/* * Copyright (c) 1991, 1993 *	The Regents of the University of California.  All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *	This product includes software developed by the University of *	California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors *    may be used to endorse or promote products derived from this software *    without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * modified for flow-tools to prevent conflicts with sys/queue.h on some * systems. * *	@(#)queue.h	8.5 (Berkeley) 8/20/94 * $Id: ftqueue.h,v 1.2 2001/04/08 13:43:01 maf Exp $ */#ifndef _FT_QUEUE_H_#define	_FT_QUEUE_H_/* * This file defines five types of data structures: singly-linked lists, * slingly-linked tail queues, lists, tail queues, and circular queues. * * A singly-linked list is headed by a single forward pointer. The elements * are singly linked for minimum space and pointer manipulation overhead at * the expense of O(n) removal for arbitrary elements. New elements can be * added to the list after an existing element or at the head of the list. * Elements being removed from the head of the list should use the explicit * macro for this purpose for optimum efficiency. A singly-linked list may * only be traversed in the forward direction.  Singly-linked lists are ideal * for applications with large datasets and few or no removals or for * implementing a LIFO queue. * * A singly-linked tail queue is headed by a pair of pointers, one to the * head of the list and the other to the tail of the list. The elements are * singly linked for minimum space and pointer manipulation overhead at the * expense of O(n) removal for arbitrary elements. New elements can be added * to the list after an existing element, at the head of the list, or at the * end of the list. Elements being removed from the head of the tail queue * should use the explicit macro for this purpose for optimum efficiency. * A singly-linked tail queue may only be traversed in the forward direction. * Singly-linked tail queues are ideal for applications with large datasets * and few or no removals or for implementing a FIFO queue. * * A list is headed by a single forward pointer (or an array of forward * pointers for a hash table header). The elements are doubly linked * so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before * or after an existing element or at the head of the list. A list * may only be traversed in the forward direction. * * A tail queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or * after an existing element, at the head of the list, or at the end of * the list. A tail queue may only be traversed in the forward direction. * * A circle queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or after * an existing element, at the head of the list, or at the end of the list. * A circle queue may be traversed in either direction, but has a more * complex end of list detection. * * For details on the use of these macros, see the queue(3) manual page. * * *			SLIST	LIST	STAILQ	TAILQ	CIRCLEQ * _HEAD		+	+	+	+	+ * _ENTRY		+	+	+	+	+ * _INIT		+	+	+	+	+ * _EMPTY		+	+	+	+	+ * _FIRST		+	+	-	+	+ * _NEXT		+	+	-	+	+ * _PREV		-	-	-	+	+ * _LAST		-	-	-	+	+ * _FOREACH		+	+	-	+	- * _INSERT_HEAD		+	+	+	+	+ * _INSERT_BEFORE	-	+	-	+	+ * _INSERT_AFTER	+	+	+	+	+ * _INSERT_TAIL		-	-	+	+	+ * _REMOVE_HEAD		+	-	+	-	- * _REMOVE		+	+	+	+	+ * *//* * Singly-linked List definitions. */#define FT_SLIST_HEAD(name, type)					\struct name {								\	struct type *slh_first;	/* first element */			\} #define FT_SLIST_ENTRY(type)						\struct {								\	struct type *sle_next;	/* next element */			\} /* * Singly-linked List functions. */#define	FT_SLIST_EMPTY(head)	((head)->slh_first == NULL)#define	FT_SLIST_FIRST(head)	((head)->slh_first)#define FT_SLIST_FOREACH(var, head, field)				\	for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)#define FT_SLIST_INIT(head) {						\	(head)->slh_first = NULL;					\}#define FT_SLIST_INSERT_AFTER(slistelm, elm, field) do  {		\	(elm)->field.sle_next = (slistelm)->field.sle_next;		\	(slistelm)->field.sle_next = (elm);				\} while (0)#define FT_SLIST_INSERT_HEAD(head, elm, field) do {			\	(elm)->field.sle_next = (head)->slh_first;			\	(head)->slh_first = (elm);					\} while (0)#define FT_SLIST_NEXT(elm, field)	((elm)->field.sle_next)#define FT_SLIST_REMOVE_HEAD(head, field) do {				\	(head)->slh_first = (head)->slh_first->field.sle_next;		\} while (0)#define FT_SLIST_REMOVE(head, elm, type, field) do {			\	if ((head)->slh_first == (elm)) {				\		FT_SLIST_REMOVE_HEAD((head), field);			\	}								\	else {								\		struct type *curelm = (head)->slh_first;		\		while( curelm->field.sle_next != (elm) )		\			curelm = curelm->field.sle_next;		\		curelm->field.sle_next =				\		    curelm->field.sle_next->field.sle_next;		\	}								\} while (0)/* * Singly-linked Tail queue definitions. */#define FT_STAILQ_HEAD(name, type)					\struct name {								\	struct type *stqh_first;/* first element */			\	struct type **stqh_last;/* addr of last next element */		\}#define FT_STAILQ_ENTRY(type)						\struct {								\	struct type *stqe_next;	/* next element */			\}/* * Singly-linked Tail queue functions. */#define FT_STAILQ_EMPTY(head) ((head)->stqh_first == NULL)#define	FT_STAILQ_INIT(head) do {					\	(head)->stqh_first = NULL;					\	(head)->stqh_last = &(head)->stqh_first;			\} while (0)#define FT_STAILQ_FIRST(head)	((head)->stqh_first)#define FT_STAILQ_LAST(head)	(*(head)->stqh_last)#define FT_STAILQ_INSERT_HEAD(head, elm, field) do {			\	if (((elm)->field.stqe_next = (head)->stqh_first) == NULL)	\		(head)->stqh_last = &(elm)->field.stqe_next;		\	(head)->stqh_first = (elm);					\} while (0)#define FT_STAILQ_INSERT_TAIL(head, elm, field) do {			\	(elm)->field.stqe_next = NULL;					\	*(head)->stqh_last = (elm);					\	(head)->stqh_last = &(elm)->field.stqe_next;			\} while (0)#define FT_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {		\	if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\		(head)->stqh_last = &(elm)->field.stqe_next;		\	(tqelm)->field.stqe_next = (elm);				\} while (0)#define FT_STAILQ_NEXT(elm, field)	((elm)->field.stqe_next)#define FT_STAILQ_FOREACH(var, head, field)                    \	for (var = FT_STAILQ_FIRST(head); var; var = FT_STAILQ_NEXT(var, field))#define FT_STAILQ_REMOVE_HEAD(head, field) do {				\	if (((head)->stqh_first =					\	     (head)->stqh_first->field.stqe_next) == NULL)		\		(head)->stqh_last = &(head)->stqh_first;		\} while (0)#define FT_STAILQ_REMOVE(head, elm, type, field) do {			\	if ((head)->stqh_first == (elm)) {				\		FT_STAILQ_REMOVE_HEAD(head, field);			\	}								\	else {								\		struct type *curelm = (head)->stqh_first;		\		while( curelm->field.stqe_next != (elm) )		\			curelm = curelm->field.stqe_next;		\		if((curelm->field.stqe_next =				\		    curelm->field.stqe_next->field.stqe_next) == NULL)	\			(head)->stqh_last = &(curelm)->field.stqe_next;	\	}								\} while (0)/* * List definitions. */#define FT_LIST_HEAD(name, type)					\struct name {								\	struct type *lh_first;	/* first element */			\}#define FT_LIST_ENTRY(type)						\struct {								\	struct type *le_next;	/* next element */			\	struct type **le_prev;	/* address of previous next element */	\}/* * List functions. */#define	FT_LIST_EMPTY(head) ((head)->lh_first == NULL)#define FT_LIST_FIRST(head)	((head)->lh_first)