#define AQUEUE_HEAD(name, type) \
struct name { \
	struct type *aqh_next; \
	struct type *aqh_prev; \
	struct type *aqh_tailprev; \
}

#define AQUEUE_HEAD_INITIALIZER(head) { \
	(__typeof (head.aqh_next))&(head.aqh_prev), \
	NULL, \
	(__typeof (head.aqh_tailprev))&(head.aqh_prev) \
}

#define AQUEUE_ENTRY(type) \
struct { \
	struct type *aqe_next; \
	struct type *aqe_prev; \
}

#define AQUEUE_EMPTY(head) ((head)->aqh_next == &(head)->aqh_prev)

#define AQUEUE_FIRST(head) ((head)->aqh_next)

#define AQUEUE_FOREACH(var, head, field) \
	for ((var) = AQUEUE_FIRST((head)); \
	     AQUEUE_NEXT((var), field) != NULL; \
	     (var) = AQUEUE_NEXT((var), field))

#define AQUEUE_FOREACH_REVERSE(var, head, field) \
	for ((var) = AQUEUE_LAST((head)); \
	     (var); \
	     AQUEUE_PREV((var), field) != NULL; \
	     (var) = AQUEUE_PREV((var), field))

#define AQUEUE_INIT(head) do { \
	(head)->aqh_next = \
	    (__typeof ((*(head)).aqh_next))(&((head)->aqh_prev)); \
	(head)->aqh_prev = NULL; \
	(head)->aqh_tailprev = \
	    (__typeof ((*(head)).aqh_tailprev))(&((head)->aqh_prev)); \
} while (0)

/* insert elm2 after eml1 */
#define AQUEUE_INSERT_AFTER(elm1, elm2, field) do { \
	AQUEUE_PREV((elm2), field) = (elm1); \
	AQUEUE_NEXT((elm2), field) = AQUEUE_NEXT((elm1), field); \
	AQUEUE_NEXT((elm1), field) = (elm2); \
	AQUEUE_PREV(AQUEUE_NEXT((elm1), field) = (elm2); \
} while (0)

/* insert elm2 before eml1 */
#define AQUEUE_INSERT_BEFORE(elm1, elm2, field) do { \
	AQUEUE_NEXT((elm2), field) = (elm1); \
	AQUEUE_PREV((elm2), field) = AQUEUE_NEXT((elm1), field); \
	AQUEUE_PREV((elm1), field) = (elm2); \
	AQUEUE_NEXT(AQUEUE_PREV((elm1), field) = (elm2); \
} while (0)

#define AQUEUE_INSERT_HEAD(head, elm, field) do { \
	AQUEUE_PREV((elm), field) = (head); \
	AQUEUE_NEXT((elm), field) = (head)->aqh_next; \
	AQUEUE_PREV((head)->aqh_next, field) = (elm); \
	(head)->aqh_next = (elm); \
} while (0)

/* 	AQUEUE_NEXT((elm), field) = (__typeof (elm))&(head)->aqh_prev; */

#define AQUEUE_INSERT_TAIL(head, elm, field) do { \
	AQUEUE_NEXT((elm), field) = (head)->aqh_tailprev; \
	AQUEUE_PREV((elm), field) = AQUEUE_PREV((head)->aqh_tailprev, field); \
	AQUEUE_NEXT((head)->aqh_tailprev, field) = (elm); \
	(head)->aqh_tailprev = (elm); \
} while (0)

#define AQUEUE_LAST(head) ((head)->aqh_tailprev)

#define AQUEUE_NEXT(elm, field) ((elm)->field.aqe_next)

#define AQUEUE_PREV(elm, field) ((elm)->field.aqe_prev)

#define AQUEUE_REMOVE(elm, field) do { \
	AQUEUE_NEXT(AQUEUE_PREV((elm), field), field) = \
	    AQUEUE_NEXT((elm), field); \
	AQUEUE_PREV(AQUEUE_NEXT((elm), field), field) = \
	    AQUEUE_PREV((elm), field); \
} while (0)

#define AQUEUE_ISLAST(elm, field) \
	(AQUEUE_NEXT(AQUEUE_NEXT((elm), field), field) == NULL)

#define AQUEUE_ISFIRST(elm, field) \
	(AQUEUE_PREV(AQUEUE_PREV((elm), field), field) == NULL)

#define AQUEUE_VALID(elm, field) \
	(AQUEUE_PREV((elm), field) != NULL && AQUEUE_NEXT((elm), field) != NULL)