1 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
2  *
3  * Redistribution and use in source and binary forms, with or without
4  * modification, are permitted provided that the following conditions are
5  * 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
9  *       copyright notice, this list of conditions and the following
10  *       disclaimer in the documentation and/or other materials provided
11  *       with the distribution.
12  *     * Neither the name of The Linux Foundation nor the names of its
13  *       contributors may be used to endorse or promote products derived
14  *       from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
23  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
25  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
26  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  */
29 
30 #include "cam_list.h"
31 
32 typedef struct {
33     struct cam_list list;
34     void *data;
35 } cam_node_t;
36 
37 typedef struct {
38     cam_node_t head; /* dummy head */
39     uint32_t size;
40     pthread_mutex_t lock;
41 } cam_queue_t;
42 
cam_queue_init(cam_queue_t * queue)43 static inline int32_t cam_queue_init(cam_queue_t *queue)
44 {
45     pthread_mutex_init(&queue->lock, NULL);
46     cam_list_init(&queue->head.list);
47     queue->size = 0;
48     return 0;
49 }
50 
cam_queue_enq(cam_queue_t * queue,void * data)51 static inline int32_t cam_queue_enq(cam_queue_t *queue, void *data)
52 {
53     cam_node_t *node =
54         (cam_node_t *)malloc(sizeof(cam_node_t));
55     if (NULL == node) {
56         return -1;
57     }
58 
59     memset(node, 0, sizeof(cam_node_t));
60     node->data = data;
61 
62     pthread_mutex_lock(&queue->lock);
63     cam_list_add_tail_node(&node->list, &queue->head.list);
64     queue->size++;
65     pthread_mutex_unlock(&queue->lock);
66 
67     return 0;
68 }
69 
cam_queue_deq(cam_queue_t * queue)70 static inline void *cam_queue_deq(cam_queue_t *queue)
71 {
72     cam_node_t *node = NULL;
73     void *data = NULL;
74     struct cam_list *head = NULL;
75     struct cam_list *pos = NULL;
76 
77     pthread_mutex_lock(&queue->lock);
78     head = &queue->head.list;
79     pos = head->next;
80     if (pos != head) {
81         node = member_of(pos, cam_node_t, list);
82         cam_list_del_node(&node->list);
83         queue->size--;
84     }
85     pthread_mutex_unlock(&queue->lock);
86 
87     if (NULL != node) {
88         data = node->data;
89         free(node);
90     }
91 
92     return data;
93 }
94 
cam_queue_flush(cam_queue_t * queue)95 static inline int32_t cam_queue_flush(cam_queue_t *queue)
96 {
97     cam_node_t *node = NULL;
98     struct cam_list *head = NULL;
99     struct cam_list *pos = NULL;
100 
101     pthread_mutex_lock(&queue->lock);
102     head = &queue->head.list;
103     pos = head->next;
104 
105     while(pos != head) {
106         node = member_of(pos, cam_node_t, list);
107         pos = pos->next;
108         cam_list_del_node(&node->list);
109         queue->size--;
110 
111         /* TODO later to consider ptr inside data */
112         /* for now we only assume there is no ptr inside data
113          * so we free data directly */
114         if (NULL != node->data) {
115             free(node->data);
116         }
117         free(node);
118 
119     }
120     queue->size = 0;
121     pthread_mutex_unlock(&queue->lock);
122     return 0;
123 }
124 
cam_queue_deinit(cam_queue_t * queue)125 static inline int32_t cam_queue_deinit(cam_queue_t *queue)
126 {
127     cam_queue_flush(queue);
128     pthread_mutex_destroy(&queue->lock);
129     return 0;
130 }
131