1 /*--------------------------------------------------------------------------
2 Copyright (c) 2010-2013, The Linux Foundation. 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 The Linux Foundation nor
12       the names of its contributors may be used to endorse or promote
13       products derived from this software without specific prior written
14       permission.
15 
16 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
20 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 --------------------------------------------------------------------------*/
28 #include "message_queue.h"
29 
check_if_queue_empty(unsigned int queuetocheck,void * queuecontext)30 int check_if_queue_empty ( unsigned int queuetocheck, void* queuecontext )
31 {
32     struct video_queue_context *ptr_q = NULL;
33 
34     /*
35      * queuetocheck - 0 command queue
36      * queuetocheck - 1 data queue
37      */
38     if ( queuecontext == NULL || (queuetocheck > 1 ) ) {
39         return 1;
40     }
41 
42     ptr_q = (struct video_queue_context *)queuecontext;
43 
44     if (queuetocheck == 0) {
45         if (ptr_q->read_comq == ptr_q->write_comq) {
46             return 1;
47         }
48     } else if (queuetocheck == 1) {
49         if (ptr_q->write_dataq == ptr_q->read_dataq) {
50             return 1;
51         }
52     }
53 
54     return 0;
55 }
56 
57 
58 
queue_get_cmd(void * queuecontext)59 struct video_msgq * queue_get_cmd (void* queuecontext ) {
60     struct video_queue_context *ptr_q = NULL;
61     struct video_msgq *pitem = NULL;
62 
63     if ( NULL == queuecontext ) {
64         printf("queue_get_cmd: Invalid Input parameter");
65         return NULL;
66     }
67 
68     ptr_q = (struct video_queue_context *)queuecontext;
69 
70     /* Wait on the semaphore till it is released */
71     sem_wait(&ptr_q->sem_message);
72 
73     /* Lock the mutex to protect the critical section */
74     pthread_mutex_lock(&ptr_q->mutex);
75 
76     if (ptr_q->read_comq != ptr_q->write_comq) {
77         pitem = &ptr_q->ptr_cmdq [ptr_q->read_comq];
78         ptr_q->read_comq = (ptr_q->read_comq + 1) % \
79                    ptr_q->commandq_size;
80     } else if (ptr_q->write_dataq != ptr_q->read_dataq) {
81         pitem = &ptr_q->ptr_dataq [ptr_q->read_dataq];
82         ptr_q->read_dataq = (ptr_q->read_dataq + 1) % \
83                     ptr_q->dataq_size;
84     }
85 
86     /* Unlock the mutex to release the critical section */
87     pthread_mutex_unlock(&ptr_q->mutex);
88 
89     return pitem;
90 }
91 
92 
queue_post_cmdq(void * queuecontext,struct video_msgq * pitem)93 int queue_post_cmdq ( void* queuecontext,
94         struct video_msgq *pitem
95         )
96 {
97     struct video_queue_context *ptr_q = NULL;
98 
99     if (pitem == NULL || queuecontext == NULL) {
100         return -1;
101     }
102 
103     ptr_q = (struct video_queue_context *)queuecontext;
104 
105     /* Lock the mutex to protect the critical section */
106     pthread_mutex_lock(&ptr_q->mutex);
107 
108     if ((ptr_q->write_comq + 1) % ptr_q->commandq_size == ptr_q->read_comq) {
109         printf("QUEUE is FULL");
110         /* Unlock the mutex to release the critical section */
111         pthread_mutex_unlock(&ptr_q->mutex);
112         return 0;
113     } else {
114         /* Store the command in the Message Queue & increment write offset */
115         memcpy ( &ptr_q->ptr_cmdq [ptr_q->write_comq],pitem, \
116                 sizeof (struct video_msgq));
117         ptr_q->write_comq = (ptr_q->write_comq + 1) % ptr_q->commandq_size;
118     }
119 
120     /* Unlock the mutex to release the critical section */
121     pthread_mutex_unlock(&ptr_q->mutex);
122 
123     /* Post the semaphore */
124     sem_post(&ptr_q->sem_message);
125     return 1;
126 }
127 
128 
queue_post_dataq(void * queuecontext,struct video_msgq * pitem)129 int queue_post_dataq ( void *queuecontext,
130         struct video_msgq *pitem
131         )
132 {
133     struct video_queue_context *ptr_q = NULL;
134 
135     if (pitem == NULL || queuecontext == NULL) {
136         return -1;
137     }
138 
139     ptr_q = (struct video_queue_context *)queuecontext;
140 
141     /* Lock the mutex to protect the critical section */
142     pthread_mutex_lock(&ptr_q->mutex);
143 
144     if ((ptr_q->write_dataq + 1) % ptr_q->dataq_size == ptr_q->read_dataq) {
145         printf("QUEUE is FULL");
146         /* Unlock the mutex to release the critical section */
147         pthread_mutex_unlock(&ptr_q->mutex);
148         return 0;
149     } else {
150         /* Store the command in the Message Queue & increment write offset */
151         memcpy ( &ptr_q->ptr_dataq [ptr_q->write_dataq],pitem, \
152                 sizeof (struct video_msgq));
153         ptr_q->write_dataq = (ptr_q->write_dataq + 1) % ptr_q->dataq_size;
154     }
155 
156     /* Unlock the mutex to release the critical section */
157     pthread_mutex_unlock(&ptr_q->mutex);
158 
159     /* Post the semaphore */
160     sem_post(&ptr_q->sem_message);
161     return 1;
162 
163 }
164