]> git.ipfire.org Git - thirdparty/dhcpcd.git/commitdiff
Import queue.h v1.77 from NetBSD vendor/QUEUE
authorRoy Marples <roy@marples.name>
Thu, 30 Oct 2025 11:19:40 +0000 (11:19 +0000)
committerRoy Marples <roy@marples.name>
Thu, 30 Oct 2025 11:19:40 +0000 (11:19 +0000)
vendor/queue.h [new file with mode: 0644]

diff --git a/vendor/queue.h b/vendor/queue.h
new file mode 100644 (file)
index 0000000..5e11055
--- /dev/null
@@ -0,0 +1,655 @@
+/*     $NetBSD: queue.h,v 1.77 2024/05/12 10:34:56 rillig Exp $        */
+
+/*
+ * Copyright (c) 1991, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)queue.h     8.5 (Berkeley) 8/20/94
+ */
+
+#ifndef        _SYS_QUEUE_H_
+#define        _SYS_QUEUE_H_
+
+/*
+ * This file defines five types of data structures: singly-linked lists,
+ * lists, simple queues, tail queues, and circular queues.
+ *
+ * A singly-linked list is headed by a single forward pointer. The
+ * elements are singly linked for minimum space and pointer manipulation
+ * overhead at the expense of O(n) removal for arbitrary elements. New
+ * elements can be added to the list after an existing element or at the
+ * head of the list.  Elements being removed from the head of the list
+ * should use the explicit macro for this purpose for optimum
+ * efficiency. A singly-linked list may only be traversed in the forward
+ * direction.  Singly-linked lists are ideal for applications with large
+ * datasets and few or no removals or for implementing a LIFO queue.
+ *
+ * A list is headed by a single forward pointer (or an array of forward
+ * pointers for a hash table header). The elements are doubly linked
+ * so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before
+ * or after an existing element or at the head of the list. A list
+ * may only be traversed in the forward direction.
+ *
+ * A simple queue is headed by a pair of pointers, one the head of the
+ * list and the other to the tail of the list. The elements are singly
+ * linked to save space, so elements can only be removed from the
+ * head of the list. New elements can be added to the list after
+ * an existing element, at the head of the list, or at the end of the
+ * list. A simple queue may only be traversed in the forward direction.
+ *
+ * A tail queue is headed by a pair of pointers, one to the head of the
+ * list and the other to the tail of the list. The elements are doubly
+ * linked so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before or
+ * after an existing element, at the head of the list, or at the end of
+ * the list. A tail queue may be traversed in either direction.
+ *
+ * For details on the use of these macros, see the queue(3) manual page.
+ */
+
+/*
+ * Include the definition of NULL only on NetBSD because sys/null.h
+ * is not available elsewhere.  This conditional makes the header
+ * portable and it can simply be dropped verbatim into any system.
+ * The caveat is that on other systems some other header
+ * must provide NULL before the macros can be used.
+ */
+#ifdef __NetBSD__
+#include <sys/null.h>
+#endif
+
+#if defined(_KERNEL) && defined(DIAGNOSTIC)
+#define QUEUEDEBUG     1
+#endif
+
+#if defined(QUEUEDEBUG)
+# if defined(_KERNEL)
+#  define QUEUEDEBUG_ABORT(...) panic(__VA_ARGS__)
+# else
+#  include <err.h>
+#  define QUEUEDEBUG_ABORT(...) err(1, __VA_ARGS__)
+# endif
+#endif
+
+/*
+ * Singly-linked List definitions.
+ */
+#define        SLIST_HEAD(name, type)                                          \
+struct name {                                                          \
+       struct type *slh_first; /* first element */                     \
+}
+
+#define        SLIST_HEAD_INITIALIZER(head)                                    \
+       { NULL }
+
+#define        SLIST_ENTRY(type)                                               \
+struct {                                                               \
+       struct type *sle_next;  /* next element */                      \
+}
+
+/*
+ * Singly-linked List access methods.
+ */
+#define        SLIST_FIRST(head)       ((head)->slh_first)
+#define        SLIST_END(head)         NULL
+#define        SLIST_EMPTY(head)       ((head)->slh_first == NULL)
+#define        SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
+
+#define        SLIST_FOREACH(var, head, field)                                 \
+       for((var) = (head)->slh_first;                                  \
+           (var) != SLIST_END(head);                                   \
+           (var) = (var)->field.sle_next)
+
+#define        SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
+       for ((var) = SLIST_FIRST((head));                               \
+           (var) != SLIST_END(head) &&                                 \
+           ((tvar) = SLIST_NEXT((var), field), 1);                     \
+           (var) = (tvar))
+
+/*
+ * Singly-linked List functions.
+ */
+#define        SLIST_INIT(head) do {                                           \
+       (head)->slh_first = SLIST_END(head);                            \
+} while (0)
+
+#define        SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
+       (elm)->field.sle_next = (slistelm)->field.sle_next;             \
+       (slistelm)->field.sle_next = (elm);                             \
+} while (0)
+
+#define        SLIST_INSERT_HEAD(head, elm, field) do {                        \
+       (elm)->field.sle_next = (head)->slh_first;                      \
+       (head)->slh_first = (elm);                                      \
+} while (0)
+
+#define        SLIST_REMOVE_AFTER(slistelm, field) do {                        \
+       (slistelm)->field.sle_next =                                    \
+           SLIST_NEXT(SLIST_NEXT((slistelm), field), field);           \
+} while (0)
+
+#define        SLIST_REMOVE_HEAD(head, field) do {                             \
+       (head)->slh_first = (head)->slh_first->field.sle_next;          \
+} while (0)
+
+#define        SLIST_REMOVE(head, elm, type, field) do {                       \
+       if ((head)->slh_first == (elm)) {                               \
+               SLIST_REMOVE_HEAD((head), field);                       \
+       }                                                               \
+       else {                                                          \
+               struct type *curelm = (head)->slh_first;                \
+               while(curelm->field.sle_next != (elm))                  \
+                       curelm = curelm->field.sle_next;                \
+               curelm->field.sle_next =                                \
+                   curelm->field.sle_next->field.sle_next;             \
+       }                                                               \
+} while (0)
+
+
+/*
+ * List definitions.
+ */
+#define        LIST_HEAD(name, type)                                           \
+struct name {                                                          \
+       struct type *lh_first;  /* first element */                     \
+}
+
+#define        LIST_HEAD_INITIALIZER(head)                                     \
+       { NULL }
+
+#define        LIST_ENTRY(type)                                                \
+struct {                                                               \
+       struct type *le_next;   /* next element */                      \
+       struct type **le_prev;  /* address of previous next element */  \
+}
+
+/*
+ * List access methods.
+ */
+#define        LIST_FIRST(head)                ((head)->lh_first)
+#define        LIST_END(head)                  NULL
+#define        LIST_EMPTY(head)                ((head)->lh_first == LIST_END(head))
+#define        LIST_NEXT(elm, field)           ((elm)->field.le_next)
+
+#define        LIST_FOREACH(var, head, field)                                  \
+       for ((var) = ((head)->lh_first);                                \
+           (var) != LIST_END(head);                                    \
+           (var) = ((var)->field.le_next))
+
+#define        LIST_FOREACH_SAFE(var, head, field, tvar)                       \
+       for ((var) = LIST_FIRST((head));                                \
+           (var) != LIST_END(head) &&                                  \
+           ((tvar) = LIST_NEXT((var), field), 1);                      \
+           (var) = (tvar))
+
+#define        LIST_MOVE(head1, head2, field) do {                             \
+       LIST_INIT((head2));                                             \
+       if (!LIST_EMPTY((head1))) {                                     \
+               (head2)->lh_first = (head1)->lh_first;                  \
+               (head2)->lh_first->field.le_prev = &(head2)->lh_first;  \
+               LIST_INIT((head1));                                     \
+       }                                                               \
+} while (0)
+
+/*
+ * List functions.
+ */
+#if defined(QUEUEDEBUG)
+#define        QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field)                   \
+       if ((head)->lh_first &&                                         \
+           (head)->lh_first->field.le_prev != &(head)->lh_first)       \
+               QUEUEDEBUG_ABORT("LIST_INSERT_HEAD %p %s:%d", (head),   \
+                   __FILE__, __LINE__);
+#define        QUEUEDEBUG_LIST_OP(elm, field)                                  \
+       if ((elm)->field.le_next &&                                     \
+           (elm)->field.le_next->field.le_prev !=                      \
+           &(elm)->field.le_next)                                      \
+               QUEUEDEBUG_ABORT("LIST_* forw %p %s:%d", (elm),         \
+                   __FILE__, __LINE__);                                \
+       if (*(elm)->field.le_prev != (elm))                             \
+               QUEUEDEBUG_ABORT("LIST_* back %p %s:%d", (elm),         \
+                   __FILE__, __LINE__);
+#define        QUEUEDEBUG_LIST_POSTREMOVE(elm, field)                          \
+       (elm)->field.le_next = (void *)1L;                              \
+       (elm)->field.le_prev = (void *)1L;
+#else
+#define        QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field)
+#define        QUEUEDEBUG_LIST_OP(elm, field)
+#define        QUEUEDEBUG_LIST_POSTREMOVE(elm, field)
+#endif
+
+#define        LIST_INIT(head) do {                                            \
+       (head)->lh_first = LIST_END(head);                              \
+} while (0)
+
+#define        LIST_INSERT_AFTER(listelm, elm, field) do {                     \
+       QUEUEDEBUG_LIST_OP((listelm), field)                            \
+       if (((elm)->field.le_next = (listelm)->field.le_next) !=        \
+           LIST_END(head))                                             \
+               (listelm)->field.le_next->field.le_prev =               \
+                   &(elm)->field.le_next;                              \
+       (listelm)->field.le_next = (elm);                               \
+       (elm)->field.le_prev = &(listelm)->field.le_next;               \
+} while (0)
+
+#define        LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
+       QUEUEDEBUG_LIST_OP((listelm), field)                            \
+       (elm)->field.le_prev = (listelm)->field.le_prev;                \
+       (elm)->field.le_next = (listelm);                               \
+       *(listelm)->field.le_prev = (elm);                              \
+       (listelm)->field.le_prev = &(elm)->field.le_next;               \
+} while (0)
+
+#define        LIST_INSERT_HEAD(head, elm, field) do {                         \
+       QUEUEDEBUG_LIST_INSERT_HEAD((head), (elm), field)               \
+       if (((elm)->field.le_next = (head)->lh_first) != LIST_END(head))\
+               (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
+       (head)->lh_first = (elm);                                       \
+       (elm)->field.le_prev = &(head)->lh_first;                       \
+} while (0)
+
+#define        LIST_REMOVE(elm, field) do {                                    \
+       QUEUEDEBUG_LIST_OP((elm), field)                                \
+       if ((elm)->field.le_next != NULL)                               \
+               (elm)->field.le_next->field.le_prev =                   \
+                   (elm)->field.le_prev;                               \
+       *(elm)->field.le_prev = (elm)->field.le_next;                   \
+       QUEUEDEBUG_LIST_POSTREMOVE((elm), field)                        \
+} while (0)
+
+#define LIST_REPLACE(elm, elm2, field) do {                            \
+       if (((elm2)->field.le_next = (elm)->field.le_next) != NULL)     \
+               (elm2)->field.le_next->field.le_prev =                  \
+                   &(elm2)->field.le_next;                             \
+       (elm2)->field.le_prev = (elm)->field.le_prev;                   \
+       *(elm2)->field.le_prev = (elm2);                                \
+       QUEUEDEBUG_LIST_POSTREMOVE((elm), field)                        \
+} while (0)
+
+/*
+ * Simple queue definitions.
+ */
+#define        SIMPLEQ_HEAD(name, type)                                        \
+struct name {                                                          \
+       struct type *sqh_first; /* first element */                     \
+       struct type **sqh_last; /* addr of last next element */         \
+}
+
+#define        SIMPLEQ_HEAD_INITIALIZER(head)                                  \
+       { NULL, &(head).sqh_first }
+
+#define        SIMPLEQ_ENTRY(type)                                             \
+struct {                                                               \
+       struct type *sqe_next;  /* next element */                      \
+}
+
+/*
+ * Simple queue access methods.
+ */
+#define        SIMPLEQ_FIRST(head)             ((head)->sqh_first)
+#define        SIMPLEQ_END(head)               NULL
+#define        SIMPLEQ_EMPTY(head)             ((head)->sqh_first == SIMPLEQ_END(head))
+#define        SIMPLEQ_NEXT(elm, field)        ((elm)->field.sqe_next)
+
+#define        SIMPLEQ_FOREACH(var, head, field)                               \
+       for ((var) = ((head)->sqh_first);                               \
+           (var) != SIMPLEQ_END(head);                                 \
+           (var) = ((var)->field.sqe_next))
+
+#define        SIMPLEQ_FOREACH_SAFE(var, head, field, next)                    \
+       for ((var) = ((head)->sqh_first);                               \
+           (var) != SIMPLEQ_END(head) &&                               \
+           ((next = ((var)->field.sqe_next)), 1);                      \
+           (var) = (next))
+
+/*
+ * Simple queue functions.
+ */
+#define        SIMPLEQ_INIT(head) do {                                         \
+       (head)->sqh_first = NULL;                                       \
+       (head)->sqh_last = &(head)->sqh_first;                          \
+} while (0)
+
+#define        SIMPLEQ_INSERT_HEAD(head, elm, field) do {                      \
+       if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)        \
+               (head)->sqh_last = &(elm)->field.sqe_next;              \
+       (head)->sqh_first = (elm);                                      \
+} while (0)
+
+#define        SIMPLEQ_INSERT_TAIL(head, elm, field) do {                      \
+       (elm)->field.sqe_next = NULL;                                   \
+       *(head)->sqh_last = (elm);                                      \
+       (head)->sqh_last = &(elm)->field.sqe_next;                      \
+} while (0)
+
+#define        SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
+       if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
+               (head)->sqh_last = &(elm)->field.sqe_next;              \
+       (listelm)->field.sqe_next = (elm);                              \
+} while (0)
+
+#define        SIMPLEQ_REMOVE_HEAD(head, field) do {                           \
+       if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \
+               (head)->sqh_last = &(head)->sqh_first;                  \
+} while (0)
+
+#define SIMPLEQ_REMOVE_AFTER(head, elm, field) do {                    \
+       if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \
+           == NULL)                                                    \
+               (head)->sqh_last = &(elm)->field.sqe_next;              \
+} while (0)
+
+#define        SIMPLEQ_REMOVE(head, elm, type, field) do {                     \
+       if ((head)->sqh_first == (elm)) {                               \
+               SIMPLEQ_REMOVE_HEAD((head), field);                     \
+       } else {                                                        \
+               struct type *curelm = (head)->sqh_first;                \
+               while (curelm->field.sqe_next != (elm))                 \
+                       curelm = curelm->field.sqe_next;                \
+               if ((curelm->field.sqe_next =                           \
+                       curelm->field.sqe_next->field.sqe_next) == NULL) \
+                           (head)->sqh_last = &(curelm)->field.sqe_next; \
+       }                                                               \
+} while (0)
+
+#define        SIMPLEQ_CONCAT(head1, head2) do {                               \
+       if (!SIMPLEQ_EMPTY((head2))) {                                  \
+               *(head1)->sqh_last = (head2)->sqh_first;                \
+               (head1)->sqh_last = (head2)->sqh_last;          \
+               SIMPLEQ_INIT((head2));                                  \
+       }                                                               \
+} while (0)
+
+#define        SIMPLEQ_LAST(head, type, field)                                 \
+       (SIMPLEQ_EMPTY((head)) ?                                                \
+               NULL :                                                  \
+               ((struct type *)(void *)                                \
+               ((char *)((head)->sqh_last) - offsetof(struct type, field))))
+
+/*
+ * Tail queue definitions.
+ */
+#define        _TAILQ_HEAD(name, type, qual)                                   \
+struct name {                                                          \
+       qual type *tqh_first;           /* first element */             \
+       qual type *qual *tqh_last;      /* addr of last next element */ \
+}
+#define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,)
+
+#define        TAILQ_HEAD_INITIALIZER(head)                                    \
+       { TAILQ_END(head), &(head).tqh_first }
+
+#define        _TAILQ_ENTRY(type, qual)                                        \
+struct {                                                               \
+       qual type *tqe_next;            /* next element */              \
+       qual type *qual *tqe_prev;      /* address of previous next element */\
+}
+#define TAILQ_ENTRY(type)      _TAILQ_ENTRY(struct type,)
+
+/*
+ * Tail queue access methods.
+ */
+#define        TAILQ_FIRST(head)               ((head)->tqh_first)
+#define        TAILQ_END(head)                 (NULL)
+#define        TAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
+#define        TAILQ_LAST(head, headname) \
+       (*(((struct headname *)(void *)((head)->tqh_last))->tqh_last))
+#define        TAILQ_PREV(elm, headname, field) \
+       (*(((struct headname *)(void *)((elm)->field.tqe_prev))->tqh_last))
+#define        TAILQ_EMPTY(head)               (TAILQ_FIRST(head) == TAILQ_END(head))
+
+
+#define        TAILQ_FOREACH(var, head, field)                                 \
+       for ((var) = ((head)->tqh_first);                               \
+           (var) != TAILQ_END(head);                                   \
+           (var) = ((var)->field.tqe_next))
+
+#define        TAILQ_FOREACH_SAFE(var, head, field, next)                      \
+       for ((var) = ((head)->tqh_first);                               \
+           (var) != TAILQ_END(head) &&                                 \
+           ((next) = TAILQ_NEXT(var, field), 1); (var) = (next))
+
+#define        TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
+       for ((var) = TAILQ_LAST((head), headname);                      \
+           (var) != TAILQ_END(head);                                   \
+           (var) = TAILQ_PREV((var), headname, field))
+
+#define        TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, prev)    \
+       for ((var) = TAILQ_LAST((head), headname);                      \
+           (var) != TAILQ_END(head) &&                                 \
+           ((prev) = TAILQ_PREV((var), headname, field), 1); (var) = (prev))
+
+/*
+ * Tail queue functions.
+ */
+#if defined(QUEUEDEBUG)
+#define        QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field)                  \
+       if ((head)->tqh_first &&                                        \
+           (head)->tqh_first->field.tqe_prev != &(head)->tqh_first)    \
+               QUEUEDEBUG_ABORT("TAILQ_INSERT_HEAD %p %s:%d", (head),  \
+                   __FILE__, __LINE__);
+#define        QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field)                  \
+       if (*(head)->tqh_last != NULL)                                  \
+               QUEUEDEBUG_ABORT("TAILQ_INSERT_TAIL %p %s:%d", (head),  \
+                   __FILE__, __LINE__);
+#define        QUEUEDEBUG_TAILQ_OP(elm, field)                                 \
+       if ((elm)->field.tqe_next &&                                    \
+           (elm)->field.tqe_next->field.tqe_prev !=                    \
+           &(elm)->field.tqe_next)                                     \
+               QUEUEDEBUG_ABORT("TAILQ_* forw %p %s:%d", (elm),        \
+                   __FILE__, __LINE__);                                \
+       if (*(elm)->field.tqe_prev != (elm))                            \
+               QUEUEDEBUG_ABORT("TAILQ_* back %p %s:%d", (elm),        \
+                   __FILE__, __LINE__);
+#define        QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field)                    \
+       if ((elm)->field.tqe_next == NULL &&                            \
+           (head)->tqh_last != &(elm)->field.tqe_next)                 \
+               QUEUEDEBUG_ABORT("TAILQ_PREREMOVE head %p elm %p %s:%d",\
+                   (head), (elm), __FILE__, __LINE__);
+#define        QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field)                         \
+       (elm)->field.tqe_next = (void *)1L;                             \
+       (elm)->field.tqe_prev = (void *)1L;
+#else
+#define        QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field)
+#define        QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field)
+#define        QUEUEDEBUG_TAILQ_OP(elm, field)
+#define        QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field)
+#define        QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field)
+#endif
+
+#define        TAILQ_INIT(head) do {                                           \
+       (head)->tqh_first = TAILQ_END(head);                            \
+       (head)->tqh_last = &(head)->tqh_first;                          \
+} while (0)
+
+#define        TAILQ_INSERT_HEAD(head, elm, field) do {                        \
+       QUEUEDEBUG_TAILQ_INSERT_HEAD((head), (elm), field)              \
+       if (((elm)->field.tqe_next = (head)->tqh_first) != TAILQ_END(head))\
+               (head)->tqh_first->field.tqe_prev =                     \
+                   &(elm)->field.tqe_next;                             \
+       else                                                            \
+               (head)->tqh_last = &(elm)->field.tqe_next;              \
+       (head)->tqh_first = (elm);                                      \
+       (elm)->field.tqe_prev = &(head)->tqh_first;                     \
+} while (0)
+
+#define        TAILQ_INSERT_TAIL(head, elm, field) do {                        \
+       QUEUEDEBUG_TAILQ_INSERT_TAIL((head), (elm), field)              \
+       (elm)->field.tqe_next = TAILQ_END(head);                        \
+       (elm)->field.tqe_prev = (head)->tqh_last;                       \
+       *(head)->tqh_last = (elm);                                      \
+       (head)->tqh_last = &(elm)->field.tqe_next;                      \
+} while (0)
+
+#define        TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
+       QUEUEDEBUG_TAILQ_OP((listelm), field)                           \
+       if (((elm)->field.tqe_next = (listelm)->field.tqe_next) !=      \
+           TAILQ_END(head))                                            \
+               (elm)->field.tqe_next->field.tqe_prev =                 \
+                   &(elm)->field.tqe_next;                             \
+       else                                                            \
+               (head)->tqh_last = &(elm)->field.tqe_next;              \
+       (listelm)->field.tqe_next = (elm);                              \
+       (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
+} while (0)
+
+#define        TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
+       QUEUEDEBUG_TAILQ_OP((listelm), field)                           \
+       (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
+       (elm)->field.tqe_next = (listelm);                              \
+       *(listelm)->field.tqe_prev = (elm);                             \
+       (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
+} while (0)
+
+#define        TAILQ_REMOVE(head, elm, field) do {                             \
+       QUEUEDEBUG_TAILQ_PREREMOVE((head), (elm), field)                \
+       QUEUEDEBUG_TAILQ_OP((elm), field)                               \
+       if (((elm)->field.tqe_next) != TAILQ_END(head))                 \
+               (elm)->field.tqe_next->field.tqe_prev =                 \
+                   (elm)->field.tqe_prev;                              \
+       else                                                            \
+               (head)->tqh_last = (elm)->field.tqe_prev;               \
+       *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
+       QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field);                      \
+} while (0)
+
+#define TAILQ_REPLACE(head, elm, elm2, field) do {                     \
+        if (((elm2)->field.tqe_next = (elm)->field.tqe_next) !=        \
+           TAILQ_END(head))                                            \
+                (elm2)->field.tqe_next->field.tqe_prev =               \
+                    &(elm2)->field.tqe_next;                           \
+        else                                                           \
+                (head)->tqh_last = &(elm2)->field.tqe_next;            \
+        (elm2)->field.tqe_prev = (elm)->field.tqe_prev;                        \
+        *(elm2)->field.tqe_prev = (elm2);                              \
+       QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field);                      \
+} while (0)
+
+#define        TAILQ_CONCAT(head1, head2, field) do {                          \
+       if (!TAILQ_EMPTY(head2)) {                                      \
+               *(head1)->tqh_last = (head2)->tqh_first;                \
+               (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
+               (head1)->tqh_last = (head2)->tqh_last;                  \
+               TAILQ_INIT((head2));                                    \
+       }                                                               \
+} while (0)
+
+/*
+ * Singly-linked Tail queue declarations.
+ */
+#define        STAILQ_HEAD(name, type)                                         \
+struct name {                                                          \
+       struct type *stqh_first;        /* first element */             \
+       struct type **stqh_last;        /* addr of last next element */ \
+}
+
+#define        STAILQ_HEAD_INITIALIZER(head)                                   \
+       { NULL, &(head).stqh_first }
+
+#define        STAILQ_ENTRY(type)                                              \
+struct {                                                               \
+       struct type *stqe_next; /* next element */                      \
+}
+
+/*
+ * Singly-linked Tail queue access methods.
+ */
+#define        STAILQ_FIRST(head)      ((head)->stqh_first)
+#define        STAILQ_END(head)        NULL
+#define        STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
+#define        STAILQ_EMPTY(head)      (STAILQ_FIRST(head) == STAILQ_END(head))
+
+/*
+ * Singly-linked Tail queue functions.
+ */
+#define        STAILQ_INIT(head) do {                                          \
+       (head)->stqh_first = NULL;                                      \
+       (head)->stqh_last = &(head)->stqh_first;                                \
+} while (0)
+
+#define        STAILQ_INSERT_HEAD(head, elm, field) do {                       \
+       if (((elm)->field.stqe_next = (head)->stqh_first) == NULL)      \
+               (head)->stqh_last = &(elm)->field.stqe_next;            \
+       (head)->stqh_first = (elm);                                     \
+} while (0)
+
+#define        STAILQ_INSERT_TAIL(head, elm, field) do {                       \
+       (elm)->field.stqe_next = NULL;                                  \
+       *(head)->stqh_last = (elm);                                     \
+       (head)->stqh_last = &(elm)->field.stqe_next;                    \
+} while (0)
+
+#define        STAILQ_INSERT_AFTER(head, listelm, elm, field) do {             \
+       if (((elm)->field.stqe_next = (listelm)->field.stqe_next) == NULL)\
+               (head)->stqh_last = &(elm)->field.stqe_next;            \
+       (listelm)->field.stqe_next = (elm);                             \
+} while (0)
+
+#define        STAILQ_REMOVE_HEAD(head, field) do {                            \
+       if (((head)->stqh_first = (head)->stqh_first->field.stqe_next) == NULL) \
+               (head)->stqh_last = &(head)->stqh_first;                        \
+} while (0)
+
+#define        STAILQ_REMOVE(head, elm, type, field) do {                      \
+       if ((head)->stqh_first == (elm)) {                              \
+               STAILQ_REMOVE_HEAD((head), field);                      \
+       } else {                                                        \
+               struct type *curelm = (head)->stqh_first;               \
+               while (curelm->field.stqe_next != (elm))                        \
+                       curelm = curelm->field.stqe_next;               \
+               if ((curelm->field.stqe_next =                          \
+                       curelm->field.stqe_next->field.stqe_next) == NULL) \
+                           (head)->stqh_last = &(curelm)->field.stqe_next; \
+       }                                                               \
+} while (0)
+
+#define        STAILQ_FOREACH(var, head, field)                                \
+       for ((var) = ((head)->stqh_first);                              \
+               (var);                                                  \
+               (var) = ((var)->field.stqe_next))
+
+#define        STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
+       for ((var) = STAILQ_FIRST((head));                              \
+           (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
+           (var) = (tvar))
+
+#define        STAILQ_CONCAT(head1, head2) do {                                \
+       if (!STAILQ_EMPTY((head2))) {                                   \
+               *(head1)->stqh_last = (head2)->stqh_first;              \
+               (head1)->stqh_last = (head2)->stqh_last;                \
+               STAILQ_INIT((head2));                                   \
+       }                                                               \
+} while (0)
+
+#define        STAILQ_LAST(head, type, field)                                  \
+       (STAILQ_EMPTY((head)) ?                                         \
+               NULL :                                                  \
+               ((struct type *)(void *)                                \
+               ((char *)((head)->stqh_last) - offsetof(struct type, field))))
+
+#endif /* !_SYS_QUEUE_H_ */