1 /* $NetBSD: pthread_queue.h,v 1.2 2003/01/18 10:34:16 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nathan J. Williams. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* pthread_queue.h 40 * Definition of a queue interface for the pthread library. 41 * Style modeled on the sys/queue.h macros; implementation taken from 42 * the tail queue, with the added property of static initializability 43 * (and a corresponding extra cost in the _INSERT_TAIL() function. 44 */ 45 46 47 48 /* 49 * Queue definitions. 50 */ 51 #define PTQ_HEAD(name, type) \ 52 struct name { \ 53 struct type *ptqh_first;/* first element */ \ 54 struct type **ptqh_last;/* addr of last next element */ \ 55 } 56 57 #define PTQ_HEAD_INITIALIZER { NULL, NULL } 58 59 60 #define PTQ_ENTRY(type) \ 61 struct { \ 62 struct type *ptqe_next; /* next element */ \ 63 struct type **ptqe_prev;/* address of previous next element */ \ 64 } 65 66 /* 67 * Queue functions. 68 */ 69 70 #define PTQ_INIT(head) do { \ 71 (head)->ptqh_first = NULL; \ 72 (head)->ptqh_last = &(head)->ptqh_first; \ 73 } while (/*CONSTCOND*/0) 74 75 #define PTQ_INSERT_HEAD(head, elm, field) do { \ 76 if (((elm)->field.ptqe_next = (head)->ptqh_first) != NULL) \ 77 (head)->ptqh_first->field.ptqe_prev = \ 78 &(elm)->field.ptqe_next; \ 79 else \ 80 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 81 (head)->ptqh_first = (elm); \ 82 (elm)->field.ptqe_prev = &(head)->ptqh_first; \ 83 } while (/*CONSTCOND*/0) 84 85 #define PTQ_INSERT_TAIL(head, elm, field) do { \ 86 (elm)->field.ptqe_next = NULL; \ 87 if ((head)->ptqh_last == NULL) \ 88 (head)->ptqh_last = &(head)->ptqh_first; \ 89 (elm)->field.ptqe_prev = (head)->ptqh_last; \ 90 *(head)->ptqh_last = (elm); \ 91 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 92 } while (/*CONSTCOND*/0) 93 94 #define PTQ_INSERT_AFTER(head, listelm, elm, field) do { \ 95 if (((elm)->field.ptqe_next = (listelm)->field.ptqe_next) != NULL)\ 96 (elm)->field.ptqe_next->field.ptqe_prev = \ 97 &(elm)->field.ptqe_next; \ 98 else \ 99 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 100 (listelm)->field.ptqe_next = (elm); \ 101 (elm)->field.ptqe_prev = &(listelm)->field.ptqe_next; \ 102 } while (/*CONSTCOND*/0) 103 104 #define PTQ_INSERT_BEFORE(listelm, elm, field) do { \ 105 (elm)->field.ptqe_prev = (listelm)->field.ptqe_prev; \ 106 (elm)->field.ptqe_next = (listelm); \ 107 *(listelm)->field.ptqe_prev = (elm); \ 108 (listelm)->field.ptqe_prev = &(elm)->field.ptqe_next; \ 109 } while (/*CONSTCOND*/0) 110 111 #define PTQ_REMOVE(head, elm, field) do { \ 112 if (((elm)->field.ptqe_next) != NULL) \ 113 (elm)->field.ptqe_next->field.ptqe_prev = \ 114 (elm)->field.ptqe_prev; \ 115 else \ 116 (head)->ptqh_last = (elm)->field.ptqe_prev; \ 117 *(elm)->field.ptqe_prev = (elm)->field.ptqe_next; \ 118 } while (/*CONSTCOND*/0) 119 120 /* 121 * Queue access methods. 122 */ 123 #define PTQ_EMPTY(head) ((head)->ptqh_first == NULL) 124 #define PTQ_FIRST(head) ((head)->ptqh_first) 125 #define PTQ_NEXT(elm, field) ((elm)->field.ptqe_next) 126 127 #define PTQ_LAST(head, headname) \ 128 (*(((struct headname *)((head)->ptqh_last))->ptqh_last)) 129 #define PTQ_PREV(elm, headname, field) \ 130 (*(((struct headname *)((elm)->field.ptqe_prev))->ptqh_last)) 131 132 #define PTQ_FOREACH(var, head, field) \ 133 for ((var) = ((head)->ptqh_first); \ 134 (var); \ 135 (var) = ((var)->field.ptqe_next)) 136 137 #define PTQ_FOREACH_REVERSE(var, head, headname, field) \ 138 for ((var) = (*(((struct headname *)((head)->ptqh_last))->ptqh_last)); \ 139 (var); \ 140 (var) = (*(((struct headname *)((var)->field.ptqe_prev))->ptqh_last))) 141