NetBSD/sys/vm/queue.h

134 lines
5.0 KiB
C

/*
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 7.3 (Berkeley) 4/21/91
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Avadis Tevanian, Jr.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Type definitions for generic queues.
*/
#ifndef _QUEUE_H_
#define _QUEUE_H_
struct queue_entry {
struct queue_entry *next; /* next element */
struct queue_entry *prev; /* previous element */
};
typedef struct queue_entry *queue_t;
typedef struct queue_entry queue_head_t;
typedef struct queue_entry queue_chain_t;
typedef struct queue_entry *queue_entry_t;
#define round_queue(size) (((size)+7) & (~7))
#define enqueue(queue,elt) enqueue_tail(queue, elt)
#define dequeue(queue) dequeue_head(queue)
#define enqueue_head(queue,elt) insque(elt,queue)
#define enqueue_tail(queue,elt) insque(elt,(queue)->prev)
#define remqueue(queue,elt) remque(elt)
#define queue_init(q) ((q)->next = (q)->prev = q)
#define queue_first(q) ((q)->next)
#define queue_next(qc) ((qc)->next)
#define queue_end(q, qe) ((q) == (qe))
#define queue_empty(q) queue_end((q), queue_first(q))
#define queue_enter(head, elt, type, field) { \
if (queue_empty((head))) { \
(head)->next = (queue_entry_t) elt; \
(head)->prev = (queue_entry_t) elt; \
(elt)->field.next = head; \
(elt)->field.prev = head; \
} else { \
register queue_entry_t prev = (head)->prev; \
(elt)->field.prev = prev; \
(elt)->field.next = head; \
(head)->prev = (queue_entry_t)(elt); \
((type)prev)->field.next = (queue_entry_t)(elt);\
} \
}
#define queue_field(head, thing, type, field) \
(((head) == (thing)) ? (head) : &((type)(thing))->field)
#define queue_remove(head, elt, type, field) { \
register queue_entry_t next = (elt)->field.next; \
register queue_entry_t prev = (elt)->field.prev; \
queue_field((head), next, type, field)->prev = prev; \
queue_field((head), prev, type, field)->next = next; \
}
#define queue_assign(to, from, type, field) { \
((type)((from)->prev))->field.next = (to); \
((type)((from)->next))->field.prev = (to); \
*to = *from; \
}
#define queue_remove_first(h, e, t, f) { \
e = (t) queue_first((h)); \
queue_remove((h), (e), t, f); \
}
#endif /* !_QUEUE_H_ */