btpd/btpd/queue.h

/*
 *	@(#)queue.h	8.5 (Berkeley) 8/20/94
 * $FreeBSD: src/sys/sys/queue.h,v 1.58.2.1 2005/01/31 23:26:57 imp Exp $
 */

#ifndef BTPD_QUEUE_H
#define BTPD_QUEUE_H

/*
 * Tail queue declarations.
 */
#define	BTPDQ_HEAD(name, type)						\
struct name {								\
	struct type *tqh_first;	/* first element */			\
	struct type **tqh_last;	/* addr of last next element */		\
}

#define	BTPDQ_HEAD_INITIALIZER(head)					\
	{ NULL, &(head).tqh_first }

#define	BTPDQ_ENTRY(type)						\
struct {								\
	struct type *tqe_next;	/* next element */			\
	struct type **tqe_prev;	/* address of previous next element */	\
}

#define	BTPDQ_EMPTY(head)	((head)->tqh_first == NULL)

#define	BTPDQ_FIRST(head)	((head)->tqh_first)

#define	BTPDQ_NEXT(elm, field) ((elm)->field.tqe_next)

#define	BTPDQ_FOREACH(var, head, field)					\
	for ((var) = BTPDQ_FIRST((head));				\
	    (var);							\
	    (var) = BTPDQ_NEXT((var), field))

#define	BTPDQ_INIT(head) do {						\
	BTPDQ_FIRST((head)) = NULL;					\
	(head)->tqh_last = &BTPDQ_FIRST((head));			\
} while (0)

#define	BTPDQ_INSERT_AFTER(head, listelm, elm, field) do {		\
	if ((BTPDQ_NEXT((elm), field) = BTPDQ_NEXT((listelm), field)) != NULL)\
		BTPDQ_NEXT((elm), field)->field.tqe_prev = 		\
		    &BTPDQ_NEXT((elm), field);				\
	else {								\
		(head)->tqh_last = &BTPDQ_NEXT((elm), field);		\
	}								\
	BTPDQ_NEXT((listelm), field) = (elm);				\
	(elm)->field.tqe_prev = &BTPDQ_NEXT((listelm), field);		\
} while (0)

#define	BTPDQ_INSERT_HEAD(head, elm, field) do {			\
	if ((BTPDQ_NEXT((elm), field) = BTPDQ_FIRST((head))) != NULL)	\
		BTPDQ_FIRST((head))->field.tqe_prev =			\
		    &BTPDQ_NEXT((elm), field);				\
	else								\
		(head)->tqh_last = &BTPDQ_NEXT((elm), field);		\
	BTPDQ_FIRST((head)) = (elm);					\
	(elm)->field.tqe_prev = &BTPDQ_FIRST((head));			\
} while (0)

#define	BTPDQ_INSERT_TAIL(head, elm, field) do {			\
	BTPDQ_NEXT((elm), field) = NULL;				\
	(elm)->field.tqe_prev = (head)->tqh_last;			\
	*(head)->tqh_last = (elm);					\
	(head)->tqh_last = &BTPDQ_NEXT((elm), field);			\
} while (0)

#define	BTPDQ_REMOVE(head, elm, field) do {				\
	if ((BTPDQ_NEXT((elm), field)) != NULL)				\
		BTPDQ_NEXT((elm), field)->field.tqe_prev = 		\
		    (elm)->field.tqe_prev;				\
	else {								\
		(head)->tqh_last = (elm)->field.tqe_prev;		\
	}								\
	*(elm)->field.tqe_prev = BTPDQ_NEXT((elm), field);		\
} while (0)

#endif