#ifndef SRC_QUEUE_H_

#define SRC_QUEUE_H_

typedef void *QUEUE[2];

#define QUEUE_NEXT(q) (*(QUEUE **) &((*(q))[0]))

#define QUEUE_PREV(q) (*(QUEUE **) &((*(q))[1]))

#define QUEUE_PREV_NEXT(q) (QUEUE_NEXT(QUEUE_PREV(q)))

#define QUEUE_NEXT_PREV(q) (QUEUE_PREV(QUEUE_NEXT(q)))

#define QUEUE_DATA(ptr, type, field) \

((type *) ((char *) (ptr) - ((char *) &((type *) 0)->field)))

#define QUEUE_FOREACH(q, h) \

for ((q) = QUEUE_NEXT(h); (q) != (h); (q) = QUEUE_NEXT(q))

#define QUEUE_EMPTY(q) \

((const QUEUE *) (q) == (const QUEUE *) QUEUE_NEXT(q))

#define QUEUE_HEAD(q) \

(QUEUE_NEXT(q))

#define QUEUE_INIT(q) \

do { \

QUEUE_NEXT(q) = (q); \

QUEUE_PREV(q) = (q); \

} \

while (0)

#define QUEUE_ADD(h, n) \

do { \

QUEUE_PREV_NEXT(h) = QUEUE_NEXT(n); \

QUEUE_NEXT_PREV(n) = QUEUE_PREV(h); \

QUEUE_PREV(h) = QUEUE_PREV(n); \

QUEUE_PREV_NEXT(h) = (h); \

} \

while (0)

#define QUEUE_SPLIT(h, q, n) \

do { \

QUEUE_PREV(n) = QUEUE_PREV(h); \

QUEUE_PREV_NEXT(n) = (n); \

QUEUE_NEXT(n) = (q); \

QUEUE_PREV(h) = QUEUE_PREV(q); \

QUEUE_PREV_NEXT(h) = (h); \

QUEUE_PREV(q) = (n); \

} \

while (0)

#define QUEUE_INSERT_HEAD(h, q) \

do { \

QUEUE_NEXT(q) = QUEUE_NEXT(h); \

QUEUE_PREV(q) = (h); \

QUEUE_NEXT_PREV(q) = (q); \

QUEUE_NEXT(h) = (q); \

} \

while (0)

#define QUEUE_INSERT_TAIL(h, q) \

do { \

QUEUE_NEXT(q) = (h); \

QUEUE_PREV(q) = QUEUE_PREV(h); \

QUEUE_PREV_NEXT(q) = (q); \

QUEUE_PREV(h) = (q); \

} \

while (0)

#define QUEUE_REMOVE(q) \

do { \

QUEUE_PREV_NEXT(q) = QUEUE_NEXT(q); \

QUEUE_NEXT_PREV(q) = QUEUE_PREV(q); \

} \

while (0)

#endif /* SRC_QUEUE_H_ */