NetBSD/lib/libpthread/pthread_queue.h

138 lines
4.9 KiB
C

/* $NetBSD: pthread_queue.h,v 1.5 2009/10/05 23:33:48 rmind Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _LIB_PTHREAD_QUEUE_H
#define _LIB_PTHREAD_QUEUE_H
/*
* Definition of a queue interface for the pthread library.
* Style modeled on the sys/queue.h macros; implementation taken from
* the tail queue, with the added property of static initializability
* (and a corresponding extra cost in the _INSERT_TAIL() function.
*/
/*
* Queue definitions.
*/
#define PTQ_HEAD(name, type) \
struct name { \
struct type *ptqh_first;/* first element */ \
struct type **ptqh_last;/* addr of last next element */ \
}
#define PTQ_HEAD_INITIALIZER { NULL, NULL }
#define PTQ_ENTRY(type) \
struct { \
struct type *ptqe_next; /* next element */ \
struct type **ptqe_prev;/* address of previous next element */ \
}
/*
* Queue functions.
*/
#define PTQ_INIT(head) do { \
(head)->ptqh_first = NULL; \
(head)->ptqh_last = &(head)->ptqh_first; \
} while (/*CONSTCOND*/0)
#define PTQ_INSERT_HEAD(head, elm, field) do { \
if (((elm)->field.ptqe_next = (head)->ptqh_first) != NULL) \
(head)->ptqh_first->field.ptqe_prev = \
&(elm)->field.ptqe_next; \
else \
(head)->ptqh_last = &(elm)->field.ptqe_next; \
(head)->ptqh_first = (elm); \
(elm)->field.ptqe_prev = &(head)->ptqh_first; \
} while (/*CONSTCOND*/0)
#define PTQ_INSERT_TAIL(head, elm, field) do { \
(elm)->field.ptqe_next = NULL; \
if ((head)->ptqh_last == NULL) \
(head)->ptqh_last = &(head)->ptqh_first; \
(elm)->field.ptqe_prev = (head)->ptqh_last; \
*(head)->ptqh_last = (elm); \
(head)->ptqh_last = &(elm)->field.ptqe_next; \
} while (/*CONSTCOND*/0)
#define PTQ_INSERT_AFTER(head, listelm, elm, field) do { \
if (((elm)->field.ptqe_next = (listelm)->field.ptqe_next) != NULL)\
(elm)->field.ptqe_next->field.ptqe_prev = \
&(elm)->field.ptqe_next; \
else \
(head)->ptqh_last = &(elm)->field.ptqe_next; \
(listelm)->field.ptqe_next = (elm); \
(elm)->field.ptqe_prev = &(listelm)->field.ptqe_next; \
} while (/*CONSTCOND*/0)
#define PTQ_INSERT_BEFORE(listelm, elm, field) do { \
(elm)->field.ptqe_prev = (listelm)->field.ptqe_prev; \
(elm)->field.ptqe_next = (listelm); \
*(listelm)->field.ptqe_prev = (elm); \
(listelm)->field.ptqe_prev = &(elm)->field.ptqe_next; \
} while (/*CONSTCOND*/0)
#define PTQ_REMOVE(head, elm, field) do { \
if (((elm)->field.ptqe_next) != NULL) \
(elm)->field.ptqe_next->field.ptqe_prev = \
(elm)->field.ptqe_prev; \
else \
(head)->ptqh_last = (elm)->field.ptqe_prev; \
*(elm)->field.ptqe_prev = (elm)->field.ptqe_next; \
} while (/*CONSTCOND*/0)
/*
* Queue access methods.
*/
#define PTQ_EMPTY(head) ((head)->ptqh_first == NULL)
#define PTQ_FIRST(head) ((head)->ptqh_first)
#define PTQ_NEXT(elm, field) ((elm)->field.ptqe_next)
#define PTQ_LAST(head, headname) \
(*(((struct headname *)(void *)((head)->ptqh_last))->ptqh_last))
#define PTQ_PREV(elm, headname, field) \
(*(((struct headname *)(void *)((elm)->field.ptqe_prev))->ptqh_last))
#define PTQ_FOREACH(var, head, field) \
for ((var) = ((head)->ptqh_first); \
(var); \
(var) = ((var)->field.ptqe_next))
#define PTQ_FOREACH_REVERSE(var, head, headname, field) \
for ((var) = (*(((struct headname *)(void *)((head)->ptqh_last))->ptqh_last)); \
(var); \
(var) = (*(((struct headname *)(void *)((var)->field.ptqe_prev))->ptqh_last)))
#endif /* _LIB_PTHREAD_QUEUE_H */