1 /* $eterna: queue.h,v 1.6 2009/04/18 08:36:03 mrg Exp $ */ 2 /* from: NetBSD: queue.h,v 1.51 2009/03/11 06:51:53 mrg Exp */ 3 4 /* 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)queue.h 8.5 (Berkeley) 8/20/94 33 */ 34 35 #ifndef _SYS_QUEUE_H_ 36 #define _SYS_QUEUE_H_ 37 38 /* 39 * Simple queue definitions. 40 */ 41 #define SIMPLEQ_HEAD(name, type) \ 42 struct name { \ 43 struct type *sqh_first; /* first element */ \ 44 struct type **sqh_last; /* addr of last next element */ \ 45 } 46 47 #define SIMPLEQ_ENTRY(type) \ 48 struct { \ 49 struct type *sqe_next; /* next element */ \ 50 } 51 52 /* 53 * Simple queue functions. 54 */ 55 #define SIMPLEQ_INIT(head) do { \ 56 (head)->sqh_first = NULL; \ 57 (head)->sqh_last = &(head)->sqh_first; \ 58 } while (/*CONSTCOND*/0) 59 60 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 61 (elm)->field.sqe_next = NULL; \ 62 *(head)->sqh_last = (elm); \ 63 (head)->sqh_last = &(elm)->field.sqe_next; \ 64 } while (/*CONSTCOND*/0) 65 66 #define SIMPLEQ_FOREACH(var, head, field) \ 67 for ((var) = ((head)->sqh_first); \ 68 (var); \ 69 (var) = ((var)->field.sqe_next)) 70 71 #define SIMPLEQ_FOREACH_SAFE(var, head, field, next) \ 72 for ((var) = ((head)->sqh_first); \ 73 (var) && ((next = ((var)->field.sqe_next)), 1); \ 74 (var) = (next)) 75 76 /* 77 * Simple queue access methods. 78 */ 79 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 80 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 81 82 #endif /* !_SYS_QUEUE_H_ */ 83