source: trunk/sys/libphoenix/queue.h @ 1

Last change on this file since 1 was 1, checked in by alain, 5 years ago

First import

File size: 2.9 KB
Line 
1/* Copyright (c) 2007-2009, Stanford University
2* All rights reserved.
3*
4* Redistribution and use in source and binary forms, with or without
5* modification, are permitted provided that the following conditions are met:
6*     * Redistributions of source code must retain the above copyright
7*       notice, this list of conditions and the following disclaimer.
8*     * Redistributions in binary form must reproduce the above copyright
9*       notice, this list of conditions and the following disclaimer in the
10*       documentation and/or other materials provided with the distribution.
11*     * Neither the name of Stanford University nor the names of its
12*       contributors may be used to endorse or promote products derived from
13*       this software without specific prior written permission.
14*
15* THIS SOFTWARE IS PROVIDED BY STANFORD UNIVERSITY ``AS IS'' AND ANY
16* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18* DISCLAIMED. IN NO EVENT SHALL STANFORD UNIVERSITY BE LIABLE FOR ANY
19* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
22* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25*/ 
26
27#ifndef QUEUE_H_
28#define QUEUE_H_
29
30#include "list.h"
31
32typedef list queue_t;
33typedef list_ent queue_elem_t;
34
35#define queue_entry(QUEUE_ELEM, STRUCT, MEMBER)    \
36    list_entry(QUEUE_ELEM, STRUCT, MEMBER)
37
38/**
39 * Initialize queue for use
40 */
41static inline void queue_init (queue_t *q)
42{
43    assert (q != NULL);
44    list_init(q);
45}
46
47/**
48 * Add element to end of queue
49 */
50static inline void queue_push_back (queue_t *q, queue_elem_t *qe)
51{
52    assert (q != NULL);
53    assert (qe != NULL);
54
55    list_add_tail(q, qe);
56}
57
58/**
59 * Remove element at end of queue
60 * @return 0 on empty, 1 if found
61 */
62static inline int queue_pop_back (queue_t *q, queue_elem_t **qe)
63{
64    queue_elem_t    *tail;
65
66    assert (q != NULL);
67    assert (qe != NULL);
68
69    tail = list_remove_tail(q);
70    if (tail == NULL)
71        return 0;
72
73    *qe = tail;
74
75    return 1;
76}
77
78/**
79 * Put element at front of queue
80 */
81static inline void queue_push_front (queue_t *q, queue_elem_t *qe)
82{
83    assert (q != NULL);
84    assert (qe != NULL);
85
86    list_add_head(q, qe);
87}
88
89/**
90 * Remove element from front of queue
91 * @return 0 if queue was empty, 1 if successful
92 */
93static inline int queue_pop_front (queue_t *q, queue_elem_t **qe)
94{
95    queue_elem_t    *head;
96
97    assert (q != NULL);
98    assert (qe != NULL);
99
100    head = list_remove_head(q);
101    if (head == NULL)
102        return 0;
103
104    *qe = head;
105
106    return 1;
107}
108
109#endif /* QUEUE_H_ */
Note: See TracBrowser for help on using the repository browser.