/* $NetBSD: queue.h,v 1.70 2015/11/02 15:21:23 christos Exp $ */ /* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)queue.h 8.5 (Berkeley) 8/20/94 */ #ifndef _SYS_QUEUE_H_ #define _SYS_QUEUE_H_ /* * This file defines five types of data structures: singly-linked lists, * lists, simple queues, tail queues, and circular queues. * * A singly-linked list is headed by a single forward pointer. The * elements are singly linked for minimum space and pointer manipulation * overhead at the expense of O(n) removal for arbitrary elements. New * elements can be added to the list after an existing element or at the * head of the list. Elements being removed from the head of the list * should use the explicit macro for this purpose for optimum * efficiency. A singly-linked list may only be traversed in the forward * direction. Singly-linked lists are ideal for applications with large * datasets and few or no removals or for implementing a LIFO queue. * * A list is headed by a single forward pointer (or an array of forward * pointers for a hash table header). The elements are doubly linked * so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before * or after an existing element or at the head of the list. A list * may only be traversed in the forward direction. * * A simple queue is headed by a pair of pointers, one the head of the * list and the other to the tail of the list. The elements are singly * linked to save space, so elements can only be removed from the * head of the list. New elements can be added to the list after * an existing element, at the head of the list, or at the end of the * list. A simple queue may only be traversed in the forward direction. * * A tail queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * * A circle queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or after * an existing element, at the head of the list, or at the end of the list. * A circle queue may be traversed in either direction, but has a more * complex end of list detection. * * For details on the use of these macros, see the queue(3) manual page. */ /* * Include the definition of NULL only on NetBSD because sys/null.h * is not available elsewhere. This conditional makes the header * portable and it can simply be dropped verbatim into any system. * The caveat is that on other systems some other header * must provide NULL before the macros can be used. */ #ifdef __NetBSD__ #include <sys/null.h> #endif #if defined(QUEUEDEBUG) # if defined(_KERNEL) # define QUEUEDEBUG_ABORT(...) panic(__VA_ARGS__) # else # include <err.h> # define QUEUEDEBUG_ABORT(...) err(1, __VA_ARGS__) # endif #endif /* * Singly-linked List definitions. */ #define SLIST_HEAD(name, type) \ struct name { \ struct type *slh_first; /* first element */ \ } #define SLIST_HEAD_INITIALIZER(head) \ { NULL } #define SLIST_ENTRY(type) \ struct { \ struct type *sle_next; /* next element */ \ } /* * Singly-linked List access methods. */ #define SLIST_FIRST(head) ((head)->slh_first) #define SLIST_END(head) NULL #define SLIST_EMPTY(head) ((head)->slh_first == NULL) #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) #define SLIST_FOREACH(var, head, field) \ for((var) = (head)->slh_first; \ (var) != SLIST_END(head); \ (var) = (var)->field.sle_next) #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ for ((var) = SLIST_FIRST((head)); \ (var) != SLIST_END(head) && \ ((tvar) = SLIST_NEXT((var), field), 1); \ (var) = (tvar)) /* * Singly-linked List functions. */ #define SLIST_INIT(head) do { \ (head)->slh_first = SLIST_END(head); \ } while (/*CONSTCOND*/0) #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ (elm)->field.sle_next = (slistelm)->field.sle_next; \ (slistelm)->field.sle_next = (elm); \ } while (/*CONSTCOND*/0) #define SLIST_INSERT_HEAD(head, elm, field) do { \ (elm)->field.sle_next = (head)->slh_first; \ (head)->slh_first = (elm); \ } while (/*CONSTCOND*/0) #define SLIST_REMOVE_AFTER(slistelm, field) do { \ (slistelm)->field.sle_next = \ SLIST_NEXT(SLIST_NEXT((slistelm), field), field); \ } while (/*CONSTCOND*/0) #define SLIST_REMOVE_HEAD(head, field) do { \ (head)->slh_first = (head)->slh_first->field.sle_next; \ } while (/*CONSTCOND*/0) #define SLIST_REMOVE(head, elm, type, field) do { \ if ((head)->slh_first == (elm)) { \ SLIST_REMOVE_HEAD((head), field); \ } \ else { \ struct type *curelm = (head)->slh_first; \ while(curelm->field.sle_next != (elm)) \ curelm = curelm->field.sle_next; \ curelm->field.sle_next = \ curelm->field.sle_next->field.sle_next; \ } \ } while (/*CONSTCOND*/0) /* * List definitions. */ #define LIST_HEAD(name, type) \ struct name { \ struct type *lh_first; /* first element */ \ } #define LIST_HEAD_INITIALIZER(head) \ { NULL } #define LIST_ENTRY(type) \ struct { \ struct type *le_next; /* next element */ \ struct type **le_prev; /* address of previous next element */ \ } /* * List access methods. */ #define LIST_FIRST(head) ((head)->lh_first) #define LIST_END(head) NULL #define LIST_EMPTY(head) ((head)->lh_first == LIST_END(head)) #define LIST_NEXT(elm, field) ((elm)->field.le_next) #define LIST_FOREACH(var, head, field) \ for ((var) = ((head)->lh_first); \ (var) != LIST_END(head); \ (var) = ((var)->field.le_next)) #define LIST_FOREACH_SAFE(var, head, field, tvar) \ for ((var) = LIST_FIRST((head)); \ (var) != LIST_END(head) && \ ((tvar) = LIST_NEXT((var), field), 1); \ (var) = (tvar)) #define LIST_MOVE(head1, head2) do { \ LIST_INIT((head2)); \ if (!LIST_EMPTY((head1))) { \ (head2)->lh_first = (head1)->lh_first; \ LIST_INIT((head1)); \ } \ } while (/*CONSTCOND*/0) /* * List functions. */ #if defined(QUEUEDEBUG) #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) \ if ((head)->lh_first && \ (head)->lh_first->field.le_prev != &(head)->lh_first) \ QUEUEDEBUG_ABORT("LIST_INSERT_HEAD %p %s:%d", (head), \ __FILE__, __LINE__); #define QUEUEDEBUG_LIST_OP(elm, field) \ if ((elm)->field.le_next && \ (elm)->field.le_next->field.le_prev != \ &(elm)->field.le_next) \ QUEUEDEBUG_ABORT("LIST_* forw %p %s:%d", (elm), \ __FILE__, __LINE__); \ if (*(elm)->field.le_prev != (elm)) \ QUEUEDEBUG_ABORT("LIST_* back %p %s:%d", (elm), \ __FILE__, __LINE__); #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) \ (elm)->field.le_next = (void *)1L; \ (elm)->field.le_prev = (void *)1L; #else #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) #define QUEUEDEBUG_LIST_OP(elm, field) #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) #endif #define LIST_INIT(head) do { \ (head)->lh_first = LIST_END(head); \ } while (/*CONSTCOND*/0) #define LIST_INSERT_AFTER(listelm, elm, field) do { \ QUEUEDEBUG_LIST_OP((listelm), field) \ if (((elm)->field.le_next = (listelm)->field.le_next) != \ LIST_END(head)) \ (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 LIST_INSERT_BEFORE(listelm, elm, field) do { \ QUEUEDEBUG_LIST_OP((listelm), field) \ (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 LIST_INSERT_HEAD(head, elm, field) do { \ QUEUEDEBUG_LIST_INSERT_HEAD((head), (elm), field) \ if (((elm)->field.le_next = (head)->lh_first) != LIST_END(head))\ (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 LIST_REMOVE(elm, field) do { \ QUEUEDEBUG_LIST_OP((elm), field) \ 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; \ QUEUEDEBUG_LIST_POSTREMOVE((elm), field) \ } while (/*CONSTCOND*/0) #define LIST_REPLACE(elm, elm2, field) do { \ if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ (elm2)->field.le_next->field.le_prev = \ &(elm2)->field.le_next; \ (elm2)->field.le_prev = (elm)->field.le_prev; \ *(elm2)->field.le_prev = (elm2); \ QUEUEDEBUG_LIST_POSTREMOVE((elm), field) \ } while (/*CONSTCOND*/0) /* * Simple queue definitions. */ #define SIMPLEQ_HEAD(name, type) \ struct name { \ struct type *sqh_first; /* first element */ \ struct type **sqh_last; /* addr of last next element */ \ } #define SIMPLEQ_HEAD_INITIALIZER(head) \ { NULL, &(head).sqh_first } #define SIMPLEQ_ENTRY(type) \ struct { \ struct type *sqe_next; /* next element */ \ } /* * Simple queue access methods. */ #define SIMPLEQ_FIRST(head) ((head)->sqh_first) #define SIMPLEQ_END(head) NULL #define SIMPLEQ_EMPTY(head) ((head)->sqh_first == SIMPLEQ_END(head)) #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) #define SIMPLEQ_FOREACH(var, head, field) \ for ((var) = ((head)->sqh_first); \ (var) != SIMPLEQ_END(head); \ (var) = ((var)->field.sqe_next)) #define SIMPLEQ_FOREACH_SAFE(var, head, field, next) \ for ((var) = ((head)->sqh_first); \ (var) != SIMPLEQ_END(head) && \ ((next = ((var)->field.sqe_next)), 1); \ (var) = (next)) /* * Simple queue functions. */ #define SIMPLEQ_INIT(head) do { \ (head)->sqh_first = NULL; \ (head)->sqh_last = &(head)->sqh_first; \ } while (/*CONSTCOND*/0) #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ (head)->sqh_last = &(elm)->field.sqe_next; \ (head)->sqh_first = (elm); \ } while (/*CONSTCOND*/0) #define SIMPLEQ_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 SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ (head)->sqh_last = &(elm)->field.sqe_next; \ (listelm)->field.sqe_next = (elm); \ } while (/*CONSTCOND*/0) #define SIMPLEQ_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 SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ == NULL) \ (head)->sqh_last = &(elm)->field.sqe_next; \ } while (/*CONSTCOND*/0) #define SIMPLEQ_REMOVE(head, elm, type, field) do { \ if ((head)->sqh_first == (elm)) { \ SIMPLEQ_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 SIMPLEQ_CONCAT(head1, head2) do { \ if (!SIMPLEQ_EMPTY((head2))) { \ *(head1)->sqh_last = (head2)->sqh_first; \ (head1)->sqh_last = (head2)->sqh_last; \ SIMPLEQ_INIT((head2)); \ } \ } while (/*CONSTCOND*/0) #define SIMPLEQ_LAST(head, type, field) \ (SIMPLEQ_EMPTY((head)) ? \ NULL : \ ((struct type *)(void *) \ ((char *)((head)->sqh_last) - offsetof(struct type, field)))) /* * Tail queue definitions. */ #define _TAILQ_HEAD(name, type, qual) \ struct name { \ qual type *tqh_first; /* first element */ \ qual type *qual *tqh_last; /* addr of last next element */ \ } #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,) #define TAILQ_HEAD_INITIALIZER(head) \ { TAILQ_END(head), &(head).tqh_first } #define _TAILQ_ENTRY(type, qual) \ struct { \ qual type *tqe_next; /* next element */ \ qual type *qual *tqe_prev; /* address of previous next element */\ } #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,) /* * Tail queue access methods. */ #define TAILQ_FIRST(head) ((head)->tqh_first) #define TAILQ_END(head) (NULL) #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) #define TAILQ_LAST(head, headname) \ (*(((struct headname *)(void *)((head)->tqh_last))->tqh_last)) #define TAILQ_PREV(elm, headname, field) \ (*(((struct headname *)(void *)((elm)->field.tqe_prev))->tqh_last)) #define TAILQ_EMPTY(head) (TAILQ_FIRST(head) == TAILQ_END(head)) #define TAILQ_FOREACH(var, head, field) \ for ((var) = ((head)->tqh_first); \ (var) != TAILQ_END(head); \ (var) = ((var)->field.tqe_next)) #define TAILQ_FOREACH_SAFE(var, head, field, next) \ for ((var) = ((head)->tqh_first); \ (var) != TAILQ_END(head) && \ ((next) = TAILQ_NEXT(var, field), 1); (var) = (next)) #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ for ((var) = TAILQ_LAST((head), headname); \ (var) != TAILQ_END(head); \ (var) = TAILQ_PREV((var), headname, field)) #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, prev) \ for ((var) = TAILQ_LAST((head), headname); \ (var) != TAILQ_END(head) && \ ((prev) = TAILQ_PREV((var), headname, field), 1); (var) = (prev)) /* * Tail queue functions. */ #if defined(QUEUEDEBUG) #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) \ if ((head)->tqh_first && \ (head)->tqh_first->field.tqe_prev != &(head)->tqh_first) \ QUEUEDEBUG_ABORT("TAILQ_INSERT_HEAD %p %s:%d", (head), \ __FILE__, __LINE__); #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) \ if (*(head)->tqh_last != NULL) \ QUEUEDEBUG_ABORT("TAILQ_INSERT_TAIL %p %s:%d", (head), \ __FILE__, __LINE__); #define QUEUEDEBUG_TAILQ_OP(elm, field) \ if ((elm)->field.tqe_next && \ (elm)->field.tqe_next->field.tqe_prev != \ &(elm)->field.tqe_next) \ QUEUEDEBUG_ABORT("TAILQ_* forw %p %s:%d", (elm), \ __FILE__, __LINE__); \ if (*(elm)->field.tqe_prev != (elm)) \ QUEUEDEBUG_ABORT("TAILQ_* back %p %s:%d", (elm), \ __FILE__, __LINE__); #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) \ if ((elm)->field.tqe_next == NULL && \ (head)->tqh_last != &(elm)->field.tqe_next) \ QUEUEDEBUG_ABORT("TAILQ_PREREMOVE head %p elm %p %s:%d",\ (head), (elm), __FILE__, __LINE__); #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) \ (elm)->field.tqe_next = (void *)1L; \ (elm)->field.tqe_prev = (void *)1L; #else #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) #define QUEUEDEBUG_TAILQ_OP(elm, field) #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) #endif #define TAILQ_INIT(head) do { \ (head)->tqh_first = TAILQ_END(head); \ (head)->tqh_last = &(head)->tqh_first; \ } while (/*CONSTCOND*/0) #define TAILQ_INSERT_HEAD(head, elm, field) do { \ QUEUEDEBUG_TAILQ_INSERT_HEAD((head), (elm), field) \ if (((elm)->field.tqe_next = (head)->tqh_first) != TAILQ_END(head))\ (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 TAILQ_INSERT_TAIL(head, elm, field) do { \ QUEUEDEBUG_TAILQ_INSERT_TAIL((head), (elm), field) \ (elm)->field.tqe_next = TAILQ_END(head); \ (elm)->field.tqe_prev = (head)->tqh_last; \ *(head)->tqh_last = (elm); \ (head)->tqh_last = &(elm)->field.tqe_next; \ } while (/*CONSTCOND*/0) #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ QUEUEDEBUG_TAILQ_OP((listelm), field) \ if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != \ TAILQ_END(head)) \ (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 TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ QUEUEDEBUG_TAILQ_OP((listelm), field) \ (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 TAILQ_REMOVE(head, elm, field) do { \ QUEUEDEBUG_TAILQ_PREREMOVE((head), (elm), field) \ QUEUEDEBUG_TAILQ_OP((elm), field) \ if (((elm)->field.tqe_next) != TAILQ_END(head)) \ (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; \ QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field); \ } while (/*CONSTCOND*/0) #define TAILQ_REPLACE(head, elm, elm2, field) do { \ if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != \ TAILQ_END(head)) \ (elm2)->field.tqe_next->field.tqe_prev = \ &(elm2)->field.tqe_next; \ else \ (head)->tqh_last = &(elm2)->field.tqe_next; \ (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ *(elm2)->field.tqe_prev = (elm2); \ QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field); \ } while (/*CONSTCOND*/0) #define TAILQ_CONCAT(head1, head2, field) do { \ if (!TAILQ_EMPTY(head2)) { \ *(head1)->tqh_last = (head2)->tqh_first; \ (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ (head1)->tqh_last = (head2)->tqh_last; \ TAILQ_INIT((head2)); \ } \ } while (/*CONSTCOND*/0) /* * Singly-linked Tail queue declarations. */ #define STAILQ_HEAD(name, type) \ struct name { \ struct type *stqh_first; /* first element */ \ struct type **stqh_last; /* addr of last next element */ \ } #define STAILQ_HEAD_INITIALIZER(head) \ { NULL, &(head).stqh_first } #define STAILQ_ENTRY(type) \ struct { \ struct type *stqe_next; /* next element */ \ } /* * Singly-linked Tail queue access methods. */ #define STAILQ_FIRST(head) ((head)->stqh_first) #define STAILQ_END(head) NULL #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) #define STAILQ_EMPTY(head) (STAILQ_FIRST(head) == STAILQ_END(head)) /* * Singly-linked Tail queue functions. */ #define STAILQ_INIT(head) do { \ (head)->stqh_first = NULL; \ (head)->stqh_last = &(head)->stqh_first; \ } while (/*CONSTCOND*/0) #define STAILQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ (head)->stqh_last = &(elm)->field.stqe_next; \ (head)->stqh_first = (elm); \ } while (/*CONSTCOND*/0) #define STAILQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.stqe_next = NULL; \ *(head)->stqh_last = (elm); \ (head)->stqh_last = &(elm)->field.stqe_next; \ } while (/*CONSTCOND*/0) #define STAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ if (((elm)->field.stqe_next = (listelm)->field.stqe_next) == NULL)\ (head)->stqh_last = &(elm)->field.stqe_next; \ (listelm)->field.stqe_next = (elm); \ } while (/*CONSTCOND*/0) #define STAILQ_REMOVE_HEAD(head, field) do { \ if (((head)->stqh_first = (head)->stqh_first->field.stqe_next) == NULL) \ (head)->stqh_last = &(head)->stqh_first; \ } while (/*CONSTCOND*/0) #define STAILQ_REMOVE(head, elm, type, field) do { \ if ((head)->stqh_first == (elm)) { \ STAILQ_REMOVE_HEAD((head), field); \ } else { \ struct type *curelm = (head)->stqh_first; \ while (curelm->field.stqe_next != (elm)) \ curelm = curelm->field.stqe_next; \ if ((curelm->field.stqe_next = \ curelm->field.stqe_next->field.stqe_next) == NULL) \ (head)->stqh_last = &(curelm)->field.stqe_next; \ } \ } while (/*CONSTCOND*/0) #define STAILQ_FOREACH(var, head, field) \ for ((var) = ((head)->stqh_first); \ (var); \ (var) = ((var)->field.stqe_next)) #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ for ((var) = STAILQ_FIRST((head)); \ (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ (var) = (tvar)) #define STAILQ_CONCAT(head1, head2) do { \ if (!STAILQ_EMPTY((head2))) { \ *(head1)->stqh_last = (head2)->stqh_first; \ (head1)->stqh_last = (head2)->stqh_last; \ STAILQ_INIT((head2)); \ } \ } while (/*CONSTCOND*/0) #define STAILQ_LAST(head, type, field) \ (STAILQ_EMPTY((head)) ? \ NULL : \ ((struct type *)(void *) \ ((char *)((head)->stqh_last) - offsetof(struct type, field)))) #ifndef _KERNEL /* * Circular queue definitions. Do not use. We still keep the macros * for compatibility but because of pointer aliasing issues their use * is discouraged! */ /* * __launder_type(): We use this ugly hack to work around the the compiler * noticing that two types may not alias each other and elide tests in code. * We hit this in the CIRCLEQ macros when comparing 'struct name *' and * 'struct type *' (see CIRCLEQ_HEAD()). Modern compilers (such as GCC * 4.8) declare these comparisons as always false, causing the code to * not run as designed. * * This hack is only to be used for comparisons and thus can be fully const. * Do not use for assignment. * * If we ever choose to change the ABI of the CIRCLEQ macros, we could fix * this by changing the head/tail sentinal values, but see the note above * this one. */ static __inline const void * __launder_type(const void *); static __inline const void * __launder_type(const void *__x) { __asm __volatile("" : "+r" (__x)); return __x; } #if defined(QUEUEDEBUG) #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) \ if ((head)->cqh_first != CIRCLEQ_ENDC(head) && \ (head)->cqh_first->field.cqe_prev != CIRCLEQ_ENDC(head)) \ QUEUEDEBUG_ABORT("CIRCLEQ head forw %p %s:%d", (head), \ __FILE__, __LINE__); \ if ((head)->cqh_last != CIRCLEQ_ENDC(head) && \ (head)->cqh_last->field.cqe_next != CIRCLEQ_ENDC(head)) \ QUEUEDEBUG_ABORT("CIRCLEQ head back %p %s:%d", (head), \ __FILE__, __LINE__); #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) \ if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) { \ if ((head)->cqh_last != (elm)) \ QUEUEDEBUG_ABORT("CIRCLEQ elm last %p %s:%d", \ (elm), __FILE__, __LINE__); \ } else { \ if ((elm)->field.cqe_next->field.cqe_prev != (elm)) \ QUEUEDEBUG_ABORT("CIRCLEQ elm forw %p %s:%d", \ (elm), __FILE__, __LINE__); \ } \ if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) { \ if ((head)->cqh_first != (elm)) \ QUEUEDEBUG_ABORT("CIRCLEQ elm first %p %s:%d", \ (elm), __FILE__, __LINE__); \ } else { \ if ((elm)->field.cqe_prev->field.cqe_next != (elm)) \ QUEUEDEBUG_ABORT("CIRCLEQ elm prev %p %s:%d", \ (elm), __FILE__, __LINE__); \ } #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) \ (elm)->field.cqe_next = (void *)1L; \ (elm)->field.cqe_prev = (void *)1L; #else #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) #endif #define CIRCLEQ_HEAD(name, type) \ struct name { \ struct type *cqh_first; /* first element */ \ struct type *cqh_last; /* last element */ \ } #define CIRCLEQ_HEAD_INITIALIZER(head) \ { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } #define CIRCLEQ_ENTRY(type) \ struct { \ struct type *cqe_next; /* next element */ \ struct type *cqe_prev; /* previous element */ \ } /* * Circular queue functions. */ #define CIRCLEQ_INIT(head) do { \ (head)->cqh_first = CIRCLEQ_END(head); \ (head)->cqh_last = CIRCLEQ_END(head); \ } while (/*CONSTCOND*/0) #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ (elm)->field.cqe_next = (listelm)->field.cqe_next; \ (elm)->field.cqe_prev = (listelm); \ if ((listelm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ (head)->cqh_last = (elm); \ else \ (listelm)->field.cqe_next->field.cqe_prev = (elm); \ (listelm)->field.cqe_next = (elm); \ } while (/*CONSTCOND*/0) #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ (elm)->field.cqe_next = (listelm); \ (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ if ((listelm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ (head)->cqh_first = (elm); \ else \ (listelm)->field.cqe_prev->field.cqe_next = (elm); \ (listelm)->field.cqe_prev = (elm); \ } while (/*CONSTCOND*/0) #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ (elm)->field.cqe_next = (head)->cqh_first; \ (elm)->field.cqe_prev = CIRCLEQ_END(head); \ if ((head)->cqh_last == CIRCLEQ_ENDC(head)) \ (head)->cqh_last = (elm); \ else \ (head)->cqh_first->field.cqe_prev = (elm); \ (head)->cqh_first = (elm); \ } while (/*CONSTCOND*/0) #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ (elm)->field.cqe_next = CIRCLEQ_END(head); \ (elm)->field.cqe_prev = (head)->cqh_last; \ if ((head)->cqh_first == CIRCLEQ_ENDC(head)) \ (head)->cqh_first = (elm); \ else \ (head)->cqh_last->field.cqe_next = (elm); \ (head)->cqh_last = (elm); \ } while (/*CONSTCOND*/0) #define CIRCLEQ_REMOVE(head, elm, field) do { \ QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ QUEUEDEBUG_CIRCLEQ_ELM((head), (elm), field) \ if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ (head)->cqh_last = (elm)->field.cqe_prev; \ else \ (elm)->field.cqe_next->field.cqe_prev = \ (elm)->field.cqe_prev; \ if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ (head)->cqh_first = (elm)->field.cqe_next; \ else \ (elm)->field.cqe_prev->field.cqe_next = \ (elm)->field.cqe_next; \ QUEUEDEBUG_CIRCLEQ_POSTREMOVE((elm), field) \ } while (/*CONSTCOND*/0) #define CIRCLEQ_FOREACH(var, head, field) \ for ((var) = ((head)->cqh_first); \ (var) != CIRCLEQ_ENDC(head); \ (var) = ((var)->field.cqe_next)) #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ for ((var) = ((head)->cqh_last); \ (var) != CIRCLEQ_ENDC(head); \ (var) = ((var)->field.cqe_prev)) /* * Circular queue access methods. */ #define CIRCLEQ_FIRST(head) ((head)->cqh_first) #define CIRCLEQ_LAST(head) ((head)->cqh_last) /* For comparisons */ #define CIRCLEQ_ENDC(head) (__launder_type(head)) /* For assignments */ #define CIRCLEQ_END(head) ((void *)(head)) #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) #define CIRCLEQ_EMPTY(head) \ (CIRCLEQ_FIRST(head) == CIRCLEQ_ENDC(head)) #define CIRCLEQ_LOOP_NEXT(head, elm, field) \ (((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ ? ((head)->cqh_first) \ : (elm->field.cqe_next)) #define CIRCLEQ_LOOP_PREV(head, elm, field) \ (((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ ? ((head)->cqh_last) \ : (elm->field.cqe_prev)) #endif /* !_KERNEL */ #endif /* !_SYS_QUEUE_H_ */