| /* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */ |
| |
| /* |
| * slirp version: Copy from QEMU, removed all but tail queues. |
| */ |
| |
| /* |
| * 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 QTAILQ_H |
| #define QTAILQ_H |
| |
| /* |
| * 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. |
| */ |
| typedef struct QTailQLink { |
| void *tql_next; |
| struct QTailQLink *tql_prev; |
| } QTailQLink; |
| |
| /* |
| * Tail queue definitions. The union acts as a poor man template, as if |
| * it were QTailQLink<type>. |
| */ |
| #define QTAILQ_HEAD(name, type) \ |
| union name { \ |
| struct type *tqh_first; /* first element */ \ |
| QTailQLink tqh_circ; /* link for circular backwards list */ \ |
| } |
| |
| #define QTAILQ_HEAD_INITIALIZER(head) \ |
| { .tqh_circ = { NULL, &(head).tqh_circ } } |
| |
| #define QTAILQ_ENTRY(type) \ |
| union { \ |
| struct type *tqe_next; /* next element */ \ |
| QTailQLink tqe_circ; /* link for circular backwards list */ \ |
| } |
| |
| #define QTAILQ_INIT(head) do { \ |
| (head)->tqh_first = NULL; \ |
| (head)->tqh_circ.tql_prev = &(head)->tqh_circ; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_INSERT_HEAD(head, elm, field) do { \ |
| if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ |
| (head)->tqh_first->field.tqe_circ.tql_prev = \ |
| &(elm)->field.tqe_circ; \ |
| else \ |
| (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ |
| (head)->tqh_first = (elm); \ |
| (elm)->field.tqe_circ.tql_prev = &(head)->tqh_circ; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_INSERT_TAIL(head, elm, field) do { \ |
| (elm)->field.tqe_next = NULL; \ |
| (elm)->field.tqe_circ.tql_prev = (head)->tqh_circ.tql_prev; \ |
| (head)->tqh_circ.tql_prev->tql_next = (elm); \ |
| (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
| if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ |
| (elm)->field.tqe_next->field.tqe_circ.tql_prev = \ |
| &(elm)->field.tqe_circ; \ |
| else \ |
| (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ |
| (listelm)->field.tqe_next = (elm); \ |
| (elm)->field.tqe_circ.tql_prev = &(listelm)->field.tqe_circ; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \ |
| (elm)->field.tqe_circ.tql_prev = (listelm)->field.tqe_circ.tql_prev; \ |
| (elm)->field.tqe_next = (listelm); \ |
| (listelm)->field.tqe_circ.tql_prev->tql_next = (elm); \ |
| (listelm)->field.tqe_circ.tql_prev = &(elm)->field.tqe_circ; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_REMOVE(head, elm, field) do { \ |
| if (((elm)->field.tqe_next) != NULL) \ |
| (elm)->field.tqe_next->field.tqe_circ.tql_prev = \ |
| (elm)->field.tqe_circ.tql_prev; \ |
| else \ |
| (head)->tqh_circ.tql_prev = (elm)->field.tqe_circ.tql_prev; \ |
| (elm)->field.tqe_circ.tql_prev->tql_next = (elm)->field.tqe_next; \ |
| (elm)->field.tqe_circ.tql_prev = NULL; \ |
| } while (/*CONSTCOND*/0) |
| |
| #define QTAILQ_FOREACH(var, head, field) \ |
| for ((var) = ((head)->tqh_first); \ |
| (var); \ |
| (var) = ((var)->field.tqe_next)) |
| |
| #define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \ |
| for ((var) = ((head)->tqh_first); \ |
| (var) && ((next_var) = ((var)->field.tqe_next), 1); \ |
| (var) = (next_var)) |
| |
| #define QTAILQ_FOREACH_REVERSE(var, head, field) \ |
| for ((var) = QTAILQ_LAST(head); \ |
| (var); \ |
| (var) = QTAILQ_PREV(var, field)) |
| |
| #define QTAILQ_FOREACH_REVERSE_SAFE(var, head, field, prev_var) \ |
| for ((var) = QTAILQ_LAST(head); \ |
| (var) && ((prev_var) = QTAILQ_PREV(var, field)); \ |
| (var) = (prev_var)) |
| |
| /* |
| * Tail queue access methods. |
| */ |
| #define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL) |
| #define QTAILQ_FIRST(head) ((head)->tqh_first) |
| #define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next) |
| #define QTAILQ_IN_USE(elm, field) ((elm)->field.tqe_circ.tql_prev != NULL) |
| |
| #define QTAILQ_LINK_PREV(link) \ |
| ((link).tql_prev->tql_prev->tql_next) |
| #define QTAILQ_LAST(head) \ |
| ((typeof((head)->tqh_first)) QTAILQ_LINK_PREV((head)->tqh_circ)) |
| #define QTAILQ_PREV(elm, field) \ |
| ((typeof((elm)->field.tqe_next)) QTAILQ_LINK_PREV((elm)->field.tqe_circ)) |
| |
| #define field_at_offset(base, offset, type) \ |
| ((type *) (((char *) (base)) + (offset))) |
| |
| /* |
| * Raw access of elements of a tail queue head. Offsets are all zero |
| * because it's a union. |
| */ |
| #define QTAILQ_RAW_FIRST(head) \ |
| field_at_offset(head, 0, void *) |
| #define QTAILQ_RAW_TQH_CIRC(head) \ |
| field_at_offset(head, 0, QTailQLink) |
| |
| /* |
| * Raw access of elements of a tail entry |
| */ |
| #define QTAILQ_RAW_NEXT(elm, entry) \ |
| field_at_offset(elm, entry, void *) |
| #define QTAILQ_RAW_TQE_CIRC(elm, entry) \ |
| field_at_offset(elm, entry, QTailQLink) |
| /* |
| * Tail queue traversal using pointer arithmetic. |
| */ |
| #define QTAILQ_RAW_FOREACH(elm, head, entry) \ |
| for ((elm) = *QTAILQ_RAW_FIRST(head); \ |
| (elm); \ |
| (elm) = *QTAILQ_RAW_NEXT(elm, entry)) |
| /* |
| * Tail queue insertion using pointer arithmetic. |
| */ |
| #define QTAILQ_RAW_INSERT_TAIL(head, elm, entry) do { \ |
| *QTAILQ_RAW_NEXT(elm, entry) = NULL; \ |
| QTAILQ_RAW_TQE_CIRC(elm, entry)->tql_prev = QTAILQ_RAW_TQH_CIRC(head)->tql_prev; \ |
| QTAILQ_RAW_TQH_CIRC(head)->tql_prev->tql_next = (elm); \ |
| QTAILQ_RAW_TQH_CIRC(head)->tql_prev = QTAILQ_RAW_TQE_CIRC(elm, entry); \ |
| } while (/*CONSTCOND*/0) |
| |
| #endif /* QTAILQ_H */ |
