1 /***
2 This file is part of PulseAudio.
3
4 Copyright 2004-2008 Lennart Poettering
5 Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
6
7 PulseAudio is free software; you can redistribute it and/or modify
8 it under the terms of the GNU Lesser General Public License as published
9 by the Free Software Foundation; either version 2 of the License,
10 or (at your option) any later version.
11
12 PulseAudio is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
19 ***/
20
21 #ifdef HAVE_CONFIG_H
22 #include <config.h>
23 #endif
24
25 #include <stdlib.h>
26 #include <stdio.h>
27 #include <errno.h>
28 #include <unistd.h>
29
30 #include <pulse/rtclock.h>
31 #include <pulse/timeval.h>
32 #include <pulse/util.h>
33 #include <pulse/xmalloc.h>
34
35 #include <pulsecore/core-util.h>
36 #include <pulsecore/log.h>
37 #include <pulsecore/macro.h>
38 #include <pulsecore/modargs.h>
39 #include <pulsecore/module.h>
40 #include <pulsecore/rtpoll.h>
41 #include <pulsecore/source.h>
42 #include <pulsecore/thread-mq.h>
43 #include <pulsecore/thread.h>
44
45 PA_MODULE_AUTHOR("Lennart Poettering & Marc-Andre Lureau");
46 PA_MODULE_DESCRIPTION("Clocked NULL source");
47 PA_MODULE_VERSION(PACKAGE_VERSION);
48 PA_MODULE_LOAD_ONCE(false);
49 PA_MODULE_USAGE(
50 "format=<sample format> "
51 "channels=<number of channels> "
52 "rate=<sample rate> "
53 "source_name=<name of source> "
54 "channel_map=<channel map> "
55 "max_latency_msec=<maximum latency in ms> "
56 "description=<description for the source> ");
57
58 #define DEFAULT_SOURCE_NAME "source.null"
59 #define MAX_LATENCY_USEC (PA_USEC_PER_SEC * 2)
60 #define MIN_LATENCY_USEC (500)
61
62 struct userdata {
63 pa_core *core;
64 pa_module *module;
65 pa_source *source;
66
67 pa_thread *thread;
68 pa_thread_mq thread_mq;
69 pa_rtpoll *rtpoll;
70
71 size_t block_size;
72
73 pa_usec_t block_usec;
74 pa_usec_t timestamp;
75 };
76
77 static const char* const valid_modargs[] = {
78 "rate",
79 "format",
80 "channels",
81 "source_name",
82 "channel_map",
83 "max_latency_msec",
84 "description",
85 NULL
86 };
87
source_process_msg(pa_msgobject * o,int code,void * data,int64_t offset,pa_memchunk * chunk)88 static int source_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
89 struct userdata *u = PA_SOURCE(o)->userdata;
90
91 switch (code) {
92 case PA_SOURCE_MESSAGE_GET_LATENCY: {
93 pa_usec_t now;
94
95 now = pa_rtclock_now();
96 *((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
97
98 return 0;
99 }
100 }
101
102 return pa_source_process_msg(o, code, data, offset, chunk);
103 }
104
105 /* Called from the IO thread. */
source_set_state_in_io_thread_cb(pa_source * s,pa_source_state_t new_state,pa_suspend_cause_t new_suspend_cause)106 static int source_set_state_in_io_thread_cb(pa_source *s, pa_source_state_t new_state, pa_suspend_cause_t new_suspend_cause) {
107 struct userdata *u;
108
109 pa_assert(s);
110 pa_assert_se(u = s->userdata);
111
112 if (s->thread_info.state == PA_SOURCE_SUSPENDED || s->thread_info.state == PA_SOURCE_INIT) {
113 if (PA_SOURCE_IS_OPENED(new_state))
114 u->timestamp = pa_rtclock_now();
115 }
116
117 return 0;
118 }
119
source_update_requested_latency_cb(pa_source * s)120 static void source_update_requested_latency_cb(pa_source *s) {
121 struct userdata *u;
122
123 pa_source_assert_ref(s);
124 u = s->userdata;
125 pa_assert(u);
126
127 u->block_usec = pa_source_get_requested_latency_within_thread(s);
128
129 if (u->block_usec == (pa_usec_t)-1)
130 u->block_usec = u->source->thread_info.max_latency;
131
132 pa_source_set_max_rewind_within_thread(s, pa_usec_to_bytes(u->block_usec, &u->source->sample_spec));
133 }
134
thread_func(void * userdata)135 static void thread_func(void *userdata) {
136 struct userdata *u = userdata;
137 bool timer_elapsed = false;
138 size_t max_block_size;
139
140 pa_assert(u);
141
142 pa_log_debug("Thread starting up");
143
144 if (u->core->realtime_scheduling)
145 pa_thread_make_realtime(u->core->realtime_priority);
146
147 pa_thread_mq_install(&u->thread_mq);
148
149 max_block_size = pa_frame_align(pa_mempool_block_size_max(u->core->mempool), &u->source->sample_spec);
150 u->timestamp = pa_rtclock_now();
151
152 for (;;) {
153 int ret;
154
155 /* Generate some null data */
156 if (PA_SOURCE_IS_OPENED(u->source->thread_info.state)) {
157 pa_usec_t now;
158 pa_memchunk chunk;
159
160 now = pa_rtclock_now();
161
162 if (timer_elapsed && (chunk.length = pa_usec_to_bytes(now - u->timestamp, &u->source->sample_spec)) > 0) {
163
164 chunk.length = PA_MIN(max_block_size, chunk.length);
165
166 chunk.memblock = pa_memblock_new(u->core->mempool, chunk.length);
167 chunk.index = 0;
168 pa_silence_memchunk(&chunk, &u->source->sample_spec);
169 pa_source_post(u->source, &chunk);
170 pa_memblock_unref(chunk.memblock);
171
172 u->timestamp += pa_bytes_to_usec(chunk.length, &u->source->sample_spec);
173 }
174
175 pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp + u->block_usec);
176 } else
177 pa_rtpoll_set_timer_disabled(u->rtpoll);
178
179 /* Hmm, nothing to do. Let's sleep */
180 if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
181 goto fail;
182
183 timer_elapsed = pa_rtpoll_timer_elapsed(u->rtpoll);
184
185 if (ret == 0)
186 goto finish;
187 }
188
189 fail:
190 /* If this was no regular exit from the loop we have to continue
191 * processing messages until we received PA_MESSAGE_SHUTDOWN */
192 pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
193 pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
194
195 finish:
196 pa_log_debug("Thread shutting down");
197 }
198
pa__init(pa_module * m)199 int pa__init(pa_module*m) {
200 struct userdata *u = NULL;
201 pa_sample_spec ss;
202 pa_channel_map map;
203 pa_modargs *ma = NULL;
204 pa_source_new_data data;
205 uint32_t max_latency_msec;
206
207 pa_assert(m);
208
209 if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
210 pa_log("Failed to parse module arguments.");
211 goto fail;
212 }
213
214 ss = m->core->default_sample_spec;
215 map = m->core->default_channel_map;
216 if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
217 pa_log("Invalid sample format specification or channel map");
218 goto fail;
219 }
220
221 m->userdata = u = pa_xnew0(struct userdata, 1);
222 u->core = m->core;
223 u->module = m;
224 u->rtpoll = pa_rtpoll_new();
225
226 if (pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll) < 0) {
227 pa_log("pa_thread_mq_init() failed.");
228 goto fail;
229 }
230
231 pa_source_new_data_init(&data);
232 data.driver = __FILE__;
233 data.module = m;
234 pa_source_new_data_set_name(&data, pa_modargs_get_value(ma, "source_name", DEFAULT_SOURCE_NAME));
235 pa_source_new_data_set_sample_spec(&data, &ss);
236 pa_source_new_data_set_channel_map(&data, &map);
237 pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Input"));
238 pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
239
240 u->source = pa_source_new(m->core, &data, PA_SOURCE_LATENCY | PA_SOURCE_DYNAMIC_LATENCY);
241 pa_source_new_data_done(&data);
242
243 if (!u->source) {
244 pa_log("Failed to create source object.");
245 goto fail;
246 }
247
248 u->source->parent.process_msg = source_process_msg;
249 u->source->set_state_in_io_thread = source_set_state_in_io_thread_cb;
250 u->source->update_requested_latency = source_update_requested_latency_cb;
251 u->source->userdata = u;
252
253 pa_source_set_asyncmsgq(u->source, u->thread_mq.inq);
254 pa_source_set_rtpoll(u->source, u->rtpoll);
255
256 max_latency_msec = MAX_LATENCY_USEC / PA_USEC_PER_MSEC;
257 if (pa_modargs_get_value_u32(ma, "max_latency_msec", &max_latency_msec) < 0) {
258 pa_log("Failed to get max_latency_msec.");
259 goto fail;
260 }
261
262 pa_source_set_latency_range(u->source, MIN_LATENCY_USEC, max_latency_msec * PA_USEC_PER_MSEC);
263
264 u->block_usec = u->source->thread_info.max_latency;
265
266 u->source->thread_info.max_rewind =
267 pa_usec_to_bytes(u->block_usec, &u->source->sample_spec);
268
269 if (!(u->thread = pa_thread_new("null-source", thread_func, u))) {
270 pa_log("Failed to create thread.");
271 goto fail;
272 }
273
274 pa_source_put(u->source);
275
276 pa_modargs_free(ma);
277
278 return 0;
279
280 fail:
281 if (ma)
282 pa_modargs_free(ma);
283
284 pa__done(m);
285
286 return -1;
287 }
288
pa__done(pa_module * m)289 void pa__done(pa_module*m) {
290 struct userdata *u;
291
292 pa_assert(m);
293
294 if (!(u = m->userdata))
295 return;
296
297 if (u->source)
298 pa_source_unlink(u->source);
299
300 if (u->thread) {
301 pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
302 pa_thread_free(u->thread);
303 }
304
305 pa_thread_mq_done(&u->thread_mq);
306
307 if (u->source)
308 pa_source_unref(u->source);
309
310 if (u->rtpoll)
311 pa_rtpoll_free(u->rtpoll);
312
313 pa_xfree(u);
314 }
315