1203329Sjasone/****************************************************************************** 2203329Sjasone * 3203329Sjasone * Copyright (C) 2002 Jason Evans <jasone@FreeBSD.org>. 4203329Sjasone * All rights reserved. 5203329Sjasone * 6203329Sjasone * Redistribution and use in source and binary forms, with or without 7203329Sjasone * modification, are permitted provided that the following conditions 8203329Sjasone * are met: 9203329Sjasone * 1. Redistributions of source code must retain the above copyright 10203329Sjasone * notice(s), this list of conditions and the following disclaimer 11203329Sjasone * unmodified other than the allowable addition of one or more 12203329Sjasone * copyright notices. 13203329Sjasone * 2. Redistributions in binary form must reproduce the above copyright 14203329Sjasone * notice(s), this list of conditions and the following disclaimer in 15203329Sjasone * the documentation and/or other materials provided with the 16203329Sjasone * distribution. 17203329Sjasone * 18203329Sjasone * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 19203329Sjasone * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20203329Sjasone * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21203329Sjasone * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 22203329Sjasone * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23203329Sjasone * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24203329Sjasone * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 25203329Sjasone * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 26203329Sjasone * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 27203329Sjasone * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 28203329Sjasone * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29203329Sjasone * 30203329Sjasone ******************************************************************************/ 31203329Sjasone 32203329Sjasone#ifndef QR_H_ 33203329Sjasone#define QR_H_ 34203329Sjasone 35203329Sjasone#include <sys/cdefs.h> 36203329Sjasone__FBSDID("$FreeBSD$"); 37203329Sjasone 38203329Sjasone/* Ring definitions. */ 39203329Sjasone#define qr(a_type) \ 40203329Sjasonestruct { \ 41203329Sjasone a_type *qre_next; \ 42203329Sjasone a_type *qre_prev; \ 43203329Sjasone} 44203329Sjasone 45203329Sjasone/* Ring functions. */ 46203329Sjasone#define qr_new(a_qr, a_field) do { \ 47203329Sjasone (a_qr)->a_field.qre_next = (a_qr); \ 48203329Sjasone (a_qr)->a_field.qre_prev = (a_qr); \ 49203329Sjasone} while (0) 50203329Sjasone 51203329Sjasone#define qr_next(a_qr, a_field) ((a_qr)->a_field.qre_next) 52203329Sjasone 53203329Sjasone#define qr_prev(a_qr, a_field) ((a_qr)->a_field.qre_prev) 54203329Sjasone 55203329Sjasone#define qr_before_insert(a_qrelm, a_qr, a_field) do { \ 56203329Sjasone (a_qr)->a_field.qre_prev = (a_qrelm)->a_field.qre_prev; \ 57203329Sjasone (a_qr)->a_field.qre_next = (a_qrelm); \ 58203329Sjasone (a_qr)->a_field.qre_prev->a_field.qre_next = (a_qr); \ 59203329Sjasone (a_qrelm)->a_field.qre_prev = (a_qr); \ 60203329Sjasone} while (0) 61203329Sjasone 62203329Sjasone#define qr_after_insert(a_qrelm, a_qr, a_field) \ 63203329Sjasone do \ 64203329Sjasone { \ 65203329Sjasone (a_qr)->a_field.qre_next = (a_qrelm)->a_field.qre_next; \ 66203329Sjasone (a_qr)->a_field.qre_prev = (a_qrelm); \ 67203329Sjasone (a_qr)->a_field.qre_next->a_field.qre_prev = (a_qr); \ 68203329Sjasone (a_qrelm)->a_field.qre_next = (a_qr); \ 69203329Sjasone } while (0) 70203329Sjasone 71203329Sjasone#define qr_meld(a_qr_a, a_qr_b, a_field) do { \ 72203329Sjasone void *t; \ 73203329Sjasone (a_qr_a)->a_field.qre_prev->a_field.qre_next = (a_qr_b); \ 74203329Sjasone (a_qr_b)->a_field.qre_prev->a_field.qre_next = (a_qr_a); \ 75203329Sjasone t = (a_qr_a)->a_field.qre_prev; \ 76203329Sjasone (a_qr_a)->a_field.qre_prev = (a_qr_b)->a_field.qre_prev; \ 77203329Sjasone (a_qr_b)->a_field.qre_prev = t; \ 78203329Sjasone} while (0) 79203329Sjasone 80203329Sjasone/* qr_meld() and qr_split() are functionally equivalent, so there's no need to 81203329Sjasone * have two copies of the code. */ 82203329Sjasone#define qr_split(a_qr_a, a_qr_b, a_field) \ 83203329Sjasone qr_meld((a_qr_a), (a_qr_b), a_field) 84203329Sjasone 85203329Sjasone#define qr_remove(a_qr, a_field) do { \ 86203329Sjasone (a_qr)->a_field.qre_prev->a_field.qre_next \ 87203329Sjasone = (a_qr)->a_field.qre_next; \ 88203329Sjasone (a_qr)->a_field.qre_next->a_field.qre_prev \ 89203329Sjasone = (a_qr)->a_field.qre_prev; \ 90203329Sjasone (a_qr)->a_field.qre_next = (a_qr); \ 91203329Sjasone (a_qr)->a_field.qre_prev = (a_qr); \ 92203329Sjasone} while (0) 93203329Sjasone 94203329Sjasone#define qr_foreach(var, a_qr, a_field) \ 95203329Sjasone for ((var) = (a_qr); \ 96203329Sjasone (var) != NULL; \ 97203329Sjasone (var) = (((var)->a_field.qre_next != (a_qr)) \ 98203329Sjasone ? (var)->a_field.qre_next : NULL)) 99203329Sjasone 100203329Sjasone#define qr_reverse_foreach(var, a_qr, a_field) \ 101203329Sjasone for ((var) = ((a_qr) != NULL) ? qr_prev(a_qr, a_field) : NULL; \ 102203329Sjasone (var) != NULL; \ 103203329Sjasone (var) = (((var) != (a_qr)) \ 104203329Sjasone ? (var)->a_field.qre_prev : NULL)) 105203329Sjasone 106203329Sjasone#endif /* QR_H_ */ 107