[mirror_frr.git] / lib / freebsd-queue.h

// SPDX-License-Identifier: BSD-3-Clause
/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 *	@(#)queue.h	8.5 (Berkeley) 8/20/94
 * $FreeBSD$
 */

#ifndef _SYS_QUEUE_H_
#define	_SYS_QUEUE_H_

#ifdef __cplusplus
extern "C" {
#endif

/*
 * This file defines four types of data structures: singly-linked lists,
 * singly-linked tail queues, lists and tail 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 be traversed in either direction.
 *
 * For details on the use of these macros, see the queue(3) manual page.
 *
 *
 *				SLIST	LIST	STAILQ	TAILQ
 * _HEAD			+	+	+	+
 * _HEAD_INITIALIZER		+	+	+	+
 * _ENTRY			+	+	+	+
 * _INIT			+	+	+	+
 * _EMPTY			+	+	+	+
 * _FIRST			+	+	+	+
 * _NEXT			+	+	+	+
 * _PREV			-	-	-	+
 * _LAST			-	-	+	+
 * _FOREACH			+	+	+	+
 * _FOREACH_SAFE		+	+	+	+
 * _FOREACH_REVERSE		-	-	-	+
 * _FOREACH_REVERSE_SAFE	-	-	-	+
 * _INSERT_HEAD			+	+	+	+
 * _INSERT_BEFORE		-	+	-	+
 * _INSERT_AFTER		+	+	+	+
 * _INSERT_TAIL			-	-	+	+
 * _CONCAT			-	-	+	+
 * _REMOVE_AFTER		+	-	+	-
 * _REMOVE_HEAD			+	-	+	-
 * _REMOVE			+	+	+	+
 * _SWAP			+	+	+	+
 *
 */
#ifdef QUEUE_MACRO_DEBUG
/* Store the last 2 places the queue element or head was altered */
struct qm_trace {
	char *lastfile;
	int lastline;
	char *prevfile;
	int prevline;
};

#define	TRACEBUF	struct qm_trace trace;
#define	TRASHIT(x)	do {(x) = (void *)-1;} while (0)
#define	QMD_SAVELINK(name, link)	void **name = (void *)&(link)

#define QMD_TRACE_HEAD(head)                                                   \
	do {                                                                   \
		(head)->trace.prevline = (head)->trace.lastline;               \
		(head)->trace.prevfile = (head)->trace.lastfile;               \
		(head)->trace.lastline = __LINE__;                             \
		(head)->trace.lastfile = __FILE__;                             \
	} while (0)

#define QMD_TRACE_ELEM(elem)                                                   \
	do {                                                                   \
		(elem)->trace.prevline = (elem)->trace.lastline;               \
		(elem)->trace.prevfile = (elem)->trace.lastfile;               \
		(elem)->trace.lastline = __LINE__;                             \
		(elem)->trace.lastfile = __FILE__;                             \
	} while (0)

#else
#define	QMD_TRACE_ELEM(elem)
#define	QMD_TRACE_HEAD(head)
#define	QMD_SAVELINK(name, link)
#define	TRACEBUF
#define	TRASHIT(x)
#endif /* QUEUE_MACRO_DEBUG */

/*
 * Singly-linked List declarations.
 */
#define SLIST_HEAD(name, type)                                                 \
	struct name {                                                          \
		struct type *slh_first; /* first element */                    \
	}

#define SLIST_HEAD_INITIALIZER(head)                                           \
	{                                                                      \
		NULL                                                           \
	}

#define SLIST_ENTRY(type)                                                      \
	struct {                                                               \
		struct type *sle_next; /* next element */                      \
	}

/*
 * Singly-linked List functions.
 */
#define	SLIST_EMPTY(head)	((head)->slh_first == NULL)

#define	SLIST_FIRST(head)	((head)->slh_first)

#define SLIST_FOREACH(var, head, field)                                        \
	for ((var) = SLIST_FIRST((head)); (var);                               \
	     (var) = SLIST_NEXT((var), field))

#define SLIST_FOREACH_SAFE(var, head, field, tvar)                             \
	for ((var) = SLIST_FIRST((head));                                      \
	     (var) && ((tvar) = SLIST_NEXT((var), field), 1); (var) = (tvar))

#define SLIST_FOREACH_PREVPTR(var, varp, head, field)                          \
	for ((varp) = &SLIST_FIRST((head)); ((var) = *(varp)) != NULL;         \
	     (varp) = &SLIST_NEXT((var), field))

#define SLIST_INIT(head)                                                       \
	do {                                                                   \
		SLIST_FIRST((head)) = NULL;                                    \
	} while (0)

#define SLIST_INSERT_AFTER(slistelm, elm, field)                               \
	do {                                                                   \
		SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);      \
		SLIST_NEXT((slistelm), field) = (elm);                         \
	} while (0)

#define SLIST_INSERT_HEAD(head, elm, field)                                    \
	do {                                                                   \
		SLIST_NEXT((elm), field) = SLIST_FIRST((head));                \
		SLIST_FIRST((head)) = (elm);                                   \
	} while (0)

#define	SLIST_NEXT(elm, field)	((elm)->field.sle_next)

#define SLIST_REMOVE(head, elm, type, field)                                   \
	do {                                                                   \
		QMD_SAVELINK(oldnext, (elm)->field.sle_next);                  \
		if (SLIST_FIRST((head)) == (elm)) {                            \
			SLIST_REMOVE_HEAD((head), field);                      \
		} else {                                                       \
			struct type *curelm = SLIST_FIRST((head));             \
			while (SLIST_NEXT(curelm, field) != (elm))             \
				curelm = SLIST_NEXT(curelm, field);            \
			SLIST_REMOVE_AFTER(curelm, field);                     \
		}                                                              \
		TRASHIT(*oldnext);                                             \
	} while (0)

#define SLIST_REMOVE_AFTER(elm, field)                                         \
	do {                                                                   \
		SLIST_NEXT(elm, field) =                                       \
			SLIST_NEXT(SLIST_NEXT(elm, field), field);             \
	} while (0)

#define SLIST_REMOVE_HEAD(head, field)                                         \
	do {                                                                   \
		SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);  \
	} while (0)

#define SLIST_SWAP(head1, head2, type)                                         \
	do {                                                                   \
		struct type *swap_first = SLIST_FIRST(head1);                  \
		SLIST_FIRST(head1) = SLIST_FIRST(head2);                       \
		SLIST_FIRST(head2) = swap_first;                               \
	} while (0)

/*
 * Singly-linked Tail queue declarations.
 */
#define STAILQ_HEAD(name, type)                                                \
	struct name {                                                          \
		struct type *stqh_first; /* first element */                   \
		struct type **stqh_last; /* addr of last next element */       \
	}

#define STAILQ_HEAD_INITIALIZER(head)                                          \
	{                                                                      \
		NULL, &(head).stqh_first                                       \
	}

#define STAILQ_ENTRY(type)                                                     \
	struct {                                                               \
		struct type *stqe_next; /* next element */                     \
	}

/*
 * Singly-linked Tail queue functions.
 */
#define STAILQ_CONCAT(head1, head2)                                            \
	do {                                                                   \
		if (!STAILQ_EMPTY((head2))) {                                  \
			*(head1)->stqh_last = (head2)->stqh_first;             \
			(head1)->stqh_last = (head2)->stqh_last;               \
			STAILQ_INIT((head2));                                  \
		}                                                              \
	} while (0)

#define	STAILQ_EMPTY(head)	((head)->stqh_first == NULL)

#define	STAILQ_FIRST(head)	((head)->stqh_first)

#define STAILQ_FOREACH(var, head, field)                                       \
	for ((var) = STAILQ_FIRST((head)); (var);                              \
	     (var) = STAILQ_NEXT((var), field))


#define STAILQ_FOREACH_SAFE(var, head, field, tvar)                            \
	for ((var) = STAILQ_FIRST((head));                                     \
	     (var) && ((tvar) = STAILQ_NEXT((var), field), 1); (var) = (tvar))

#define STAILQ_INIT(head)                                                      \
	do {                                                                   \
		STAILQ_FIRST((head)) = NULL;                                   \
		(head)->stqh_last = &STAILQ_FIRST((head));                     \
	} while (0)

#define STAILQ_INSERT_AFTER(head, tqelm, elm, field)                           \
	do {                                                                   \
		if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field))  \
		    == NULL)                                                   \
			(head)->stqh_last = &STAILQ_NEXT((elm), field);        \
		STAILQ_NEXT((tqelm), field) = (elm);                           \
	} while (0)

#define STAILQ_INSERT_HEAD(head, elm, field)                                   \
	do {                                                                   \
		if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head)))         \
		    == NULL)                                                   \
			(head)->stqh_last = &STAILQ_NEXT((elm), field);        \
		STAILQ_FIRST((head)) = (elm);                                  \
	} while (0)

#define STAILQ_INSERT_TAIL(head, elm, field)                                   \
	do {                                                                   \
		STAILQ_NEXT((elm), field) = NULL;                              \
		*(head)->stqh_last = (elm);                                    \
		(head)->stqh_last = &STAILQ_NEXT((elm), field);                \
	} while (0)

#define STAILQ_LAST(head, type, field)                                         \
	(STAILQ_EMPTY((head))                                                  \
		 ? NULL                                                        \
		 : ((struct type *)(void *)((char *)((head)->stqh_last)        \
					    - offsetof(struct type, field))))

#define	STAILQ_NEXT(elm, field)	((elm)->field.stqe_next)

#define STAILQ_REMOVE(head, elm, type, field)                                  \
	do {                                                                   \
		QMD_SAVELINK(oldnext, (elm)->field.stqe_next);                 \
		if (STAILQ_FIRST((head)) == (elm)) {                           \
			STAILQ_REMOVE_HEAD((head), field);                     \
		} else {                                                       \
			struct type *curelm = STAILQ_FIRST((head));            \
			while (STAILQ_NEXT(curelm, field) != (elm))            \
				curelm = STAILQ_NEXT(curelm, field);           \
			STAILQ_REMOVE_AFTER(head, curelm, field);              \
		}                                                              \
		TRASHIT(*oldnext);                                             \
	} while (0)

#define STAILQ_REMOVE_AFTER(head, elm, field)                                  \
	do {                                                                   \
		if ((STAILQ_NEXT(elm, field) =                                 \
			     STAILQ_NEXT(STAILQ_NEXT(elm, field), field))      \
		    == NULL)                                                   \
			(head)->stqh_last = &STAILQ_NEXT((elm), field);        \
	} while (0)

#define STAILQ_REMOVE_HEAD(head, field)                                        \
	do {                                                                   \
		if ((STAILQ_FIRST((head)) =                                    \
			     STAILQ_NEXT(STAILQ_FIRST((head)), field))         \
		    == NULL)                                                   \
			(head)->stqh_last = &STAILQ_FIRST((head));             \
	} while (0)

#define STAILQ_SWAP(head1, head2, type)                                        \
	do {                                                                   \
		struct type *swap_first = STAILQ_FIRST(head1);                 \
		struct type **swap_last = (head1)->stqh_last;                  \
		STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                     \
		(head1)->stqh_last = (head2)->stqh_last;                       \
		STAILQ_FIRST(head2) = swap_first;                              \
		(head2)->stqh_last = swap_last;                                \
		if (STAILQ_EMPTY(head1))                                       \
			(head1)->stqh_last = &STAILQ_FIRST(head1);             \
		if (STAILQ_EMPTY(head2))                                       \
			(head2)->stqh_last = &STAILQ_FIRST(head2);             \
	} while (0)


/*
 * List declarations.
 */
#define LIST_HEAD(name, type)                                                  \
	struct name {                                                          \
		struct type *lh_first; /* first element */                     \
	}

#define LIST_HEAD_INITIALIZER(head)                                            \
	{                                                                      \
		NULL                                                           \
	}

#define LIST_ENTRY(type)                                                       \
	struct {                                                               \
		struct type *le_next;  /* next element */                      \
		struct type **le_prev; /* address of previous next element */  \
	}

/*
 * List functions.
 */

#if (defined(_KERNEL) && defined(INVARIANTS))
#define QMD_LIST_CHECK_HEAD(head, field)                                       \
	do {                                                                   \
		if (LIST_FIRST((head)) != NULL                                 \
		    && LIST_FIRST((head))->field.le_prev                       \
			       != &LIST_FIRST((head)))                         \
			panic("Bad list head %p first->prev != head", (head)); \
	} while (0)

#define QMD_LIST_CHECK_NEXT(elm, field)                                        \
	do {                                                                   \
		if (LIST_NEXT((elm), field) != NULL                            \
		    && LIST_NEXT((elm), field)->field.le_prev                  \
			       != &((elm)->field.le_next))                     \
			panic("Bad link elm %p next->prev != elm", (elm));     \
	} while (0)

#define QMD_LIST_CHECK_PREV(elm, field)                                        \
	do {                                                                   \
		if (*(elm)->field.le_prev != (elm))                            \
			panic("Bad link elm %p prev->next != elm", (elm));     \
	} while (0)
#else
#define	QMD_LIST_CHECK_HEAD(head, field)
#define	QMD_LIST_CHECK_NEXT(elm, field)
#define	QMD_LIST_CHECK_PREV(elm, field)
#endif /* (_KERNEL && INVARIANTS) */

#define	LIST_EMPTY(head)	((head)->lh_first == NULL)

#define	LIST_FIRST(head)	((head)->lh_first)

#define LIST_FOREACH(var, head, field)                                         \
	for ((var) = LIST_FIRST((head)); (var); (var) = LIST_NEXT((var), field))

#define LIST_FOREACH_SAFE(var, head, field, tvar)                              \
	for ((var) = LIST_FIRST((head));                                       \
	     (var) && ((tvar) = LIST_NEXT((var), field), 1); (var) = (tvar))

#define LIST_INIT(head)                                                        \
	do {                                                                   \
		LIST_FIRST((head)) = NULL;                                     \
	} while (0)

#define LIST_INSERT_AFTER(listelm, elm, field)                                 \
	do {                                                                   \
		QMD_LIST_CHECK_NEXT(listelm, field);                           \
		if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field))    \
		    != NULL)                                                   \
			LIST_NEXT((listelm), field)->field.le_prev =           \
				&LIST_NEXT((elm), field);                      \
		LIST_NEXT((listelm), field) = (elm);                           \
		(elm)->field.le_prev = &LIST_NEXT((listelm), field);           \
	} while (0)

#define LIST_INSERT_BEFORE(listelm, elm, field)                                \
	do {                                                                   \
		QMD_LIST_CHECK_PREV(listelm, field);                           \
		(elm)->field.le_prev = (listelm)->field.le_prev;               \
		LIST_NEXT((elm), field) = (listelm);                           \
		*(listelm)->field.le_prev = (elm);                             \
		(listelm)->field.le_prev = &LIST_NEXT((elm), field);           \
	} while (0)

#define LIST_INSERT_HEAD(head, elm, field)                                     \
	do {                                                                   \
		QMD_LIST_CHECK_HEAD((head), field);                            \
		if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)    \
			LIST_FIRST((head))->field.le_prev =                    \
				&LIST_NEXT((elm), field);                      \
		LIST_FIRST((head)) = (elm);                                    \
		(elm)->field.le_prev = &LIST_FIRST((head));                    \
	} while (0)

#define	LIST_NEXT(elm, field)	((elm)->field.le_next)

#define LIST_REMOVE(elm, field)                                                \
	do {                                                                   \
		QMD_SAVELINK(oldnext, (elm)->field.le_next);                   \
		QMD_SAVELINK(oldprev, (elm)->field.le_prev);                   \
		QMD_LIST_CHECK_NEXT(elm, field);                               \
		QMD_LIST_CHECK_PREV(elm, field);                               \
		if (LIST_NEXT((elm), field) != NULL)                           \
			LIST_NEXT((elm), field)->field.le_prev =               \
				(elm)->field.le_prev;                          \
		*(elm)->field.le_prev = LIST_NEXT((elm), field);               \
		TRASHIT(*oldnext);                                             \
		TRASHIT(*oldprev);                                             \
	} while (0)

#define LIST_SWAP(head1, head2, type, field)                                   \
	do {                                                                   \
		struct type *swap_tmp = LIST_FIRST((head1));                   \
		LIST_FIRST((head1)) = LIST_FIRST((head2));                     \
		LIST_FIRST((head2)) = swap_tmp;                                \
		if ((swap_tmp = LIST_FIRST((head1))) != NULL)                  \
			swap_tmp->field.le_prev = &LIST_FIRST((head1));        \
		if ((swap_tmp = LIST_FIRST((head2))) != NULL)                  \
			swap_tmp->field.le_prev = &LIST_FIRST((head2));        \
	} while (0)

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

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

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

/*
 * Tail queue functions.
 */
#if (defined(_KERNEL) && defined(INVARIANTS))
#define QMD_TAILQ_CHECK_HEAD(head, field)                                      \
	do {                                                                   \
		if (!TAILQ_EMPTY(head)                                         \
		    && TAILQ_FIRST((head))->field.tqe_prev                     \
			       != &TAILQ_FIRST((head)))                        \
			panic("Bad tailq head %p first->prev != head",         \
			      (head));                                         \
	} while (0)

#define QMD_TAILQ_CHECK_TAIL(head, field)                                      \
	do {                                                                   \
		if (*(head)->tqh_last != NULL)                                 \
			panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
	} while (0)

#define QMD_TAILQ_CHECK_NEXT(elm, field)                                       \
	do {                                                                   \
		if (TAILQ_NEXT((elm), field) != NULL                           \
		    && TAILQ_NEXT((elm), field)->field.tqe_prev                \
			       != &((elm)->field.tqe_next))                    \
			panic("Bad link elm %p next->prev != elm", (elm));     \
	} while (0)

#define QMD_TAILQ_CHECK_PREV(elm, field)                                       \
	do {                                                                   \
		if (*(elm)->field.tqe_prev != (elm))                           \
			panic("Bad link elm %p prev->next != elm", (elm));     \
	} while (0)
#else
#define	QMD_TAILQ_CHECK_HEAD(head, field)
#define	QMD_TAILQ_CHECK_TAIL(head, headname)
#define	QMD_TAILQ_CHECK_NEXT(elm, field)
#define	QMD_TAILQ_CHECK_PREV(elm, field)
#endif /* (_KERNEL && INVARIANTS) */

#define TAILQ_CONCAT(head1, head2, field)                                      \
	do {                                                                   \
		if (!TAILQ_EMPTY(head2)) {                                     \
			*(head1)->tqh_last = (head2)->tqh_first;               \
			(head2)->tqh_first->field.tqe_prev =                   \
				(head1)->tqh_last;                             \
			(head1)->tqh_last = (head2)->tqh_last;                 \
			TAILQ_INIT((head2));                                   \
			QMD_TRACE_HEAD(head1);                                 \
			QMD_TRACE_HEAD(head2);                                 \
		}                                                              \
	} while (0)

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

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

#define TAILQ_FOREACH(var, head, field)                                        \
	for ((var) = TAILQ_FIRST((head)); (var);                               \
	     (var) = TAILQ_NEXT((var), field))

#define TAILQ_FOREACH_SAFE(var, head, field, tvar)                             \
	for ((var) = TAILQ_FIRST((head));                                      \
	     (var) && ((tvar) = TAILQ_NEXT((var), field), 1); (var) = (tvar))

#define TAILQ_FOREACH_REVERSE(var, head, headname, field)                      \
	for ((var) = TAILQ_LAST((head), headname); (var);                      \
	     (var) = TAILQ_PREV((var), headname, field))

#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)           \
	for ((var) = TAILQ_LAST((head), headname);                             \
	     (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);        \
	     (var) = (tvar))

#define TAILQ_INIT(head)                                                       \
	do {                                                                   \
		TAILQ_FIRST((head)) = NULL;                                    \
		(head)->tqh_last = &TAILQ_FIRST((head));                       \
		QMD_TRACE_HEAD(head);                                          \
	} while (0)

#define TAILQ_INSERT_AFTER(head, listelm, elm, field)                          \
	do {                                                                   \
		QMD_TAILQ_CHECK_NEXT(listelm, field);                          \
		if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field))  \
		    != NULL)                                                   \
			TAILQ_NEXT((elm), field)->field.tqe_prev =             \
				&TAILQ_NEXT((elm), field);                     \
		else {                                                         \
			(head)->tqh_last = &TAILQ_NEXT((elm), field);          \
			QMD_TRACE_HEAD(head);                                  \
		}                                                              \
		TAILQ_NEXT((listelm), field) = (elm);                          \
		(elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);         \
		QMD_TRACE_ELEM(&(elm)->field);                                 \
		QMD_TRACE_ELEM(&listelm->field);                               \
	} while (0)

#define TAILQ_INSERT_BEFORE(listelm, elm, field)                               \
	do {                                                                   \
		QMD_TAILQ_CHECK_PREV(listelm, field);                          \
		(elm)->field.tqe_prev = (listelm)->field.tqe_prev;             \
		TAILQ_NEXT((elm), field) = (listelm);                          \
		*(listelm)->field.tqe_prev = (elm);                            \
		(listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);         \
		QMD_TRACE_ELEM(&(elm)->field);                                 \
		QMD_TRACE_ELEM(&listelm->field);                               \
	} while (0)

#define TAILQ_INSERT_HEAD(head, elm, field)                                    \
	do {                                                                   \
		QMD_TAILQ_CHECK_HEAD(head, field);                             \
		if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)  \
			TAILQ_FIRST((head))->field.tqe_prev =                  \
				&TAILQ_NEXT((elm), field);                     \
		else                                                           \
			(head)->tqh_last = &TAILQ_NEXT((elm), field);          \
		TAILQ_FIRST((head)) = (elm);                                   \
		(elm)->field.tqe_prev = &TAILQ_FIRST((head));                  \
		QMD_TRACE_HEAD(head);                                          \
		QMD_TRACE_ELEM(&(elm)->field);                                 \
	} while (0)

#define TAILQ_INSERT_TAIL(head, elm, field)                                    \
	do {                                                                   \
		QMD_TAILQ_CHECK_TAIL(head, field);                             \
		TAILQ_NEXT((elm), field) = NULL;                               \
		(elm)->field.tqe_prev = (head)->tqh_last;                      \
		*(head)->tqh_last = (elm);                                     \
		(head)->tqh_last = &TAILQ_NEXT((elm), field);                  \
		QMD_TRACE_HEAD(head);                                          \
		QMD_TRACE_ELEM(&(elm)->field);                                 \
	} while (0)

#define TAILQ_LAST(head, headname)                                             \
	(*(((struct headname *)((head)->tqh_last))->tqh_last))

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

#define TAILQ_PREV(elm, headname, field)                                       \
	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))

#define TAILQ_REMOVE(head, elm, field)                                         \
	do {                                                                   \
		QMD_SAVELINK(oldnext, (elm)->field.tqe_next);                  \
		QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);                  \
		QMD_TAILQ_CHECK_NEXT(elm, field);                              \
		QMD_TAILQ_CHECK_PREV(elm, field);                              \
		if ((TAILQ_NEXT((elm), field)) != NULL)                        \
			TAILQ_NEXT((elm), field)->field.tqe_prev =             \
				(elm)->field.tqe_prev;                         \
		else {                                                         \
			(head)->tqh_last = (elm)->field.tqe_prev;              \
			QMD_TRACE_HEAD(head);                                  \
		}                                                              \
		*(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);             \
		TRASHIT(*oldnext);                                             \
		TRASHIT(*oldprev);                                             \
		QMD_TRACE_ELEM(&(elm)->field);                                 \
	} while (0)

#define TAILQ_SWAP(head1, head2, type, field)                                  \
	do {                                                                   \
		struct type *swap_first = (head1)->tqh_first;                  \
		struct type **swap_last = (head1)->tqh_last;                   \
		(head1)->tqh_first = (head2)->tqh_first;                       \
		(head1)->tqh_last = (head2)->tqh_last;                         \
		(head2)->tqh_first = swap_first;                               \
		(head2)->tqh_last = swap_last;                                 \
		if ((swap_first = (head1)->tqh_first) != NULL)                 \
			swap_first->field.tqe_prev = &(head1)->tqh_first;      \
		else                                                           \
			(head1)->tqh_last = &(head1)->tqh_first;               \
		if ((swap_first = (head2)->tqh_first) != NULL)                 \
			swap_first->field.tqe_prev = &(head2)->tqh_first;      \
		else                                                           \
			(head2)->tqh_last = &(head2)->tqh_first;               \
	} while (0)

#ifdef __cplusplus
}
#endif

#endif /* !_SYS_QUEUE_H_ */
Commit	Line	Data
47a3a827	1	// SPDX-License-Identifier: BSD-3-Clause
cd85bc2e JB	2	/*-
	3	* Copyright (c) 1991, 1993
	4	* The Regents of the University of California. All rights reserved.
	5	*
cd85bc2e JB	6	* @(#)queue.h 8.5 (Berkeley) 8/20/94
	7	* $FreeBSD$
	8	*/
	9
	10	#ifndef _SYS_QUEUE_H_
	11	#define _SYS_QUEUE_H_
	12
5e244469 RW	13	#ifdef __cplusplus
	14	extern "C" {
	15	#endif
	16
cd85bc2e JB	17	/*
	18	* This file defines four types of data structures: singly-linked lists,
	19	* singly-linked tail queues, lists and tail queues.
	20	*
	21	* A singly-linked list is headed by a single forward pointer. The elements
	22	* are singly linked for minimum space and pointer manipulation overhead at
	23	* the expense of O(n) removal for arbitrary elements. New elements can be
	24	* added to the list after an existing element or at the head of the list.
	25	* Elements being removed from the head of the list should use the explicit
	26	* macro for this purpose for optimum efficiency. A singly-linked list may
	27	* only be traversed in the forward direction. Singly-linked lists are ideal
	28	* for applications with large datasets and few or no removals or for
	29	* implementing a LIFO queue.
	30	*
	31	* A singly-linked tail queue is headed by a pair of pointers, one to the
	32	* head of the list and the other to the tail of the list. The elements are
	33	* singly linked for minimum space and pointer manipulation overhead at the
	34	* expense of O(n) removal for arbitrary elements. New elements can be added
	35	* to the list after an existing element, at the head of the list, or at the
	36	* end of the list. Elements being removed from the head of the tail queue
	37	* should use the explicit macro for this purpose for optimum efficiency.
	38	* A singly-linked tail queue may only be traversed in the forward direction.
	39	* Singly-linked tail queues are ideal for applications with large datasets
	40	* and few or no removals or for implementing a FIFO queue.
	41	*
	42	* A list is headed by a single forward pointer (or an array of forward
	43	* pointers for a hash table header). The elements are doubly linked
	44	* so that an arbitrary element can be removed without a need to
	45	* traverse the list. New elements can be added to the list before
	46	* or after an existing element or at the head of the list. A list
	47	* may only be traversed in the forward direction.
	48	*
	49	* A tail queue is headed by a pair of pointers, one to the head of the
	50	* list and the other to the tail of the list. The elements are doubly
	51	* linked so that an arbitrary element can be removed without a need to
	52	* traverse the list. New elements can be added to the list before or
	53	* after an existing element, at the head of the list, or at the end of
	54	* the list. A tail queue may be traversed in either direction.
	55	*
	56	* For details on the use of these macros, see the queue(3) manual page.
	57	*
	58	*
	59	* SLIST LIST STAILQ TAILQ
	60	* _HEAD + + + +
	61	* _HEAD_INITIALIZER + + + +
	62	* _ENTRY + + + +
	63	* _INIT + + + +
	64	* _EMPTY + + + +
	65	* _FIRST + + + +
	66	* _NEXT + + + +
	67	* _PREV - - - +
	68	* _LAST - - + +
	69	* _FOREACH + + + +
	70	* _FOREACH_SAFE + + + +
	71	* _FOREACH_REVERSE - - - +
	72	* _FOREACH_REVERSE_SAFE - - - +
	73	* _INSERT_HEAD + + + +
	74	* _INSERT_BEFORE - + - +
	75	* _INSERT_AFTER + + + +
	76	* _INSERT_TAIL - - + +
	77	* _CONCAT - - + +
	78	* _REMOVE_AFTER + - + -
	79	* _REMOVE_HEAD + - + -
	80	* _REMOVE + + + +
81	* _SWAP + + + +
82	*
83	*/
84	#ifdef QUEUE_MACRO_DEBUG
85	/* Store the last 2 places the queue element or head was altered */
86	struct qm_trace {
87	char *lastfile;
88	int lastline;
89	char *prevfile;
90	int prevline;
91	};
92
93	#define TRACEBUF struct qm_trace trace;
94	#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
95	#define QMD_SAVELINK(name, link) void *name = (void )&(link)
96
97	#define QMD_TRACE_HEAD(head) \
98	do { \
99	(head)->trace.prevline = (head)->trace.lastline; \
100	(head)->trace.prevfile = (head)->trace.lastfile; \
101	(head)->trace.lastline = __LINE__; \
102	(head)->trace.lastfile = __FILE__; \
103	} while (0)
104
105	#define QMD_TRACE_ELEM(elem) \
106	do { \
107	(elem)->trace.prevline = (elem)->trace.lastline; \
108	(elem)->trace.prevfile = (elem)->trace.lastfile; \
109	(elem)->trace.lastline = __LINE__; \
110	(elem)->trace.lastfile = __FILE__; \
111	} while (0)
112
113	#else
114	#define QMD_TRACE_ELEM(elem)
115	#define QMD_TRACE_HEAD(head)
116	#define QMD_SAVELINK(name, link)
117	#define TRACEBUF
118	#define TRASHIT(x)
119	#endif /* QUEUE_MACRO_DEBUG */
120
121	/*
122	* Singly-linked List declarations.
123	*/
124	#define SLIST_HEAD(name, type) \
125	struct name { \
126	struct type slh_first; / first element */ \
127	}
128
129	#define SLIST_HEAD_INITIALIZER(head) \
130	{ \
131	NULL \
132	}
133
134	#define SLIST_ENTRY(type) \
135	struct { \
136	struct type sle_next; / next element */ \
137	}
138
139	/*
140	* Singly-linked List functions.
141	*/
142	#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
143
144	#define SLIST_FIRST(head) ((head)->slh_first)
145
146	#define SLIST_FOREACH(var, head, field) \
147	for ((var) = SLIST_FIRST((head)); (var); \
148	(var) = SLIST_NEXT((var), field))
149
150	#define SLIST_FOREACH_SAFE(var, head, field, tvar) \
151	for ((var) = SLIST_FIRST((head)); \
152	(var) && ((tvar) = SLIST_NEXT((var), field), 1); (var) = (tvar))
153
154	#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
155	for ((varp) = &SLIST_FIRST((head)); ((var) = *(varp)) != NULL; \
156	(varp) = &SLIST_NEXT((var), field))
157
158	#define SLIST_INIT(head) \
159	do { \
160	SLIST_FIRST((head)) = NULL; \
161	} while (0)
162
163	#define SLIST_INSERT_AFTER(slistelm, elm, field) \
164	do { \
165	SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
166	SLIST_NEXT((slistelm), field) = (elm); \
167	} while (0)
168
169	#define SLIST_INSERT_HEAD(head, elm, field) \
170	do { \
171	SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
172	SLIST_FIRST((head)) = (elm); \
173	} while (0)
174
175	#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
176
177	#define SLIST_REMOVE(head, elm, type, field) \
178	do { \
179	QMD_SAVELINK(oldnext, (elm)->field.sle_next); \
180	if (SLIST_FIRST((head)) == (elm)) { \
181	SLIST_REMOVE_HEAD((head), field); \
182	} else { \
183	struct type *curelm = SLIST_FIRST((head)); \
184	while (SLIST_NEXT(curelm, field) != (elm)) \
185	curelm = SLIST_NEXT(curelm, field); \
186	SLIST_REMOVE_AFTER(curelm, field); \
187	} \
188	TRASHIT(*oldnext); \
189	} while (0)
190
191	#define SLIST_REMOVE_AFTER(elm, field) \
192	do { \
193	SLIST_NEXT(elm, field) = \
194	SLIST_NEXT(SLIST_NEXT(elm, field), field); \
195	} while (0)
196
197	#define SLIST_REMOVE_HEAD(head, field) \
198	do { \
199	SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
200	} while (0)
201
202	#define SLIST_SWAP(head1, head2, type) \
203	do { \
204	struct type *swap_first = SLIST_FIRST(head1); \
205	SLIST_FIRST(head1) = SLIST_FIRST(head2); \
206	SLIST_FIRST(head2) = swap_first; \
207	} while (0)
208
209	/*
210	* Singly-linked Tail queue declarations.
211	*/
212	#define STAILQ_HEAD(name, type) \
213	struct name { \
214	struct type stqh_first; / first element */ \
215	struct type *stqh_last; / addr of last next element */ \
216	}
217
218	#define STAILQ_HEAD_INITIALIZER(head) \
219	{ \
220	NULL, &(head).stqh_first \
221	}
222
223	#define STAILQ_ENTRY(type) \
224	struct { \
225	struct type stqe_next; / next element */ \
226	}
227
228	/*
229	* Singly-linked Tail queue functions.
230	*/
231	#define STAILQ_CONCAT(head1, head2) \
232	do { \
233	if (!STAILQ_EMPTY((head2))) { \
234	*(head1)->stqh_last = (head2)->stqh_first; \
235	(head1)->stqh_last = (head2)->stqh_last; \
236	STAILQ_INIT((head2)); \
237	} \
238	} while (0)
239
240	#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
241
242	#define STAILQ_FIRST(head) ((head)->stqh_first)
243
244	#define STAILQ_FOREACH(var, head, field) \
245	for ((var) = STAILQ_FIRST((head)); (var); \
246	(var) = STAILQ_NEXT((var), field))
247
248
249	#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
250	for ((var) = STAILQ_FIRST((head)); \
251	(var) && ((tvar) = STAILQ_NEXT((var), field), 1); (var) = (tvar))
252
253	#define STAILQ_INIT(head) \
254	do { \
255	STAILQ_FIRST((head)) = NULL; \
256	(head)->stqh_last = &STAILQ_FIRST((head)); \
257	} while (0)
258
259	#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) \
260	do { \
261	if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) \
262	== NULL) \
263	(head)->stqh_last = &STAILQ_NEXT((elm), field); \
264	STAILQ_NEXT((tqelm), field) = (elm); \
265	} while (0)
266
267	#define STAILQ_INSERT_HEAD(head, elm, field) \
268	do { \
269	if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) \
270	== NULL) \
271	(head)->stqh_last = &STAILQ_NEXT((elm), field); \
272	STAILQ_FIRST((head)) = (elm); \
273	} while (0)
274
275	#define STAILQ_INSERT_TAIL(head, elm, field) \
276	do { \
277	STAILQ_NEXT((elm), field) = NULL; \
278	*(head)->stqh_last = (elm); \
279	(head)->stqh_last = &STAILQ_NEXT((elm), field); \
280	} while (0)
281
282	#define STAILQ_LAST(head, type, field) \
283	(STAILQ_EMPTY((head)) \
284	? NULL \
285	: ((struct type )(void )((char *)((head)->stqh_last) \
996c9314	286	- offsetof(struct type, field))))
cd85bc2e JB	287
	288	#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
	289
	290	#define STAILQ_REMOVE(head, elm, type, field) \
	291	do { \
	292	QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
	293	if (STAILQ_FIRST((head)) == (elm)) { \
	294	STAILQ_REMOVE_HEAD((head), field); \
	295	} else { \
	296	struct type *curelm = STAILQ_FIRST((head)); \
	297	while (STAILQ_NEXT(curelm, field) != (elm)) \
	298	curelm = STAILQ_NEXT(curelm, field); \
	299	STAILQ_REMOVE_AFTER(head, curelm, field); \
	300	} \
	301	TRASHIT(*oldnext); \
	302	} while (0)
	303
	304	#define STAILQ_REMOVE_AFTER(head, elm, field) \
	305	do { \
	306	if ((STAILQ_NEXT(elm, field) = \
	307	STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) \
	308	== NULL) \
	309	(head)->stqh_last = &STAILQ_NEXT((elm), field); \
	310	} while (0)
	311
	312	#define STAILQ_REMOVE_HEAD(head, field) \
	313	do { \
	314	if ((STAILQ_FIRST((head)) = \
	315	STAILQ_NEXT(STAILQ_FIRST((head)), field)) \
	316	== NULL) \
	317	(head)->stqh_last = &STAILQ_FIRST((head)); \
	318	} while (0)
	319
	320	#define STAILQ_SWAP(head1, head2, type) \
	321	do { \
	322	struct type *swap_first = STAILQ_FIRST(head1); \
	323	struct type **swap_last = (head1)->stqh_last; \
	324	STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
	325	(head1)->stqh_last = (head2)->stqh_last; \
	326	STAILQ_FIRST(head2) = swap_first; \
	327	(head2)->stqh_last = swap_last; \
	328	if (STAILQ_EMPTY(head1)) \
	329	(head1)->stqh_last = &STAILQ_FIRST(head1); \
	330	if (STAILQ_EMPTY(head2)) \
	331	(head2)->stqh_last = &STAILQ_FIRST(head2); \
	332	} while (0)
	333
	334
	335	/*
	336	* List declarations.
	337	*/
	338	#define LIST_HEAD(name, type) \
	339	struct name { \
	340	struct type lh_first; / first element */ \
	341	}
	342
	343	#define LIST_HEAD_INITIALIZER(head) \
	344	{ \
	345	NULL \
	346	}
	347
	348	#define LIST_ENTRY(type) \
	349	struct { \
	350	struct type le_next; / next element */ \
351	struct type *le_prev; / address of previous next element */ \
352	}
353
354	/*
355	* List functions.
356	*/
357
358	#if (defined(_KERNEL) && defined(INVARIANTS))
359	#define QMD_LIST_CHECK_HEAD(head, field) \
360	do { \
361	if (LIST_FIRST((head)) != NULL \
362	&& LIST_FIRST((head))->field.le_prev \
363	!= &LIST_FIRST((head))) \
364	panic("Bad list head %p first->prev != head", (head)); \
365	} while (0)
366
367	#define QMD_LIST_CHECK_NEXT(elm, field) \
368	do { \
369	if (LIST_NEXT((elm), field) != NULL \
370	&& LIST_NEXT((elm), field)->field.le_prev \
371	!= &((elm)->field.le_next)) \
372	panic("Bad link elm %p next->prev != elm", (elm)); \
373	} while (0)
374
375	#define QMD_LIST_CHECK_PREV(elm, field) \
376	do { \
377	if (*(elm)->field.le_prev != (elm)) \
378	panic("Bad link elm %p prev->next != elm", (elm)); \
379	} while (0)
380	#else
381	#define QMD_LIST_CHECK_HEAD(head, field)
382	#define QMD_LIST_CHECK_NEXT(elm, field)
383	#define QMD_LIST_CHECK_PREV(elm, field)
384	#endif /* (_KERNEL && INVARIANTS) */
385
386	#define LIST_EMPTY(head) ((head)->lh_first == NULL)
387
388	#define LIST_FIRST(head) ((head)->lh_first)
389
390	#define LIST_FOREACH(var, head, field) \
391	for ((var) = LIST_FIRST((head)); (var); (var) = LIST_NEXT((var), field))
392
393	#define LIST_FOREACH_SAFE(var, head, field, tvar) \
394	for ((var) = LIST_FIRST((head)); \
395	(var) && ((tvar) = LIST_NEXT((var), field), 1); (var) = (tvar))
396
397	#define LIST_INIT(head) \
398	do { \
399	LIST_FIRST((head)) = NULL; \
400	} while (0)
401
402	#define LIST_INSERT_AFTER(listelm, elm, field) \
403	do { \
404	QMD_LIST_CHECK_NEXT(listelm, field); \
405	if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) \
406	!= NULL) \
407	LIST_NEXT((listelm), field)->field.le_prev = \
408	&LIST_NEXT((elm), field); \
409	LIST_NEXT((listelm), field) = (elm); \
410	(elm)->field.le_prev = &LIST_NEXT((listelm), field); \
411	} while (0)
412
413	#define LIST_INSERT_BEFORE(listelm, elm, field) \
414	do { \
415	QMD_LIST_CHECK_PREV(listelm, field); \
416	(elm)->field.le_prev = (listelm)->field.le_prev; \
417	LIST_NEXT((elm), field) = (listelm); \
418	*(listelm)->field.le_prev = (elm); \
419	(listelm)->field.le_prev = &LIST_NEXT((elm), field); \
420	} while (0)
421
422	#define LIST_INSERT_HEAD(head, elm, field) \
423	do { \
424	QMD_LIST_CHECK_HEAD((head), field); \
425	if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
426	LIST_FIRST((head))->field.le_prev = \
427	&LIST_NEXT((elm), field); \
428	LIST_FIRST((head)) = (elm); \
429	(elm)->field.le_prev = &LIST_FIRST((head)); \
430	} while (0)
431
432	#define LIST_NEXT(elm, field) ((elm)->field.le_next)
433
434	#define LIST_REMOVE(elm, field) \
435	do { \
436	QMD_SAVELINK(oldnext, (elm)->field.le_next); \
437	QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
438	QMD_LIST_CHECK_NEXT(elm, field); \
439	QMD_LIST_CHECK_PREV(elm, field); \
440	if (LIST_NEXT((elm), field) != NULL) \
441	LIST_NEXT((elm), field)->field.le_prev = \
442	(elm)->field.le_prev; \
443	*(elm)->field.le_prev = LIST_NEXT((elm), field); \
444	TRASHIT(*oldnext); \
445	TRASHIT(*oldprev); \
446	} while (0)
447
448	#define LIST_SWAP(head1, head2, type, field) \
449	do { \
450	struct type *swap_tmp = LIST_FIRST((head1)); \
451	LIST_FIRST((head1)) = LIST_FIRST((head2)); \
452	LIST_FIRST((head2)) = swap_tmp; \
453	if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
454	swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
455	if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
456	swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
457	} while (0)
458
459	/*
460	* Tail queue declarations.
461	*/
462	#define TAILQ_HEAD(name, type) \
463	struct name { \
464	struct type tqh_first; / first element */ \
465	struct type *tqh_last; / addr of last next element */ \
466	TRACEBUF \
467	}
468
469	#define TAILQ_HEAD_INITIALIZER(head) \
470	{ \
471	NULL, &(head).tqh_first \
472	}
473
474	#define TAILQ_ENTRY(type) \
475	struct { \
476	struct type tqe_next; / next element */ \
477	struct type *tqe_prev; / address of previous next element */ \
478	TRACEBUF \
479	}
480
481	/*
482	* Tail queue functions.
483	*/
484	#if (defined(_KERNEL) && defined(INVARIANTS))
485	#define QMD_TAILQ_CHECK_HEAD(head, field) \
486	do { \
487	if (!TAILQ_EMPTY(head) \
488	&& TAILQ_FIRST((head))->field.tqe_prev \
489	!= &TAILQ_FIRST((head))) \
490	panic("Bad tailq head %p first->prev != head", \
491	(head)); \
492	} while (0)
493
494	#define QMD_TAILQ_CHECK_TAIL(head, field) \
495	do { \
496	if (*(head)->tqh_last != NULL) \
497	panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
498	} while (0)
499
500	#define QMD_TAILQ_CHECK_NEXT(elm, field) \
501	do { \
502	if (TAILQ_NEXT((elm), field) != NULL \
503	&& TAILQ_NEXT((elm), field)->field.tqe_prev \
504	!= &((elm)->field.tqe_next)) \
505	panic("Bad link elm %p next->prev != elm", (elm)); \
506	} while (0)
507
508	#define QMD_TAILQ_CHECK_PREV(elm, field) \
509	do { \
510	if (*(elm)->field.tqe_prev != (elm)) \
511	panic("Bad link elm %p prev->next != elm", (elm)); \
512	} while (0)
513	#else
514	#define QMD_TAILQ_CHECK_HEAD(head, field)
515	#define QMD_TAILQ_CHECK_TAIL(head, headname)
516	#define QMD_TAILQ_CHECK_NEXT(elm, field)
517	#define QMD_TAILQ_CHECK_PREV(elm, field)
518	#endif /* (_KERNEL && INVARIANTS) */
519
520	#define TAILQ_CONCAT(head1, head2, field) \
521	do { \
522	if (!TAILQ_EMPTY(head2)) { \
523	*(head1)->tqh_last = (head2)->tqh_first; \
524	(head2)->tqh_first->field.tqe_prev = \
525	(head1)->tqh_last; \
526	(head1)->tqh_last = (head2)->tqh_last; \
527	TAILQ_INIT((head2)); \
528	QMD_TRACE_HEAD(head1); \
529	QMD_TRACE_HEAD(head2); \
530	} \
531	} while (0)
532
533	#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
534
535	#define TAILQ_FIRST(head) ((head)->tqh_first)
536
537	#define TAILQ_FOREACH(var, head, field) \
538	for ((var) = TAILQ_FIRST((head)); (var); \
539	(var) = TAILQ_NEXT((var), field))
540
541	#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
542	for ((var) = TAILQ_FIRST((head)); \
543	(var) && ((tvar) = TAILQ_NEXT((var), field), 1); (var) = (tvar))
544
545	#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
546	for ((var) = TAILQ_LAST((head), headname); (var); \
547	(var) = TAILQ_PREV((var), headname, field))
548
549	#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
550	for ((var) = TAILQ_LAST((head), headname); \
551	(var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
552	(var) = (tvar))
553
554	#define TAILQ_INIT(head) \
555	do { \
556	TAILQ_FIRST((head)) = NULL; \
557	(head)->tqh_last = &TAILQ_FIRST((head)); \
558	QMD_TRACE_HEAD(head); \
559	} while (0)
560
561	#define TAILQ_INSERT_AFTER(head, listelm, elm, field) \
562	do { \
563	QMD_TAILQ_CHECK_NEXT(listelm, field); \
564	if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) \
565	!= NULL) \
566	TAILQ_NEXT((elm), field)->field.tqe_prev = \
567	&TAILQ_NEXT((elm), field); \
568	else { \
569	(head)->tqh_last = &TAILQ_NEXT((elm), field); \
570	QMD_TRACE_HEAD(head); \
571	} \
572	TAILQ_NEXT((listelm), field) = (elm); \
573	(elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
574	QMD_TRACE_ELEM(&(elm)->field); \
575	QMD_TRACE_ELEM(&listelm->field); \
576	} while (0)
577
578	#define TAILQ_INSERT_BEFORE(listelm, elm, field) \
579	do { \
580	QMD_TAILQ_CHECK_PREV(listelm, field); \
581	(elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
582	TAILQ_NEXT((elm), field) = (listelm); \
583	*(listelm)->field.tqe_prev = (elm); \
584	(listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
585	QMD_TRACE_ELEM(&(elm)->field); \
586	QMD_TRACE_ELEM(&listelm->field); \
587	} while (0)
588
589	#define TAILQ_INSERT_HEAD(head, elm, field) \
590	do { \
591	QMD_TAILQ_CHECK_HEAD(head, field); \
592	if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
593	TAILQ_FIRST((head))->field.tqe_prev = \
594	&TAILQ_NEXT((elm), field); \
595	else \
596	(head)->tqh_last = &TAILQ_NEXT((elm), field); \
597	TAILQ_FIRST((head)) = (elm); \
598	(elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
599	QMD_TRACE_HEAD(head); \
600	QMD_TRACE_ELEM(&(elm)->field); \
601	} while (0)
602
603	#define TAILQ_INSERT_TAIL(head, elm, field) \
604	do { \
605	QMD_TAILQ_CHECK_TAIL(head, field); \
606	TAILQ_NEXT((elm), field) = NULL; \
607	(elm)->field.tqe_prev = (head)->tqh_last; \
608	*(head)->tqh_last = (elm); \
609	(head)->tqh_last = &TAILQ_NEXT((elm), field); \
610	QMD_TRACE_HEAD(head); \
611	QMD_TRACE_ELEM(&(elm)->field); \
612	} while (0)
613
614	#define TAILQ_LAST(head, headname) \
615	((((struct headname )((head)->tqh_last))->tqh_last))
616
617	#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
618
619	#define TAILQ_PREV(elm, headname, field) \
620	((((struct headname )((elm)->field.tqe_prev))->tqh_last))
621
622	#define TAILQ_REMOVE(head, elm, field) \
623	do { \
624	QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
625	QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
626	QMD_TAILQ_CHECK_NEXT(elm, field); \
627	QMD_TAILQ_CHECK_PREV(elm, field); \
628	if ((TAILQ_NEXT((elm), field)) != NULL) \
629	TAILQ_NEXT((elm), field)->field.tqe_prev = \
630	(elm)->field.tqe_prev; \
631	else { \
632	(head)->tqh_last = (elm)->field.tqe_prev; \
633	QMD_TRACE_HEAD(head); \
634	} \
635	*(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
636	TRASHIT(*oldnext); \
637	TRASHIT(*oldprev); \
638	QMD_TRACE_ELEM(&(elm)->field); \
639	} while (0)
640
641	#define TAILQ_SWAP(head1, head2, type, field) \
642	do { \
643	struct type *swap_first = (head1)->tqh_first; \
644	struct type **swap_last = (head1)->tqh_last; \
645	(head1)->tqh_first = (head2)->tqh_first; \
646	(head1)->tqh_last = (head2)->tqh_last; \
647	(head2)->tqh_first = swap_first; \
648	(head2)->tqh_last = swap_last; \
649	if ((swap_first = (head1)->tqh_first) != NULL) \
650	swap_first->field.tqe_prev = &(head1)->tqh_first; \
651	else \
652	(head1)->tqh_last = &(head1)->tqh_first; \
653	if ((swap_first = (head2)->tqh_first) != NULL) \
654	swap_first->field.tqe_prev = &(head2)->tqh_first; \
655	else \
656	(head2)->tqh_last = &(head2)->tqh_first; \
657	} while (0)
658
5e244469 RW	659	#ifdef __cplusplus
	660	}
	661	#endif
	662
cd85bc2e	663	#endif /* !_SYS_QUEUE_H_ */