Systemd/list.h

91 lines
4.7 KiB
C

/*-*- Mode: C; c-basic-offset: 8 -*-*/
#ifndef foolisthfoo
#define foolisthfoo
/* The head of the linked list. Use this in the structure that shall
* contain the head of the linked list */
#define LIST_HEAD(t,name) \
t *name
/* The pointers in the linked list's items. Use this in the item structure */
#define LIST_FIELDS(t) \
t *next, *prev
/* Initialize the list's head */
#define LIST_HEAD_INIT(t,item) \
do { \
(item) = (t*) NULL; } \
while(false)
/* Initialize a list item */
#define LIST_INIT(t,item) \
do { \
t *_item = (item); \
assert(_item); \
_item->prev = _item->next = NULL; \
} while(false)
/* Prepend an item to the list */
#define LIST_PREPEND(t,head,item) \
do { \
t **_head = &(head), *_item = (item); \
assert(_item); \
if ((_item->next = *_head)) \
_item->next->prev = _item; \
_item->prev = NULL; \
*_head = _item; \
} while(false)
/* Remove an item from the list */
#define LIST_REMOVE(t,head,item) \
do { \
t **_head = &(head), *_item = (item); \
assert(_item); \
if (_item->next) \
_item->next->prev = _item->prev; \
if (_item->prev) \
_item->prev->next = _item->next; \
else { \
assert(*_head == _item); \
*_head = _item->next; \
} \
_item->next = _item->prev = NULL; \
} while(false)
/* Find the head of the list */
#define LIST_FIND_HEAD(t,item,head) \
do { \
t **_head = (head), *_item = (item); \
*_head = _item; \
assert(_head); \
while ((*_head)->prev) \
*_head = (*_head)->prev; \
} while (false)
/* Insert an item after another one (a = where, b = what) */
#define LIST_INSERT_AFTER(t,head,a,b) \
do { \
t **_head = &(head), *_a = (a), *_b = (b); \
assert(_b); \
if (!_a) { \
if ((_b->next = *_head)) \
_b->next->prev = _b; \
_b->prev = NULL; \
*_head = _b; \
} else { \
if ((_b->next = _a->next)) \
_b->next->prev = _b; \
_b->prev = _a; \
_a->next = _b; \
} \
} while(false)
#define LIST_FOREACH(i,head) \
for (i = (head); i; i = i->next)
#define LIST_FOREACH_SAFE(i,n,head) \
for (i = (head); i && ((n = i->next), 1); i = n)
#endif