1 /*
2 * Copyright (c) 2014 Nicolas George
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public License
8 * as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "fifo.h"
22 #include "threadmessage.h"
23 #include "thread.h"
24
25 struct AVThreadMessageQueue {
26 #if HAVE_THREADS
27 AVFifoBuffer *fifo;
28 pthread_mutex_t lock;
29 pthread_cond_t cond_recv;
30 pthread_cond_t cond_send;
31 int err_send;
32 int err_recv;
33 unsigned elsize;
34 void (*free_func)(void *msg);
35 #else
36 int dummy;
37 #endif
38 };
39
av_thread_message_queue_alloc(AVThreadMessageQueue ** mq,unsigned nelem,unsigned elsize)40 int av_thread_message_queue_alloc(AVThreadMessageQueue **mq,
41 unsigned nelem,
42 unsigned elsize)
43 {
44 #if HAVE_THREADS
45 AVThreadMessageQueue *rmq;
46 int ret = 0;
47
48 if (nelem > INT_MAX / elsize)
49 return AVERROR(EINVAL);
50 if (!(rmq = av_mallocz(sizeof(*rmq))))
51 return AVERROR(ENOMEM);
52 if ((ret = pthread_mutex_init(&rmq->lock, NULL))) {
53 av_free(rmq);
54 return AVERROR(ret);
55 }
56 if ((ret = pthread_cond_init(&rmq->cond_recv, NULL))) {
57 pthread_mutex_destroy(&rmq->lock);
58 av_free(rmq);
59 return AVERROR(ret);
60 }
61 if ((ret = pthread_cond_init(&rmq->cond_send, NULL))) {
62 pthread_cond_destroy(&rmq->cond_recv);
63 pthread_mutex_destroy(&rmq->lock);
64 av_free(rmq);
65 return AVERROR(ret);
66 }
67 if (!(rmq->fifo = av_fifo_alloc(elsize * nelem))) {
68 pthread_cond_destroy(&rmq->cond_send);
69 pthread_cond_destroy(&rmq->cond_recv);
70 pthread_mutex_destroy(&rmq->lock);
71 av_free(rmq);
72 return AVERROR(ENOMEM);
73 }
74 rmq->elsize = elsize;
75 *mq = rmq;
76 return 0;
77 #else
78 *mq = NULL;
79 return AVERROR(ENOSYS);
80 #endif /* HAVE_THREADS */
81 }
82
av_thread_message_queue_set_free_func(AVThreadMessageQueue * mq,void (* free_func)(void * msg))83 void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq,
84 void (*free_func)(void *msg))
85 {
86 #if HAVE_THREADS
87 mq->free_func = free_func;
88 #endif
89 }
90
av_thread_message_queue_free(AVThreadMessageQueue ** mq)91 void av_thread_message_queue_free(AVThreadMessageQueue **mq)
92 {
93 #if HAVE_THREADS
94 if (*mq) {
95 av_thread_message_flush(*mq);
96 av_fifo_freep(&(*mq)->fifo);
97 pthread_cond_destroy(&(*mq)->cond_send);
98 pthread_cond_destroy(&(*mq)->cond_recv);
99 pthread_mutex_destroy(&(*mq)->lock);
100 av_freep(mq);
101 }
102 #endif
103 }
104
av_thread_message_queue_nb_elems(AVThreadMessageQueue * mq)105 int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq)
106 {
107 #if HAVE_THREADS
108 int ret;
109 pthread_mutex_lock(&mq->lock);
110 ret = av_fifo_size(mq->fifo);
111 pthread_mutex_unlock(&mq->lock);
112 return ret / mq->elsize;
113 #else
114 return AVERROR(ENOSYS);
115 #endif
116 }
117
118 #if HAVE_THREADS
119
av_thread_message_queue_send_locked(AVThreadMessageQueue * mq,void * msg,unsigned flags)120 static int av_thread_message_queue_send_locked(AVThreadMessageQueue *mq,
121 void *msg,
122 unsigned flags)
123 {
124 while (!mq->err_send && av_fifo_space(mq->fifo) < mq->elsize) {
125 if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
126 return AVERROR(EAGAIN);
127 pthread_cond_wait(&mq->cond_send, &mq->lock);
128 }
129 if (mq->err_send)
130 return mq->err_send;
131 av_fifo_generic_write(mq->fifo, msg, mq->elsize, NULL);
132 /* one message is sent, signal one receiver */
133 pthread_cond_signal(&mq->cond_recv);
134 return 0;
135 }
136
av_thread_message_queue_recv_locked(AVThreadMessageQueue * mq,void * msg,unsigned flags)137 static int av_thread_message_queue_recv_locked(AVThreadMessageQueue *mq,
138 void *msg,
139 unsigned flags)
140 {
141 while (!mq->err_recv && av_fifo_size(mq->fifo) < mq->elsize) {
142 if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
143 return AVERROR(EAGAIN);
144 pthread_cond_wait(&mq->cond_recv, &mq->lock);
145 }
146 if (av_fifo_size(mq->fifo) < mq->elsize)
147 return mq->err_recv;
148 av_fifo_generic_read(mq->fifo, msg, mq->elsize, NULL);
149 /* one message space appeared, signal one sender */
150 pthread_cond_signal(&mq->cond_send);
151 return 0;
152 }
153
154 #endif /* HAVE_THREADS */
155
av_thread_message_queue_send(AVThreadMessageQueue * mq,void * msg,unsigned flags)156 int av_thread_message_queue_send(AVThreadMessageQueue *mq,
157 void *msg,
158 unsigned flags)
159 {
160 #if HAVE_THREADS
161 int ret;
162
163 pthread_mutex_lock(&mq->lock);
164 ret = av_thread_message_queue_send_locked(mq, msg, flags);
165 pthread_mutex_unlock(&mq->lock);
166 return ret;
167 #else
168 return AVERROR(ENOSYS);
169 #endif /* HAVE_THREADS */
170 }
171
av_thread_message_queue_recv(AVThreadMessageQueue * mq,void * msg,unsigned flags)172 int av_thread_message_queue_recv(AVThreadMessageQueue *mq,
173 void *msg,
174 unsigned flags)
175 {
176 #if HAVE_THREADS
177 int ret;
178
179 pthread_mutex_lock(&mq->lock);
180 ret = av_thread_message_queue_recv_locked(mq, msg, flags);
181 pthread_mutex_unlock(&mq->lock);
182 return ret;
183 #else
184 return AVERROR(ENOSYS);
185 #endif /* HAVE_THREADS */
186 }
187
av_thread_message_queue_set_err_send(AVThreadMessageQueue * mq,int err)188 void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq,
189 int err)
190 {
191 #if HAVE_THREADS
192 pthread_mutex_lock(&mq->lock);
193 mq->err_send = err;
194 pthread_cond_broadcast(&mq->cond_send);
195 pthread_mutex_unlock(&mq->lock);
196 #endif /* HAVE_THREADS */
197 }
198
av_thread_message_queue_set_err_recv(AVThreadMessageQueue * mq,int err)199 void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq,
200 int err)
201 {
202 #if HAVE_THREADS
203 pthread_mutex_lock(&mq->lock);
204 mq->err_recv = err;
205 pthread_cond_broadcast(&mq->cond_recv);
206 pthread_mutex_unlock(&mq->lock);
207 #endif /* HAVE_THREADS */
208 }
209
210 #if HAVE_THREADS
free_func_wrap(void * arg,void * msg,int size)211 static void free_func_wrap(void *arg, void *msg, int size)
212 {
213 AVThreadMessageQueue *mq = arg;
214 mq->free_func(msg);
215 }
216 #endif
217
av_thread_message_flush(AVThreadMessageQueue * mq)218 void av_thread_message_flush(AVThreadMessageQueue *mq)
219 {
220 #if HAVE_THREADS
221 int used, off;
222 void *free_func = mq->free_func;
223
224 pthread_mutex_lock(&mq->lock);
225 used = av_fifo_size(mq->fifo);
226 if (free_func)
227 for (off = 0; off < used; off += mq->elsize)
228 av_fifo_generic_peek_at(mq->fifo, mq, off, mq->elsize, free_func_wrap);
229 av_fifo_drain(mq->fifo, used);
230 /* only the senders need to be notified since the queue is empty and there
231 * is nothing to read */
232 pthread_cond_broadcast(&mq->cond_send);
233 pthread_mutex_unlock(&mq->lock);
234 #endif /* HAVE_THREADS */
235 }
236