使用现成的Kernel里的list.h来写用户程序

#ifndef _LINUX_LIST_H #define _LINUX_LIST_H /*  * 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.  */ #define prefetch(x) __builtin_prefetch(x) #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) #define container_of(ptr, type, member) ({ \          const typeof( ((type *)0)->member ) *__mptr = (ptr); \          (type *)( (char *)__mptr - offsetof(type,member) );}) struct list_head {     struct list_head *next, *prev; }; #define LIST_HEAD_INIT(name) { &(name), &(name) } #define LIST_HEAD(name) \     struct list_head name = LIST_HEAD_INIT(name) static inline void INIT_LIST_HEAD(struct list_head *list) {     list->next = list;     list->prev = list; } /*  * Insert a new entry between two known consecutive entries.  *  * This is only for internal list manipulation where we know  * the prev/next entries already!  */ #ifndef CONFIG_DEBUG_LIST static inline void __list_add(struct list_head *new,              struct list_head *prev,              struct list_head *next) {     next->prev = new;     new->next = next;     new->prev = prev;     prev->next = new; } #else extern void __list_add(struct list_head *new,              struct list_head *prev,              struct list_head *next); #endif /**  * list_add - add a new entry  * @new: new entry to be added  * @head: list head to add it after  *  * Insert a new entry after the specified head.  * This is good for implementing stacks.  */ static inline void list_add(struct list_head *new, struct list_head *head) {     __list_add(new, head, head->next); } /**  * list_add_tail - add a new entry  * @new: new entry to be added  * @head: list head to add it before  *  * Insert a new entry before the specified head.  * This is useful for implementing queues.  */ static inline void list_add_tail(struct list_head *new, struct list_head *head) {     __list_add(new, head->prev, head); } /*  * Delete a list entry by making the prev/next entries  * point to each other.  *  * This is only for internal list manipulation where we know  * the prev/next entries already!  */ static inline void __list_del(struct list_head * prev, struct list_head * 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.  */ #ifndef CONFIG_DEBUG_LIST static inline void list_del(struct list_head *entry) {     __list_del(entry->prev, entry->next); } #else extern void list_del(struct list_head *entry); #endif /**  * list_replace - replace old entry by new one  * @old : the element to be replaced  * @new : the new element to insert  *  * If @old was empty, it will be overwritten.  */ static inline void list_replace(struct list_head *old,                 struct list_head *new) {     new->next = old->next;     new->next->prev = new;     new->prev = old->prev;     new->prev->next = new; } static inline void list_replace_init(struct list_head *old,                     struct list_head *new) {     list_replace(old, new);     INIT_LIST_HEAD(old); } /**  * list_del_init - deletes entry from list and reinitialize it.  * @entry: the element to delete from the list.  */ static inline void list_del_init(struct list_head *entry) {     __list_del(entry->prev, entry->next);     INIT_LIST_HEAD(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 list_move(struct list_head *list, struct list_head *head) {     __list_del(list->prev, list->next);     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 list_move_tail(struct list_head *list,                  struct list_head *head) {     __list_del(list->prev, list->next);     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 list_is_last(const struct list_head *list,                 const struct list_head *head) {     return list->next == head; } /**  * list_empty - tests whether a list is empty  * @head: the list to test.  */ static inline int list_empty(const struct list_head *head) {     return head->next == head; } /**  * 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 list_empty_careful() without synchronization  * can only be safe if the only activity that can happen  * to the list entry is list_del_init(). Eg. it cannot be used  * if another CPU could re-list_add() it.  */ static inline int list_empty_careful(const struct list_head *head) {     struct list_head *next = head->next;     return (next == head) && (next == head->prev); } /**  * list_is_singular - tests whether a list has just one entry.  * @head: the list to test.  */ static inline int list_is_singular(const struct list_head *head) {     return !list_empty(head) && (head->next == head->prev); } static inline void __list_cut_position(struct list_head *list,         struct list_head *head, struct list_head *entry) {     struct list_head *new_first = entry->next;     list->next = head->next;     list->next->prev = list;     list->prev = entry;     entry->next = list;     head->next = new_first;     new_first->prev = head; } /**  * list_cut_position - cut a list into two  * @list: a new 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 list_cut_position(struct list_head *list,         struct list_head *head, struct list_head *entry) {     if (list_empty(head))         return;     if (list_is_singular(head) &&         (head->next != entry && head != entry))         return;     if (entry == head)         INIT_LIST_HEAD(list);     else         __list_cut_position(list, head, entry); } static inline void __list_splice(const struct list_head *list,                  struct list_head *prev,                  struct list_head *next) {     struct list_head *first = list->next;     struct list_head *last = list->prev;     first->prev = prev;     prev->next = first;     last->next = next;     next->prev = last; } /**  * list_splice - join two lists, this is designed for stacks  * @list: the new list to add.  * @head: the place to add it in the first list.  */ static inline void list_splice(const struct list_head *list,                 struct list_head *head) {     if (!list_empty(list))         __list_splice(list, head, head->next); } /**  * list_splice_tail - join two lists, each list being a queue  * @list: the new list to add.  * @head: the place to add it in the first list.  */ static inline void list_splice_tail(struct list_head *list,                 struct list_head *head) {     if (!list_empty(list))         __list_splice(list, head->prev, head); } /**  * list_splice_init - join two lists and reinitialise the emptied list.  * @list: the new list to add.  * @head: the place to add it in the first list.  *  * The list at @list is reinitialised  */ static inline void list_splice_init(struct list_head *list,                  struct list_head *head) {     if (!list_empty(list)) {         __list_splice(list, head, head->next);         INIT_LIST_HEAD(list);     } } /**  * list_splice_tail_init - join two lists and reinitialise the emptied list  * @list: the new 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 list_splice_tail_init(struct list_head *list,                      struct list_head *head) {     if (!list_empty(list)) {         __list_splice(list, head->prev, head);         INIT_LIST_HEAD(list);     } } /**  * 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 list_entry(ptr, type, member) \     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 list_first_entry(ptr, type, member) \     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 list_for_each(pos, head) \     for (pos = (head)->next; prefetch(pos->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 differs from list_for_each() in that it's the  * simplest possible list iteration code, no prefetching is done.  * Use this for code that knows the list to be very short (empty  * or 1 entry) most of the time.  */ #define __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 list_for_each_prev(pos, head) \     for (pos = (head)->prev; prefetch(pos->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 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 list_for_each_prev_safe(pos, n, head) \     for (pos = (head)->prev, n = pos->prev; \      prefetch(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 list_for_each_entry(pos, head, member)                \     for (pos = list_entry((head)->next, typeof(*pos), member);    \      prefetch(pos->member.next), &pos->member != (head);     \      pos = list_entry(pos->member.next, typeof(*pos), 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 list_for_each_entry_reverse(pos, head, member)            \     for (pos = list_entry((head)->prev, typeof(*pos), member);    \      prefetch(pos->member.prev), &pos->member != (head);     \      pos = list_entry(pos->member.prev, typeof(*pos), 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 list_prepare_entry(pos, head, member) \     ((pos) ? : list_entry(head, typeof(*pos), 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 list_for_each_entry_continue(pos, head, member)         \     for (pos = list_entry(pos->member.next, typeof(*pos), member);    \      prefetch(pos->member.next), &pos->member != (head);    \      pos = list_entry(pos->member.next, typeof(*pos), 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 list_for_each_entry_continue_reverse(pos, head, member)        \     for (pos = list_entry(pos->member.prev, typeof(*pos), member);    \      prefetch(pos->member.prev), &pos->member != (head);    \      pos = list_entry(pos->member.prev, typeof(*pos), 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 list_for_each_entry_from(pos, head, member)             \     for (; prefetch(pos->member.next), &pos->member != (head);    \      pos = list_entry(pos->member.next, typeof(*pos), 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 list_for_each_entry_safe(pos, n, head, member)            \     for (pos = list_entry((head)->next, typeof(*pos), member),    \         n = list_entry(pos->member.next, typeof(*pos), member);    \      &pos->member != (head);                     \      pos = n, n = list_entry(n->member.next, typeof(*n), member)) /**  * list_for_each_entry_safe_continue  * @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 list_for_each_entry_safe_continue(pos, n, head, member)         \     for (pos = list_entry(pos->member.next, typeof(*pos), member),         \         n = list_entry(pos->member.next, typeof(*pos), member);        \      &pos->member != (head);                        \      pos = n, n = list_entry(n->member.next, typeof(*n), member)) /**  * list_for_each_entry_safe_from  * @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 list_for_each_entry_safe_from(pos, n, head, member)             \     for (n = list_entry(pos->member.next, typeof(*pos), member);        \      &pos->member != (head);                        \      pos = n, n = list_entry(n->member.next, typeof(*n), member)) /**  * list_for_each_entry_safe_reverse  * @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 list_for_each_entry_safe_reverse(pos, n, head, member)        \     for (pos = list_entry((head)->prev, typeof(*pos), member),    \         n = list_entry(pos->member.prev, typeof(*pos), member);    \      &pos->member != (head);                     \      pos = n, n = list_entry(n->member.prev, typeof(*n), member)) /*  * Double linked lists with a single pointer list head.  * Mostly useful for hash tables where the two pointer list head is  * too wasteful.  * You lose the ability to access the tail in O(1).  */ struct hlist_head {     struct hlist_node *first; }; struct hlist_node {     struct hlist_node *next, **pprev; }; #define HLIST_HEAD_INIT { .first = NULL } #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) static inline void INIT_HLIST_NODE(struct hlist_node *h) {     h->next = NULL;     h->pprev = NULL; } static inline int hlist_unhashed(const struct hlist_node *h) {     return !h->pprev; } static inline int hlist_empty(const struct hlist_head *h) {     return !h->first; } static inline void __hlist_del(struct hlist_node *n) {     struct hlist_node *next = n->next;     struct hlist_node **pprev = n->pprev;     *pprev = next;     if (next)         next->pprev = pprev; } static inline void hlist_del(struct hlist_node *n) {     __hlist_del(n); } static inline void hlist_del_init(struct hlist_node *n) {     if (!hlist_unhashed(n)) {         __hlist_del(n);         INIT_HLIST_NODE(n);     } } static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) {     struct hlist_node *first = h->first;     n->next = first;     if (first)         first->pprev = &n->next;     h->first = n;     n->pprev = &h->first; } /* next must be != NULL */ static inline void hlist_add_before(struct hlist_node *n,                     struct hlist_node *next) {     n->pprev = next->pprev;     n->next = next;     next->pprev = &n->next;     *(n->pprev) = n; } static inline void hlist_add_after(struct hlist_node *n,                     struct hlist_node *next) {     next->next = n->next;     n->next = next;     next->pprev = &n->next;     if(next->next)         next->next->pprev = &next->next; } /*  * Move a list from one list head to another. Fixup the pprev  * reference of the first entry if it exists.  */ static inline void hlist_move_list(struct hlist_head *old,                  struct hlist_head *new) {     new->first = old->first;     if (new->first)         new->first->pprev = &new->first;     old->first = NULL; } #define hlist_entry(ptr, type, member) container_of(ptr,type,member) #define hlist_for_each(pos, head) \     for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \      pos = pos->next) #define hlist_for_each_safe(pos, n, head) \     for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \      pos = n) /**  * hlist_for_each_entry    - iterate over list of given type  * @tpos:    the type * to use as a loop cursor.  * @pos:    the &struct hlist_node to use as a loop cursor.  * @head:    the head for your list.  * @member:    the name of the hlist_node within the struct.  */ #define hlist_for_each_entry(tpos, pos, head, member)             \     for (pos = (head)->first;                     \      pos && ({ prefetch(pos->next); 1;}) &&             \         ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \      pos = pos->next) /**  * hlist_for_each_entry_continue - iterate over a hlist continuing after current point  * @tpos:    the type * to use as a loop cursor.  * @pos:    the &struct hlist_node to use as a loop cursor.  * @member:    the name of the hlist_node within the struct.  */ #define hlist_for_each_entry_continue(tpos, pos, member)         \     for (pos = (pos)->next;                         \      pos && ({ prefetch(pos->next); 1;}) &&             \         ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \      pos = pos->next) /**  * hlist_for_each_entry_from - iterate over a hlist continuing from current point  * @tpos:    the type * to use as a loop cursor.  * @pos:    the &struct hlist_node to use as a loop cursor.  * @member:    the name of the hlist_node within the struct.  */ #define hlist_for_each_entry_from(tpos, pos, member)             \     for (; pos && ({ prefetch(pos->next); 1;}) &&             \         ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \      pos = pos->next) /**  * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry  * @tpos:    the type * to use as a loop cursor.  * @pos:    the &struct hlist_node to use as a loop cursor.  * @n:        another &struct hlist_node to use as temporary storage  * @head:    the head for your list.  * @member:    the name of the hlist_node within the struct.  */ #define hlist_for_each_entry_safe(tpos, pos, n, head, member)          \     for (pos = (head)->first;                     \      pos && ({ n = pos->next; 1; }) &&                  \         ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \      pos = n) #endif