1 /***
2   This file is part of PulseAudio.
3 
4   Copyright 2004-2006 Lennart Poettering
5 
6   PulseAudio is free software; you can redistribute it and/or modify
7   it under the terms of the GNU Lesser General Public License as published
8   by the Free Software Foundation; either version 2.1 of the License,
9   or (at your option) any later version.
10 
11   PulseAudio is distributed in the hope that it will be useful, but
12   WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14   General Public License for more details.
15 
16   You should have received a copy of the GNU Lesser General Public License
17   along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18 ***/
19 
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23 
24 #include <stdlib.h>
25 #include <sys/stat.h>
26 #include <stdio.h>
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <unistd.h>
30 #include <sys/ioctl.h>
31 
32 #ifdef HAVE_SYS_FILIO_H
33 #include <sys/filio.h>
34 #endif
35 
36 #include <pulse/xmalloc.h>
37 #include <pulse/timeval.h>
38 #include <pulse/util.h>
39 #include <pulse/rtclock.h>
40 
41 #include <pulsecore/core-error.h>
42 #include <pulsecore/sink.h>
43 #include <pulsecore/module.h>
44 #include <pulsecore/core-util.h>
45 #include <pulsecore/modargs.h>
46 #include <pulsecore/log.h>
47 #include <pulsecore/thread.h>
48 #include <pulsecore/thread-mq.h>
49 #include <pulsecore/rtpoll.h>
50 #include <pulsecore/poll.h>
51 
52 PA_MODULE_AUTHOR("Lennart Poettering");
53 PA_MODULE_DESCRIPTION("UNIX pipe sink");
54 PA_MODULE_VERSION(PACKAGE_VERSION);
55 PA_MODULE_LOAD_ONCE(false);
56 PA_MODULE_USAGE(
57         "sink_name=<name for the sink> "
58         "sink_properties=<properties for the sink> "
59         "file=<path of the FIFO> "
60         "format=<sample format> "
61         "rate=<sample rate> "
62         "channels=<number of channels> "
63         "channel_map=<channel map> "
64         "use_system_clock_for_timing=<yes or no> "
65 );
66 
67 #define DEFAULT_FILE_NAME "fifo_output"
68 #define DEFAULT_SINK_NAME "fifo_output"
69 
70 struct userdata {
71     pa_core *core;
72     pa_module *module;
73     pa_sink *sink;
74 
75     pa_thread *thread;
76     pa_thread_mq thread_mq;
77     pa_rtpoll *rtpoll;
78 
79     char *filename;
80     int fd;
81     bool do_unlink_fifo;
82     size_t buffer_size;
83     size_t bytes_dropped;
84     bool fifo_error;
85 
86     pa_memchunk memchunk;
87 
88     pa_rtpoll_item *rtpoll_item;
89 
90     int write_type;
91     pa_usec_t block_usec;
92     pa_usec_t timestamp;
93 
94     bool use_system_clock_for_timing;
95 };
96 
97 static const char* const valid_modargs[] = {
98     "sink_name",
99     "sink_properties",
100     "file",
101     "format",
102     "rate",
103     "channels",
104     "channel_map",
105     "use_system_clock_for_timing",
106     NULL
107 };
108 
sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk)109 static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
110     struct userdata *u = PA_SINK(o)->userdata;
111 
112     switch (code) {
113         case PA_SINK_MESSAGE_GET_LATENCY:
114             if (u->use_system_clock_for_timing) {
115                 pa_usec_t now;
116                 now = pa_rtclock_now();
117                 *((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
118             } else {
119                 size_t n = 0;
120 
121 #ifdef FIONREAD
122                 int l;
123 
124                 if (ioctl(u->fd, FIONREAD, &l) >= 0 && l > 0)
125                     n = (size_t) l;
126 #endif
127 
128                 n += u->memchunk.length;
129 
130                 *((int64_t*) data) = pa_bytes_to_usec(n, &u->sink->sample_spec);
131             }
132             return 0;
133     }
134 
135     return pa_sink_process_msg(o, code, data, offset, chunk);
136 }
137 
138 /* Called from the IO thread. */
sink_set_state_in_io_thread_cb(pa_sink *s, pa_sink_state_t new_state, pa_suspend_cause_t new_suspend_cause)139 static int sink_set_state_in_io_thread_cb(pa_sink *s, pa_sink_state_t new_state, pa_suspend_cause_t new_suspend_cause) {
140     struct userdata *u;
141 
142     pa_assert(s);
143     pa_assert_se(u = s->userdata);
144 
145     if (s->thread_info.state == PA_SINK_SUSPENDED || s->thread_info.state == PA_SINK_INIT) {
146         if (PA_SINK_IS_OPENED(new_state))
147             u->timestamp = pa_rtclock_now();
148     } else if (PA_SINK_IS_OPENED(s->thread_info.state)) {
149         if (new_state == PA_SINK_SUSPENDED) {
150             /* Clear potential FIFO error flag */
151             u->fifo_error = false;
152 
153             /* Continuously dropping data (clear counter on entering suspended state. */
154             if (u->bytes_dropped != 0) {
155                 pa_log_debug("Pipe-sink continuously dropping data - clear statistics (%zu -> 0 bytes dropped)", u->bytes_dropped);
156                 u->bytes_dropped = 0;
157             }
158         }
159     }
160 
161     return 0;
162 }
163 
sink_update_requested_latency_cb(pa_sink *s)164 static void sink_update_requested_latency_cb(pa_sink *s) {
165     struct userdata *u;
166     size_t nbytes;
167 
168     pa_sink_assert_ref(s);
169     pa_assert_se(u = s->userdata);
170 
171     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
172 
173     if (u->block_usec == (pa_usec_t) -1)
174         u->block_usec = s->thread_info.max_latency;
175 
176     nbytes = pa_usec_to_bytes(u->block_usec, &s->sample_spec);
177     pa_sink_set_max_request_within_thread(s, nbytes);
178 }
179 
pipe_sink_write(struct userdata *u, pa_memchunk *pchunk)180 static ssize_t pipe_sink_write(struct userdata *u, pa_memchunk *pchunk) {
181     size_t index, length;
182     ssize_t count = 0;
183     void *p;
184 
185     pa_assert(u);
186     pa_assert(pchunk);
187 
188     index = pchunk->index;
189     length = pchunk->length;
190     p = pa_memblock_acquire(pchunk->memblock);
191 
192     for (;;) {
193         ssize_t l;
194 
195         l = pa_write(u->fd, (uint8_t*) p + index, length, &u->write_type);
196 
197         pa_assert(l != 0);
198 
199         if (l < 0) {
200             if (errno == EAGAIN)
201                 break;
202 
203             if (!u->fifo_error) {
204                 pa_log("Failed to write data to FIFO: %s", pa_cstrerror(errno));
205                 u->fifo_error = true;
206             }
207             count = -1 - count;
208             break;
209         } else {
210             if (u->fifo_error) {
211                 pa_log_debug("Recovered from FIFO error");
212                 u->fifo_error = false;
213             }
214             count += l;
215             index += l;
216             length -= l;
217 
218             if (length <= 0) {
219                 break;
220             }
221         }
222     }
223 
224     pa_memblock_release(pchunk->memblock);
225 
226     return count;
227 }
228 
process_render_use_timing(struct userdata *u, pa_usec_t now)229 static void process_render_use_timing(struct userdata *u, pa_usec_t now) {
230     size_t dropped = 0;
231     size_t consumed = 0;
232 
233     pa_assert(u);
234 
235     /* Fill the buffer up the latency size */
236     while (u->timestamp < now + u->block_usec) {
237         ssize_t written = 0;
238         pa_memchunk chunk;
239 
240         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
241 
242         pa_assert(chunk.length > 0);
243 
244         if ((written = pipe_sink_write(u, &chunk)) < 0)
245             written = -1 - written;
246 
247         pa_memblock_unref(chunk.memblock);
248 
249         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
250 
251         dropped = chunk.length - written;
252 
253         if (u->bytes_dropped != 0 && dropped != chunk.length) {
254             pa_log_debug("Pipe-sink continuously dropped %zu bytes", u->bytes_dropped);
255             u->bytes_dropped = 0;
256         }
257 
258         if (u->bytes_dropped == 0 && dropped != 0)
259             pa_log_debug("Pipe-sink just dropped %zu bytes", dropped);
260 
261         u->bytes_dropped += dropped;
262 
263         consumed += chunk.length;
264 
265         if (consumed >= u->sink->thread_info.max_request)
266             break;
267     }
268 }
269 
process_render(struct userdata *u)270 static int process_render(struct userdata *u) {
271     pa_assert(u);
272 
273     if (u->memchunk.length <= 0)
274         pa_sink_render(u->sink, u->buffer_size, &u->memchunk);
275 
276     pa_assert(u->memchunk.length > 0);
277 
278     for (;;) {
279         ssize_t l;
280         void *p;
281 
282         p = pa_memblock_acquire(u->memchunk.memblock);
283         l = pa_write(u->fd, (uint8_t*) p + u->memchunk.index, u->memchunk.length, &u->write_type);
284         pa_memblock_release(u->memchunk.memblock);
285 
286         pa_assert(l != 0);
287 
288         if (l < 0) {
289 
290             if (errno == EAGAIN)
291                 return 0;
292             else {
293                 pa_log("Failed to write data to FIFO: %s", pa_cstrerror(errno));
294                 return -1;
295             }
296 
297         } else {
298 
299             u->memchunk.index += (size_t) l;
300             u->memchunk.length -= (size_t) l;
301 
302             if (u->memchunk.length <= 0) {
303                 pa_memblock_unref(u->memchunk.memblock);
304                 pa_memchunk_reset(&u->memchunk);
305             }
306         }
307 
308         return 0;
309     }
310 }
311 
thread_func_use_timing(void *userdata)312 static void thread_func_use_timing(void *userdata) {
313     struct userdata *u = userdata;
314 
315     pa_assert(u);
316 
317     pa_log_debug("Thread (use timing) starting up");
318 
319     pa_thread_mq_install(&u->thread_mq);
320 
321     u->timestamp = pa_rtclock_now();
322 
323     for (;;) {
324         pa_usec_t now = 0;
325         int ret;
326 
327         if (PA_SINK_IS_OPENED(u->sink->thread_info.state))
328             now = pa_rtclock_now();
329 
330         if (PA_UNLIKELY(u->sink->thread_info.rewind_requested))
331             pa_sink_process_rewind(u->sink, 0);
332 
333         /* Render some data and write it to the fifo */
334         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
335             if (u->timestamp <= now)
336                 process_render_use_timing(u, now);
337 
338             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
339         } else
340             pa_rtpoll_set_timer_disabled(u->rtpoll);
341 
342         /* Hmm, nothing to do. Let's sleep */
343         if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
344             goto fail;
345 
346         if (ret == 0)
347             goto finish;
348     }
349 
350 fail:
351     /* If this was no regular exit from the loop we have to continue
352      * processing messages until we received PA_MESSAGE_SHUTDOWN */
353     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
354     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
355 
356 finish:
357     pa_log_debug("Thread (use timing) shutting down");
358 }
359 
thread_func(void *userdata)360 static void thread_func(void *userdata) {
361     struct userdata *u = userdata;
362 
363     pa_assert(u);
364 
365     pa_log_debug("Thread starting up");
366 
367     pa_thread_mq_install(&u->thread_mq);
368 
369     for (;;) {
370         struct pollfd *pollfd;
371         int ret;
372 
373         pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
374 
375         if (PA_UNLIKELY(u->sink->thread_info.rewind_requested))
376             pa_sink_process_rewind(u->sink, 0);
377 
378         /* Render some data and write it to the fifo */
379         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
380             if (pollfd->revents) {
381                 if (process_render(u) < 0)
382                     goto fail;
383 
384                 pollfd->revents = 0;
385             }
386         }
387 
388         /* Hmm, nothing to do. Let's sleep */
389         pollfd->events = (short) (u->sink->thread_info.state == PA_SINK_RUNNING ? POLLOUT : 0);
390 
391         if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
392             goto fail;
393 
394         if (ret == 0)
395             goto finish;
396 
397         pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
398 
399         if (pollfd->revents & ~POLLOUT) {
400             pa_log("FIFO shutdown.");
401             goto fail;
402         }
403     }
404 
405 fail:
406     /* If this was no regular exit from the loop we have to continue
407      * processing messages until we received PA_MESSAGE_SHUTDOWN */
408     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
409     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
410 
411 finish:
412     pa_log_debug("Thread shutting down");
413 }
414 
pa__init(pa_module *m)415 int pa__init(pa_module *m) {
416     struct userdata *u;
417     struct stat st;
418     pa_sample_spec ss;
419     pa_channel_map map;
420     pa_modargs *ma;
421     struct pollfd *pollfd;
422     pa_sink_new_data data;
423     pa_thread_func_t thread_routine;
424 
425     pa_assert(m);
426 
427     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
428         pa_log("Failed to parse module arguments.");
429         goto fail;
430     }
431 
432     ss = m->core->default_sample_spec;
433     map = m->core->default_channel_map;
434     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
435         pa_log("Invalid sample format specification or channel map");
436         goto fail;
437     }
438 
439     u = pa_xnew0(struct userdata, 1);
440     u->core = m->core;
441     u->module = m;
442     m->userdata = u;
443     pa_memchunk_reset(&u->memchunk);
444     u->rtpoll = pa_rtpoll_new();
445 
446     if (pa_modargs_get_value_boolean(ma, "use_system_clock_for_timing", &u->use_system_clock_for_timing) < 0) {
447         pa_log("Failed to parse use_system_clock_for_timing argument.");
448         goto fail;
449     }
450 
451     if (pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll) < 0) {
452         pa_log("pa_thread_mq_init() failed.");
453         goto fail;
454     }
455 
456     u->write_type = 0;
457 
458     u->filename = pa_runtime_path(pa_modargs_get_value(ma, "file", DEFAULT_FILE_NAME));
459     u->do_unlink_fifo = false;
460 
461     if (mkfifo(u->filename, 0666) < 0) {
462         if (errno != EEXIST) {
463             pa_log("mkfifo('%s'): %s", u->filename, pa_cstrerror(errno));
464             goto fail;
465         }
466     } else {
467         u->do_unlink_fifo = true;
468 
469         /* Our umask is 077, so the pipe won't be created with the requested
470          * permissions. Let's fix the permissions with chmod(). */
471         if (chmod(u->filename, 0666) < 0)
472             pa_log_warn("chomd('%s'): %s", u->filename, pa_cstrerror(errno));
473     }
474 
475     if ((u->fd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
476         pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
477         goto fail;
478     }
479 
480     pa_make_fd_nonblock(u->fd);
481 
482     if (fstat(u->fd, &st) < 0) {
483         pa_log("fstat('%s'): %s", u->filename, pa_cstrerror(errno));
484         goto fail;
485     }
486 
487     if (!S_ISFIFO(st.st_mode)) {
488         pa_log("'%s' is not a FIFO.", u->filename);
489         goto fail;
490     }
491 
492     pa_sink_new_data_init(&data);
493     data.driver = __FILE__;
494     data.module = m;
495     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
496     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_STRING, u->filename);
497     pa_proplist_setf(data.proplist, PA_PROP_DEVICE_DESCRIPTION, "Unix FIFO sink %s", u->filename);
498     pa_sink_new_data_set_sample_spec(&data, &ss);
499     pa_sink_new_data_set_channel_map(&data, &map);
500 
501     if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
502         pa_log("Invalid properties");
503         pa_sink_new_data_done(&data);
504         goto fail;
505     }
506 
507     if (u->use_system_clock_for_timing)
508         u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY);
509     else
510         u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY);
511     pa_sink_new_data_done(&data);
512 
513     if (!u->sink) {
514         pa_log("Failed to create sink.");
515         goto fail;
516     }
517 
518     u->sink->parent.process_msg = sink_process_msg;
519     u->sink->set_state_in_io_thread = sink_set_state_in_io_thread_cb;
520     if (u->use_system_clock_for_timing)
521         u->sink->update_requested_latency = sink_update_requested_latency_cb;
522     u->sink->userdata = u;
523 
524     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
525     pa_sink_set_rtpoll(u->sink, u->rtpoll);
526 
527     u->bytes_dropped = 0;
528     u->fifo_error = false;
529     u->buffer_size = pa_frame_align(pa_pipe_buf(u->fd), &u->sink->sample_spec);
530     if (u->use_system_clock_for_timing) {
531         u->block_usec = pa_bytes_to_usec(u->buffer_size, &u->sink->sample_spec);
532         pa_sink_set_latency_range(u->sink, 0, u->block_usec);
533         thread_routine = thread_func_use_timing;
534     } else {
535         pa_sink_set_fixed_latency(u->sink, pa_bytes_to_usec(u->buffer_size, &u->sink->sample_spec));
536         thread_routine = thread_func;
537     }
538     pa_sink_set_max_request(u->sink, u->buffer_size);
539 
540     u->rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1);
541     pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
542     pollfd->fd = u->fd;
543     pollfd->events = pollfd->revents = 0;
544 
545     if (!(u->thread = pa_thread_new("pipe-sink", thread_routine, u))) {
546         pa_log("Failed to create thread.");
547         goto fail;
548     }
549 
550     pa_sink_put(u->sink);
551 
552     pa_modargs_free(ma);
553 
554     return 0;
555 
556 fail:
557     if (ma)
558         pa_modargs_free(ma);
559 
560     pa__done(m);
561 
562     return -1;
563 }
564 
pa__get_n_used(pa_module *m)565 int pa__get_n_used(pa_module *m) {
566     struct userdata *u;
567 
568     pa_assert(m);
569     pa_assert_se(u = m->userdata);
570 
571     return pa_sink_linked_by(u->sink);
572 }
573 
pa__done(pa_module *m)574 void pa__done(pa_module *m) {
575     struct userdata *u;
576 
577     pa_assert(m);
578 
579     if (!(u = m->userdata))
580         return;
581 
582     if (u->sink)
583         pa_sink_unlink(u->sink);
584 
585     if (u->thread) {
586         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
587         pa_thread_free(u->thread);
588     }
589 
590     pa_thread_mq_done(&u->thread_mq);
591 
592     if (u->sink)
593         pa_sink_unref(u->sink);
594 
595     if (u->memchunk.memblock)
596         pa_memblock_unref(u->memchunk.memblock);
597 
598     if (u->rtpoll_item)
599         pa_rtpoll_item_free(u->rtpoll_item);
600 
601     if (u->rtpoll)
602         pa_rtpoll_free(u->rtpoll);
603 
604     if (u->filename) {
605         if (u->do_unlink_fifo)
606             unlink(u->filename);
607         pa_xfree(u->filename);
608     }
609 
610     if (u->fd >= 0)
611         pa_assert_se(pa_close(u->fd) == 0);
612 
613     pa_xfree(u);
614 }
615