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@@ -0,0 +1,534 @@ +/* $OpenBSD: queue.h,v 1.45 2018/07/12 14:22:54 sashan 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 XOR simple 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 to 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. + * + * An XOR simple queue is used in the same way as a regular simple queue. + * The difference is that the head structure also includes a "cookie" that + * is XOR'd with the queue pointer (first, last or next) to generate the + * real pointer value. + * + * For details on the use of these macros, see the queue(3) manual page. + */ + +#if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) +#define _Q_INVALID ((void *)-1) +#define _Q_INVALIDATE(a) (a) = _Q_INVALID +#else +#define _Q_INVALIDATE(a) +#endif + +/* + * Singly-linked List definitions. + */ +#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 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)) + +#define SLIST_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = SLIST_FIRST(head); \ + (var) && ((tvar) = SLIST_NEXT(var, field), 1); \ + (var) = (tvar)) + +/* + * 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_AFTER(elm, field) do { \ + (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ +} while (0) + +#define SLIST_REMOVE_HEAD(head, field) do { \ + (head)->slh_first = (head)->slh_first->field.sle_next; \ +} while (0) + +#define SLIST_REMOVE(head, elm, type, field) do { \ + if ((head)->slh_first == (elm)) { \ + 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; \ + } \ + _Q_INVALIDATE((elm)->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)) + +#define LIST_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = LIST_FIRST(head); \ + (var) && ((tvar) = LIST_NEXT(var, field), 1); \ + (var) = (tvar)) + +/* + * 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; \ + _Q_INVALIDATE((elm)->field.le_prev); \ + _Q_INVALIDATE((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); \ + _Q_INVALIDATE((elm)->field.le_prev); \ + _Q_INVALIDATE((elm)->field.le_next); \ +} 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)) + +#define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = SIMPLEQ_FIRST(head); \ + (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \ + (var) = (tvar)) + +/* + * 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, field) do { \ + if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ + (head)->sqh_last = &(head)->sqh_first; \ +} while (0) + +#define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ + if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ + == NULL) \ + (head)->sqh_last = &(elm)->field.sqe_next; \ +} while (0) + +#define SIMPLEQ_CONCAT(head1, head2) do { \ + if (!SIMPLEQ_EMPTY((head2))) { \ + *(head1)->sqh_last = (head2)->sqh_first; \ + (head1)->sqh_last = (head2)->sqh_last; \ + SIMPLEQ_INIT((head2)); \ + } \ +} while (0) + +/* + * XOR Simple queue definitions. + */ +#define XSIMPLEQ_HEAD(name, type) \ +struct name { \ + struct type *sqx_first; /* first element */ \ + struct type **sqx_last; /* addr of last next element */ \ + unsigned long sqx_cookie; \ +} + +#define XSIMPLEQ_ENTRY(type) \ +struct { \ + struct type *sqx_next; /* next element */ \ +} + +/* + * XOR Simple queue access methods. + */ +#define XSIMPLEQ_XOR(head, ptr) ((__typeof(ptr))((head)->sqx_cookie ^ \ + (unsigned long)(ptr))) +#define XSIMPLEQ_FIRST(head) XSIMPLEQ_XOR(head, ((head)->sqx_first)) +#define XSIMPLEQ_END(head) NULL +#define XSIMPLEQ_EMPTY(head) (XSIMPLEQ_FIRST(head) == XSIMPLEQ_END(head)) +#define XSIMPLEQ_NEXT(head, elm, field) XSIMPLEQ_XOR(head, ((elm)->field.sqx_next)) + + +#define XSIMPLEQ_FOREACH(var, head, field) \ + for ((var) = XSIMPLEQ_FIRST(head); \ + (var) != XSIMPLEQ_END(head); \ + (var) = XSIMPLEQ_NEXT(head, var, field)) + +#define XSIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = XSIMPLEQ_FIRST(head); \ + (var) && ((tvar) = XSIMPLEQ_NEXT(head, var, field), 1); \ + (var) = (tvar)) + +/* + * XOR Simple queue functions. + */ +#define XSIMPLEQ_INIT(head) do { \ + arc4random_buf(&(head)->sqx_cookie, sizeof((head)->sqx_cookie)); \ + (head)->sqx_first = XSIMPLEQ_XOR(head, NULL); \ + (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ +} while (0) + +#define XSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ + if (((elm)->field.sqx_next = (head)->sqx_first) == \ + XSIMPLEQ_XOR(head, NULL)) \ + (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ + (head)->sqx_first = XSIMPLEQ_XOR(head, (elm)); \ +} while (0) + +#define XSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ + (elm)->field.sqx_next = XSIMPLEQ_XOR(head, NULL); \ + *(XSIMPLEQ_XOR(head, (head)->sqx_last)) = XSIMPLEQ_XOR(head, (elm)); \ + (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ +} while (0) + +#define XSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ + if (((elm)->field.sqx_next = (listelm)->field.sqx_next) == \ + XSIMPLEQ_XOR(head, NULL)) \ + (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ + (listelm)->field.sqx_next = XSIMPLEQ_XOR(head, (elm)); \ +} while (0) + +#define XSIMPLEQ_REMOVE_HEAD(head, field) do { \ + if (((head)->sqx_first = XSIMPLEQ_XOR(head, \ + (head)->sqx_first)->field.sqx_next) == XSIMPLEQ_XOR(head, NULL)) \ + (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ +} while (0) + +#define XSIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ + if (((elm)->field.sqx_next = XSIMPLEQ_XOR(head, \ + (elm)->field.sqx_next)->field.sqx_next) \ + == XSIMPLEQ_XOR(head, NULL)) \ + (head)->sqx_last = \ + XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ +} 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_SAFE(var, head, field, tvar) \ + for ((var) = TAILQ_FIRST(head); \ + (var) != TAILQ_END(head) && \ + ((tvar) = TAILQ_NEXT(var, field), 1); \ + (var) = (tvar)) + + +#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ + for((var) = TAILQ_LAST(head, headname); \ + (var) != TAILQ_END(head); \ + (var) = TAILQ_PREV(var, headname, field)) + +#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ + for ((var) = TAILQ_LAST(head, headname); \ + (var) != TAILQ_END(head) && \ + ((tvar) = TAILQ_PREV(var, headname, field), 1); \ + (var) = (tvar)) + +/* + * 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; \ + _Q_INVALIDATE((elm)->field.tqe_prev); \ + _Q_INVALIDATE((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); \ + _Q_INVALIDATE((elm)->field.tqe_prev); \ + _Q_INVALIDATE((elm)->field.tqe_next); \ +} while (0) + +#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)); \ + } \ +} while (0) + +#endif /* !_SYS_QUEUE_H_ */ |