2009-11-30 18:21:20 +01:00
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/* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */
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2008-12-14 09:53:17 +01:00
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/*
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2012-04-07 09:23:39 +02:00
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* QEMU version: Copy from netbsd, removed debug code, removed some of
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2012-01-13 17:34:02 +01:00
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* the implementations. Left in singly-linked lists, lists, simple
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2012-01-13 17:34:03 +01:00
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* queues, and tail queues.
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2008-12-14 09:53:17 +01:00
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*/
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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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*/
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2016-06-29 13:47:03 +02:00
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#ifndef QEMU_SYS_QUEUE_H
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#define QEMU_SYS_QUEUE_H
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2008-12-14 09:53:17 +01:00
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/*
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2012-01-13 17:34:03 +01:00
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* This file defines four types of data structures: singly-linked lists,
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* lists, simple queues, and tail queues.
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2008-12-14 09:53:17 +01:00
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*
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2012-01-13 17:34:02 +01:00
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* A singly-linked list is headed by a single forward pointer. The
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* elements are singly linked for minimum space and pointer manipulation
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* overhead at the expense of O(n) removal for arbitrary elements. New
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* elements can be added to the list after an existing element or at the
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* head of the list. Elements being removed from the head of the list
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* should use the explicit macro for this purpose for optimum
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* efficiency. A singly-linked list may only be traversed in the forward
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* direction. Singly-linked lists are ideal for applications with large
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* datasets and few or no removals or for implementing a LIFO queue.
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*
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2008-12-14 09:53:17 +01:00
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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 only be traversed in the forward direction.
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*
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2009-11-30 18:21:20 +01:00
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* A simple queue is headed by a pair of pointers, one the head of the
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* list and the other to the tail of the list. The elements are singly
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* linked to save space, so elements can only be removed from the
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* head of the list. New elements can be added to the list after
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* an existing element, at the head of the list, or at the end of the
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* list. A simple queue may only be traversed in the forward direction.
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*
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2008-12-14 09:53:17 +01:00
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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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2012-12-17 18:20:00 +01:00
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#include "qemu/atomic.h" /* for smp_wmb() */
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2011-10-25 08:40:40 +02:00
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2008-12-14 09:53:17 +01:00
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/*
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* List definitions.
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*/
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2009-09-12 09:36:22 +02:00
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#define QLIST_HEAD(name, type) \
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2008-12-14 09:53:17 +01:00
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struct name { \
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struct type *lh_first; /* first element */ \
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}
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2009-09-12 09:36:22 +02:00
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#define QLIST_HEAD_INITIALIZER(head) \
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2008-12-14 09:53:17 +01:00
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{ NULL }
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2009-09-12 09:36:22 +02:00
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#define QLIST_ENTRY(type) \
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2008-12-14 09:53:17 +01:00
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struct { \
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struct type *le_next; /* next element */ \
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struct type **le_prev; /* address of previous next element */ \
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}
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/*
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* List functions.
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*/
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2009-09-12 09:36:22 +02:00
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#define QLIST_INIT(head) do { \
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2008-12-14 09:53:17 +01:00
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(head)->lh_first = NULL; \
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} while (/*CONSTCOND*/0)
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2013-05-13 13:29:47 +02:00
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#define QLIST_SWAP(dstlist, srclist, field) do { \
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void *tmplist; \
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tmplist = (srclist)->lh_first; \
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(srclist)->lh_first = (dstlist)->lh_first; \
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if ((srclist)->lh_first != NULL) { \
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(srclist)->lh_first->field.le_prev = &(srclist)->lh_first; \
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} \
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(dstlist)->lh_first = tmplist; \
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if ((dstlist)->lh_first != NULL) { \
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(dstlist)->lh_first->field.le_prev = &(dstlist)->lh_first; \
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} \
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} while (/*CONSTCOND*/0)
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2008-12-14 09:53:17 +01:00
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2009-09-12 09:36:22 +02:00
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#define QLIST_INSERT_AFTER(listelm, elm, field) do { \
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2008-12-14 09:53:17 +01:00
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if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
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(listelm)->field.le_next->field.le_prev = \
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&(elm)->field.le_next; \
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(listelm)->field.le_next = (elm); \
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(elm)->field.le_prev = &(listelm)->field.le_next; \
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} while (/*CONSTCOND*/0)
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2009-09-12 09:36:22 +02:00
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#define QLIST_INSERT_BEFORE(listelm, elm, field) do { \
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2008-12-14 09:53:17 +01:00
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(elm)->field.le_prev = (listelm)->field.le_prev; \
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(elm)->field.le_next = (listelm); \
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*(listelm)->field.le_prev = (elm); \
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(listelm)->field.le_prev = &(elm)->field.le_next; \
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} while (/*CONSTCOND*/0)
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2009-09-12 09:36:22 +02:00
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#define QLIST_INSERT_HEAD(head, elm, field) do { \
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2008-12-14 09:53:17 +01:00
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if (((elm)->field.le_next = (head)->lh_first) != NULL) \
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(head)->lh_first->field.le_prev = &(elm)->field.le_next;\
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(head)->lh_first = (elm); \
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(elm)->field.le_prev = &(head)->lh_first; \
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} while (/*CONSTCOND*/0)
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2009-09-12 09:36:22 +02:00
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#define QLIST_REMOVE(elm, field) do { \
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2008-12-14 09:53:17 +01:00
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if ((elm)->field.le_next != NULL) \
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(elm)->field.le_next->field.le_prev = \
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(elm)->field.le_prev; \
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*(elm)->field.le_prev = (elm)->field.le_next; \
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} while (/*CONSTCOND*/0)
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2009-09-12 09:36:22 +02:00
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#define QLIST_FOREACH(var, head, field) \
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2008-12-14 09:53:17 +01:00
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for ((var) = ((head)->lh_first); \
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(var); \
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(var) = ((var)->field.le_next))
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2009-09-12 09:36:22 +02:00
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#define QLIST_FOREACH_SAFE(var, head, field, next_var) \
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2009-09-01 02:12:32 +02:00
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for ((var) = ((head)->lh_first); \
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(var) && ((next_var) = ((var)->field.le_next), 1); \
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(var) = (next_var))
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2008-12-14 09:53:17 +01:00
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/*
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* List access methods.
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*/
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2009-09-12 09:36:22 +02:00
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#define QLIST_EMPTY(head) ((head)->lh_first == NULL)
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#define QLIST_FIRST(head) ((head)->lh_first)
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#define QLIST_NEXT(elm, field) ((elm)->field.le_next)
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2008-12-14 09:53:17 +01:00
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2012-01-13 17:34:02 +01:00
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/*
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* Singly-linked List definitions.
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*/
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#define QSLIST_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 QSLIST_HEAD_INITIALIZER(head) \
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{ NULL }
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#define QSLIST_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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/*
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* Singly-linked List functions.
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*/
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#define QSLIST_INIT(head) do { \
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(head)->slh_first = NULL; \
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} while (/*CONSTCOND*/0)
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#define QSLIST_INSERT_AFTER(slistelm, elm, field) do { \
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(elm)->field.sle_next = (slistelm)->field.sle_next; \
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(slistelm)->field.sle_next = (elm); \
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} while (/*CONSTCOND*/0)
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#define QSLIST_INSERT_HEAD(head, elm, field) do { \
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2014-12-02 12:05:47 +01:00
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(elm)->field.sle_next = (head)->slh_first; \
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(head)->slh_first = (elm); \
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} while (/*CONSTCOND*/0)
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queue: fix QSLIST_INSERT_HEAD_ATOMIC race
There is a not-so-subtle race in QSLIST_INSERT_HEAD_ATOMIC.
Because atomic_cmpxchg returns the old value instead of a success flag,
QSLIST_INSERT_HEAD_ATOMIC was checking for success by comparing against
the second argument to atomic_cmpxchg. Unfortunately, this only works
if the second argument is a local or thread-local variable.
If it is in memory, it can be subject to common subexpression elimination
(and then everything's fine) or reloaded after the atomic_cmpxchg,
depending on the compiler's whims. If the latter happens, the race can
happen. A thread can sneak in, doing something on elm->field.sle_next
after the atomic_cmpxchg and before the comparison. This causes a wrong
failure, and then two threads are using "elm" at the same time. In the
case discovered by Christian, the sequence was likely something like this:
thread 1 | thread 2
QSLIST_INSERT_HEAD_ATOMIC |
atomic_cmpxchg succeeds |
elm added to list |
| steal release_pool
| QSLIST_REMOVE_HEAD
| elm removed from list
| ...
| QSLIST_INSERT_HEAD_ATOMIC
| (overwrites sle_next)
spurious failure |
atomic_cmpxchg succeeds |
elm added to list again |
|
steal release_pool |
QSLIST_REMOVE_HEAD |
elm removed again |
The last three steps could be done by a third thread as well.
A reproducer that failed in a matter of seconds is as follows:
- the guest has 32 VCPUs on a 28 core host (hyperthreading was enabled),
memory was 16G just to err on the safe side (the host has 64G, but hey
at least you need no s390)
- the guest has 24 null-aio virtio-blk devices using dataplane
(-object iothread,id=ioN -drive if=none,id=blkN,driver=null-aio,size=500G
-device virtio-blk-pci,iothread=ioN,drive=blkN)
- the guest also has a single network interface. It's only doing loopback
tests so slirp vs. tap and the model doesn't matter.
- the guest is running fio with the following script:
[global]
rw=randread
blocksize=16k
ioengine=libaio
runtime=10m
buffered=0
fallocate=none
time_based
iodepth=32
[virtio1a]
filename=/dev/block/252\:16
[virtio1b]
filename=/dev/block/252\:16
...
[virtio24a]
filename=/dev/block/252\:384
[virtio24b]
filename=/dev/block/252\:384
[listen1]
protocol=tcp
ioengine=net
port=12345
listen
rw=read
bs=4k
size=1000g
[connect1]
protocol=tcp
hostname=localhost
ioengine=net
port=12345
protocol=tcp
rw=write
startdelay=1
size=1000g
...
[listen8]
protocol=tcp
ioengine=net
port=12352
listen
rw=read
bs=4k
size=1000g
[connect8]
protocol=tcp
hostname=localhost
ioengine=net
port=12352
rw=write
startdelay=1
size=1000g
Moral of the story: I should refrain from writing more clever stuff.
At least it looks like it is not too clever to be undebuggable.
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1426002357-6889-1-git-send-email-pbonzini@redhat.com
Fixes: c740ad92d0d958fa785e5d7aa1b67ecaf30a6a54
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-03-10 16:45:57 +01:00
|
|
|
#define QSLIST_INSERT_HEAD_ATOMIC(head, elm, field) do { \
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typeof(elm) save_sle_next; \
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do { \
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save_sle_next = (elm)->field.sle_next = (head)->slh_first; \
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} while (atomic_cmpxchg(&(head)->slh_first, save_sle_next, (elm)) != \
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|
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save_sle_next); \
|
2014-12-02 12:05:47 +01:00
|
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|
} while (/*CONSTCOND*/0)
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|
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#define QSLIST_MOVE_ATOMIC(dest, src) do { \
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|
(dest)->slh_first = atomic_xchg(&(src)->slh_first, NULL); \
|
2012-01-13 17:34:02 +01:00
|
|
|
} while (/*CONSTCOND*/0)
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#define QSLIST_REMOVE_HEAD(head, field) do { \
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(head)->slh_first = (head)->slh_first->field.sle_next; \
|
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|
} while (/*CONSTCOND*/0)
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|
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#define QSLIST_REMOVE_AFTER(slistelm, field) do { \
|
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|
(slistelm)->field.sle_next = \
|
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QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field); \
|
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} while (/*CONSTCOND*/0)
|
|
|
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|
|
|
|
#define QSLIST_FOREACH(var, head, field) \
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for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
|
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#define QSLIST_FOREACH_SAFE(var, head, field, tvar) \
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for ((var) = QSLIST_FIRST((head)); \
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(var) && ((tvar) = QSLIST_NEXT((var), field), 1); \
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(var) = (tvar))
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/*
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|
* Singly-linked List access methods.
|
|
|
|
*/
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|
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|
#define QSLIST_EMPTY(head) ((head)->slh_first == NULL)
|
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|
#define QSLIST_FIRST(head) ((head)->slh_first)
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|
#define QSLIST_NEXT(elm, field) ((elm)->field.sle_next)
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|
2009-11-30 18:21:20 +01:00
|
|
|
/*
|
|
|
|
* Simple queue definitions.
|
|
|
|
*/
|
|
|
|
#define QSIMPLEQ_HEAD(name, type) \
|
|
|
|
struct name { \
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|
|
struct type *sqh_first; /* first element */ \
|
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|
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struct type **sqh_last; /* addr of last next element */ \
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}
|
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|
#define QSIMPLEQ_HEAD_INITIALIZER(head) \
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{ NULL, &(head).sqh_first }
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#define QSIMPLEQ_ENTRY(type) \
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|
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struct { \
|
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|
struct type *sqe_next; /* next element */ \
|
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}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Simple queue functions.
|
|
|
|
*/
|
|
|
|
#define QSIMPLEQ_INIT(head) do { \
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|
(head)->sqh_first = NULL; \
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|
(head)->sqh_last = &(head)->sqh_first; \
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|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_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 (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_INSERT_TAIL(head, elm, field) do { \
|
|
|
|
(elm)->field.sqe_next = NULL; \
|
|
|
|
*(head)->sqh_last = (elm); \
|
|
|
|
(head)->sqh_last = &(elm)->field.sqe_next; \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_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 (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_REMOVE_HEAD(head, field) do { \
|
|
|
|
if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL)\
|
|
|
|
(head)->sqh_last = &(head)->sqh_first; \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
2014-12-11 14:52:30 +01:00
|
|
|
#define QSIMPLEQ_SPLIT_AFTER(head, elm, field, removed) do { \
|
|
|
|
QSIMPLEQ_INIT(removed); \
|
|
|
|
if (((removed)->sqh_first = (head)->sqh_first) != NULL) { \
|
|
|
|
if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) { \
|
|
|
|
(head)->sqh_last = &(head)->sqh_first; \
|
|
|
|
} \
|
|
|
|
(removed)->sqh_last = &(elm)->field.sqe_next; \
|
|
|
|
(elm)->field.sqe_next = NULL; \
|
|
|
|
} \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
2009-11-30 18:21:20 +01:00
|
|
|
#define QSIMPLEQ_REMOVE(head, elm, type, field) do { \
|
|
|
|
if ((head)->sqh_first == (elm)) { \
|
|
|
|
QSIMPLEQ_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 (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_FOREACH(var, head, field) \
|
|
|
|
for ((var) = ((head)->sqh_first); \
|
|
|
|
(var); \
|
|
|
|
(var) = ((var)->field.sqe_next))
|
|
|
|
|
|
|
|
#define QSIMPLEQ_FOREACH_SAFE(var, head, field, next) \
|
|
|
|
for ((var) = ((head)->sqh_first); \
|
|
|
|
(var) && ((next = ((var)->field.sqe_next)), 1); \
|
|
|
|
(var) = (next))
|
|
|
|
|
|
|
|
#define QSIMPLEQ_CONCAT(head1, head2) do { \
|
|
|
|
if (!QSIMPLEQ_EMPTY((head2))) { \
|
|
|
|
*(head1)->sqh_last = (head2)->sqh_first; \
|
|
|
|
(head1)->sqh_last = (head2)->sqh_last; \
|
|
|
|
QSIMPLEQ_INIT((head2)); \
|
|
|
|
} \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
|
|
|
#define QSIMPLEQ_LAST(head, type, field) \
|
|
|
|
(QSIMPLEQ_EMPTY((head)) ? \
|
|
|
|
NULL : \
|
|
|
|
((struct type *)(void *) \
|
|
|
|
((char *)((head)->sqh_last) - offsetof(struct type, field))))
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Simple queue access methods.
|
|
|
|
*/
|
|
|
|
#define QSIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL)
|
|
|
|
#define QSIMPLEQ_FIRST(head) ((head)->sqh_first)
|
|
|
|
#define QSIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
|
|
|
|
|
|
|
|
|
2008-12-14 09:53:17 +01:00
|
|
|
/*
|
|
|
|
* Tail queue definitions.
|
|
|
|
*/
|
2009-09-12 09:36:22 +02:00
|
|
|
#define Q_TAILQ_HEAD(name, type, qual) \
|
2008-12-14 09:53:17 +01:00
|
|
|
struct name { \
|
|
|
|
qual type *tqh_first; /* first element */ \
|
|
|
|
qual type *qual *tqh_last; /* addr of last next element */ \
|
|
|
|
}
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_HEAD(name, type) Q_TAILQ_HEAD(name, struct type,)
|
2008-12-14 09:53:17 +01:00
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_HEAD_INITIALIZER(head) \
|
2008-12-14 09:53:17 +01:00
|
|
|
{ NULL, &(head).tqh_first }
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define Q_TAILQ_ENTRY(type, qual) \
|
2008-12-14 09:53:17 +01:00
|
|
|
struct { \
|
|
|
|
qual type *tqe_next; /* next element */ \
|
|
|
|
qual type *qual *tqe_prev; /* address of previous next element */\
|
|
|
|
}
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_ENTRY(type) Q_TAILQ_ENTRY(struct type,)
|
2008-12-14 09:53:17 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Tail queue functions.
|
|
|
|
*/
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_INIT(head) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
(head)->tqh_first = NULL; \
|
|
|
|
(head)->tqh_last = &(head)->tqh_first; \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_INSERT_HEAD(head, elm, field) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
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 (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_INSERT_TAIL(head, elm, field) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
(elm)->field.tqe_next = NULL; \
|
|
|
|
(elm)->field.tqe_prev = (head)->tqh_last; \
|
|
|
|
*(head)->tqh_last = (elm); \
|
|
|
|
(head)->tqh_last = &(elm)->field.tqe_next; \
|
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
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 (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
(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 (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_REMOVE(head, elm, field) do { \
|
2008-12-14 09:53:17 +01:00
|
|
|
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; \
|
2016-07-25 14:47:12 +02:00
|
|
|
(elm)->field.tqe_prev = NULL; \
|
2008-12-14 09:53:17 +01:00
|
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_FOREACH(var, head, field) \
|
2008-12-14 09:53:17 +01:00
|
|
|
for ((var) = ((head)->tqh_first); \
|
|
|
|
(var); \
|
|
|
|
(var) = ((var)->field.tqe_next))
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \
|
2008-12-14 09:53:17 +01:00
|
|
|
for ((var) = ((head)->tqh_first); \
|
|
|
|
(var) && ((next_var) = ((var)->field.tqe_next), 1); \
|
|
|
|
(var) = (next_var))
|
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_FOREACH_REVERSE(var, head, headname, field) \
|
2008-12-14 09:53:17 +01:00
|
|
|
for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
|
|
|
|
(var); \
|
|
|
|
(var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Tail queue access methods.
|
|
|
|
*/
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL)
|
|
|
|
#define QTAILQ_FIRST(head) ((head)->tqh_first)
|
|
|
|
#define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
|
2016-07-25 14:47:12 +02:00
|
|
|
#define QTAILQ_IN_USE(elm, field) ((elm)->field.tqe_prev != NULL)
|
2008-12-14 09:53:17 +01:00
|
|
|
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_LAST(head, headname) \
|
2008-12-14 09:53:17 +01:00
|
|
|
(*(((struct headname *)((head)->tqh_last))->tqh_last))
|
2009-09-12 09:36:22 +02:00
|
|
|
#define QTAILQ_PREV(elm, headname, field) \
|
2008-12-14 09:53:17 +01:00
|
|
|
(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
|
|
|
|
|
2016-06-29 13:47:03 +02:00
|
|
|
#endif /* QEMU_SYS_QUEUE_H */
|