list.h revision e12f2ae74c2eb8997bf13adf8fdd7e7313971eae
1e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#if !defined(_BLKID_LIST_H) && !defined(LIST_HEAD) 2e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define _BLKID_LIST_H 3e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 4e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#ifdef __cplusplus 5e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'oextern "C" { 6e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#endif 7e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 8e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/* 9e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Simple doubly linked list implementation. 10e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 11e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Some of the internal functions ("__xxx") are useful when 12e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * manipulating whole lists rather than single entries, as 13e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * sometimes we already know the next/prev entries and we can 14e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * generate better code by using them directly rather than 15e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * using the generic single-entry routines. 16e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 17e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 18e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostruct list_head { 19e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head *next, *prev; 20e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o}; 21e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 22e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define LIST_HEAD_INIT(name) { &(name), &(name) } 23e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 24e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define LIST_HEAD(name) \ 25e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head name = LIST_HEAD_INIT(name) 26e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 27e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define INIT_LIST_HEAD(ptr) do { \ 28e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o (ptr)->next = (ptr); (ptr)->prev = (ptr); \ 29e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} while (0) 30e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 31e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/* 32e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Insert a new entry between two known consecutive entries. 33e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 34e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * This is only for internal list manipulation where we know 35e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * the prev/next entries already! 36e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 37e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void __list_add(struct list_head * add, 38e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head * prev, 39e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head * next) 40e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 41e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o next->prev = add; 42e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o add->next = next; 43e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o add->prev = prev; 44e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o prev->next = add; 45e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 46e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 47e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 48e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_add - add a new entry 49e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @add: new entry to be added 50e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: list head to add it after 51e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 52e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Insert a new entry after the specified head. 53e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * This is good for implementing stacks. 54e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 55e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void list_add(struct list_head *add, struct list_head *head) 56e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 57e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o __list_add(add, head, head->next); 58e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 59e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 60e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 61e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_add_tail - add a new entry 62e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @add: new entry to be added 63e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: list head to add it before 64e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 65e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Insert a new entry before the specified head. 66e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * This is useful for implementing queues. 67e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 68e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void list_add_tail(struct list_head *add, struct list_head *head) 69e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 70e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o __list_add(add, head->prev, head); 71e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 72e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 73e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/* 74e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * Delete a list entry by making the prev/next entries 75e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * point to each other. 76e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 77e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * This is only for internal list manipulation where we know 78e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * the prev/next entries already! 79e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 80e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void __list_del(struct list_head * prev, 81e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head * next) 82e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 83e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o next->prev = prev; 84e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o prev->next = next; 85e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 86e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 87e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 88e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_del - deletes entry from list. 89e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @entry: the element to delete from the list. 90e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * 91e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_empty() on @entry does not return true after this, @entry is 92e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * in an undefined state. 93e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 94e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void list_del(struct list_head *entry) 95e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 96e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o __list_del(entry->prev, entry->next); 97e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 98e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 99e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 100e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_del_init - deletes entry from list and reinitialize it. 101e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @entry: the element to delete from the list. 102e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 103e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void list_del_init(struct list_head *entry) 104e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 105e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o __list_del(entry->prev, entry->next); 106e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o INIT_LIST_HEAD(entry); 107e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 108e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 109e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 110e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_empty - tests whether a list is empty 111e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: the list to test. 112e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 113e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ int list_empty(struct list_head *head) 114e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 115e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o return head->next == head; 116e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 117e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 118e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 119e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_splice - join two lists 120e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @list: the new list to add. 121e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: the place to add it in the first list. 122e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 123e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'ostatic __inline__ void list_splice(struct list_head *list, struct list_head *head) 124e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o{ 125e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head *first = list->next; 126e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 127e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o if (first != list) { 128e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head *last = list->prev; 129e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o struct list_head *at = head->next; 130e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 131e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o first->prev = head; 132e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o head->next = first; 133e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 134e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o last->next = at; 135e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o at->prev = last; 136e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o } 137e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 138e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 139e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 140e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_entry - get the struct for this entry 141e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @ptr: the &struct list_head pointer. 142e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @type: the type of the struct this is embedded in. 143e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @member: the name of the list_struct within the struct. 144e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 145e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define list_entry(ptr, type, member) \ 146e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) 147e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 148e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 149e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_for_each - iterate over elements in a list 150e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @pos: the &struct list_head to use as a loop counter. 151e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: the head for your list. 152e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 153e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define list_for_each(pos, head) \ 154e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o for (pos = (head)->next; pos != (head); pos = pos->next) 155e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 156e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o/** 157e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * list_for_each_safe - iterate over elements in a list, but don't dereference 158e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * pos after the body is done (in case it is freed) 159e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @pos: the &struct list_head to use as a loop counter. 160e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @pnext: the &struct list_head to use as a pointer to the next item. 161e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o * @head: the head for your list (not included in iteration). 162e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o */ 163e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#define list_for_each_safe(pos, pnext, head) \ 164e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o for (pos = (head)->next, pnext = pos->next; pos != (head); \ 165e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o pos = pnext, pnext = pos->next) 166e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 167e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#ifdef __cplusplus 168e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o} 169e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#endif 170e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o 171e12f2ae74c2eb8997bf13adf8fdd7e7313971eaeTheodore Ts'o#endif /* _BLKID_LIST_H */ 172