| /* |
| * 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: src/sys/sys/queue.h,v 1.32.2.7 2002/04/17 14:21:02 des Exp $ |
| */ |
| |
| #ifndef _QUEUE_H_ |
| #define _QUEUE_H_ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* |
| * This file defines five types of data structures: singly-linked lists, |
| * singly-linked tail queues, lists, 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 singly-linked tail queue is headed by a pair of pointers, one to the |
| * head of the list and the other to the tail of the list. The elements are |
| * singly linked for minimum space and pointer manipulation overhead at the |
| * expense of O(n) removal for arbitrary elements. New elements can be added |
| * to the list after an existing element, at the head of the list, or at the |
| * end of the list. Elements being removed from the head of the tail queue |
| * should use the explicit macro for this purpose for optimum efficiency. |
| * A singly-linked tail queue may only be traversed in the forward direction. |
| * Singly-linked tail queues are ideal for applications with large datasets |
| * and few or no removals or for implementing a FIFO queue. |
| * |
| * A list is headed by a single forward pointer (or an array of forward |
| * pointers for a hash table header). The elements are doubly linked |
| * so that an arbitrary element can be removed without a need to |
| * traverse the list. New elements can be added to the list before |
| * or after an existing element or at the head of the list. A list |
| * may only be traversed in the forward direction. |
| * |
| * A tail queue is headed by a pair of pointers, one to the head of the |
| * list and the other to the tail of the list. The elements are doubly |
| * linked so that an arbitrary element can be removed without a need to |
| * traverse the list. New elements can be added to the list before or |
| * after an existing element, at the head of the list, or at the end of |
| * the list. A tail queue may be traversed in either direction. |
| * |
| * 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. |
| * |
| * |
| * SLIST LIST STAILQ TAILQ CIRCLEQ |
| * _HEAD + + + + + |
| * _HEAD_INITIALIZER + + + + + |
| * _ENTRY + + + + + |
| * _INIT + + + + + |
| * _EMPTY + + + + + |
| * _FIRST + + + + + |
| * _NEXT + + + + + |
| * _PREV - - - + + |
| * _LAST - - + + + |
| * _FOREACH + + + + + |
| * _FOREACH_REVERSE - - - + + |
| * _INSERT_HEAD + + + + + |
| * _INSERT_BEFORE - + - + + |
| * _INSERT_AFTER + + + + + |
| * _INSERT_TAIL - - + + + |
| * _REMOVE_HEAD + - + - - |
| * _REMOVE + + + + + |
| * |
| */ |
| |
| /* |
| * Singly-linked List declarations. |
| */ |
| #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 functions. |
| */ |
| #define SLIST_EMPTY(head) ((head)->slh_first == NULL) |
| |
| #define SLIST_FIRST(head) ((head)->slh_first) |
| |
| #define SLIST_FOREACH(var, head, field) \ |
| for ((var) = SLIST_FIRST((head)); \ |
| (var); \ |
| (var) = SLIST_NEXT((var), field)) |
| |
| #define SLIST_INIT(head) do { \ |
| SLIST_FIRST((head)) = NULL; \ |
| } while (0) |
| |
| #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ |
| SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ |
| SLIST_NEXT((slistelm), field) = (elm); \ |
| } while (0) |
| |
| #define SLIST_INSERT_HEAD(head, elm, field) do { \ |
| SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ |
| SLIST_FIRST((head)) = (elm); \ |
| } while (0) |
| |
| #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) |
| |
| #define SLIST_REMOVE(head, elm, type, field) do { \ |
| if (SLIST_FIRST((head)) == (elm)) { \ |
| SLIST_REMOVE_HEAD((head), field); \ |
| } \ |
| else { \ |
| struct type *curelm = SLIST_FIRST((head)); \ |
| while (SLIST_NEXT(curelm, field) != (elm)) \ |
| curelm = SLIST_NEXT(curelm, field); \ |
| SLIST_NEXT(curelm, field) = \ |
| SLIST_NEXT(SLIST_NEXT(curelm, field), field); \ |
| } \ |
| } while (0) |
| |
| #define SLIST_REMOVE_HEAD(head, field) do { \ |
| SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ |
| } while (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 functions. |
| */ |
| #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) |
| |
| #define STAILQ_FIRST(head) ((head)->stqh_first) |
| |
| #define STAILQ_FOREACH(var, head, field) \ |
| for((var) = STAILQ_FIRST((head)); \ |
| (var); \ |
| (var) = STAILQ_NEXT((var), field)) |
| |
| #define STAILQ_INIT(head) do { \ |
| STAILQ_FIRST((head)) = NULL; \ |
| (head)->stqh_last = &STAILQ_FIRST((head)); \ |
| } while (0) |
| |
| #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ |
| if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ |
| (head)->stqh_last = &STAILQ_NEXT((elm), field); \ |
| STAILQ_NEXT((tqelm), field) = (elm); \ |
| } while (0) |
| |
| #define STAILQ_INSERT_HEAD(head, elm, field) do { \ |
| if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ |
| (head)->stqh_last = &STAILQ_NEXT((elm), field); \ |
| STAILQ_FIRST((head)) = (elm); \ |
| } while (0) |
| |
| #define STAILQ_INSERT_TAIL(head, elm, field) do { \ |
| STAILQ_NEXT((elm), field) = NULL; \ |
| *(head)->stqh_last = (elm); \ |
| (head)->stqh_last = &STAILQ_NEXT((elm), field); \ |
| } while (0) |
| |
| #define STAILQ_LAST(head, type, field) \ |
| (STAILQ_EMPTY(head) ? \ |
| NULL : \ |
| ((struct type *) \ |
| ((char *)((head)->stqh_last) - offsetof(struct type, field)))) |
| |
| #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) |
| |
| #define STAILQ_REMOVE(head, elm, type, field) do { \ |
| if (STAILQ_FIRST((head)) == (elm)) { \ |
| STAILQ_REMOVE_HEAD(head, field); \ |
| } \ |
| else { \ |
| struct type *curelm = STAILQ_FIRST((head)); \ |
| while (STAILQ_NEXT(curelm, field) != (elm)) \ |
| curelm = STAILQ_NEXT(curelm, field); \ |
| if ((STAILQ_NEXT(curelm, field) = \ |
| STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\ |
| (head)->stqh_last = &STAILQ_NEXT((curelm), field);\ |
| } \ |
| } while (0) |
| |
| #define STAILQ_REMOVE_HEAD(head, field) do { \ |
| if ((STAILQ_FIRST((head)) = \ |
| STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ |
| (head)->stqh_last = &STAILQ_FIRST((head)); \ |
| } while (0) |
| |
| #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ |
| if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \ |
| (head)->stqh_last = &STAILQ_FIRST((head)); \ |
| } while (0) |
| |
| #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ |
| if ((STAILQ_NEXT(elm, field) = \ |
| STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ |
| (head)->stqh_last = &STAILQ_NEXT((elm), field); \ |
| } while (0) |
| |
| /* |
| * List declarations. |
| */ |
| #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 functions. |
| */ |
| |
| #define LIST_EMPTY(head) ((head)->lh_first == NULL) |
| |
| #define LIST_FIRST(head) ((head)->lh_first) |
| |
| #define LIST_FOREACH(var, head, field) \ |
| for ((var) = LIST_FIRST((head)); \ |
| (var); \ |
| (var) = LIST_NEXT((var), field)) |
| |
| #define LIST_INIT(head) do { \ |
| LIST_FIRST((head)) = NULL; \ |
| } while (0) |
| |
| #define LIST_INSERT_AFTER(listelm, elm, field) do { \ |
| if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ |
| LIST_NEXT((listelm), field)->field.le_prev = \ |
| &LIST_NEXT((elm), field); \ |
| LIST_NEXT((listelm), field) = (elm); \ |
| (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ |
| } while (0) |
| |
| #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ |
| (elm)->field.le_prev = (listelm)->field.le_prev; \ |
| LIST_NEXT((elm), field) = (listelm); \ |
| *(listelm)->field.le_prev = (elm); \ |
| (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ |
| } while (0) |
| |
| #define LIST_INSERT_HEAD(head, elm, field) do { \ |
| if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ |
| LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ |
| LIST_FIRST((head)) = (elm); \ |
| (elm)->field.le_prev = &LIST_FIRST((head)); \ |
| } while (0) |
| |
| #define LIST_NEXT(elm, field) ((elm)->field.le_next) |
| |
| #define LIST_REMOVE(elm, field) do { \ |
| if (LIST_NEXT((elm), field) != NULL) \ |
| LIST_NEXT((elm), field)->field.le_prev = \ |
| (elm)->field.le_prev; \ |
| *(elm)->field.le_prev = LIST_NEXT((elm), field); \ |
| } while (0) |
| |
| /* |
| * 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 */ \ |
| } |
| |
| #define TAILQ_HEAD_INITIALIZER(head) \ |
| { NULL, &(head).tqh_first } |
| |
| #define TAILQ_ENTRY(type) \ |
| struct { \ |
| struct type *tqe_next; /* next element */ \ |
| struct type **tqe_prev; /* address of previous next element */ \ |
| } |
| |
| /* |
| * Tail queue functions. |
| */ |
| #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_REVERSE(var, head, headname, field) \ |
| for ((var) = TAILQ_LAST((head), headname); \ |
| (var); \ |
| (var) = TAILQ_PREV((var), headname, field)) |
| |
| #define TAILQ_INIT(head) do { \ |
| TAILQ_FIRST((head)) = NULL; \ |
| (head)->tqh_last = &TAILQ_FIRST((head)); \ |
| } while (0) |
| |
| #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
| 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); \ |
| TAILQ_NEXT((listelm), field) = (elm); \ |
| (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ |
| } while (0) |
| |
| #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ |
| (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); \ |
| } while (0) |
| |
| #define TAILQ_INSERT_HEAD(head, elm, field) do { \ |
| 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)); \ |
| } while (0) |
| |
| #define TAILQ_INSERT_TAIL(head, elm, field) do { \ |
| TAILQ_NEXT((elm), field) = NULL; \ |
| (elm)->field.tqe_prev = (head)->tqh_last; \ |
| *(head)->tqh_last = (elm); \ |
| (head)->tqh_last = &TAILQ_NEXT((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 { \ |
| 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; \ |
| *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ |
| } while (0) |
| |
| /* |
| * Circular queue declarations. |
| */ |
| #define CIRCLEQ_HEAD(name, type) \ |
| struct name { \ |
| struct type *cqh_first; /* first element */ \ |
| struct type *cqh_last; /* last element */ \ |
| } |
| |
| #define CIRCLEQ_HEAD_INITIALIZER(head) \ |
| { (void *)&(head), (void *)&(head) } |
| |
| #define CIRCLEQ_ENTRY(type) \ |
| struct { \ |
| struct type *cqe_next; /* next element */ \ |
| struct type *cqe_prev; /* previous element */ \ |
| } |
| |
| /* |
| * Circular queue functions. |
| */ |
| #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) |
| |
| #define CIRCLEQ_FIRST(head) ((head)->cqh_first) |
| |
| #define CIRCLEQ_FOREACH(var, head, field) \ |
| for ((var) = CIRCLEQ_FIRST((head)); \ |
| (var) != (void *)(head) || ((var) = NULL); \ |
| (var) = CIRCLEQ_NEXT((var), field)) |
| |
| #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ |
| for ((var) = CIRCLEQ_LAST((head)); \ |
| (var) != (void *)(head) || ((var) = NULL); \ |
| (var) = CIRCLEQ_PREV((var), field)) |
| |
| #define CIRCLEQ_INIT(head) do { \ |
| CIRCLEQ_FIRST((head)) = (void *)(head); \ |
| CIRCLEQ_LAST((head)) = (void *)(head); \ |
| } while (0) |
| |
| #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
| CIRCLEQ_NEXT((elm), field) = CIRCLEQ_NEXT((listelm), field); \ |
| CIRCLEQ_PREV((elm), field) = (listelm); \ |
| if (CIRCLEQ_NEXT((listelm), field) == (void *)(head)) \ |
| CIRCLEQ_LAST((head)) = (elm); \ |
| else \ |
| CIRCLEQ_PREV(CIRCLEQ_NEXT((listelm), field), field) = (elm);\ |
| CIRCLEQ_NEXT((listelm), field) = (elm); \ |
| } while (0) |
| |
| #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ |
| CIRCLEQ_NEXT((elm), field) = (listelm); \ |
| CIRCLEQ_PREV((elm), field) = CIRCLEQ_PREV((listelm), field); \ |
| if (CIRCLEQ_PREV((listelm), field) == (void *)(head)) \ |
| CIRCLEQ_FIRST((head)) = (elm); \ |
| else \ |
| CIRCLEQ_NEXT(CIRCLEQ_PREV((listelm), field), field) = (elm);\ |
| CIRCLEQ_PREV((listelm), field) = (elm); \ |
| } while (0) |
| |
| #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ |
| CIRCLEQ_NEXT((elm), field) = CIRCLEQ_FIRST((head)); \ |
| CIRCLEQ_PREV((elm), field) = (void *)(head); \ |
| if (CIRCLEQ_LAST((head)) == (void *)(head)) \ |
| CIRCLEQ_LAST((head)) = (elm); \ |
| else \ |
| CIRCLEQ_PREV(CIRCLEQ_FIRST((head)), field) = (elm); \ |
| CIRCLEQ_FIRST((head)) = (elm); \ |
| } while (0) |
| |
| #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ |
| CIRCLEQ_NEXT((elm), field) = (void *)(head); \ |
| CIRCLEQ_PREV((elm), field) = CIRCLEQ_LAST((head)); \ |
| if (CIRCLEQ_FIRST((head)) == (void *)(head)) \ |
| CIRCLEQ_FIRST((head)) = (elm); \ |
| else \ |
| CIRCLEQ_NEXT(CIRCLEQ_LAST((head)), field) = (elm); \ |
| CIRCLEQ_LAST((head)) = (elm); \ |
| } while (0) |
| |
| #define CIRCLEQ_LAST(head) ((head)->cqh_last) |
| |
| #define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) |
| |
| #define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) |
| |
| #define CIRCLEQ_REMOVE(head, elm, field) do { \ |
| if (CIRCLEQ_NEXT((elm), field) == (void *)(head)) \ |
| CIRCLEQ_LAST((head)) = CIRCLEQ_PREV((elm), field); \ |
| else \ |
| CIRCLEQ_PREV(CIRCLEQ_NEXT((elm), field), field) = \ |
| CIRCLEQ_PREV((elm), field); \ |
| if (CIRCLEQ_PREV((elm), field) == (void *)(head)) \ |
| CIRCLEQ_FIRST((head)) = CIRCLEQ_NEXT((elm), field); \ |
| else \ |
| CIRCLEQ_NEXT(CIRCLEQ_PREV((elm), field), field) = \ |
| CIRCLEQ_NEXT((elm), field); \ |
| } while (0) |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* !_QUEUE_H_ */ |
