1 /* 2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (c) 1997,1999 by Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #ifndef LIST_H 19 #define LIST_H 1 20 #ifdef _LIBC 21 #include <assert.h> 22 #define INSIST(cond) assert(cond) 23 #else 24 #include <isc/assertions.h> 25 #endif 26 #define LIST(type) struct { type *head, *tail; } 27 #define INIT_LIST(list) \ 28 do { (list).head = NULL; (list).tail = NULL; } while (0) 29 30 #define LINK(type) struct { type *prev, *next; } 31 #define INIT_LINK_TYPE(elt, link, type) \ 32 do { \ 33 (elt)->link.prev = (type *)(-1); \ 34 (elt)->link.next = (type *)(-1); \ 35 } while (0) 36 #define INIT_LINK(elt, link) \ 37 INIT_LINK_TYPE(elt, link, void) 38 #define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1)) 39 40 #define HEAD(list) ((list).head) 41 #define TAIL(list) ((list).tail) 42 #define EMPTY(list) ((list).head == NULL) 43 44 #define PREPEND(list, elt, link) \ 45 do { \ 46 INSIST(!LINKED(elt, link));\ 47 if ((list).head != NULL) \ 48 (list).head->link.prev = (elt); \ 49 else \ 50 (list).tail = (elt); \ 51 (elt)->link.prev = NULL; \ 52 (elt)->link.next = (list).head; \ 53 (list).head = (elt); \ 54 } while (0) 55 56 #define APPEND(list, elt, link) \ 57 do { \ 58 INSIST(!LINKED(elt, link));\ 59 if ((list).tail != NULL) \ 60 (list).tail->link.next = (elt); \ 61 else \ 62 (list).head = (elt); \ 63 (elt)->link.prev = (list).tail; \ 64 (elt)->link.next = NULL; \ 65 (list).tail = (elt); \ 66 } while (0) 67 68 #define UNLINK_TYPE(list, elt, link, type) \ 69 do { \ 70 INSIST(LINKED(elt, link));\ 71 if ((elt)->link.next != NULL) \ 72 (elt)->link.next->link.prev = (elt)->link.prev; \ 73 else { \ 74 INSIST((list).tail == (elt)); \ 75 (list).tail = (elt)->link.prev; \ 76 } \ 77 if ((elt)->link.prev != NULL) \ 78 (elt)->link.prev->link.next = (elt)->link.next; \ 79 else { \ 80 INSIST((list).head == (elt)); \ 81 (list).head = (elt)->link.next; \ 82 } \ 83 INIT_LINK_TYPE(elt, link, type); \ 84 } while (0) 85 #define UNLINK(list, elt, link) \ 86 UNLINK_TYPE(list, elt, link, void) 87 88 #define PREV(elt, link) ((elt)->link.prev) 89 #define NEXT(elt, link) ((elt)->link.next) 90 91 #define INSERT_BEFORE(list, before, elt, link) \ 92 do { \ 93 INSIST(!LINKED(elt, link));\ 94 if ((before)->link.prev == NULL) \ 95 PREPEND(list, elt, link); \ 96 else { \ 97 (elt)->link.prev = (before)->link.prev; \ 98 (before)->link.prev = (elt); \ 99 (elt)->link.prev->link.next = (elt); \ 100 (elt)->link.next = (before); \ 101 } \ 102 } while (0) 103 104 #define INSERT_AFTER(list, after, elt, link) \ 105 do { \ 106 INSIST(!LINKED(elt, link));\ 107 if ((after)->link.next == NULL) \ 108 APPEND(list, elt, link); \ 109 else { \ 110 (elt)->link.next = (after)->link.next; \ 111 (after)->link.next = (elt); \ 112 (elt)->link.next->link.prev = (elt); \ 113 (elt)->link.prev = (after); \ 114 } \ 115 } while (0) 116 117 #define ENQUEUE(list, elt, link) APPEND(list, elt, link) 118 #define DEQUEUE(list, elt, link) UNLINK(list, elt, link) 119 120 #endif /* LIST_H */ 121 /*! \file */ 122