queue.h revision 952db80cc5b668e33a0be435d217f3dcb5a87990
/* $Id$ */
/** @file
* NAT - Queue handling.
*/
/*
* Copyright (C) 2006-2013 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*/
/*
* This code is based on:
*
* 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
* 4. 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_
#ifdef RT_OS_WINDOWS
#ifdef SLIST_ENTRY
/*Here is a conflict with winnt.h*/
#endif
#endif /* RT_OS_WINDOWS */
/*
* This file defines four types of data structures: singly-linked lists,
* singly-linked tail queues, lists and tail 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 singly-linked 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
* 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, at the head of the list, or at the
* end of the list. Elements being removed from the head of the tail queue
* should use the explicit macro for this purpose for optimum efficiency.
* A singly-linked tail queue may only be traversed in the forward direction.
* Singly-linked tail queues are ideal for applications with large datasets
* and few or no removals or for implementing a FIFO 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 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.
*
*
* SLIST LIST STAILQ TAILQ
* _HEAD + + + +
* _HEAD_INITIALIZER + + + +
* _ENTRY + + + +
* _INIT + + + +
* _EMPTY + + + +
* _FIRST + + + +
* _NEXT + + + +
* _PREV - - - +
* _LAST - - + +
* _FOREACH + + + +
* _FOREACH_SAFE + + + +
* _FOREACH_REVERSE - - - +
* _FOREACH_REVERSE_SAFE - - - +
* _INSERT_HEAD + + + +
* _INSERT_BEFORE - + - +
* _INSERT_AFTER + + + +
* _INSERT_TAIL - - + +
* _CONCAT - - + +
* _REMOVE_HEAD + - + -
* _REMOVE + + + +
*
*/
#ifdef QUEUE_MACRO_DEBUG
/* Store the last 2 places the queue element or head was altered */
struct qm_trace {
char * lastfile;
int lastline;
char * prevfile;
int prevline;
};
#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
#define QMD_TRACE_HEAD(head) do { \
} while (0)
#define QMD_TRACE_ELEM(elem) do { \
} while (0)
#else
#define QMD_TRACE_ELEM(elem)
#define QMD_TRACE_HEAD(head)
#define TRACEBUF
#define TRASHIT(x)
#endif /* QUEUE_MACRO_DEBUG */
/*
* Singly-linked List declarations.
*/
struct name { \
}
#define SLIST_HEAD_INITIALIZER(head) \
{ NULL }
#define SLIST_ENTRY(type) \
struct { \
}
/*
* Singly-linked List functions.
*/
(var); \
#define SLIST_INIT(head) do { \
} while (0)
} while (0)
} while (0)
} \
else { \
} \
} while (0)
} while (0)
/*
* Singly-linked Tail queue declarations.
*/
struct name { \
}
#define STAILQ_HEAD_INITIALIZER(head) \
#define STAILQ_ENTRY(type) \
struct { \
}
/*
* Singly-linked Tail queue functions.
*/
if (!STAILQ_EMPTY((head2))) { \
STAILQ_INIT((head2)); \
} \
} while (0)
(var); \
#define STAILQ_INIT(head) do { \
} while (0)
} while (0)
} while (0)
} while (0)
(STAILQ_EMPTY((head)) ? \
NULL : \
((struct type *)(void *) \
} \
else { \
} \
} while (0)
if ((STAILQ_FIRST((head)) = \
} while (0)
/*
* List declarations.
*/
struct name { \
}
#define LIST_HEAD_INITIALIZER(head) \
{ NULL }
#define LIST_ENTRY(type) \
struct { \
}
/*
* List functions.
*/
#if (defined(_KERNEL) && defined(INVARIANTS))
&LIST_FIRST((head))) \
} while (0)
} while (0)
} while (0)
#else
#endif /* (_KERNEL && INVARIANTS) */
(var); \
} while (0)
} while (0)
} while (0)
} while (0)
} while (0)
/*
* Tail queue declarations.
*/
struct name { \
TRACEBUF \
}
#define TAILQ_HEAD_INITIALIZER(head) \
#define TAILQ_ENTRY(type) \
struct { \
TRACEBUF \
}
/*
* Tail queue functions.
*/
#if (defined(_KERNEL) && defined(INVARIANTS))
if (!TAILQ_EMPTY(head) && \
&TAILQ_FIRST((head))) \
} while (0)
} while (0)
} while (0)
} while (0)
#else
#endif /* (_KERNEL && INVARIANTS) */
if (!TAILQ_EMPTY(head2)) { \
TAILQ_INIT((head2)); \
QMD_TRACE_HEAD(head1); \
QMD_TRACE_HEAD(head2); \
} \
} while (0)
(var); \
(var); \
#define TAILQ_INIT(head) do { \
QMD_TRACE_HEAD(head); \
} while (0)
else { \
QMD_TRACE_HEAD(head); \
} \
} while (0)
} while (0)
else \
QMD_TRACE_HEAD(head); \
} while (0)
QMD_TRACE_HEAD(head); \
} while (0)
else { \
QMD_TRACE_HEAD(head); \
} \
} while (0)
#ifdef _KERNEL
/*
* XXX insque() and remque() are an old way of handling certain queues.
* They bogusly assumes that all queue heads look alike.
*/
struct quehead {
};
#ifdef __CC_SUPPORTS___INLINE
static __inline void
insque(void *a, void *b)
{
}
static __inline void
remque(void *a)
{
}
#else /* !__CC_SUPPORTS___INLINE */
void insque(void *a, void *b);
void remque(void *a);
#endif /* __CC_SUPPORTS___INLINE */
#endif /* _KERNEL */
#endif /* !_SYS_QUEUE_H_ */