lib/queue.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * lists and queues implementations
   4  */
   5
   6 #ifndef _FRR_QUEUE_H
   7 #define _FRR_QUEUE_H
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 #if defined(__OpenBSD__) && !defined(STAILQ_HEAD)
  14 #include "openbsd-queue.h"
  15
  16 /* Try to map FreeBSD implementation to OpenBSD one. */
  17 #define STAILQ_HEAD(name, type)                         SIMPLEQ_HEAD(name, type)
  18 #define STAILQ_HEAD_INITIALIZER(head)                   SIMPLEQ_HEAD_INITIALIZER(head)
  19 #define STAILQ_ENTRY(entry)                             SIMPLEQ_ENTRY(entry)
  20
  21 #define STAILQ_CONCAT(head1, head2)                     SIMPLEQ_CONCAT(head1, head2)
  22 #define STAILQ_EMPTY(head)                              SIMPLEQ_EMPTY(head)
  23 #define STAILQ_FIRST(head)                              SIMPLEQ_FIRST(head)
  24 #define STAILQ_FOREACH(var, head, field)                SIMPLEQ_FOREACH(var, head, field)
  25 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)     SIMPLEQ_FOREACH_SAFE(var, head, field, tvar)
  26 #define STAILQ_INIT(head)                               SIMPLEQ_INIT(head)
  27 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field)    SIMPLEQ_INSERT_AFTER(head, tqelm, elm, field)
  28 #define STAILQ_INSERT_HEAD(head, elm, field)            SIMPLEQ_INSERT_HEAD(head, elm, field)
  29 #define STAILQ_INSERT_TAIL(head, elm, field)            SIMPLEQ_INSERT_TAIL(head, elm, field)
  30 #define STAILQ_LAST(head, type, field)                                         \
  31         (SIMPLEQ_EMPTY((head))                                                 \
  32                  ? NULL                                                        \
  33                  : ((struct type *)(void *)((char *)((head)->sqh_last)         \
  34                                             - offsetof(struct type, field))))
  35 #define STAILQ_NEXT(elm, field)                         SIMPLEQ_NEXT(elm, field)
  36 #define STAILQ_REMOVE(head, elm, type, field)                                  \
  37         do {                                                                   \
  38                 if (SIMPLEQ_FIRST((head)) == (elm)) {                          \
  39                         SIMPLEQ_REMOVE_HEAD((head), field);                    \
  40                 } else {                                                       \
  41                         struct type *curelm = SIMPLEQ_FIRST((head));           \
  42                         while (SIMPLEQ_NEXT(curelm, field) != (elm))           \
  43                                 curelm = SIMPLEQ_NEXT(curelm, field);          \
  44                         SIMPLEQ_REMOVE_AFTER(head, curelm, field);             \
  45                 }                                                              \
  46         } while (0)
  47 #define STAILQ_REMOVE_AFTER(head, elm, field)           SIMPLEQ_REMOVE_AFTER(head, elm, field)
  48 #define STAILQ_REMOVE_HEAD(head, field)                 SIMPLEQ_REMOVE_HEAD(head, field)
  49 #define STAILQ_SWAP(head1, head2, type)                                        \
  50         do {                                                                   \
  51                 struct type *swap_first = STAILQ_FIRST(head1);                 \
  52                 struct type **swap_last = (head1)->sqh_last;                   \
  53                 STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                     \
  54                 (head1)->sqh_last = (head2)->sqh_last;                         \
  55                 STAILQ_FIRST(head2) = swap_first;                              \
  56                 (head2)->sqh_last = swap_last;                                 \
  57                 if (STAILQ_EMPTY(head1))                                       \
  58                         (head1)->sqh_last = &STAILQ_FIRST(head1);              \
  59                 if (STAILQ_EMPTY(head2))                                       \
  60                         (head2)->sqh_last = &STAILQ_FIRST(head2);              \
  61         } while (0)
  62 #else
  63 #include "freebsd-queue.h"
  64 #endif /* defined(__OpenBSD__) && !defined(STAILQ_HEAD) */
  65
  66 #ifndef TAILQ_POP_FIRST
  67 #define TAILQ_POP_FIRST(head, field)                                           \
  68         ({  typeof((head)->tqh_first) _elm = TAILQ_FIRST(head);                \
  69             if (_elm) {                                                        \
  70                 if ((TAILQ_NEXT((_elm), field)) != NULL)                       \
  71                         TAILQ_NEXT((_elm), field)->field.tqe_prev =            \
  72                                 &TAILQ_FIRST(head);                            \
  73                 else                                                           \
  74                         (head)->tqh_last = &TAILQ_FIRST(head);                 \
  75                 TAILQ_FIRST(head) = TAILQ_NEXT((_elm), field);                 \
  76         }; _elm; })
  77 #endif
  78
  79 #ifdef __cplusplus
  80 }
  81 #endif
  82
  83 #endif /* _FRR_QUEUE_H */