1 /* $NetBSD: pthread_queue.h,v 1.5 2009/10/05 23:33:48 rmind 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _LIB_PTHREAD_QUEUE_H 33 #define _LIB_PTHREAD_QUEUE_H 34 35 /* 36 * Definition of a queue interface for the pthread library. 37 * Style modeled on the sys/queue.h macros; implementation taken from 38 * the tail queue, with the added property of static initializability 39 * (and a corresponding extra cost in the _INSERT_TAIL() function. 40 */ 41 42 /* 43 * Queue definitions. 44 */ 45 46 #define PTQ_HEAD(name, type) \ 47 struct name { \ 48 struct type *ptqh_first;/* first element */ \ 49 struct type **ptqh_last;/* addr of last next element */ \ 50 } 51 52 #define PTQ_HEAD_INITIALIZER { NULL, NULL } 53 54 #define PTQ_ENTRY(type) \ 55 struct { \ 56 struct type *ptqe_next; /* next element */ \ 57 struct type **ptqe_prev;/* address of previous next element */ \ 58 } 59 60 /* 61 * Queue functions. 62 */ 63 64 #define PTQ_INIT(head) do { \ 65 (head)->ptqh_first = NULL; \ 66 (head)->ptqh_last = &(head)->ptqh_first; \ 67 } while (/*CONSTCOND*/0) 68 69 #define PTQ_INSERT_HEAD(head, elm, field) do { \ 70 if (((elm)->field.ptqe_next = (head)->ptqh_first) != NULL) \ 71 (head)->ptqh_first->field.ptqe_prev = \ 72 &(elm)->field.ptqe_next; \ 73 else \ 74 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 75 (head)->ptqh_first = (elm); \ 76 (elm)->field.ptqe_prev = &(head)->ptqh_first; \ 77 } while (/*CONSTCOND*/0) 78 79 #define PTQ_INSERT_TAIL(head, elm, field) do { \ 80 (elm)->field.ptqe_next = NULL; \ 81 if ((head)->ptqh_last == NULL) \ 82 (head)->ptqh_last = &(head)->ptqh_first; \ 83 (elm)->field.ptqe_prev = (head)->ptqh_last; \ 84 *(head)->ptqh_last = (elm); \ 85 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 86 } while (/*CONSTCOND*/0) 87 88 #define PTQ_INSERT_AFTER(head, listelm, elm, field) do { \ 89 if (((elm)->field.ptqe_next = (listelm)->field.ptqe_next) != NULL)\ 90 (elm)->field.ptqe_next->field.ptqe_prev = \ 91 &(elm)->field.ptqe_next; \ 92 else \ 93 (head)->ptqh_last = &(elm)->field.ptqe_next; \ 94 (listelm)->field.ptqe_next = (elm); \ 95 (elm)->field.ptqe_prev = &(listelm)->field.ptqe_next; \ 96 } while (/*CONSTCOND*/0) 97 98 #define PTQ_INSERT_BEFORE(listelm, elm, field) do { \ 99 (elm)->field.ptqe_prev = (listelm)->field.ptqe_prev; \ 100 (elm)->field.ptqe_next = (listelm); \ 101 *(listelm)->field.ptqe_prev = (elm); \ 102 (listelm)->field.ptqe_prev = &(elm)->field.ptqe_next; \ 103 } while (/*CONSTCOND*/0) 104 105 #define PTQ_REMOVE(head, elm, field) do { \ 106 if (((elm)->field.ptqe_next) != NULL) \ 107 (elm)->field.ptqe_next->field.ptqe_prev = \ 108 (elm)->field.ptqe_prev; \ 109 else \ 110 (head)->ptqh_last = (elm)->field.ptqe_prev; \ 111 *(elm)->field.ptqe_prev = (elm)->field.ptqe_next; \ 112 } while (/*CONSTCOND*/0) 113 114 /* 115 * Queue access methods. 116 */ 117 118 #define PTQ_EMPTY(head) ((head)->ptqh_first == NULL) 119 #define PTQ_FIRST(head) ((head)->ptqh_first) 120 #define PTQ_NEXT(elm, field) ((elm)->field.ptqe_next) 121 122 #define PTQ_LAST(head, headname) \ 123 (*(((struct headname *)(void *)((head)->ptqh_last))->ptqh_last)) 124 #define PTQ_PREV(elm, headname, field) \ 125 (*(((struct headname *)(void *)((elm)->field.ptqe_prev))->ptqh_last)) 126 127 #define PTQ_FOREACH(var, head, field) \ 128 for ((var) = ((head)->ptqh_first); \ 129 (var); \ 130 (var) = ((var)->field.ptqe_next)) 131 132 #define PTQ_FOREACH_REVERSE(var, head, headname, field) \ 133 for ((var) = (*(((struct headname *)(void *)((head)->ptqh_last))->ptqh_last)); \ 134 (var); \ 135 (var) = (*(((struct headname *)(void *)((var)->field.ptqe_prev))->ptqh_last))) 136 137 #endif /* _LIB_PTHREAD_QUEUE_H */ 138