/*- * 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. * 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 * $FreeBSD$ */ #pragma once /* * This is a stripped-down version of the FreeBSD sys/queue.h include file. * * WiredTiger only uses the TAILQ macros (we've gotten into trouble in the past * by trying to use simpler queues and subsequently discovering a list we didn't * think would ever get to be large could, under some workloads, become large, * and the linear performance for removal of elements from simpler macros proved * to be more trouble than the memory savings were worth. * * We #undef all of the macros because there are incompatible versions of this * file and these macros on various systems. What makes the problem worse is * they are included and/or defined by system include files which we may have * already loaded into Berkeley DB before getting here. For example, FreeBSD's * includes its system , and VxWorks UnixLib.h defines * several of the LIST_XXX macros. Visual C.NET 7.0 also defines some of these * same macros in Vc7\PlatformSDK\Include\WinNT.h. Make sure we use ours. */ #undef QMD_SAVELINK #undef QMD_TAILQ_CHECK_HEAD #undef QMD_TAILQ_CHECK_NEXT #undef QMD_TAILQ_CHECK_PREV #undef QMD_TAILQ_CHECK_TAIL #undef QMD_TRACE_ELEM #undef QMD_TRACE_HEAD #undef QUEUE_TYPEOF #undef TAILQ_CLASS_ENTRY #undef TAILQ_CLASS_HEAD #undef TAILQ_CONCAT #undef TAILQ_EMPTY #undef TAILQ_ENTRY #undef TAILQ_FIRST #undef TAILQ_FOREACH #undef TAILQ_FOREACH_FROM #undef TAILQ_FOREACH_FROM_SAFE #undef TAILQ_FOREACH_REVERSE #undef TAILQ_FOREACH_REVERSE_FROM #undef TAILQ_FOREACH_REVERSE_FROM_SAFE #undef TAILQ_FOREACH_REVERSE_SAFE #undef TAILQ_FOREACH_SAFE #undef TAILQ_HEAD #undef TAILQ_HEAD_INITIALIZER #undef TAILQ_INIT #undef TAILQ_INSERT_AFTER #undef TAILQ_INSERT_BEFORE #undef TAILQ_INSERT_HEAD #undef TAILQ_INSERT_TAIL #undef TAILQ_LAST #undef TAILQ_NEXT #undef TAILQ_PREV #undef TAILQ_REMOVE #undef TRACEBUF #undef TRACEBUF_INITIALIZER #undef TRASHIT #undef TAILQ_SWAP #define QMD_TRACE_ELEM(elem) #define QMD_TRACE_HEAD(head) #define QMD_SAVELINK(name, link) #define TRACEBUF #define TRACEBUF_INITIALIZER #define TRASHIT(x) #ifdef __cplusplus /* * In C++ there can be structure lists and class lists: */ #define QUEUE_TYPEOF(type) type #else #define QUEUE_TYPEOF(type) struct type #endif /* * Tail queue declarations. */ #define TAILQ_HEAD(name, type) \ struct name { \ struct type *tqh_first; /* first element */ \ struct type **tqh_last; /* addr of last next element */ \ TRACEBUF \ } #define TAILQ_CLASS_HEAD(name, type) \ struct name { \ class type *tqh_first; /* first element */ \ class type **tqh_last; /* addr of last next element */ \ TRACEBUF \ } #define TAILQ_HEAD_INITIALIZER(head) \ { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } #define TAILQ_ENTRY(type) \ struct { \ struct type *tqe_next; /* next element */ \ struct type **tqe_prev; /* address of previous next element */ \ TRACEBUF \ } #define TAILQ_CLASS_ENTRY(type) \ struct { \ class type *tqe_next; /* next element */ \ class type **tqe_prev; /* address of previous next element */ \ TRACEBUF \ } /* * Tail queue functions. */ #define QMD_TAILQ_CHECK_HEAD(head, field) #define QMD_TAILQ_CHECK_TAIL(head, headname) #define QMD_TAILQ_CHECK_NEXT(elm, field) #define QMD_TAILQ_CHECK_PREV(elm, field) #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)); \ QMD_TRACE_HEAD(head1); \ QMD_TRACE_HEAD(head2); \ } \ } while (0) #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) #define TAILQ_FIRST(head) ((head)->tqh_first) #define TAILQ_FOREACH(var, head, field) \ for ((var) = TAILQ_FIRST((head)); \ (var); \ (var) = TAILQ_NEXT((var), field)) #define TAILQ_FOREACH_FROM(var, head, field) \ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ (var); \ (var) = TAILQ_NEXT((var), field)) #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ for ((var) = TAILQ_FIRST((head)); \ (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ (var) = (tvar)) #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ (var) = (tvar)) #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ for ((var) = TAILQ_LAST((head), headname); \ (var); \ (var) = TAILQ_PREV((var), headname, field)) #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ (var); \ (var) = TAILQ_PREV((var), headname, field)) #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ for ((var) = TAILQ_LAST((head), headname); \ (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ (var) = (tvar)) #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ (var) = (tvar)) #define TAILQ_INIT(head) do { \ TAILQ_FIRST((head)) = NULL; \ (head)->tqh_last = &TAILQ_FIRST((head)); \ QMD_TRACE_HEAD(head); \ } while (0) #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ QMD_TAILQ_CHECK_NEXT(listelm, field); \ if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ TAILQ_NEXT((elm), field)->field.tqe_prev = \ &TAILQ_NEXT((elm), field); \ else { \ (head)->tqh_last = &TAILQ_NEXT((elm), field); \ QMD_TRACE_HEAD(head); \ } \ TAILQ_NEXT((listelm), field) = (elm); \ (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ QMD_TRACE_ELEM(&(elm)->field); \ QMD_TRACE_ELEM(&(listelm)->field); \ } while (0) #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ QMD_TAILQ_CHECK_PREV(listelm, field); \ (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ TAILQ_NEXT((elm), field) = (listelm); \ *(listelm)->field.tqe_prev = (elm); \ (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ QMD_TRACE_ELEM(&(elm)->field); \ QMD_TRACE_ELEM(&(listelm)->field); \ } while (0) #define TAILQ_INSERT_HEAD(head, elm, field) do { \ QMD_TAILQ_CHECK_HEAD(head, field); \ if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ TAILQ_FIRST((head))->field.tqe_prev = \ &TAILQ_NEXT((elm), field); \ else \ (head)->tqh_last = &TAILQ_NEXT((elm), field); \ TAILQ_FIRST((head)) = (elm); \ (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ QMD_TRACE_HEAD(head); \ QMD_TRACE_ELEM(&(elm)->field); \ } while (0) #define TAILQ_INSERT_TAIL(head, elm, field) do { \ QMD_TAILQ_CHECK_TAIL(head, field); \ TAILQ_NEXT((elm), field) = NULL; \ (elm)->field.tqe_prev = (head)->tqh_last; \ *(head)->tqh_last = (elm); \ (head)->tqh_last = &TAILQ_NEXT((elm), field); \ QMD_TRACE_HEAD(head); \ QMD_TRACE_ELEM(&(elm)->field); \ } while (0) #define TAILQ_LAST(head, headname) \ (*(((struct headname *)((head)->tqh_last))->tqh_last)) #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) #define TAILQ_PREV(elm, headname, field) \ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) #define TAILQ_REMOVE(head, elm, field) do { \ QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ QMD_TAILQ_CHECK_NEXT(elm, field); \ QMD_TAILQ_CHECK_PREV(elm, field); \ if ((TAILQ_NEXT((elm), field)) != NULL) \ TAILQ_NEXT((elm), field)->field.tqe_prev = \ (elm)->field.tqe_prev; \ else { \ (head)->tqh_last = (elm)->field.tqe_prev; \ QMD_TRACE_HEAD(head); \ } \ *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ TRASHIT(*oldnext); \ TRASHIT(*oldprev); \ QMD_TRACE_ELEM(&(elm)->field); \ } while (0) #define TAILQ_SWAP(head1, head2, type, field) do { \ QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ (head1)->tqh_first = (head2)->tqh_first; \ (head1)->tqh_last = (head2)->tqh_last; \ (head2)->tqh_first = swap_first; \ (head2)->tqh_last = swap_last; \ if ((swap_first = (head1)->tqh_first) != NULL) \ swap_first->field.tqe_prev = &(head1)->tqh_first; \ else \ (head1)->tqh_last = &(head1)->tqh_first; \ if ((swap_first = (head2)->tqh_first) != NULL) \ swap_first->field.tqe_prev = &(head2)->tqh_first; \ else \ (head2)->tqh_last = &(head2)->tqh_first; \ } while (0)