NeoMutt
2019-12-07
Teaching an old dog new tricks
DOXYGEN
queue.h
Go to the documentation of this file.
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/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)queue.h 8.5 (Berkeley) 8/20/94
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* $FreeBSD: head/sys/sys/queue.h 314436 2017-02-28 23:42:47Z imp $
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*/
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#ifndef SYS_QUEUE_H_
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#define SYS_QUEUE_H_
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/*
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* This file defines four types of data structures: singly-linked lists,
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* singly-linked tail queues, lists and tail queues.
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*
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* A singly-linked list is headed by a single forward pointer. The elements
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* are singly linked for minimum space and pointer manipulation overhead at
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* the expense of O(n) removal for arbitrary elements. New elements can be
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* added to the list after an existing element or at the head of the list.
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* Elements being removed from the head of the list should use the explicit
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* macro for this purpose for optimum efficiency. A singly-linked list may
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* only be traversed in the forward direction. Singly-linked lists are ideal
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* for applications with large datasets and few or no removals or for
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* implementing a LIFO queue.
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*
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* A singly-linked tail queue is headed by a pair of pointers, one to the
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* head of the list and the other to the tail of the list. The elements are
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* singly linked for minimum space and pointer manipulation overhead at the
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* expense of O(n) removal for arbitrary elements. New elements can be added
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* to the list after an existing element, at the head of the list, or at the
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* end of the list. Elements being removed from the head of the tail queue
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* should use the explicit macro for this purpose for optimum efficiency.
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* A singly-linked tail queue may only be traversed in the forward direction.
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* Singly-linked tail queues are ideal for applications with large datasets
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* and few or no removals or for implementing a FIFO queue.
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*
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* A list is headed by a single forward pointer (or an array of forward
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* pointers for a hash table header). The elements are doubly linked
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* so that an arbitrary element can be removed without a need to
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* traverse the list. New elements can be added to the list before
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* or after an existing element or at the head of the list. A list
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* may be traversed in either direction.
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*
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* A tail queue is headed by a pair of pointers, one to the head of the
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* list and the other to the tail of the list. The elements are doubly
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* linked so that an arbitrary element can be removed without a need to
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* traverse the list. New elements can be added to the list before or
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* after an existing element, at the head of the list, or at the end of
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* the list. A tail queue may be traversed in either direction.
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*
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* For details on the use of these macros, see the queue(3) manual page.
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*
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* Below is a summary of implemented functions where:
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* + means the macro is available
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* - means the macro is not available
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* s means the macro is available but is slow (runs in O(n) time)
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*
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* SLIST LIST STAILQ TAILQ
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* _HEAD + + + +
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* _CLASS_HEAD + + + +
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* _HEAD_INITIALIZER + + + +
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* _ENTRY + + + +
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* _CLASS_ENTRY + + + +
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* _INIT + + + +
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* _EMPTY + + + +
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* _FIRST + + + +
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* _NEXT + + + +
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* _PREV - + - +
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* _LAST - - + +
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* _FOREACH + + + +
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* _FOREACH_FROM + + + +
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* _FOREACH_SAFE + + + +
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* _FOREACH_FROM_SAFE + + + +
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* _FOREACH_REVERSE - - - +
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* _FOREACH_REVERSE_FROM - - - +
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* _FOREACH_REVERSE_SAFE - - - +
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* _FOREACH_REVERSE_FROM_SAFE - - - +
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* _INSERT_HEAD + + + +
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* _INSERT_BEFORE - + - +
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* _INSERT_AFTER + + + +
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* _INSERT_TAIL - - + +
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* _CONCAT s s + +
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* _REMOVE_AFTER + - + -
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* _REMOVE_HEAD + - + -
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* _REMOVE s + s +
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* _SWAP + + + +
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*
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*/
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#ifdef QUEUE_MACRO_DEBUG
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#warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH
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#define QUEUE_MACRO_DEBUG_TRACE
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#define QUEUE_MACRO_DEBUG_TRASH
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#endif
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#ifdef QUEUE_MACRO_DEBUG_TRACE
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/* Store the last 2 places the queue element or head was altered */
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struct
qm_trace {
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unsigned
long
lastline;
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unsigned
long
prevline;
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const
char
*lastfile;
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const
char
*prevfile;
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};
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#define TRACEBUF struct qm_trace trace;
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#define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } ,
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#define QMD_TRACE_HEAD(head) do { \
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(head)->trace.prevline = (head)->trace.lastline; \
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(head)->trace.prevfile = (head)->trace.lastfile; \
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(head)->trace.lastline = __LINE__; \
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(head)->trace.lastfile = __FILE__; \
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} while (0)
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#define QMD_TRACE_ELEM(elem) do { \
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(elem)->trace.prevline = (elem)->trace.lastline; \
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(elem)->trace.prevfile = (elem)->trace.lastfile; \
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(elem)->trace.lastline = __LINE__; \
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(elem)->trace.lastfile = __FILE__; \
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} while (0)
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#else
/* !QUEUE_MACRO_DEBUG_TRACE */
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#define QMD_TRACE_ELEM(elem)
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#define QMD_TRACE_HEAD(head)
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#define TRACEBUF
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#define TRACEBUF_INITIALIZER
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#endif
/* QUEUE_MACRO_DEBUG_TRACE */
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#ifdef QUEUE_MACRO_DEBUG_TRASH
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#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
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#define QMD_IS_TRASHED(x) ((x) == (void *)(intptr_t)-1)
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#else
/* !QUEUE_MACRO_DEBUG_TRASH */
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#define TRASHIT(x)
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#define QMD_IS_TRASHED(x) 0
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#endif
/* QUEUE_MACRO_DEBUG_TRASH */
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#if defined(QUEUE_MACRO_DEBUG_TRACE) || defined(QUEUE_MACRO_DEBUG_TRASH)
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#define QMD_SAVELINK(name, link) void **name = (void *)&(link)
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#else
/* !QUEUE_MACRO_DEBUG_TRACE && !QUEUE_MACRO_DEBUG_TRASH */
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#define QMD_SAVELINK(name, link)
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#endif
/* QUEUE_MACRO_DEBUG_TRACE || QUEUE_MACRO_DEBUG_TRASH */
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#ifdef __cplusplus
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/*
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* In C++ there can be structure lists and class lists:
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*/
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#define QUEUE_TYPEOF(type) type
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#else
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#define QUEUE_TYPEOF(type) struct type
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#endif
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/*
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* Singly-linked List declarations.
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*/
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#define SLIST_HEAD(name, type) \
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struct name { \
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struct type *slh_first;
/* first element */
\
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}
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#define SLIST_CLASS_HEAD(name, type) \
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struct name { \
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class type *slh_first;
/* first element */
\
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}
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#define SLIST_HEAD_INITIALIZER(head) \
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{ NULL }
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#define SLIST_ENTRY(type) \
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struct { \
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struct type *sle_next;
/* next element */
\
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}
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#define SLIST_CLASS_ENTRY(type) \
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struct { \
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class type *sle_next;
/* next element */
\
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}
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/*
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* Singly-linked List functions.
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*/
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#if (defined(_KERNEL) && defined(INVARIANTS))
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#define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do { \
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if (*(prevp) != (elm)) \
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panic("Bad prevptr *(%p) == %p != %p", \
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(prevp), *(prevp), (elm)); \
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} while (0)
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#else
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#define QMD_SLIST_CHECK_PREVPTR(prevp, elm)
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#endif
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#define SLIST_CONCAT(head1, head2, type, field) do { \
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QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \
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if (curelm == NULL) { \
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if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \
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SLIST_INIT(head2); \
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} else if (SLIST_FIRST(head2) != NULL) { \
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while (SLIST_NEXT(curelm, field) != NULL) \
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curelm = SLIST_NEXT(curelm, field); \
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SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \
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SLIST_INIT(head2); \
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} \
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} while (0)
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#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
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#define SLIST_FIRST(head) ((head)->slh_first)
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#define SLIST_FOREACH(var, head, field) \
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for ((var) = SLIST_FIRST((head)); \
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(var); \
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(var) = SLIST_NEXT((var), field))
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#define SLIST_FOREACH_FROM(var, head, field) \
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for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
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(var); \
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(var) = SLIST_NEXT((var), field))
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#define SLIST_FOREACH_SAFE(var, head, field, tvar) \
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for ((var) = SLIST_FIRST((head)); \
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(var) && ((tvar) = SLIST_NEXT((var), field), 1); \
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(var) = (tvar))
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#define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
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for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
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(var) && ((tvar) = SLIST_NEXT((var), field), 1); \
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(var) = (tvar))
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#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
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for ((varp) = &SLIST_FIRST((head)); \
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((var) = *(varp)) != NULL; \
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(varp) = &SLIST_NEXT((var), field))
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#define SLIST_INIT(head) do { \
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SLIST_FIRST((head)) = NULL; \
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} while (0)
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#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
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SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
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SLIST_NEXT((slistelm), field) = (elm); \
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} while (0)
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#define SLIST_INSERT_HEAD(head, elm, field) do { \
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SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
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SLIST_FIRST((head)) = (elm); \
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} while (0)
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#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
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#define SLIST_REMOVE(head, elm, type, field) do { \
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QMD_SAVELINK(oldnext, (elm)->field.sle_next); \
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if (SLIST_FIRST((head)) == (elm)) { \
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SLIST_REMOVE_HEAD((head), field); \
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} \
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else { \
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QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \
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while (SLIST_NEXT(curelm, field) != (elm)) \
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curelm = SLIST_NEXT(curelm, field); \
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SLIST_REMOVE_AFTER(curelm, field); \
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} \
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TRASHIT(*oldnext); \
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} while (0)
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#define SLIST_REMOVE_AFTER(elm, field) do { \
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SLIST_NEXT(elm, field) = \
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SLIST_NEXT(SLIST_NEXT(elm, field), field); \
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} while (0)
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#define SLIST_REMOVE_HEAD(head, field) do { \
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SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
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} while (0)
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#define SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \
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QMD_SLIST_CHECK_PREVPTR(prevp, elm); \
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*(prevp) = SLIST_NEXT(elm, field); \
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TRASHIT((elm)->field.sle_next); \
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} while (0)
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#define SLIST_SWAP(head1, head2, type) do { \
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QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \
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SLIST_FIRST(head1) = SLIST_FIRST(head2); \
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SLIST_FIRST(head2) = swap_first; \
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} while (0)
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/*
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* Singly-linked Tail queue declarations.
309
*/
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#define STAILQ_HEAD(name, type) \
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struct name { \
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struct type *stqh_first;
/* first element */
\
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struct type **stqh_last;
/* addr of last next element */
\
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}
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#define STAILQ_CLASS_HEAD(name, type) \
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struct name { \
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class type *stqh_first;
/* first element */
\
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class type **stqh_last;
/* addr of last next element */
\
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}
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#define STAILQ_HEAD_INITIALIZER(head) \
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{ NULL, &(head).stqh_first }
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#define STAILQ_ENTRY(type) \
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struct { \
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struct type *stqe_next;
/* next element */
\
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}
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#define STAILQ_CLASS_ENTRY(type) \
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struct { \
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class type *stqe_next;
/* next element */
\
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}
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/*
336
* Singly-linked Tail queue functions.
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*/
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#define STAILQ_CONCAT(head1, head2) do { \
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if (!STAILQ_EMPTY((head2))) { \
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*(head1)->stqh_last = (head2)->stqh_first; \
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(head1)->stqh_last = (head2)->stqh_last; \
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STAILQ_INIT((head2)); \
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} \
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} while (0)
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#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
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#define STAILQ_FIRST(head) ((head)->stqh_first)
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#define STAILQ_FOREACH(var, head, field) \
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for((var) = STAILQ_FIRST((head)); \
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(var); \
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(var) = STAILQ_NEXT((var), field))
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#define STAILQ_FOREACH_FROM(var, head, field) \
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for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
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(var); \
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(var) = STAILQ_NEXT((var), field))
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#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
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for ((var) = STAILQ_FIRST((head)); \
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(var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
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(var) = (tvar))
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#define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
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for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
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(var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
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(var) = (tvar))
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#define STAILQ_INIT(head) do { \
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STAILQ_FIRST((head)) = NULL; \
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(head)->stqh_last = &STAILQ_FIRST((head)); \
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} while (0)
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#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
376
if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
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(head)->stqh_last = &STAILQ_NEXT((elm), field); \
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STAILQ_NEXT((tqelm), field) = (elm); \
379
} while (0)
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381
#define STAILQ_INSERT_HEAD(head, elm, field) do { \
382
if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
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(head)->stqh_last = &STAILQ_NEXT((elm), field); \
384
STAILQ_FIRST((head)) = (elm); \
385
} while (0)
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387
#define STAILQ_INSERT_TAIL(head, elm, field) do { \
388
STAILQ_NEXT((elm), field) = NULL; \
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*(head)->stqh_last = (elm); \
390
(head)->stqh_last = &STAILQ_NEXT((elm), field); \
391
} while (0)
392
393
#define STAILQ_LAST(head, type, field) \
394
(STAILQ_EMPTY((head)) ? NULL : \
395
__containerof((head)->stqh_last, \
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QUEUE_TYPEOF(type), field.stqe_next))
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398
#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
399
400
#define STAILQ_REMOVE(head, elm, type, field) do { \
401
QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
402
if (STAILQ_FIRST((head)) == (elm)) { \
403
STAILQ_REMOVE_HEAD((head), field); \
404
} \
405
else { \
406
QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \
407
while (STAILQ_NEXT(curelm, field) != (elm)) \
408
curelm = STAILQ_NEXT(curelm, field); \
409
STAILQ_REMOVE_AFTER(head, curelm, field); \
410
} \
411
TRASHIT(*oldnext); \
412
} while (0)
413
414
#define STAILQ_REMOVE_AFTER(head, elm, field) do { \
415
if ((STAILQ_NEXT(elm, field) = \
416
STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
417
(head)->stqh_last = &STAILQ_NEXT((elm), field); \
418
} while (0)
419
420
#define STAILQ_REMOVE_HEAD(head, field) do { \
421
if ((STAILQ_FIRST((head)) = \
422
STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
423
(head)->stqh_last = &STAILQ_FIRST((head)); \
424
} while (0)
425
426
#define STAILQ_SWAP(head1, head2, type) do { \
427
QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \
428
QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \
429
STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
430
(head1)->stqh_last = (head2)->stqh_last; \
431
STAILQ_FIRST(head2) = swap_first; \
432
(head2)->stqh_last = swap_last; \
433
if (STAILQ_EMPTY(head1)) \
434
(head1)->stqh_last = &STAILQ_FIRST(head1); \
435
if (STAILQ_EMPTY(head2)) \
436
(head2)->stqh_last = &STAILQ_FIRST(head2); \
437
} while (0)
438
439
440
/*
441
* List declarations.
442
*/
443
#define LIST_HEAD(name, type) \
444
struct name { \
445
struct type *lh_first;
/* first element */
\
446
}
447
448
#define LIST_CLASS_HEAD(name, type) \
449
struct name { \
450
class type *lh_first;
/* first element */
\
451
}
452
453
#define LIST_HEAD_INITIALIZER(head) \
454
{ NULL }
455
456
#define LIST_ENTRY(type) \
457
struct { \
458
struct type *le_next;
/* next element */
\
459
struct type **le_prev;
/* address of previous next element */
\
460
}
461
462
#define LIST_CLASS_ENTRY(type) \
463
struct { \
464
class type *le_next;
/* next element */
\
465
class type **le_prev;
/* address of previous next element */
\
466
}
467
468
/*
469
* List functions.
470
*/
471
472
#if (defined(_KERNEL) && defined(INVARIANTS))
473
/*
474
* QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME)
475
*
476
* If the list is non-empty, validates that the first element of the list
477
* points back at 'head.'
478
*/
479
#define QMD_LIST_CHECK_HEAD(head, field) do { \
480
if (LIST_FIRST((head)) != NULL && \
481
LIST_FIRST((head))->field.le_prev != \
482
&LIST_FIRST((head))) \
483
panic("Bad list head %p first->prev != head", (head)); \
484
} while (0)
485
486
/*
487
* QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME)
488
*
489
* If an element follows 'elm' in the list, validates that the next element
490
* points back at 'elm.'
491
*/
492
#define QMD_LIST_CHECK_NEXT(elm, field) do { \
493
if (LIST_NEXT((elm), field) != NULL && \
494
LIST_NEXT((elm), field)->field.le_prev != \
495
&((elm)->field.le_next)) \
496
panic("Bad link elm %p next->prev != elm", (elm)); \
497
} while (0)
498
499
/*
500
* QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME)
501
*
502
* Validates that the previous element (or head of the list) points to 'elm.'
503
*/
504
#define QMD_LIST_CHECK_PREV(elm, field) do { \
505
if (*(elm)->field.le_prev != (elm)) \
506
panic("Bad link elm %p prev->next != elm", (elm)); \
507
} while (0)
508
#else
509
#define QMD_LIST_CHECK_HEAD(head, field)
510
#define QMD_LIST_CHECK_NEXT(elm, field)
511
#define QMD_LIST_CHECK_PREV(elm, field)
512
#endif
/* (_KERNEL && INVARIANTS) */
513
514
#define LIST_CONCAT(head1, head2, type, field) do { \
515
QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \
516
if (curelm == NULL) { \
517
if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \
518
LIST_FIRST(head2)->field.le_prev = \
519
&LIST_FIRST((head1)); \
520
LIST_INIT(head2); \
521
} \
522
} else if (LIST_FIRST(head2) != NULL) { \
523
while (LIST_NEXT(curelm, field) != NULL) \
524
curelm = LIST_NEXT(curelm, field); \
525
LIST_NEXT(curelm, field) = LIST_FIRST(head2); \
526
LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \
527
LIST_INIT(head2); \
528
} \
529
} while (0)
530
531
#define LIST_EMPTY(head) ((head)->lh_first == NULL)
532
533
#define LIST_FIRST(head) ((head)->lh_first)
534
535
#define LIST_FOREACH(var, head, field) \
536
for ((var) = LIST_FIRST((head)); \
537
(var); \
538
(var) = LIST_NEXT((var), field))
539
540
#define LIST_FOREACH_FROM(var, head, field) \
541
for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
542
(var); \
543
(var) = LIST_NEXT((var), field))
544
545
#define LIST_FOREACH_SAFE(var, head, field, tvar) \
546
for ((var) = LIST_FIRST((head)); \
547
(var) && ((tvar) = LIST_NEXT((var), field), 1); \
548
(var) = (tvar))
549
550
#define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
551
for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
552
(var) && ((tvar) = LIST_NEXT((var), field), 1); \
553
(var) = (tvar))
554
555
#define LIST_INIT(head) do { \
556
LIST_FIRST((head)) = NULL; \
557
} while (0)
558
559
#define LIST_INSERT_AFTER(listelm, elm, field) do { \
560
QMD_LIST_CHECK_NEXT(listelm, field); \
561
if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
562
LIST_NEXT((listelm), field)->field.le_prev = \
563
&LIST_NEXT((elm), field); \
564
LIST_NEXT((listelm), field) = (elm); \
565
(elm)->field.le_prev = &LIST_NEXT((listelm), field); \
566
} while (0)
567
568
#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
569
QMD_LIST_CHECK_PREV(listelm, field); \
570
(elm)->field.le_prev = (listelm)->field.le_prev; \
571
LIST_NEXT((elm), field) = (listelm); \
572
*(listelm)->field.le_prev = (elm); \
573
(listelm)->field.le_prev = &LIST_NEXT((elm), field); \
574
} while (0)
575
576
#define LIST_INSERT_HEAD(head, elm, field) do { \
577
QMD_LIST_CHECK_HEAD((head), field); \
578
if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
579
LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
580
LIST_FIRST((head)) = (elm); \
581
(elm)->field.le_prev = &LIST_FIRST((head)); \
582
} while (0)
583
584
#define LIST_NEXT(elm, field) ((elm)->field.le_next)
585
586
#define LIST_PREV(elm, head, type, field) \
587
((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \
588
__containerof((elm)->field.le_prev, \
589
QUEUE_TYPEOF(type), field.le_next))
590
591
#define LIST_REMOVE(elm, field) do { \
592
QMD_SAVELINK(oldnext, (elm)->field.le_next); \
593
QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
594
QMD_LIST_CHECK_NEXT(elm, field); \
595
QMD_LIST_CHECK_PREV(elm, field); \
596
if (LIST_NEXT((elm), field) != NULL) \
597
LIST_NEXT((elm), field)->field.le_prev = \
598
(elm)->field.le_prev; \
599
*(elm)->field.le_prev = LIST_NEXT((elm), field); \
600
TRASHIT(*oldnext); \
601
TRASHIT(*oldprev); \
602
} while (0)
603
604
#define LIST_SWAP(head1, head2, type, field) do { \
605
QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \
606
LIST_FIRST((head1)) = LIST_FIRST((head2)); \
607
LIST_FIRST((head2)) = swap_tmp; \
608
if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
609
swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
610
if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
611
swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
612
} while (0)
613
614
/*
615
* Tail queue declarations.
616
*/
617
#define TAILQ_HEAD(name, type) \
618
struct name { \
619
struct type *tqh_first;
/* first element */
\
620
struct type **tqh_last;
/* addr of last next element */
\
621
TRACEBUF \
622
}
623
624
#define TAILQ_CLASS_HEAD(name, type) \
625
struct name { \
626
class type *tqh_first;
/* first element */
\
627
class type **tqh_last;
/* addr of last next element */
\
628
TRACEBUF \
629
}
630
631
#define TAILQ_HEAD_INITIALIZER(head) \
632
{ NULL, &(head).tqh_first, TRACEBUF_INITIALIZER }
633
634
#define TAILQ_ENTRY(type) \
635
struct { \
636
struct type *tqe_next;
/* next element */
\
637
struct type **tqe_prev;
/* address of previous next element */
\
638
TRACEBUF \
639
}
640
641
#define TAILQ_CLASS_ENTRY(type) \
642
struct { \
643
class type *tqe_next;
/* next element */
\
644
class type **tqe_prev;
/* address of previous next element */
\
645
TRACEBUF \
646
}
647
648
/*
649
* Tail queue functions.
650
*/
651
#if (defined(_KERNEL) && defined(INVARIANTS))
652
/*
653
* QMD_TAILQ_CHECK_HEAD(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
654
*
655
* If the tailq is non-empty, validates that the first element of the tailq
656
* points back at 'head.'
657
*/
658
#define QMD_TAILQ_CHECK_HEAD(head, field) do { \
659
if (!TAILQ_EMPTY(head) && \
660
TAILQ_FIRST((head))->field.tqe_prev != \
661
&TAILQ_FIRST((head))) \
662
panic("Bad tailq head %p first->prev != head", (head)); \
663
} while (0)
664
665
/*
666
* QMD_TAILQ_CHECK_TAIL(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
667
*
668
* Validates that the tail of the tailq is a pointer to pointer to NULL.
669
*/
670
#define QMD_TAILQ_CHECK_TAIL(head, field) do { \
671
if (*(head)->tqh_last != NULL) \
672
panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
673
} while (0)
674
675
/*
676
* QMD_TAILQ_CHECK_NEXT(TYPE *elm, TAILQ_ENTRY NAME)
677
*
678
* If an element follows 'elm' in the tailq, validates that the next element
679
* points back at 'elm.'
680
*/
681
#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \
682
if (TAILQ_NEXT((elm), field) != NULL && \
683
TAILQ_NEXT((elm), field)->field.tqe_prev != \
684
&((elm)->field.tqe_next)) \
685
panic("Bad link elm %p next->prev != elm", (elm)); \
686
} while (0)
687
688
/*
689
* QMD_TAILQ_CHECK_PREV(TYPE *elm, TAILQ_ENTRY NAME)
690
*
691
* Validates that the previous element (or head of the tailq) points to 'elm.'
692
*/
693
#define QMD_TAILQ_CHECK_PREV(elm, field) do { \
694
if (*(elm)->field.tqe_prev != (elm)) \
695
panic("Bad link elm %p prev->next != elm", (elm)); \
696
} while (0)
697
#else
698
#define QMD_TAILQ_CHECK_HEAD(head, field)
699
#define QMD_TAILQ_CHECK_TAIL(head, headname)
700
#define QMD_TAILQ_CHECK_NEXT(elm, field)
701
#define QMD_TAILQ_CHECK_PREV(elm, field)
702
#endif
/* (_KERNEL && INVARIANTS) */
703
704
#define TAILQ_CONCAT(head1, head2, field) do { \
705
if (!TAILQ_EMPTY(head2)) { \
706
*(head1)->tqh_last = (head2)->tqh_first; \
707
(head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
708
(head1)->tqh_last = (head2)->tqh_last; \
709
TAILQ_INIT((head2)); \
710
QMD_TRACE_HEAD(head1); \
711
QMD_TRACE_HEAD(head2); \
712
} \
713
} while (0)
714
715
#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
716
717
#define TAILQ_FIRST(head) ((head)->tqh_first)
718
719
#define TAILQ_FOREACH(var, head, field) \
720
for ((var) = TAILQ_FIRST((head)); \
721
(var); \
722
(var) = TAILQ_NEXT((var), field))
723
724
#define TAILQ_FOREACH_FROM(var, head, field) \
725
for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
726
(var); \
727
(var) = TAILQ_NEXT((var), field))
728
729
#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
730
for ((var) = TAILQ_FIRST((head)); \
731
(var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
732
(var) = (tvar))
733
734
#define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
735
for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
736
(var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
737
(var) = (tvar))
738
739
#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
740
for ((var) = TAILQ_LAST((head), headname); \
741
(var); \
742
(var) = TAILQ_PREV((var), headname, field))
743
744
#define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \
745
for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
746
(var); \
747
(var) = TAILQ_PREV((var), headname, field))
748
749
#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
750
for ((var) = TAILQ_LAST((head), headname); \
751
(var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
752
(var) = (tvar))
753
754
#define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
755
for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
756
(var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
757
(var) = (tvar))
758
759
#define TAILQ_INIT(head) do { \
760
TAILQ_FIRST((head)) = NULL; \
761
(head)->tqh_last = &TAILQ_FIRST((head)); \
762
QMD_TRACE_HEAD(head); \
763
} while (0)
764
765
#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
766
QMD_TAILQ_CHECK_NEXT(listelm, field); \
767
if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
768
TAILQ_NEXT((elm), field)->field.tqe_prev = \
769
&TAILQ_NEXT((elm), field); \
770
else { \
771
(head)->tqh_last = &TAILQ_NEXT((elm), field); \
772
QMD_TRACE_HEAD(head); \
773
} \
774
TAILQ_NEXT((listelm), field) = (elm); \
775
(elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
776
QMD_TRACE_ELEM(&(elm)->field); \
777
QMD_TRACE_ELEM(&(listelm)->field); \
778
} while (0)
779
780
#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
781
QMD_TAILQ_CHECK_PREV(listelm, field); \
782
(elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
783
TAILQ_NEXT((elm), field) = (listelm); \
784
*(listelm)->field.tqe_prev = (elm); \
785
(listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
786
QMD_TRACE_ELEM(&(elm)->field); \
787
QMD_TRACE_ELEM(&(listelm)->field); \
788
} while (0)
789
790
#define TAILQ_INSERT_HEAD(head, elm, field) do { \
791
QMD_TAILQ_CHECK_HEAD(head, field); \
792
if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
793
TAILQ_FIRST((head))->field.tqe_prev = \
794
&TAILQ_NEXT((elm), field); \
795
else \
796
(head)->tqh_last = &TAILQ_NEXT((elm), field); \
797
TAILQ_FIRST((head)) = (elm); \
798
(elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
799
QMD_TRACE_HEAD(head); \
800
QMD_TRACE_ELEM(&(elm)->field); \
801
} while (0)
802
803
#define TAILQ_INSERT_TAIL(head, elm, field) do { \
804
QMD_TAILQ_CHECK_TAIL(head, field); \
805
TAILQ_NEXT((elm), field) = NULL; \
806
(elm)->field.tqe_prev = (head)->tqh_last; \
807
*(head)->tqh_last = (elm); \
808
(head)->tqh_last = &TAILQ_NEXT((elm), field); \
809
QMD_TRACE_HEAD(head); \
810
QMD_TRACE_ELEM(&(elm)->field); \
811
} while (0)
812
813
#define TAILQ_LAST(head, headname) \
814
(*(((struct headname *)((head)->tqh_last))->tqh_last))
815
816
#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
817
818
#define TAILQ_PREV(elm, headname, field) \
819
(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
820
821
#define TAILQ_REMOVE(head, elm, field) do { \
822
QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
823
QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
824
QMD_TAILQ_CHECK_NEXT(elm, field); \
825
QMD_TAILQ_CHECK_PREV(elm, field); \
826
if ((TAILQ_NEXT((elm), field)) != NULL) \
827
TAILQ_NEXT((elm), field)->field.tqe_prev = \
828
(elm)->field.tqe_prev; \
829
else { \
830
(head)->tqh_last = (elm)->field.tqe_prev; \
831
QMD_TRACE_HEAD(head); \
832
} \
833
*(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
834
TRASHIT(*oldnext); \
835
TRASHIT(*oldprev); \
836
QMD_TRACE_ELEM(&(elm)->field); \
837
} while (0)
838
839
#define TAILQ_SWAP(head1, head2, type, field) do { \
840
QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \
841
QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \
842
(head1)->tqh_first = (head2)->tqh_first; \
843
(head1)->tqh_last = (head2)->tqh_last; \
844
(head2)->tqh_first = swap_first; \
845
(head2)->tqh_last = swap_last; \
846
if ((swap_first = (head1)->tqh_first) != NULL) \
847
swap_first->field.tqe_prev = &(head1)->tqh_first; \
848
else \
849
(head1)->tqh_last = &(head1)->tqh_first; \
850
if ((swap_first = (head2)->tqh_first) != NULL) \
851
swap_first->field.tqe_prev = &(head2)->tqh_first; \
852
else \
853
(head2)->tqh_last = &(head2)->tqh_first; \
854
} while (0)
855
856
#endif
/* !SYS_QUEUE_H_ */
