| 1 | /* |
| 2 | * Copyright (c) 1991 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to Berkeley by |
| 6 | * The Mach Operating System project at Carnegie-Mellon University. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. All advertising materials mentioning features or use of this software |
| 17 | * must display the following acknowledgement: |
| 18 | * This product includes software developed by the University of |
| 19 | * California, Berkeley and its contributors. |
| 20 | * 4. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * @(#)queue.h 7.3 (Berkeley) 4/21/91 |
| 37 | * |
| 38 | * |
| 39 | * Copyright (c) 1987, 1990 Carnegie-Mellon University. |
| 40 | * All rights reserved. |
| 41 | * |
| 42 | * Author: Avadis Tevanian, Jr. |
| 43 | * |
| 44 | * Permission to use, copy, modify and distribute this software and |
| 45 | * its documentation is hereby granted, provided that both the copyright |
| 46 | * notice and this permission notice appear in all copies of the |
| 47 | * software, derivative works or modified versions, and any portions |
| 48 | * thereof, and that both notices appear in supporting documentation. |
| 49 | * |
| 50 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
| 51 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND |
| 52 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
| 53 | * |
| 54 | * Carnegie Mellon requests users of this software to return to |
| 55 | * |
| 56 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
| 57 | * School of Computer Science |
| 58 | * Carnegie Mellon University |
| 59 | * Pittsburgh PA 15213-3890 |
| 60 | * |
| 61 | * any improvements or extensions that they make and grant Carnegie the |
| 62 | * rights to redistribute these changes. |
| 63 | */ |
| 64 | |
| 65 | /* |
| 66 | * Type definitions for generic queues. |
| 67 | */ |
| 68 | |
| 69 | #ifndef _QUEUE_H_ |
| 70 | #define _QUEUE_H_ |
| 71 | |
| 72 | struct queue_entry { |
| 73 | struct queue_entry *next; /* next element */ |
| 74 | struct queue_entry *prev; /* previous element */ |
| 75 | }; |
| 76 | |
| 77 | typedef struct queue_entry *queue_t; |
| 78 | typedef struct queue_entry queue_head_t; |
| 79 | typedef struct queue_entry queue_chain_t; |
| 80 | typedef struct queue_entry *queue_entry_t; |
| 81 | |
| 82 | #define round_queue(size) (((size)+7) & (~7)) |
| 83 | |
| 84 | #define enqueue(queue,elt) enqueue_tail(queue, elt) |
| 85 | #define dequeue(queue) dequeue_head(queue) |
| 86 | |
| 87 | #define enqueue_head(queue,elt) insque(elt,queue) |
| 88 | #define enqueue_tail(queue,elt) insque(elt,(queue)->prev) |
| 89 | #define remqueue(queue,elt) remque(elt) |
| 90 | |
| 91 | #define queue_init(q) ((q)->next = (q)->prev = q) |
| 92 | #define queue_first(q) ((q)->next) |
| 93 | #define queue_next(qc) ((qc)->next) |
| 94 | #define queue_end(q, qe) ((q) == (qe)) |
| 95 | #define queue_empty(q) queue_end((q), queue_first(q)) |
| 96 | |
| 97 | #define queue_enter(head, elt, type, field) { \ |
| 98 | if (queue_empty((head))) { \ |
| 99 | (head)->next = (queue_entry_t) elt; \ |
| 100 | (head)->prev = (queue_entry_t) elt; \ |
| 101 | (elt)->field.next = head; \ |
| 102 | (elt)->field.prev = head; \ |
| 103 | } else { \ |
| 104 | register queue_entry_t prev = (head)->prev; \ |
| 105 | (elt)->field.prev = prev; \ |
| 106 | (elt)->field.next = head; \ |
| 107 | (head)->prev = (queue_entry_t)(elt); \ |
| 108 | ((type)prev)->field.next = (queue_entry_t)(elt);\ |
| 109 | } \ |
| 110 | } |
| 111 | |
| 112 | #define queue_field(head, thing, type, field) \ |
| 113 | (((head) == (thing)) ? (head) : &((type)(thing))->field) |
| 114 | |
| 115 | #define queue_remove(head, elt, type, field) { \ |
| 116 | register queue_entry_t next = (elt)->field.next; \ |
| 117 | register queue_entry_t prev = (elt)->field.prev; \ |
| 118 | queue_field((head), next, type, field)->prev = prev; \ |
| 119 | queue_field((head), prev, type, field)->next = next; \ |
| 120 | } |
| 121 | |
| 122 | #define queue_assign(to, from, type, field) { \ |
| 123 | ((type)((from)->prev))->field.next = (to); \ |
| 124 | ((type)((from)->next))->field.prev = (to); \ |
| 125 | *to = *from; \ |
| 126 | } |
| 127 | |
| 128 | #define queue_remove_first(h, e, t, f) { \ |
| 129 | e = (t) queue_first((h)); \ |
| 130 | queue_remove((h), (e), t, f); \ |
| 131 | } |
| 132 | |
| 133 | #endif /* !_QUEUE_H_ */ |