external/bsd/ntp/dist/lib/isc/include/isc/list.h

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004, 2006, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1997-2002  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or 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 WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: list.h,v 1.24 2007/06/19 23:47:18 tbox Exp */
  21
  22 #ifndef ISC_LIST_H
  23 #define ISC_LIST_H 1
  24 #include <isc/boolean.h>
  25 #include <isc/assertions.h>
  26
  27 #ifdef ISC_LIST_CHECKINIT
  28 #define ISC_LINK_INSIST(x) ISC_INSIST(x)
  29 #else
  30 #define ISC_LINK_INSIST(x)
  31 #endif
  32
  33 #define ISC_LIST(type) struct { type *head, *tail; }
  34 #define ISC_LIST_INIT(list) \
  35         do { (list).head = NULL; (list).tail = NULL; } while (0)
  36
  37 #define ISC_LINK(type) struct { type *prev, *next; }
  38 #define ISC_LINK_INIT_TYPE(elt, link, type) \
  39         do { \
  40                 (elt)->link.prev = (type *)(-1); \
  41                 (elt)->link.next = (type *)(-1); \
  42         } while (0)
  43 #define ISC_LINK_INIT(elt, link) \
  44         ISC_LINK_INIT_TYPE(elt, link, void)
  45 #define ISC_LINK_LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1))
  46
  47 #define ISC_LIST_HEAD(list) ((list).head)
  48 #define ISC_LIST_TAIL(list) ((list).tail)
  49 #define ISC_LIST_EMPTY(list) ISC_TF((list).head == NULL)
  50
  51 #define __ISC_LIST_PREPENDUNSAFE(list, elt, link) \
  52         do { \
  53                 if ((list).head != NULL) \
  54                         (list).head->link.prev = (elt); \
  55                 else \
  56                         (list).tail = (elt); \
  57                 (elt)->link.prev = NULL; \
  58                 (elt)->link.next = (list).head; \
  59                 (list).head = (elt); \
  60         } while (0)
  61
  62 #define ISC_LIST_PREPEND(list, elt, link) \
  63         do { \
  64                 ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
  65                 __ISC_LIST_PREPENDUNSAFE(list, elt, link); \
  66         } while (0)
  67
  68 #define ISC_LIST_INITANDPREPEND(list, elt, link) \
  69                 __ISC_LIST_PREPENDUNSAFE(list, elt, link)
  70
  71 #define __ISC_LIST_APPENDUNSAFE(list, elt, link) \
  72         do { \
  73                 if ((list).tail != NULL) \
  74                         (list).tail->link.next = (elt); \
  75                 else \
  76                         (list).head = (elt); \
  77                 (elt)->link.prev = (list).tail; \
  78                 (elt)->link.next = NULL; \
  79                 (list).tail = (elt); \
  80         } while (0)
  81
  82 #define ISC_LIST_APPEND(list, elt, link) \
  83         do { \
  84                 ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
  85                 __ISC_LIST_APPENDUNSAFE(list, elt, link); \
  86         } while (0)
  87
  88 #define ISC_LIST_INITANDAPPEND(list, elt, link) \
  89                 __ISC_LIST_APPENDUNSAFE(list, elt, link)
  90
  91 #define __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type) \
  92         do { \
  93                 if ((elt)->link.next != NULL) \
  94                         (elt)->link.next->link.prev = (elt)->link.prev; \
  95                 else { \
  96                         ISC_INSIST((list).tail == (elt)); \
  97                         (list).tail = (elt)->link.prev; \
  98                 } \
  99                 if ((elt)->link.prev != NULL) \
 100                         (elt)->link.prev->link.next = (elt)->link.next; \
 101                 else { \
 102                         ISC_INSIST((list).head == (elt)); \
 103                         (list).head = (elt)->link.next; \
 104                 } \
 105                 (elt)->link.prev = (type *)(-1); \
 106                 (elt)->link.next = (type *)(-1); \
 107         } while (0)
 108
 109 #define __ISC_LIST_UNLINKUNSAFE(list, elt, link) \
 110         __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, void)
 111
 112 #define ISC_LIST_UNLINK_TYPE(list, elt, link, type) \
 113         do { \
 114                 ISC_LINK_INSIST(ISC_LINK_LINKED(elt, link)); \
 115                 __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type); \
 116         } while (0)
 117 #define ISC_LIST_UNLINK(list, elt, link) \
 118         ISC_LIST_UNLINK_TYPE(list, elt, link, void)
 119
 120 #define ISC_LIST_PREV(elt, link) ((elt)->link.prev)
 121 #define ISC_LIST_NEXT(elt, link) ((elt)->link.next)
 122
 123 #define __ISC_LIST_INSERTBEFOREUNSAFE(list, before, elt, link) \
 124         do { \
 125                 if ((before)->link.prev == NULL) \
 126                         ISC_LIST_PREPEND(list, elt, link); \
 127                 else { \
 128                         (elt)->link.prev = (before)->link.prev; \
 129                         (before)->link.prev = (elt); \
 130                         (elt)->link.prev->link.next = (elt); \
 131                         (elt)->link.next = (before); \
 132                 } \
 133         } while (0)
 134
 135 #define ISC_LIST_INSERTBEFORE(list, before, elt, link) \
 136         do { \
 137                 ISC_LINK_INSIST(ISC_LINK_LINKED(before, link)); \
 138                 ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
 139                 __ISC_LIST_INSERTBEFOREUNSAFE(list, before, elt, link); \
 140         } while (0)
 141
 142 #define __ISC_LIST_INSERTAFTERUNSAFE(list, after, elt, link) \
 143         do { \
 144                 if ((after)->link.next == NULL) \
 145                         ISC_LIST_APPEND(list, elt, link); \
 146                 else { \
 147                         (elt)->link.next = (after)->link.next; \
 148                         (after)->link.next = (elt); \
 149                         (elt)->link.next->link.prev = (elt); \
 150                         (elt)->link.prev = (after); \
 151                 } \
 152         } while (0)
 153
 154 #define ISC_LIST_INSERTAFTER(list, after, elt, link) \
 155         do { \
 156                 ISC_LINK_INSIST(ISC_LINK_LINKED(after, link)); \
 157                 ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
 158                 __ISC_LIST_INSERTAFTERUNSAFE(list, after, elt, link); \
 159         } while (0)
 160
 161 #define ISC_LIST_APPENDLIST(list1, list2, link) \
 162         do { \
 163                 if (ISC_LIST_EMPTY(list1)) \
 164                         (list1) = (list2); \
 165                 else if (!ISC_LIST_EMPTY(list2)) { \
 166                         (list1).tail->link.next = (list2).head; \
 167                         (list2).head->link.prev = (list1).tail; \
 168                         (list1).tail = (list2).tail; \
 169                 } \
 170                 (list2).head = NULL; \
 171                 (list2).tail = NULL; \
 172         } while (0)
 173
 174 #define ISC_LIST_ENQUEUE(list, elt, link) ISC_LIST_APPEND(list, elt, link)
 175 #define __ISC_LIST_ENQUEUEUNSAFE(list, elt, link) \
 176         __ISC_LIST_APPENDUNSAFE(list, elt, link)
 177 #define ISC_LIST_DEQUEUE(list, elt, link) \
 178          ISC_LIST_UNLINK_TYPE(list, elt, link, void)
 179 #define ISC_LIST_DEQUEUE_TYPE(list, elt, link, type) \
 180          ISC_LIST_UNLINK_TYPE(list, elt, link, type)
 181 #define __ISC_LIST_DEQUEUEUNSAFE(list, elt, link) \
 182         __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, void)
 183 #define __ISC_LIST_DEQUEUEUNSAFE_TYPE(list, elt, link, type) \
 184         __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type)
 185
 186 #endif /* ISC_LIST_H */