:        the &struct list_head to use as a loop counter.
 197  * @head:       the head for your list.
 198  */
 199 #define list_for_each(pos, head) \
 200         for (pos = (head)->next; pos != (head); \
 201                 pos = pos->next)
 202 /**
 203  * list_for_each_prev   -       iterate over a list backwards
 204  * @pos:        the &struct list_head to use as a loop counter.
 205  * @head:       the head for your list.
 206  */
 207 #define list_for_each_prev(pos, head) \
 208         for (pos = (head)->prev; pos != (head); \
 209                 pos = pos->prev)
 210
 211 /**
 212  * list_for_each_safe   -       iterate over a list safe against removal of list entry
 213  * @pos:        the &struct list_head to use as a loop counter.
 214  * @n:          another &struct list_head to use as temporary storage
 215  * @head:       the head for your list.
 216  */
 217 #define list_for_each_safe(pos, n, head) \
 218         for (pos = (head)->next, n = pos->next; pos != (head); \
 219                 pos = n, n = pos->next)
 220
 221 /**
 222  * list_for_each_entry  -       iterate over list of given type
 223  * @pos:        the type * to use as a loop counter.
 224  * @head:       the head for your list.
 225  * @member:     the name of the list_struct within the struct.
 226  */
 227 #define list_for_each_entry(pos, head, member)                          \
 228         for (pos = list_entry((head)->next, typeof(*pos), member);      \
 229              &pos->member != (head);                                    \
 230              pos = list_entry(pos->member.next, typeof(*pos), member))
 231
 232 /**
 233  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 234  * @pos:        the type * to use as a loop counter.
 235  * @n:          another type * to use as temporary storage
 236  * @head:       the head for your list.
 237  * @member:     the name of the list_struct within the struct.
 238  */
 239 #define list_for_each_entry_safe(pos, n, head, member)                  \
 240         for (pos = list_entry((head)->next, typeof(*pos), member),      \
 241                 n = list_entry(pos->member.next, typeof(*pos), member); \
 242              &pos->member != (head);                                    \
 243              pos = n, n = list_entry(n->member.next, typeof(*n), member))
 244
 245
 246 #endif