tor/src/ext/tor_queue.h
teor 13298d90a9 Silence spurious clang warnings
Silence clang warnings under --enable-expensive-hardening, including:
  + implicit truncation of 64 bit values to 32 bit;
  + const char assignment to self;
  + tautological compare; and
  + additional parentheses around equality tests. (gcc uses these to
    silence assignment, so clang warns when they're present in an
    equality test. But we need to use extra parentheses in macros to
    isolate them from other code).
2014-10-30 22:34:46 +11:00

576 lines
20 KiB
C

/* $OpenBSD: queue.h,v 1.36 2012/04/11 13:29:14 naddy Exp $ */
/* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft 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 TOR_QUEUE_H_
#define TOR_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 before or 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.
*
* A circle 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 circle queue may be traversed in either direction, but has a more
* complex end of list detection.
*
* For details on the use of these macros, see the queue(3) manual page.
*/
#if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC))
#define TOR_Q_INVALIDATE_(a) (a) = ((void *)-1)
#else
#define TOR_Q_INVALIDATE_(a)
#endif
/*
* Singly-linked List definitions.
*/
#define TOR_SLIST_HEAD(name, type) \
struct name { \
struct type *slh_first; /* first element */ \
}
#define TOR_SLIST_HEAD_INITIALIZER(head) \
{ NULL }
#define TOR_SLIST_ENTRY(type) \
struct { \
struct type *sle_next; /* next element */ \
}
/*
* Singly-linked List access methods.
*/
#define TOR_SLIST_FIRST(head) ((head)->slh_first)
#define TOR_SLIST_END(head) NULL
/* || 0 is for -Wparentheses-equality (-Wall?) appeasement under clang */
#define TOR_SLIST_EMPTY(head) ((SLIST_FIRST(head) == TOR_SLIST_END(head)) || 0)
#define TOR_SLIST_NEXT(elm, field) ((elm)->field.sle_next)
#define TOR_SLIST_FOREACH(var, head, field) \
for((var) = TOR_SLIST_FIRST(head); \
(var) != TOR_SLIST_END(head); \
(var) = TOR_SLIST_NEXT(var, field))
#define TOR_SLIST_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TOR_SLIST_FIRST(head); \
(var) && ((tvar) = TOR_SLIST_NEXT(var, field), 1); \
(var) = (tvar))
/*
* Singly-linked List functions.
*/
#define TOR_SLIST_INIT(head) { \
TOR_SLIST_FIRST(head) = TOR_SLIST_END(head); \
}
#define TOR_SLIST_INSERT_AFTER(slistelm, elm, field) do { \
(elm)->field.sle_next = (slistelm)->field.sle_next; \
(slistelm)->field.sle_next = (elm); \
} while (0)
#define TOR_SLIST_INSERT_HEAD(head, elm, field) do { \
(elm)->field.sle_next = (head)->slh_first; \
(head)->slh_first = (elm); \
} while (0)
#define TOR_SLIST_REMOVE_AFTER(elm, field) do { \
(elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \
} while (0)
#define TOR_SLIST_REMOVE_HEAD(head, field) do { \
(head)->slh_first = (head)->slh_first->field.sle_next; \
} while (0)
#define TOR_SLIST_REMOVE(head, elm, type, field) do { \
if ((head)->slh_first == (elm)) { \
TOR_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; \
TOR_Q_INVALIDATE_((elm)->field.sle_next); \
} \
} while (0)
/*
* List definitions.
*/
#define TOR_LIST_HEAD(name, type) \
struct name { \
struct type *lh_first; /* first element */ \
}
#define TOR_LIST_HEAD_INITIALIZER(head) \
{ NULL }
#define TOR_LIST_ENTRY(type) \
struct { \
struct type *le_next; /* next element */ \
struct type **le_prev; /* address of previous next element */ \
}
/*
* List access methods
*/
#define TOR_LIST_FIRST(head) ((head)->lh_first)
#define TOR_LIST_END(head) NULL
/* || 0 is for -Wparentheses-equality (-Wall?) appeasement under clang */
#define TOR_LIST_EMPTY(head) \
((TOR_LIST_FIRST(head) == TOR_LIST_END(head)) || 0)
#define TOR_LIST_NEXT(elm, field) ((elm)->field.le_next)
#define TOR_LIST_FOREACH(var, head, field) \
for((var) = TOR_LIST_FIRST(head); \
(var)!= TOR_LIST_END(head); \
(var) = TOR_LIST_NEXT(var, field))
#define TOR_LIST_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TOR_LIST_FIRST(head); \
(var) && ((tvar) = TOR_LIST_NEXT(var, field), 1); \
(var) = (tvar))
/*
* List functions.
*/
#define TOR_LIST_INIT(head) do { \
TOR_LIST_FIRST(head) = TOR_LIST_END(head); \
} while (0)
#define TOR_LIST_INSERT_AFTER(listelm, elm, field) do { \
if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
(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 TOR_LIST_INSERT_BEFORE(listelm, elm, field) do { \
(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 TOR_LIST_INSERT_HEAD(head, elm, field) do { \
if (((elm)->field.le_next = (head)->lh_first) != NULL) \
(head)->lh_first->field.le_prev = &(elm)->field.le_next;\
(head)->lh_first = (elm); \
(elm)->field.le_prev = &(head)->lh_first; \
} while (0)
#define TOR_LIST_REMOVE(elm, field) do { \
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; \
TOR_Q_INVALIDATE_((elm)->field.le_prev); \
TOR_Q_INVALIDATE_((elm)->field.le_next); \
} while (0)
#define TOR_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); \
TOR_Q_INVALIDATE_((elm)->field.le_prev); \
TOR_Q_INVALIDATE_((elm)->field.le_next); \
} while (0)
/*
* Simple queue definitions.
*/
#define TOR_SIMPLEQ_HEAD(name, type) \
struct name { \
struct type *sqh_first; /* first element */ \
struct type **sqh_last; /* addr of last next element */ \
}
#define TOR_SIMPLEQ_HEAD_INITIALIZER(head) \
{ NULL, &(head).sqh_first }
#define TOR_SIMPLEQ_ENTRY(type) \
struct { \
struct type *sqe_next; /* next element */ \
}
/*
* Simple queue access methods.
*/
#define TOR_SIMPLEQ_FIRST(head) ((head)->sqh_first)
#define TOR_SIMPLEQ_END(head) NULL
/* || 0 is for -Wparentheses-equality (-Wall?) appeasement under clang */
#define TOR_SIMPLEQ_EMPTY(head) \
((TOR_SIMPLEQ_FIRST(head) == TOR_SIMPLEQ_END(head)) || 0)
#define TOR_SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
#define TOR_SIMPLEQ_FOREACH(var, head, field) \
for((var) = TOR_SIMPLEQ_FIRST(head); \
(var) != TOR_SIMPLEQ_END(head); \
(var) = TOR_SIMPLEQ_NEXT(var, field))
#define TOR_SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TOR_SIMPLEQ_FIRST(head); \
(var) && ((tvar) = TOR_SIMPLEQ_NEXT(var, field), 1); \
(var) = (tvar))
/*
* Simple queue functions.
*/
#define TOR_SIMPLEQ_INIT(head) do { \
(head)->sqh_first = NULL; \
(head)->sqh_last = &(head)->sqh_first; \
} while (0)
#define TOR_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 TOR_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 TOR_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 TOR_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 TOR_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)
/*
* Tail queue definitions.
*/
#define TOR_TAILQ_HEAD(name, type) \
struct name { \
struct type *tqh_first; /* first element */ \
struct type **tqh_last; /* addr of last next element */ \
}
#define TOR_TAILQ_HEAD_INITIALIZER(head) \
{ NULL, &(head).tqh_first }
#define TOR_TAILQ_ENTRY(type) \
struct { \
struct type *tqe_next; /* next element */ \
struct type **tqe_prev; /* address of previous next element */ \
}
/*
* tail queue access methods
*/
#define TOR_TAILQ_FIRST(head) ((head)->tqh_first)
#define TOR_TAILQ_END(head) NULL
#define TOR_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
#define TOR_TAILQ_LAST(head, headname) \
(*(((struct headname *)((head)->tqh_last))->tqh_last))
/* XXX */
#define TOR_TAILQ_PREV(elm, headname, field) \
(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
/* || 0 is for -Wparentheses-equality (-Wall?) appeasement under clang */
#define TOR_TAILQ_EMPTY(head) \
((TOR_TAILQ_FIRST(head) == TOR_TAILQ_END(head)) || 0)
#define TOR_TAILQ_FOREACH(var, head, field) \
for((var) = TOR_TAILQ_FIRST(head); \
(var) != TOR_TAILQ_END(head); \
(var) = TOR_TAILQ_NEXT(var, field))
#define TOR_TAILQ_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TOR_TAILQ_FIRST(head); \
(var) != TOR_TAILQ_END(head) && \
((tvar) = TOR_TAILQ_NEXT(var, field), 1); \
(var) = (tvar))
#define TOR_TAILQ_FOREACH_REVERSE(var, head, headname, field) \
for((var) = TOR_TAILQ_LAST(head, headname); \
(var) != TOR_TAILQ_END(head); \
(var) = TOR_TAILQ_PREV(var, headname, field))
#define TOR_TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
for ((var) = TOR_TAILQ_LAST(head, headname); \
(var) != TOR_TAILQ_END(head) && \
((tvar) = TOR_TAILQ_PREV(var, headname, field), 1); \
(var) = (tvar))
/*
* Tail queue functions.
*/
#define TOR_TAILQ_INIT(head) do { \
(head)->tqh_first = NULL; \
(head)->tqh_last = &(head)->tqh_first; \
} while (0)
#define TOR_TAILQ_INSERT_HEAD(head, elm, field) do { \
if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
(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 TOR_TAILQ_INSERT_TAIL(head, elm, field) do { \
(elm)->field.tqe_next = NULL; \
(elm)->field.tqe_prev = (head)->tqh_last; \
*(head)->tqh_last = (elm); \
(head)->tqh_last = &(elm)->field.tqe_next; \
} while (0)
#define TOR_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
(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 TOR_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
(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 TOR_TAILQ_REMOVE(head, elm, field) do { \
if (((elm)->field.tqe_next) != NULL) \
(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; \
TOR_Q_INVALIDATE_((elm)->field.tqe_prev); \
TOR_Q_INVALIDATE_((elm)->field.tqe_next); \
} while (0)
#define TOR_TAILQ_REPLACE(head, elm, elm2, field) do { \
if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \
(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); \
TOR_Q_INVALIDATE_((elm)->field.tqe_prev); \
TOR_Q_INVALIDATE_((elm)->field.tqe_next); \
} while (0)
/*
* Circular queue definitions.
*/
#define TOR_CIRCLEQ_HEAD(name, type) \
struct name { \
struct type *cqh_first; /* first element */ \
struct type *cqh_last; /* last element */ \
}
#define TOR_CIRCLEQ_HEAD_INITIALIZER(head) \
{ TOR_CIRCLEQ_END(&head), TOR_CIRCLEQ_END(&head) }
#define TOR_CIRCLEQ_ENTRY(type) \
struct { \
struct type *cqe_next; /* next element */ \
struct type *cqe_prev; /* previous element */ \
}
/*
* Circular queue access methods
*/
#define TOR_CIRCLEQ_FIRST(head) ((head)->cqh_first)
#define TOR_CIRCLEQ_LAST(head) ((head)->cqh_last)
#define TOR_CIRCLEQ_END(head) ((void *)(head))
#define TOR_CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
#define TOR_CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
/* || 0 is for -Wparentheses-equality (-Wall?) appeasement under clang */
#define TOR_CIRCLEQ_EMPTY(head) \
((TOR_CIRCLEQ_FIRST(head) == TOR_CIRCLEQ_END(head)) || 0)
#define TOR_CIRCLEQ_FOREACH(var, head, field) \
for((var) = TOR_CIRCLEQ_FIRST(head); \
(var) != TOR_CIRCLEQ_END(head); \
(var) = TOR_CIRCLEQ_NEXT(var, field))
#define TOR_CIRCLEQ_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TOR_CIRCLEQ_FIRST(head); \
(var) != TOR_CIRCLEQ_END(head) && \
((tvar) = TOR_CIRCLEQ_NEXT(var, field), 1); \
(var) = (tvar))
#define TOR_CIRCLEQ_FOREACH_REVERSE(var, head, field) \
for((var) = TOR_CIRCLEQ_LAST(head); \
(var) != TOR_CIRCLEQ_END(head); \
(var) = TOR_CIRCLEQ_PREV(var, field))
#define TOR_CIRCLEQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
for ((var) = TOR_CIRCLEQ_LAST(head, headname); \
(var) != TOR_CIRCLEQ_END(head) && \
((tvar) = TOR_CIRCLEQ_PREV(var, headname, field), 1); \
(var) = (tvar))
/*
* Circular queue functions.
*/
#define TOR_CIRCLEQ_INIT(head) do { \
(head)->cqh_first = TOR_CIRCLEQ_END(head); \
(head)->cqh_last = TOR_CIRCLEQ_END(head); \
} while (0)
#define TOR_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
(elm)->field.cqe_next = (listelm)->field.cqe_next; \
(elm)->field.cqe_prev = (listelm); \
if ((listelm)->field.cqe_next == TOR_CIRCLEQ_END(head)) \
(head)->cqh_last = (elm); \
else \
(listelm)->field.cqe_next->field.cqe_prev = (elm); \
(listelm)->field.cqe_next = (elm); \
} while (0)
#define TOR_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
(elm)->field.cqe_next = (listelm); \
(elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
if ((listelm)->field.cqe_prev == TOR_CIRCLEQ_END(head)) \
(head)->cqh_first = (elm); \
else \
(listelm)->field.cqe_prev->field.cqe_next = (elm); \
(listelm)->field.cqe_prev = (elm); \
} while (0)
#define TOR_CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
(elm)->field.cqe_next = (head)->cqh_first; \
(elm)->field.cqe_prev = TOR_CIRCLEQ_END(head); \
if ((head)->cqh_last == TOR_CIRCLEQ_END(head)) \
(head)->cqh_last = (elm); \
else \
(head)->cqh_first->field.cqe_prev = (elm); \
(head)->cqh_first = (elm); \
} while (0)
#define TOR_CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
(elm)->field.cqe_next = TOR_CIRCLEQ_END(head); \
(elm)->field.cqe_prev = (head)->cqh_last; \
if ((head)->cqh_first == TOR_CIRCLEQ_END(head)) \
(head)->cqh_first = (elm); \
else \
(head)->cqh_last->field.cqe_next = (elm); \
(head)->cqh_last = (elm); \
} while (0)
#define TOR_CIRCLEQ_REMOVE(head, elm, field) do { \
if ((elm)->field.cqe_next == TOR_CIRCLEQ_END(head)) \
(head)->cqh_last = (elm)->field.cqe_prev; \
else \
(elm)->field.cqe_next->field.cqe_prev = \
(elm)->field.cqe_prev; \
if ((elm)->field.cqe_prev == TOR_CIRCLEQ_END(head)) \
(head)->cqh_first = (elm)->field.cqe_next; \
else \
(elm)->field.cqe_prev->field.cqe_next = \
(elm)->field.cqe_next; \
TOR_Q_INVALIDATE_((elm)->field.cqe_prev); \
TOR_Q_INVALIDATE_((elm)->field.cqe_next); \
} while (0)
#define TOR_CIRCLEQ_REPLACE(head, elm, elm2, field) do { \
if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \
TOR_CIRCLEQ_END(head)) \
(head).cqh_last = (elm2); \
else \
(elm2)->field.cqe_next->field.cqe_prev = (elm2); \
if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \
TOR_CIRCLEQ_END(head)) \
(head).cqh_first = (elm2); \
else \
(elm2)->field.cqe_prev->field.cqe_next = (elm2); \
TOR_Q_INVALIDATE_((elm)->field.cqe_prev); \
TOR_Q_INVALIDATE_((elm)->field.cqe_next); \
} while (0)
#endif /* !_SYS_QUEUE_H_ */