1 /* $NetBSD: list.h,v 1.5 2009/04/12 17:07:16 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1997,1999 by Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #ifndef LIST_H 21 #define LIST_H 1 22 #include <isc/assertions.h> 23 24 #define LIST(type) struct { type *head, *tail; } 25 #define INIT_LIST(list) \ 26 do { (list).head = NULL; (list).tail = NULL; } while (/*CONSTCOND*/0) 27 28 #define LINK(type) struct { type *prev, *next; } 29 #define INIT_LINK_TYPE(elt, link, type) \ 30 do { \ 31 (elt)->link.prev = (type *)(-1); \ 32 (elt)->link.next = (type *)(-1); \ 33 } while (/*CONSTCOND*/0) 34 #define INIT_LINK(elt, link) \ 35 INIT_LINK_TYPE(elt, link, void) 36 #define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1) && \ 37 (void *)((elt)->link.next) != (void *)(-1)) 38 39 #define HEAD(list) ((list).head) 40 #define TAIL(list) ((list).tail) 41 #define EMPTY(list) ((list).head == NULL) 42 43 #define PREPEND(list, elt, link) \ 44 do { \ 45 INSIST(!LINKED(elt, link));\ 46 if ((list).head != NULL) \ 47 (list).head->link.prev = (elt); \ 48 else \ 49 (list).tail = (elt); \ 50 (elt)->link.prev = NULL; \ 51 (elt)->link.next = (list).head; \ 52 (list).head = (elt); \ 53 } while (/*CONSTCOND*/0) 54 55 #define APPEND(list, elt, link) \ 56 do { \ 57 INSIST(!LINKED(elt, link));\ 58 if ((list).tail != NULL) \ 59 (list).tail->link.next = (elt); \ 60 else \ 61 (list).head = (elt); \ 62 (elt)->link.prev = (list).tail; \ 63 (elt)->link.next = NULL; \ 64 (list).tail = (elt); \ 65 } while (/*CONSTCOND*/0) 66 67 #define UNLINK_TYPE(list, elt, link, type) \ 68 do { \ 69 INSIST(LINKED(elt, link));\ 70 if ((elt)->link.next != NULL) \ 71 (elt)->link.next->link.prev = (elt)->link.prev; \ 72 else { \ 73 INSIST((list).tail == (elt)); \ 74 (list).tail = (elt)->link.prev; \ 75 } \ 76 if ((elt)->link.prev != NULL) \ 77 (elt)->link.prev->link.next = (elt)->link.next; \ 78 else { \ 79 INSIST((list).head == (elt)); \ 80 (list).head = (elt)->link.next; \ 81 } \ 82 INIT_LINK_TYPE(elt, link, type); \ 83 } while (/*CONSTCOND*/0) 84 #define UNLINK(list, elt, link) \ 85 UNLINK_TYPE(list, elt, link, void) 86 87 #define PREV(elt, link) ((elt)->link.prev) 88 #define NEXT(elt, link) ((elt)->link.next) 89 90 #define INSERT_BEFORE(list, before, elt, link) \ 91 do { \ 92 INSIST(!LINKED(elt, link));\ 93 if ((before)->link.prev == NULL) \ 94 PREPEND(list, elt, link); \ 95 else { \ 96 (elt)->link.prev = (before)->link.prev; \ 97 (before)->link.prev = (elt); \ 98 (elt)->link.prev->link.next = (elt); \ 99 (elt)->link.next = (before); \ 100 } \ 101 } while (/*CONSTCOND*/0) 102 103 #define INSERT_AFTER(list, after, elt, link) \ 104 do { \ 105 INSIST(!LINKED(elt, link));\ 106 if ((after)->link.next == NULL) \ 107 APPEND(list, elt, link); \ 108 else { \ 109 (elt)->link.next = (after)->link.next; \ 110 (after)->link.next = (elt); \ 111 (elt)->link.next->link.prev = (elt); \ 112 (elt)->link.prev = (after); \ 113 } \ 114 } while (/*CONSTCOND*/0) 115 116 #define ENQUEUE(list, elt, link) APPEND(list, elt, link) 117 #define DEQUEUE(list, elt, link) UNLINK(list, elt, link) 118 119 #endif /* LIST_H */ 120 /*! \file */ 121