Archipelago » qemu

/*      $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */

/*

 * QEMU version: Copy from netbsd, removed debug code, removed some of

 * the implementations.  Left in singly-linked lists, lists, simple

 * queues, and tail queues.

 */

/*

 * 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 QEMU_SYS_QUEUE_H_

#define QEMU_SYS_QUEUE_H_

/*

 * This file defines four types of data structures: singly-linked lists,

 * lists, simple queues, 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 list is headed by a single forward pointer (or an array of forward

 * pointers for a hash table header). The elements are doubly linked

 * so that an arbitrary element can be removed without a need to

 * traverse the list. New elements can be added to the list before

 * or after an existing element or at the head of the list. A list

 * may only be traversed in the forward direction.

 *

 * A simple queue is headed by a pair of pointers, one the head of the

 * list and the other to the tail of the list. The elements are singly

 * linked to save space, so elements can only be removed from the

 * head of the list. New elements can be added to the list after

 * an existing element, at the head of the list, or at the end of the

 * list. A simple queue may only be traversed in the forward direction.

 *

 * A tail queue is headed by a pair of pointers, one to the head of the

 * list and the other to the tail of the list. The elements are doubly

 * linked so that an arbitrary element can be removed without a need to

 * traverse the list. New elements can be added to the list before or

 * after an existing element, at the head of the list, or at the end of

 * the list. A tail queue may be traversed in either direction.

 *

 * For details on the use of these macros, see the queue(3) manual page.

 */

#include "qemu/atomic.h" /* for smp_wmb() */

/*

 * List definitions.

 */

#define QLIST_HEAD(name, type)                                          \

struct name {                                                           \

        struct type *lh_first;  /* first element */                     \

}

#define QLIST_HEAD_INITIALIZER(head)                                    \

        { NULL }

#define QLIST_ENTRY(type)                                               \

struct {                                                                \

        struct type *le_next;   /* next element */                      \

        struct type **le_prev;  /* address of previous next element */  \

}

/*

 * List functions.

 */

#define QLIST_INIT(head) do {                                           \

        (head)->lh_first = NULL;                                        \

} while (/*CONSTCOND*/0)

#define QLIST_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 (/*CONSTCOND*/0)

#define QLIST_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 (/*CONSTCOND*/0)

#define QLIST_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 (/*CONSTCOND*/0)

#define QLIST_INSERT_HEAD_RCU(head, elm, field) do {                    \

        (elm)->field.le_prev = &(head)->lh_first;                       \

        (elm)->field.le_next = (head)->lh_first;                        \

        smp_wmb(); /* fill elm before linking it */                     \

        if ((head)->lh_first != NULL)  {                                \

            (head)->lh_first->field.le_prev = &(elm)->field.le_next;    \

        }                                                               \

        (head)->lh_first = (elm);                                       \

        smp_wmb();                                                      \

} while (/* CONSTCOND*/0)

#define QLIST_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;                   \

} while (/*CONSTCOND*/0)

#define QLIST_FOREACH(var, head, field)                                 \

        for ((var) = ((head)->lh_first);                                \

                (var);                                                  \

                (var) = ((var)->field.le_next))

#define QLIST_FOREACH_SAFE(var, head, field, next_var)                  \

        for ((var) = ((head)->lh_first);                                \

                (var) && ((next_var) = ((var)->field.le_next), 1);      \

                (var) = (next_var))

/*

 * List access methods.

 */

#define QLIST_EMPTY(head)                ((head)->lh_first == NULL)

#define QLIST_FIRST(head)                ((head)->lh_first)

#define QLIST_NEXT(elm, field)           ((elm)->field.le_next)

/*

 * Singly-linked List definitions.

 */

#define QSLIST_HEAD(name, type)                                          \

struct name {                                                           \

        struct type *slh_first; /* first element */                     \

}

#define QSLIST_HEAD_INITIALIZER(head)                                    \

        { NULL }

#define QSLIST_ENTRY(type)                                               \

struct {                                                                \

        struct type *sle_next;  /* next element */                      \

}

/*

 * Singly-linked List functions.

 */

#define QSLIST_INIT(head) do {                                           \

        (head)->slh_first = NULL;                                       \

} while (/*CONSTCOND*/0)

#define QSLIST_INSERT_AFTER(slistelm, elm, field) do {                   \

        (elm)->field.sle_next = (slistelm)->field.sle_next;             \

        (slistelm)->field.sle_next = (elm);                             \

} while (/*CONSTCOND*/0)

#define QSLIST_INSERT_HEAD(head, elm, field) do {                        \

        (elm)->field.sle_next = (head)->slh_first;                      \

        (head)->slh_first = (elm);                                      \

} while (/*CONSTCOND*/0)

#define QSLIST_REMOVE_HEAD(head, field) do {                             \

        (head)->slh_first = (head)->slh_first->field.sle_next;          \

} while (/*CONSTCOND*/0)

#define QSLIST_REMOVE_AFTER(slistelm, field) do {                        \

        (slistelm)->field.sle_next =                                    \

            QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field);           \

} while (/*CONSTCOND*/0)

#define QSLIST_FOREACH(var, head, field)                                 \

        for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)

#define QSLIST_FOREACH_SAFE(var, head, field, tvar)                      \

        for ((var) = QSLIST_FIRST((head));                               \

            (var) && ((tvar) = QSLIST_NEXT((var), field), 1);            \

            (var) = (tvar))

/*

 * Singly-linked List access methods.

 */

#define QSLIST_EMPTY(head)       ((head)->slh_first == NULL)

#define QSLIST_FIRST(head)       ((head)->slh_first)

#define QSLIST_NEXT(elm, field)  ((elm)->field.sle_next)

/*

 * Simple queue definitions.

 */

#define QSIMPLEQ_HEAD(name, type)                                       \

struct name {                                                           \

    struct type *sqh_first;    /* first element */                      \

    struct type **sqh_last;    /* addr of last next element */          \

}

#define QSIMPLEQ_HEAD_INITIALIZER(head)                                 \

    { NULL, &(head).sqh_first }

#define QSIMPLEQ_ENTRY(type)                                            \

struct {                                                                \

    struct type *sqe_next;    /* next element */                        \

}

/*

 * Simple queue functions.

 */

#define QSIMPLEQ_INIT(head) do {                                        \

    (head)->sqh_first = NULL;                                           \

    (head)->sqh_last = &(head)->sqh_first;                              \

} 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)

#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)

/*

 * Tail queue definitions.

 */

#define Q_TAILQ_HEAD(name, type, qual)                                  \

struct name {                                                           \

        qual type *tqh_first;           /* first element */             \

        qual type *qual *tqh_last;      /* addr of last next element */ \

}

#define QTAILQ_HEAD(name, type)  Q_TAILQ_HEAD(name, struct type,)

#define QTAILQ_HEAD_INITIALIZER(head)                                   \

        { NULL, &(head).tqh_first }

#define Q_TAILQ_ENTRY(type, qual)                                       \

struct {                                                                \

        qual type *tqe_next;            /* next element */              \

        qual type *qual *tqe_prev;      /* address of previous next element */\

}

#define QTAILQ_ENTRY(type)       Q_TAILQ_ENTRY(struct type,)

/*

 * Tail queue functions.

 */

#define QTAILQ_INIT(head) do {                                          \

        (head)->tqh_first = NULL;                                       \

        (head)->tqh_last = &(head)->tqh_first;                          \

} while (/*CONSTCOND*/0)

#define QTAILQ_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 (/*CONSTCOND*/0)

#define QTAILQ_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 (/*CONSTCOND*/0)

#define QTAILQ_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 (/*CONSTCOND*/0)

#define QTAILQ_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 (/*CONSTCOND*/0)

#define QTAILQ_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;                 \

} while (/*CONSTCOND*/0)

#define QTAILQ_FOREACH(var, head, field)                                \

        for ((var) = ((head)->tqh_first);                               \

                (var);                                                  \

                (var) = ((var)->field.tqe_next))

#define QTAILQ_FOREACH_SAFE(var, head, field, next_var)                 \

        for ((var) = ((head)->tqh_first);                               \

                (var) && ((next_var) = ((var)->field.tqe_next), 1);     \

                (var) = (next_var))

#define QTAILQ_FOREACH_REVERSE(var, head, headname, field)              \

        for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last));    \

                (var);                                                  \

                (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))

/*

 * Tail queue access methods.

 */

#define QTAILQ_EMPTY(head)               ((head)->tqh_first == NULL)

#define QTAILQ_FIRST(head)               ((head)->tqh_first)

#define QTAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)

#define QTAILQ_LAST(head, headname) \

        (*(((struct headname *)((head)->tqh_last))->tqh_last))

#define QTAILQ_PREV(elm, headname, field) \

        (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))

#endif  /* !QEMU_SYS_QUEUE_H_ */