tor-browser

queue.h (16674B)

---

/*	$OpenBSD: queue.h,v 1.16 2000/09/07 19:47:59 art Exp $	*/
/*	$NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $	*/

/*
* 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. 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.
*
*	@(#)queue.h	8.5 (Berkeley) 8/20/94
*/

#ifndef	SYS_QUEUE_H__
#define	SYS_QUEUE_H__

/*
* This file defines five types of data structures: singly-linked lists,
* lists, simple queues, 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 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 simple queue is headed by a pair of pointers, one the head of the
* list and the other to the tail of the list. The elements are singly
* linked to save space, so elements can only be removed from the
* head of 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 simple queue 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.
*
* 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.
*/

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

#define	SLIST_HEAD_INITIALIZER(head)					\
{ NULL }

#ifndef _WIN32
#define SLIST_ENTRY(type)						\
struct {								\
struct type *sle_next;	/* next element */			\
}
#endif

/*
* Singly-linked List access methods.
*/
#define	SLIST_FIRST(head)	((head)->slh_first)
#define	SLIST_END(head)		NULL
#define	SLIST_EMPTY(head)	(SLIST_FIRST(head) == SLIST_END(head))
#define	SLIST_NEXT(elm, field)	((elm)->field.sle_next)

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

/*
* Singly-linked List functions.
*/
#define	SLIST_INIT(head) {						\
SLIST_FIRST(head) = SLIST_END(head);				\
}

#define	SLIST_INSERT_AFTER(slistelm, elm, field) do {			\
(elm)->field.sle_next = (slistelm)->field.sle_next;		\
(slistelm)->field.sle_next = (elm);				\
} while (0)

#define	SLIST_INSERT_HEAD(head, elm, field) do {			\
(elm)->field.sle_next = (head)->slh_first;			\
(head)->slh_first = (elm);					\
} while (0)

#define	SLIST_REMOVE_HEAD(head, field) do {				\
(head)->slh_first = (head)->slh_first->field.sle_next;		\
} while (0)

/*
* List definitions.
*/
#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 access methods
*/
#define	LIST_FIRST(head)		((head)->lh_first)
#define	LIST_END(head)			NULL
#define	LIST_EMPTY(head)		(LIST_FIRST(head) == LIST_END(head))
#define	LIST_NEXT(elm, field)		((elm)->field.le_next)

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

/*
* List functions.
*/
#define	LIST_INIT(head) do {						\
LIST_FIRST(head) = LIST_END(head);				\
} while (0)

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

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

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

#define LIST_REMOVE(elm, field) do {					\
if ((elm)->field.le_next != NULL)				\
	(elm)->field.le_next->field.le_prev =			\
	    (elm)->field.le_prev;				\
*(elm)->field.le_prev = (elm)->field.le_next;			\
} while (0)

#define LIST_REPLACE(elm, elm2, field) do {				\
if (((elm2)->field.le_next = (elm)->field.le_next) != NULL)	\
	(elm2)->field.le_next->field.le_prev =			\
	    &(elm2)->field.le_next;				\
(elm2)->field.le_prev = (elm)->field.le_prev;			\
*(elm2)->field.le_prev = (elm2);				\
} while (0)

/*
* Simple queue definitions.
*/
#define SIMPLEQ_HEAD(name, type)					\
struct name {								\
struct type *sqh_first;	/* first element */			\
struct type **sqh_last;	/* addr of last next element */		\
}

#define SIMPLEQ_HEAD_INITIALIZER(head)					\
{ NULL, &(head).sqh_first }

#define SIMPLEQ_ENTRY(type)						\
struct {								\
struct type *sqe_next;	/* next element */			\
}

/*
* Simple queue access methods.
*/
#define	SIMPLEQ_FIRST(head)	    ((head)->sqh_first)
#define	SIMPLEQ_END(head)	    NULL
#define	SIMPLEQ_EMPTY(head)	    (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
#define	SIMPLEQ_NEXT(elm, field)    ((elm)->field.sqe_next)

#define SIMPLEQ_FOREACH(var, head, field)				\
for((var) = SIMPLEQ_FIRST(head);				\
    (var) != SIMPLEQ_END(head);					\
    (var) = SIMPLEQ_NEXT(var, field))

/*
* Simple queue functions.
*/
#define	SIMPLEQ_INIT(head) do {						\
(head)->sqh_first = NULL;					\
(head)->sqh_last = &(head)->sqh_first;				\
} while (0)

#define SIMPLEQ_INSERT_HEAD(head, elm, field) do {			\
if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)	\
	(head)->sqh_last = &(elm)->field.sqe_next;		\
(head)->sqh_first = (elm);					\
} while (0)

#define SIMPLEQ_INSERT_TAIL(head, elm, field) do {			\
(elm)->field.sqe_next = NULL;					\
*(head)->sqh_last = (elm);					\
(head)->sqh_last = &(elm)->field.sqe_next;			\
} while (0)

#define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {		\
if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
	(head)->sqh_last = &(elm)->field.sqe_next;		\
(listelm)->field.sqe_next = (elm);				\
} while (0)

#define SIMPLEQ_REMOVE_HEAD(head, elm, field) do {			\
if (((head)->sqh_first = (elm)->field.sqe_next) == NULL)	\
	(head)->sqh_last = &(head)->sqh_first;			\
} while (0)

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

#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 */	\
}

/*
* tail queue access methods
*/
#define	TAILQ_FIRST(head)		((head)->tqh_first)
#define	TAILQ_END(head)			NULL
#define	TAILQ_NEXT(elm, field)		((elm)->field.tqe_next)
#define TAILQ_LAST(head, headname)					\
(*(((struct headname *)((head)->tqh_last))->tqh_last))
/* XXX */
#define TAILQ_PREV(elm, headname, field)				\
(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
#define	TAILQ_EMPTY(head)						\
(TAILQ_FIRST(head) == TAILQ_END(head))

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

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

/*
* Tail queue functions.
*/
#define	TAILQ_INIT(head) do {						\
(head)->tqh_first = NULL;					\
(head)->tqh_last = &(head)->tqh_first;				\
} while (0)

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

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

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

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

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

#define TAILQ_REPLACE(head, elm, elm2, field) do {			\
if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL)	\
	(elm2)->field.tqe_next->field.tqe_prev =		\
	    &(elm2)->field.tqe_next;				\
else								\
	(head)->tqh_last = &(elm2)->field.tqe_next;		\
(elm2)->field.tqe_prev = (elm)->field.tqe_prev;			\
*(elm2)->field.tqe_prev = (elm2);				\
} while (0)

/*
* Circular queue definitions.
*/
#define CIRCLEQ_HEAD(name, type)					\
struct name {								\
struct type *cqh_first;		/* first element */		\
struct type *cqh_last;		/* last element */		\
}

#define CIRCLEQ_HEAD_INITIALIZER(head)					\
{ CIRCLEQ_END(&head), CIRCLEQ_END(&head) }

#define CIRCLEQ_ENTRY(type)						\
struct {								\
struct type *cqe_next;		/* next element */		\
struct type *cqe_prev;		/* previous element */		\
}

/*
* Circular queue access methods
*/
#define	CIRCLEQ_FIRST(head)		((head)->cqh_first)
#define	CIRCLEQ_LAST(head)		((head)->cqh_last)
#define	CIRCLEQ_END(head)		((void *)(head))
#define	CIRCLEQ_NEXT(elm, field)	((elm)->field.cqe_next)
#define	CIRCLEQ_PREV(elm, field)	((elm)->field.cqe_prev)
#define	CIRCLEQ_EMPTY(head)						\
(CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))

#define CIRCLEQ_FOREACH(var, head, field)				\
for((var) = CIRCLEQ_FIRST(head);				\
    (var) != CIRCLEQ_END(head);					\
    (var) = CIRCLEQ_NEXT(var, field))

#define CIRCLEQ_FOREACH_REVERSE(var, head, field)			\
for((var) = CIRCLEQ_LAST(head);					\
    (var) != CIRCLEQ_END(head);					\
    (var) = CIRCLEQ_PREV(var, field))

/*
* Circular queue functions.
*/
#define	CIRCLEQ_INIT(head) do {						\
(head)->cqh_first = CIRCLEQ_END(head);				\
(head)->cqh_last = CIRCLEQ_END(head);				\
} while (0)

#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {		\
(elm)->field.cqe_next = (listelm)->field.cqe_next;		\
(elm)->field.cqe_prev = (listelm);				\
if ((listelm)->field.cqe_next == CIRCLEQ_END(head))		\
	(head)->cqh_last = (elm);				\
else								\
	(listelm)->field.cqe_next->field.cqe_prev = (elm);	\
(listelm)->field.cqe_next = (elm);				\
} while (0)

#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {		\
(elm)->field.cqe_next = (listelm);				\
(elm)->field.cqe_prev = (listelm)->field.cqe_prev;		\
if ((listelm)->field.cqe_prev == CIRCLEQ_END(head))		\
	(head)->cqh_first = (elm);				\
else								\
	(listelm)->field.cqe_prev->field.cqe_next = (elm);	\
(listelm)->field.cqe_prev = (elm);				\
} while (0)

#define CIRCLEQ_INSERT_HEAD(head, elm, field) do {			\
(elm)->field.cqe_next = (head)->cqh_first;			\
(elm)->field.cqe_prev = CIRCLEQ_END(head);			\
if ((head)->cqh_last == CIRCLEQ_END(head))			\
	(head)->cqh_last = (elm);				\
else								\
	(head)->cqh_first->field.cqe_prev = (elm);		\
(head)->cqh_first = (elm);					\
} while (0)

#define CIRCLEQ_INSERT_TAIL(head, elm, field) do {			\
(elm)->field.cqe_next = CIRCLEQ_END(head);			\
(elm)->field.cqe_prev = (head)->cqh_last;			\
if ((head)->cqh_first == CIRCLEQ_END(head))			\
	(head)->cqh_first = (elm);				\
else								\
	(head)->cqh_last->field.cqe_next = (elm);		\
(head)->cqh_last = (elm);					\
} while (0)

#define	CIRCLEQ_REMOVE(head, elm, field) do {				\
if ((elm)->field.cqe_next == CIRCLEQ_END(head))			\
	(head)->cqh_last = (elm)->field.cqe_prev;		\
else								\
	(elm)->field.cqe_next->field.cqe_prev =			\
	    (elm)->field.cqe_prev;				\
if ((elm)->field.cqe_prev == CIRCLEQ_END(head))			\
	(head)->cqh_first = (elm)->field.cqe_next;		\
else								\
	(elm)->field.cqe_prev->field.cqe_next =			\
	    (elm)->field.cqe_next;				\
} while (0)

#define CIRCLEQ_REPLACE(head, elm, elm2, field) do {			\
if (((elm2)->field.cqe_next = (elm)->field.cqe_next) ==		\
    CIRCLEQ_END(head))						\
	(head).cqh_last = (elm2);				\
else								\
	(elm2)->field.cqe_next->field.cqe_prev = (elm2);	\
if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) ==		\
    CIRCLEQ_END(head))						\
	(head).cqh_first = (elm2);				\
else								\
	(elm2)->field.cqe_prev->field.cqe_next = (elm2);	\
} while (0)

#endif	/* !SYS_QUEUE_H__ */