Merge commit '8a9de5c52401aa1e87bdb147524831c640d1ec53'
[ffmpeg.git] / libavutil / threadmessage.c
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 #if HAVE_THREADS
24 #if HAVE_PTHREADS
25 #include <pthread.h>
26 #elif HAVE_W32THREADS
27 #include "compat/w32pthreads.h"
28 #elif HAVE_OS2THREADS
29 #include "compat/os2threads.h"
30 #else
31 #error "Unknown threads implementation"
32 #endif
33 #endif
34
35 struct AVThreadMessageQueue {
36 #if HAVE_THREADS
37     AVFifoBuffer *fifo;
38     pthread_mutex_t lock;
39     pthread_cond_t cond;
40     int err_send;
41     int err_recv;
42     unsigned elsize;
43 #else
44     int dummy;
45 #endif
46 };
47
48 int av_thread_message_queue_alloc(AVThreadMessageQueue **mq,
49                                   unsigned nelem,
50                                   unsigned elsize)
51 {
52 #if HAVE_THREADS
53     AVThreadMessageQueue *rmq;
54     int ret = 0;
55
56     if (nelem > INT_MAX / elsize)
57         return AVERROR(EINVAL);
58     if (!(rmq = av_mallocz(sizeof(*rmq))))
59         return AVERROR(ENOMEM);
60     if ((ret = pthread_mutex_init(&rmq->lock, NULL))) {
61         av_free(rmq);
62         return AVERROR(ret);
63     }
64     if ((ret = pthread_cond_init(&rmq->cond, NULL))) {
65         pthread_mutex_destroy(&rmq->lock);
66         av_free(rmq);
67         return AVERROR(ret);
68     }
69     if (!(rmq->fifo = av_fifo_alloc(elsize * nelem))) {
70         pthread_cond_destroy(&rmq->cond);
71         pthread_mutex_destroy(&rmq->lock);
72         av_free(rmq);
73         return AVERROR(ret);
74     }
75     rmq->elsize = elsize;
76     *mq = rmq;
77     return 0;
78 #else
79     *mq = NULL;
80     return AVERROR(ENOSYS);
81 #endif /* HAVE_THREADS */
82 }
83
84 void av_thread_message_queue_free(AVThreadMessageQueue **mq)
85 {
86 #if HAVE_THREADS
87     if (*mq) {
88         av_fifo_freep(&(*mq)->fifo);
89         pthread_cond_destroy(&(*mq)->cond);
90         pthread_mutex_destroy(&(*mq)->lock);
91         av_freep(mq);
92     }
93 #endif
94 }
95
96 #if HAVE_THREADS
97
98 static int av_thread_message_queue_send_locked(AVThreadMessageQueue *mq,
99                                                void *msg,
100                                                unsigned flags)
101 {
102     while (!mq->err_send && av_fifo_space(mq->fifo) < mq->elsize) {
103         if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
104             return AVERROR(EAGAIN);
105         pthread_cond_wait(&mq->cond, &mq->lock);
106     }
107     if (mq->err_send)
108         return mq->err_send;
109     av_fifo_generic_write(mq->fifo, msg, mq->elsize, NULL);
110     pthread_cond_signal(&mq->cond);
111     return 0;
112 }
113
114 static int av_thread_message_queue_recv_locked(AVThreadMessageQueue *mq,
115                                                void *msg,
116                                                unsigned flags)
117 {
118     while (!mq->err_recv && av_fifo_size(mq->fifo) < mq->elsize) {
119         if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
120             return AVERROR(EAGAIN);
121         pthread_cond_wait(&mq->cond, &mq->lock);
122     }
123     if (av_fifo_size(mq->fifo) < mq->elsize)
124         return mq->err_recv;
125     av_fifo_generic_read(mq->fifo, msg, mq->elsize, NULL);
126     pthread_cond_signal(&mq->cond);
127     return 0;
128 }
129
130 #endif /* HAVE_THREADS */
131
132 int av_thread_message_queue_send(AVThreadMessageQueue *mq,
133                                  void *msg,
134                                  unsigned flags)
135 {
136 #if HAVE_THREADS
137     int ret;
138
139     pthread_mutex_lock(&mq->lock);
140     ret = av_thread_message_queue_send_locked(mq, msg, flags);
141     pthread_mutex_unlock(&mq->lock);
142     return ret;
143 #else
144     return AVERROR(ENOSYS);
145 #endif /* HAVE_THREADS */
146 }
147
148 int av_thread_message_queue_recv(AVThreadMessageQueue *mq,
149                                  void *msg,
150                                  unsigned flags)
151 {
152 #if HAVE_THREADS
153     int ret;
154
155     pthread_mutex_lock(&mq->lock);
156     ret = av_thread_message_queue_recv_locked(mq, msg, flags);
157     pthread_mutex_unlock(&mq->lock);
158     return ret;
159 #else
160     return AVERROR(ENOSYS);
161 #endif /* HAVE_THREADS */
162 }
163
164 void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq,
165                                           int err)
166 {
167 #if HAVE_THREADS
168     pthread_mutex_lock(&mq->lock);
169     mq->err_send = err;
170     pthread_cond_broadcast(&mq->cond);
171     pthread_mutex_unlock(&mq->lock);
172 #endif /* HAVE_THREADS */
173 }
174
175 void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq,
176                                           int err)
177 {
178 #if HAVE_THREADS
179     pthread_mutex_lock(&mq->lock);
180     mq->err_recv = err;
181     pthread_cond_broadcast(&mq->cond);
182     pthread_mutex_unlock(&mq->lock);
183 #endif /* HAVE_THREADS */
184 }