1 /*- 2 * SPDX-License-Identifier: ISC 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 21 #ifndef LIST_H 22 #define LIST_H 1 23 #ifdef _LIBC 24 #include <assert.h> 25 #define INSIST(cond) assert(cond) 26 #else 27 #include <isc/assertions.h> 28 #endif 29 30 #define LIST(type) struct { type *head, *tail; } 31 #define INIT_LIST(list) \ 32 do { (list).head = NULL; (list).tail = NULL; } while (0) 33 34 #define LINK(type) struct { type *prev, *next; } 35 #define INIT_LINK_TYPE(elt, link, type) \ 36 do { \ 37 (elt)->link.prev = (type *)(-1); \ 38 (elt)->link.next = (type *)(-1); \ 39 } while (0) 40 #define INIT_LINK(elt, link) \ 41 INIT_LINK_TYPE(elt, link, void) 42 #define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1) && \ 43 (void *)((elt)->link.next) != (void *)(-1)) 44 45 #define HEAD(list) ((list).head) 46 #define TAIL(list) ((list).tail) 47 #define EMPTY(list) ((list).head == NULL) 48 49 #define PREPEND(list, elt, link) \ 50 do { \ 51 INSIST(!LINKED(elt, link));\ 52 if ((list).head != NULL) \ 53 (list).head->link.prev = (elt); \ 54 else \ 55 (list).tail = (elt); \ 56 (elt)->link.prev = NULL; \ 57 (elt)->link.next = (list).head; \ 58 (list).head = (elt); \ 59 } while (0) 60 61 #define APPEND(list, elt, link) \ 62 do { \ 63 INSIST(!LINKED(elt, link));\ 64 if ((list).tail != NULL) \ 65 (list).tail->link.next = (elt); \ 66 else \ 67 (list).head = (elt); \ 68 (elt)->link.prev = (list).tail; \ 69 (elt)->link.next = NULL; \ 70 (list).tail = (elt); \ 71 } while (0) 72 73 #define UNLINK_TYPE(list, elt, link, type) \ 74 do { \ 75 INSIST(LINKED(elt, link));\ 76 if ((elt)->link.next != NULL) \ 77 (elt)->link.next->link.prev = (elt)->link.prev; \ 78 else { \ 79 INSIST((list).tail == (elt)); \ 80 (list).tail = (elt)->link.prev; \ 81 } \ 82 if ((elt)->link.prev != NULL) \ 83 (elt)->link.prev->link.next = (elt)->link.next; \ 84 else { \ 85 INSIST((list).head == (elt)); \ 86 (list).head = (elt)->link.next; \ 87 } \ 88 INIT_LINK_TYPE(elt, link, type); \ 89 } while (0) 90 #define UNLINK(list, elt, link) \ 91 UNLINK_TYPE(list, elt, link, void) 92 93 #define PREV(elt, link) ((elt)->link.prev) 94 #define NEXT(elt, link) ((elt)->link.next) 95 96 #define INSERT_BEFORE(list, before, elt, link) \ 97 do { \ 98 INSIST(!LINKED(elt, link));\ 99 if ((before)->link.prev == NULL) \ 100 PREPEND(list, elt, link); \ 101 else { \ 102 (elt)->link.prev = (before)->link.prev; \ 103 (before)->link.prev = (elt); \ 104 (elt)->link.prev->link.next = (elt); \ 105 (elt)->link.next = (before); \ 106 } \ 107 } while (0) 108 109 #define INSERT_AFTER(list, after, elt, link) \ 110 do { \ 111 INSIST(!LINKED(elt, link));\ 112 if ((after)->link.next == NULL) \ 113 APPEND(list, elt, link); \ 114 else { \ 115 (elt)->link.next = (after)->link.next; \ 116 (after)->link.next = (elt); \ 117 (elt)->link.next->link.prev = (elt); \ 118 (elt)->link.prev = (after); \ 119 } \ 120 } while (0) 121 122 #define ENQUEUE(list, elt, link) APPEND(list, elt, link) 123 #define DEQUEUE(list, elt, link) UNLINK(list, elt, link) 124 125 #endif /* LIST_H */ 126 /*! \file */ 127