1168515Sgshapiro/* $OpenBSD: queue.h,v 1.30 2005/10/25 06:37:47 otto Exp $ */ 2168515Sgshapiro/* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 3168515Sgshapiro 4168515Sgshapiro/* 5168515Sgshapiro * Copyright (c) 1991, 1993 6168515Sgshapiro * The Regents of the University of California. All rights reserved. 7168515Sgshapiro * 8168515Sgshapiro * Redistribution and use in source and binary forms, with or without 9168515Sgshapiro * modification, are permitted provided that the following conditions 10168515Sgshapiro * are met: 11168515Sgshapiro * 1. Redistributions of source code must retain the above copyright 12168515Sgshapiro * notice, this list of conditions and the following disclaimer. 13168515Sgshapiro * 2. Redistributions in binary form must reproduce the above copyright 14168515Sgshapiro * notice, this list of conditions and the following disclaimer in the 15168515Sgshapiro * documentation and/or other materials provided with the distribution. 16168515Sgshapiro * 3. Neither the name of the University nor the names of its contributors 17168515Sgshapiro * may be used to endorse or promote products derived from this software 18168515Sgshapiro * without specific prior written permission. 19168515Sgshapiro * 20168515Sgshapiro * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21168515Sgshapiro * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22168515Sgshapiro * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23168515Sgshapiro * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24168515Sgshapiro * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25168515Sgshapiro * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26168515Sgshapiro * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27168515Sgshapiro * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28168515Sgshapiro * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29168515Sgshapiro * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30168515Sgshapiro * SUCH DAMAGE. 31168515Sgshapiro * 32168515Sgshapiro * @(#)queue.h 8.5 (Berkeley) 8/20/94 33168515Sgshapiro */ 34168515Sgshapiro 35168515Sgshapiro#ifndef SM_TAILQ_H_ 36168515Sgshapiro#define SM_TAILQ_H_ 37168515Sgshapiro 38168515Sgshapiro/* 39266692Sgshapiro * $Id: tailq.h,v 1.3 2012-01-21 00:12:14 ashish Exp $ 40173340Sgshapiro * 41168515Sgshapiro * This file is a modified copy of queue.h from a BSD system: 42168515Sgshapiro * we only need tail queues here. 43173340Sgshapiro * We do not use queue.h directly because there is a conflict with 44173340Sgshapiro * some versions of that file on some OSs. 45168515Sgshapiro * 46168515Sgshapiro * A tail queue is headed by a pair of pointers, one to the head of the 47168515Sgshapiro * list and the other to the tail of the list. The elements are doubly 48168515Sgshapiro * linked so that an arbitrary element can be removed without a need to 49168515Sgshapiro * traverse the list. New elements can be added to the list before or 50168515Sgshapiro * after an existing element, at the head of the list, or at the end of 51168515Sgshapiro * the list. A tail queue may be traversed in either direction. 52168515Sgshapiro */ 53168515Sgshapiro 54168515Sgshapiro/* 55168515Sgshapiro * Tail queue definitions. 56168515Sgshapiro */ 57168515Sgshapiro#define SM_TAILQ_HEAD(name, type) \ 58168515Sgshapirostruct name { \ 59168515Sgshapiro struct type *tqh_first; /* first element */ \ 60168515Sgshapiro struct type **tqh_last; /* addr of last next element */ \ 61168515Sgshapiro} 62168515Sgshapiro 63168515Sgshapiro#define SM_TAILQ_HEAD_INITIALIZER(head) \ 64168515Sgshapiro { NULL, &(head).tqh_first } 65168515Sgshapiro 66168515Sgshapiro#define SM_TAILQ_ENTRY(type) \ 67168515Sgshapirostruct { \ 68168515Sgshapiro struct type *tqe_next; /* next element */ \ 69168515Sgshapiro struct type **tqe_prev; /* address of previous next element */ \ 70168515Sgshapiro} 71168515Sgshapiro 72244833Sgshapiro/* 73244833Sgshapiro * tail queue access methods 74168515Sgshapiro */ 75168515Sgshapiro#define SM_TAILQ_FIRST(head) ((head)->tqh_first) 76168515Sgshapiro#define SM_TAILQ_END(head) NULL 77168515Sgshapiro#define SM_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 78168515Sgshapiro#define SM_TAILQ_LAST(head, headname) \ 79168515Sgshapiro (*(((struct headname *)((head)->tqh_last))->tqh_last)) 80168515Sgshapiro/* XXX */ 81168515Sgshapiro#define SM_TAILQ_PREV(elm, headname, field) \ 82168515Sgshapiro (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 83168515Sgshapiro#define SM_TAILQ_EMPTY(head) \ 84168515Sgshapiro (SM_TAILQ_FIRST(head) == SM_TAILQ_END(head)) 85168515Sgshapiro 86168515Sgshapiro#define SM_TAILQ_FOREACH(var, head, field) \ 87168515Sgshapiro for((var) = SM_TAILQ_FIRST(head); \ 88168515Sgshapiro (var) != SM_TAILQ_END(head); \ 89168515Sgshapiro (var) = SM_TAILQ_NEXT(var, field)) 90168515Sgshapiro 91168515Sgshapiro#define SM_TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 92168515Sgshapiro for((var) = SM_TAILQ_LAST(head, headname); \ 93168515Sgshapiro (var) != SM_TAILQ_END(head); \ 94168515Sgshapiro (var) = SM_TAILQ_PREV(var, headname, field)) 95168515Sgshapiro 96168515Sgshapiro/* 97168515Sgshapiro * Tail queue functions. 98168515Sgshapiro */ 99168515Sgshapiro#define SM_TAILQ_INIT(head) do { \ 100168515Sgshapiro (head)->tqh_first = NULL; \ 101168515Sgshapiro (head)->tqh_last = &(head)->tqh_first; \ 102168515Sgshapiro} while (0) 103168515Sgshapiro 104168515Sgshapiro#define SM_TAILQ_INSERT_HEAD(head, elm, field) do { \ 105168515Sgshapiro if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 106168515Sgshapiro (head)->tqh_first->field.tqe_prev = \ 107168515Sgshapiro &(elm)->field.tqe_next; \ 108168515Sgshapiro else \ 109168515Sgshapiro (head)->tqh_last = &(elm)->field.tqe_next; \ 110168515Sgshapiro (head)->tqh_first = (elm); \ 111168515Sgshapiro (elm)->field.tqe_prev = &(head)->tqh_first; \ 112168515Sgshapiro} while (0) 113168515Sgshapiro 114168515Sgshapiro#define SM_TAILQ_INSERT_TAIL(head, elm, field) do { \ 115168515Sgshapiro (elm)->field.tqe_next = NULL; \ 116168515Sgshapiro (elm)->field.tqe_prev = (head)->tqh_last; \ 117168515Sgshapiro *(head)->tqh_last = (elm); \ 118168515Sgshapiro (head)->tqh_last = &(elm)->field.tqe_next; \ 119168515Sgshapiro} while (0) 120168515Sgshapiro 121168515Sgshapiro#define SM_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 122168515Sgshapiro if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 123168515Sgshapiro (elm)->field.tqe_next->field.tqe_prev = \ 124168515Sgshapiro &(elm)->field.tqe_next; \ 125168515Sgshapiro else \ 126168515Sgshapiro (head)->tqh_last = &(elm)->field.tqe_next; \ 127168515Sgshapiro (listelm)->field.tqe_next = (elm); \ 128168515Sgshapiro (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 129168515Sgshapiro} while (0) 130168515Sgshapiro 131168515Sgshapiro#define SM_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 132168515Sgshapiro (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 133168515Sgshapiro (elm)->field.tqe_next = (listelm); \ 134168515Sgshapiro *(listelm)->field.tqe_prev = (elm); \ 135168515Sgshapiro (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 136168515Sgshapiro} while (0) 137168515Sgshapiro 138168515Sgshapiro#define SM_TAILQ_REMOVE(head, elm, field) do { \ 139168515Sgshapiro if (((elm)->field.tqe_next) != NULL) \ 140168515Sgshapiro (elm)->field.tqe_next->field.tqe_prev = \ 141168515Sgshapiro (elm)->field.tqe_prev; \ 142168515Sgshapiro else \ 143168515Sgshapiro (head)->tqh_last = (elm)->field.tqe_prev; \ 144168515Sgshapiro *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 145168515Sgshapiro} while (0) 146168515Sgshapiro 147168515Sgshapiro#define SM_TAILQ_REPLACE(head, elm, elm2, field) do { \ 148168515Sgshapiro if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 149168515Sgshapiro (elm2)->field.tqe_next->field.tqe_prev = \ 150168515Sgshapiro &(elm2)->field.tqe_next; \ 151168515Sgshapiro else \ 152168515Sgshapiro (head)->tqh_last = &(elm2)->field.tqe_next; \ 153168515Sgshapiro (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 154168515Sgshapiro *(elm2)->field.tqe_prev = (elm2); \ 155168515Sgshapiro} while (0) 156168515Sgshapiro 157168515Sgshapiro#endif /* !SM_TAILQ_H_ */ 158