alsa_write: Avoid hung tasks.
[paraslash.git] / vss.c
1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file vss.c The virtual streaming system.
4 *
5 * This contains the audio streaming code of para_server which is independent
6 * of the current audio format, audio file selector and of the activated
7 * senders.
8 */
9
10 #include <sys/socket.h>
11 #include <netinet/in.h>
12 #include <regex.h>
13 #include <osl.h>
14 #include <sys/types.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18 #include <lopsub.h>
19
20 #include "server.lsg.h"
21 #include "para.h"
22 #include "error.h"
23 #include "portable_io.h"
24 #include "fec.h"
25 #include "string.h"
26 #include "afh.h"
27 #include "afs.h"
28 #include "net.h"
29 #include "server.h"
30 #include "list.h"
31 #include "send.h"
32 #include "sched.h"
33 #include "vss.h"
34 #include "ipc.h"
35 #include "fd.h"
36
37 extern struct misc_meta_data *mmd;
38 extern const struct sender udp_sender, dccp_sender, http_sender;
39 const struct sender * const senders[] = {
40 &http_sender, &dccp_sender, &udp_sender, NULL};
41
42 /** The possible states of the afs socket. */
43 enum afs_socket_status {
44 /** Socket is inactive. */
45 AFS_SOCKET_READY,
46 /** Socket fd was included in the write fd set for select(). */
47 AFS_SOCKET_CHECK_FOR_WRITE,
48 /** vss wrote a request to the socket and waits for reply from afs. */
49 AFS_SOCKET_AFD_PENDING
50 };
51
52 /** The task structure for the virtual streaming system. */
53 struct vss_task {
54 /** Copied from the -announce_time command line option. */
55 struct timeval announce_tv;
56 /** End of the announcing interval. */
57 struct timeval data_send_barrier;
58 /** End of the EOF interval. */
59 struct timeval eof_barrier;
60 /** Only used if --autoplay_delay was given. */
61 struct timeval autoplay_barrier;
62 /** Used for afs-server communication. */
63 int afs_socket;
64 /** The current state of \a afs_socket. */
65 enum afs_socket_status afsss;
66 /** The memory mapped audio file. */
67 char *map;
68 /** The size of the memory mapping. */
69 size_t mapsize;
70 /** Used by the scheduler. */
71 struct task *task;
72 /** Pointer to the header of the mapped audio file. */
73 char *header_buf;
74 /** Length of the audio file header. */
75 size_t header_len;
76 /** Time between audio file headers are sent. */
77 struct timeval header_interval;
78 /* Only used if afh supports dynamic chunks. */
79 void *afh_context;
80 };
81
82 /**
83 * The list of currently connected fec clients.
84 *
85 * Senders may use \ref vss_add_fec_client() to add entries to the list.
86 */
87 static struct list_head fec_client_list;
88
89 /**
90 * Data associated with one FEC group.
91 *
92 * A FEC group consists of a fixed number of slices and this number is given by
93 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
94 * group contains a number of chunks of the current audio file.
95 *
96 * FEC slices directly correspond to the data packages sent by the paraslash
97 * senders that use FEC. Each slice is identified by its group number and its
98 * number within the group. All slices have the same size, but the last slice
99 * of the group may not be filled entirely.
100 */
101 struct fec_group {
102 /** The number of the FEC group. */
103 uint32_t num;
104 /** Number of bytes in this group. */
105 uint32_t bytes;
106 /** The first chunk of the current audio file belonging to the group. */
107 uint32_t first_chunk;
108 /** The number of chunks contained in this group. */
109 uint32_t num_chunks;
110 /** When the first chunk was sent. */
111 struct timeval start;
112 /** The duration of the full group. */
113 struct timeval duration;
114 /** The group duration divided by the number of slices. */
115 struct timeval slice_duration;
116 /** Group contains the audio file header that occupies that many slices. */
117 uint8_t num_header_slices;
118 /** Number of bytes per slice for this group. */
119 uint16_t slice_bytes;
120 };
121
122 /** A FEC client is always in one of these states. */
123 enum fec_client_state {
124 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
125 FEC_STATE_DISABLED, /**< temporarily disabled */
126 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
127 };
128
129 /**
130 * Describes one connected FEC client.
131 */
132 struct fec_client {
133 /** Current state of the client */
134 enum fec_client_state state;
135 /** The connected sender client (transport layer). */
136 struct sender_client *sc;
137 /** Parameters requested by the client. */
138 struct fec_client_parms *fcp;
139 /** Used by the core FEC code. */
140 struct fec_parms *parms;
141 /** The position of this client in the fec client list. */
142 struct list_head node;
143 /** When the first slice for this client was sent. */
144 struct timeval stream_start;
145 /** The first chunk sent to this FEC client. */
146 int first_stream_chunk;
147 /** Describes the current group. */
148 struct fec_group group;
149 /** The current slice. */
150 uint8_t current_slice_num;
151 /** The data to be FEC-encoded. */
152 unsigned char **src_data;
153 /** Last time an audio header was sent. */
154 struct timeval next_header_time;
155 /** Extra slices needed to store largest chunk + header. */
156 int num_extra_slices;
157 /** Contains the FEC-encoded data. */
158 unsigned char *enc_buf;
159 /** Maximal packet size. */
160 int mps;
161 };
162
163 /**
164 * Get the chunk time of the current audio file.
165 *
166 * \return A pointer to a struct containing the chunk time, or NULL,
167 * if currently no audio file is selected.
168 */
169 struct timeval *vss_chunk_time(void)
170 {
171 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
172 mmd->afd.afhi.chunk_tv.tv_usec == 0)
173 return NULL;
174 return &mmd->afd.afhi.chunk_tv;
175 }
176
177 /**
178 * Write a fec header to a buffer.
179 *
180 * \param buf The buffer to write to.
181 * \param h The fec header to write.
182 */
183 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
184 {
185 char *buf = (char *)fc->enc_buf;
186 struct fec_group *g = &fc->group;
187 struct fec_client_parms *p = fc->fcp;
188
189 write_u32(buf, FEC_MAGIC);
190
191 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
192 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
193 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
194
195 write_u32(buf + 10, g->num);
196 write_u32(buf + 14, g->bytes);
197
198 write_u8(buf + 18, fc->current_slice_num);
199 write_u8(buf + 19, 0); /* unused */
200 write_u16(buf + 20, g->slice_bytes);
201 write_u8(buf + 22, g->first_chunk? 0 : 1);
202 write_u8(buf + 23, vsst->header_len? 1 : 0);
203 memset(buf + 24, 0, 8);
204 }
205
206 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
207 {
208 if (!mmd->current_chunk) {
209 tv_add(now, &vsst->header_interval, &fc->next_header_time);
210 return false;
211 }
212 if (!vsst->header_buf)
213 return false;
214 if (vsst->header_len == 0)
215 return false;
216 if (fc->group.num > 0) {
217 if (!fc->fcp->need_periodic_header)
218 return false;
219 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
220 return false;
221 }
222 tv_add(now, &vsst->header_interval, &fc->next_header_time);
223 return true;
224 }
225
226 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
227 {
228 if (fc->group.num > 0)
229 return true;
230 if (!vsst->header_buf)
231 return true;
232 if (vsst->header_len == 0)
233 return true;
234 if (fc->fcp->need_periodic_header)
235 return true;
236 return false;
237 }
238
239 static int fc_num_data_slices(const struct fec_client *fc)
240 {
241 return fc->fcp->data_slices_per_group + fc->num_extra_slices;
242 }
243
244 static int fc_num_slices(const struct fec_client *fc)
245 {
246 return fc->fcp->slices_per_group + fc->num_extra_slices;
247 }
248
249 static int fc_num_redundant_slices(const struct fec_client *fc)
250 {
251 return fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
252 }
253
254 static int num_slices(long unsigned bytes, int max_payload, int rs)
255 {
256 int ret;
257
258 assert(max_payload > 0);
259 assert(rs > 0);
260 ret = DIV_ROUND_UP(bytes, max_payload);
261 if (ret + rs > 255)
262 return -E_BAD_CT;
263 return ret;
264 }
265
266 /* set group start and group duration */
267 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
268 {
269 struct fec_group *g = &fc->group;
270 struct timeval *chunk_tv = vss_chunk_time();
271
272 if (!need_data_slices(fc, vsst))
273 ms2tv(200, &g->duration);
274 else
275 tv_scale(g->num_chunks, chunk_tv, &g->duration);
276 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
277 &g->duration, &g->slice_duration);
278 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
279 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
280 }
281
282 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
283 {
284 int i, k, n, ret;
285 int hs, ds, rs; /* header/data/redundant slices */
286 struct fec_client_parms *fcp = fc->fcp;
287
288 /* set mps */
289 if (fcp->init_fec) {
290 /*
291 * Set the maximum slice size to the Maximum Packet Size if the
292 * transport protocol allows determination of this value. The user
293 * can specify a slice size up to this value.
294 */
295 ret = fcp->init_fec(fc->sc);
296 if (ret < 0)
297 return ret;
298 fc->mps = ret;
299 } else
300 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
301 if (fc->mps <= FEC_HEADER_SIZE)
302 return -ERRNO_TO_PARA_ERROR(EINVAL);
303
304 /* free previous buffers, if any */
305 if (fc->src_data) {
306 k = fc_num_data_slices(fc);
307 for (i = 0; i < k; i++)
308 free(fc->src_data[i]);
309 free(fc->src_data);
310 fc->src_data = NULL;
311 }
312 free(fc->enc_buf);
313
314 rs = fc_num_redundant_slices(fc);
315 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
316 if (ret < 0)
317 return ret;
318 hs = ret;
319 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
320 if (ret < 0)
321 return ret;
322 ds = ret;
323 if (fc->fcp->need_periodic_header)
324 k = hs + ds;
325 else
326 k = PARA_MAX(hs, ds);
327 if (k < fc->fcp->data_slices_per_group)
328 k = fc->fcp->data_slices_per_group;
329 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
330 n = fc_num_slices(fc);
331 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
332 fc->mps, k, n, fc->num_extra_slices);
333
334 fec_free(fc->parms);
335 ret = fec_new(k, n, &fc->parms);
336 if (ret < 0)
337 return ret;
338 fc->src_data = para_malloc(k * sizeof(char *));
339 for (i = 0; i < k; i++)
340 fc->src_data[i] = para_malloc(fc->mps);
341 fc->enc_buf = para_malloc(fc->mps);
342
343 fc->state = FEC_STATE_READY_TO_RUN;
344 fc->next_header_time.tv_sec = 0;
345 fc->stream_start = *now;
346 fc->first_stream_chunk = mmd->current_chunk;
347 return 1;
348 }
349
350 static int vss_get_chunk(int chunk_num, struct vss_task *vsst,
351 char **buf, size_t *sz)
352 {
353 int ret;
354
355 /*
356 * Chunk zero is special for header streams: It is the first portion of
357 * the audio file which consists of the audio file header. It may be
358 * arbitrary large due to embedded meta data. Audio format handlers may
359 * replace the header by a stripped one with meta data omitted which is
360 * of bounded size. We always use the stripped header for streaming
361 * rather than the unmodified header (chunk zero).
362 */
363 if (chunk_num == 0 && vsst->header_len > 0) {
364 assert(vsst->header_buf);
365 *buf = vsst->header_buf; /* stripped header */
366 *sz = vsst->header_len;
367 return 0;
368 }
369 ret = afh_get_chunk(chunk_num, &mmd->afd.afhi,
370 mmd->afd.audio_format_id, vsst->map, vsst->mapsize,
371 (const char **)buf, sz, &vsst->afh_context);
372 if (ret < 0) {
373 *buf = NULL;
374 *sz = 0;
375 }
376 return ret;
377 }
378
379 static int compute_group_size(struct vss_task *vsst, struct fec_group *g,
380 int max_bytes)
381 {
382 char *buf;
383 size_t len;
384 int ret, i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
385
386 if (g->first_chunk == 0) {
387 g->num_chunks = 1;
388 ret = vss_get_chunk(0, vsst, &buf, &len);
389 if (ret < 0)
390 return ret;
391 g->bytes = len;
392 return 0;
393 }
394
395 g->num_chunks = 0;
396 g->bytes = 0;
397 /*
398 * Include chunks into the group until the group duration is at least
399 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
400 * super frame) is already larger than 150ms, so a FEC group consists
401 * of exactly one chunk for these audio formats.
402 */
403 for (i = 0;; i++) {
404 int chunk_num = g->first_chunk + i;
405
406 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
407 break;
408 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
409 break;
410 ret = vss_get_chunk(chunk_num, vsst, &buf, &len);
411 if (ret < 0)
412 return ret;
413 if (g->bytes + len > max_bytes)
414 break;
415 /* Include this chunk */
416 g->bytes += len;
417 g->num_chunks++;
418 }
419 assert(g->num_chunks);
420 PARA_DEBUG_LOG("group #%u: %u chunks, %u bytes total\n", g->num,
421 g->num_chunks, g->bytes);
422 return 1;
423 }
424
425 /*
426 * Compute the slice size of the next group.
427 *
428 * The FEC parameters n and k are fixed but the slice size varies per
429 * FEC group. We'd like to choose slices as small as possible to avoid
430 * unnecessary FEC calculations but large enough to guarantee that the
431 * k data slices suffice to encode the header (if needed) and the data
432 * chunk(s).
433 *
434 * Once we know the payload of the next group, we define the number s
435 * of bytes per slice for this group by
436 *
437 * s = ceil(payload / k)
438 *
439 * However, for header streams, computing s is more complicated since no
440 * overlapping of header and data slices is possible. Hence we have k >=
441 * 2 and s must satisfy
442 *
443 * (*) ceil(h / s) + ceil(d / s) <= k
444 *
445 * where h and d are payload of the header and the data chunk(s)
446 * respectively. In general there is no value for s such that (*)
447 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
448 *
449 * We use the following approach for computing a suitable value for s:
450 *
451 * Let
452 * k1 := ceil(k * min(h, d) / (h + d)),
453 * k2 := k - k1.
454 *
455 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
456 *
457 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
458 *
459 * is well-defined. Inequality (*) holds for this value of s since k1
460 * slices suffice to store min(h, d) while k2 slices suffice to store
461 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
462 * second by k2.
463 *
464 * For the above example we obtain
465 *
466 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
467 * s = max(4000 / 5, 5000 / 5) = 1000,
468 *
469 * which is optimal since a slice size of 999 bytes would already require
470 * 11 slices.
471 */
472 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
473 {
474 struct fec_group *g = &fc->group;
475 int k = fc_num_data_slices(fc);
476 int n = fc_num_slices(fc);
477 int ret, k1, k2, h, d, min, max, sum;
478 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
479 int max_group_bytes;
480
481 if (!need_audio_header(fc, vsst)) {
482 max_group_bytes = k * max_slice_bytes;
483 g->num_header_slices = 0;
484 ret = compute_group_size(vsst, g, max_group_bytes);
485 if (ret < 0)
486 return ret;
487 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
488 if (g->slice_bytes == 0)
489 g->slice_bytes = 1;
490 return 1;
491 }
492 if (!need_data_slices(fc, vsst)) {
493 g->bytes = 0;
494 g->num_chunks = 0;
495 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
496 g->num_header_slices = k;
497 return 1;
498 }
499 h = vsst->header_len;
500 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
501 * max_slice_bytes;
502 ret = compute_group_size(vsst, g, max_group_bytes);
503 if (ret < 0)
504 return ret;
505 d = g->bytes;
506 if (d == 0) {
507 g->slice_bytes = DIV_ROUND_UP(h, k);
508 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
509 if (ret < 0)
510 return ret;
511 g->num_header_slices = ret;
512 return 1;
513 }
514 min = PARA_MIN(h, d);
515 max = PARA_MAX(h, d);
516 sum = h + d;
517 k1 = DIV_ROUND_UP(k * min, sum);
518 k2 = k - k1;
519 assert(k1 > 0);
520 assert(k2 > 0);
521
522 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
523 /*
524 * This value of s := g->slice_bytes satisfies inequality (*) above,
525 * but it might be larger than max_slice_bytes. However, we know that
526 * max_slice_bytes are sufficient to store header and data, so:
527 */
528 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
529
530 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
531 if (ret < 0)
532 return ret;
533 g->num_header_slices = ret;
534 return 1;
535 }
536
537 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
538 {
539 int ret, i, c;
540 size_t copy, src_copied, slice_copied;
541 struct fec_group *g = &fc->group;
542
543 if (fc->state == FEC_STATE_NONE) {
544 ret = initialize_fec_client(fc, vsst);
545 if (ret < 0)
546 return ret;
547 g->first_chunk = mmd->current_chunk;
548 g->num = 0;
549 g->start = *now;
550 } else {
551 struct timeval tmp;
552 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
553 return 0;
554 /*
555 * Start and duration of this group depend only on the previous
556 * group. Compute the new group start as g->start += g->duration.
557 */
558 tmp = g->start;
559 tv_add(&tmp, &g->duration, &g->start);
560 set_group_timing(fc, vsst);
561 g->first_chunk += g->num_chunks;
562 g->num++;
563 }
564 compute_slice_size(fc, vsst);
565 assert(g->slice_bytes > 0);
566 fc->current_slice_num = 0;
567 if (g->num == 0)
568 set_group_timing(fc, vsst);
569 /* setup header slices */
570 for (i = 0, src_copied = 0; i < g->num_header_slices; i++) {
571 copy = PARA_MIN((size_t)g->slice_bytes, vsst->header_len - src_copied);
572 if (copy == 0)
573 break;
574 memcpy(fc->src_data[i], vsst->header_buf + src_copied, copy);
575 if (copy < g->slice_bytes)
576 memset(fc->src_data[i] + copy, 0, g->slice_bytes - copy);
577 src_copied += copy;
578 }
579 /*
580 * There might be more than one header slice to fill although only the
581 * first one will be used. Zero out any remaining header slices.
582 */
583 while (i < g->num_header_slices)
584 memset(fc->src_data[i++], 0, g->slice_bytes);
585
586 slice_copied = 0;
587 for (c = g->first_chunk; c < g->first_chunk + g->num_chunks; c++) {
588 char *buf;
589 size_t src_len;
590 ret = vss_get_chunk(c, vsst, &buf, &src_len);
591 if (ret < 0)
592 return ret;
593 if (src_len == 0)
594 continue;
595 src_copied = 0;
596 while (src_copied < src_len) {
597 copy = PARA_MIN((size_t)g->slice_bytes - slice_copied,
598 src_len - src_copied);
599 memcpy(fc->src_data[i] + slice_copied,
600 buf + src_copied, copy);
601 src_copied += copy;
602 slice_copied += copy;
603 if (slice_copied == g->slice_bytes) {
604 i++;
605 slice_copied = 0;
606 }
607 }
608 }
609 if (i < fc_num_data_slices(fc) && slice_copied < g->slice_bytes)
610 memset(fc->src_data[i] + slice_copied, 0,
611 g->slice_bytes - slice_copied);
612 /* zero out remaining slices, if any */
613 while (++i < fc_num_data_slices(fc))
614 memset(fc->src_data[i], 0, g->slice_bytes);
615 PARA_DEBUG_LOG("FEC group %u: %u chunks (%u - %u), %u bytes\n",
616 g->num, g->num_chunks, g->first_chunk,
617 g->first_chunk + g->num_chunks - 1, g->bytes
618 );
619 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
620 g->slice_bytes, g->num_header_slices, fc_num_data_slices(fc)
621 );
622 return 1;
623 }
624
625 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
626 {
627 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
628 == fc->fcp->slices_per_group + fc->num_extra_slices) {
629 int ret = setup_next_fec_group(fc, vsst);
630 if (ret == 0)
631 return 0;
632 if (ret < 0) {
633 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
634 PARA_ERROR_LOG("FEC client temporarily disabled\n");
635 fc->state = FEC_STATE_DISABLED;
636 return ret;
637 }
638 }
639 write_fec_header(fc, vsst);
640 fec_encode(fc->parms, (const unsigned char * const*)fc->src_data,
641 fc->enc_buf + FEC_HEADER_SIZE, fc->current_slice_num,
642 fc->group.slice_bytes);
643 return 1;
644 }
645
646 /**
647 * Return a buffer that marks the end of the stream.
648 *
649 * \param buf Result pointer.
650 * \return The length of the eof buffer.
651 *
652 * This is used for (multicast) udp streaming where closing the socket on the
653 * sender might not give rise to an eof condition at the peer.
654 */
655 size_t vss_get_fec_eof_packet(const char **buf)
656 {
657 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
658 *buf = fec_eof_packet;
659 return FEC_HEADER_SIZE;
660 }
661
662 /**
663 * Add one entry to the list of active fec clients.
664 *
665 * \param sc Generic sender_client data of the transport layer.
666 * \param fcp FEC parameters as supplied by the transport layer.
667 *
668 * \return Newly allocated fec_client struct.
669 */
670 struct fec_client *vss_add_fec_client(struct sender_client *sc,
671 struct fec_client_parms *fcp)
672 {
673 struct fec_client *fc = para_calloc(sizeof(*fc));
674
675 fc->sc = sc;
676 fc->fcp = fcp;
677 para_list_add(&fc->node, &fec_client_list);
678 return fc;
679 }
680
681 /**
682 * Remove one entry from the list of active fec clients.
683 *
684 * \param fc The client to be removed.
685 */
686 void vss_del_fec_client(struct fec_client *fc)
687 {
688 int i;
689
690 list_del(&fc->node);
691 free(fc->enc_buf);
692 if (fc->src_data) {
693 for (i = 0; i < fc_num_data_slices(fc); i++)
694 free(fc->src_data[i]);
695 free(fc->src_data);
696 }
697 fec_free(fc->parms);
698 free(fc);
699 }
700
701 /*
702 * Compute if/when next slice is due. If it isn't due yet and \a diff is
703 * not \p Null, compute the time difference next - now, where
704 *
705 * next = stream_start + (first_group_chunk - first_stream_chunk)
706 * * chunk_time + slice_num * slice_time
707 */
708 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
709 {
710 struct timeval tmp, next;
711 int ret;
712
713 if (fc->state == FEC_STATE_NONE)
714 return 1;
715 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
716 tv_add(&tmp, &fc->group.start, &next);
717 ret = tv_diff(&next, now, diff);
718 return ret < 0? 1 : 0;
719 }
720
721 static void set_eof_barrier(struct vss_task *vsst)
722 {
723 struct fec_client *fc;
724 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
725
726 if (!chunk_tv)
727 goto out;
728 list_for_each_entry(fc, &fec_client_list, node) {
729 struct timeval group_duration;
730
731 if (fc->state != FEC_STATE_READY_TO_RUN)
732 continue;
733 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
734 if (tv_diff(&timeout, &group_duration, NULL) < 0)
735 timeout = group_duration;
736 }
737 out:
738 tv_add(now, &timeout, &vsst->eof_barrier);
739 }
740
741 /**
742 * Check if vss status flag \a P (playing) is set.
743 *
744 * \return Greater than zero if playing, zero otherwise.
745 *
746 */
747 unsigned int vss_playing(void)
748 {
749 return mmd->new_vss_status_flags & VSS_PLAYING;
750 }
751
752 /**
753 * Check if the \a N (next) status flag is set.
754 *
755 * \return Greater than zero if set, zero if not.
756 *
757 */
758 unsigned int vss_next(void)
759 {
760 return mmd->new_vss_status_flags & VSS_NEXT;
761 }
762
763 /**
764 * Check if a reposition request is pending.
765 *
766 * \return Greater than zero if true, zero otherwise.
767 *
768 */
769 unsigned int vss_repos(void)
770 {
771 return mmd->new_vss_status_flags & VSS_REPOS;
772 }
773
774 /**
775 * Check if the vss is currently paused.
776 *
777 * \return Greater than zero if paused, zero otherwise.
778 *
779 */
780 unsigned int vss_paused(void)
781 {
782 return !(mmd->new_vss_status_flags & VSS_NEXT)
783 && !(mmd->new_vss_status_flags & VSS_PLAYING);
784 }
785
786 /**
787 * Check if the vss is currently stopped.
788 *
789 * \return Greater than zero if paused, zero otherwise.
790 *
791 */
792 unsigned int vss_stopped(void)
793 {
794 return (mmd->new_vss_status_flags & VSS_NEXT)
795 && !(mmd->new_vss_status_flags & VSS_PLAYING);
796 }
797
798 static int chk_barrier(const char *bname, const struct timeval *barrier,
799 struct timeval *diff, int print_log)
800 {
801 long ms;
802
803 if (tv_diff(now, barrier, diff) > 0)
804 return 1;
805 ms = tv2ms(diff);
806 if (print_log && ms)
807 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
808 return -1;
809 }
810
811 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
812 {
813 struct timeval tv;
814 struct fec_client *fc;
815
816 if (!vss_playing() || !vsst->map)
817 return;
818 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
819 return sched_request_timeout_ms(100, s);
820
821 /* Each of these barriers must have passed until we may proceed */
822 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
823 return;
824 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
825 return;
826 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
827 return;
828 /*
829 * Compute the select timeout as the minimal time until the next
830 * chunk/slice is due for any client.
831 */
832 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
833 &mmd->stream_start, &tv);
834 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
835 return;
836 list_for_each_entry(fc, &fec_client_list, node) {
837 if (fc->state != FEC_STATE_READY_TO_RUN)
838 continue;
839 if (next_slice_is_due(fc, &tv))
840 return sched_min_delay(s);
841 sched_request_timeout(&tv, s);
842 }
843 }
844
845 static void vss_eof(struct vss_task *vsst)
846 {
847
848 if (!vsst->map)
849 return;
850 if (mmd->new_vss_status_flags & VSS_NOMORE)
851 mmd->new_vss_status_flags = VSS_NEXT;
852 set_eof_barrier(vsst);
853 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
854 vsst->header_buf = NULL;
855 para_munmap(vsst->map, vsst->mapsize);
856 vsst->map = NULL;
857 mmd->chunks_sent = 0;
858 //mmd->offset = 0;
859 mmd->afd.afhi.seconds_total = 0;
860 mmd->afd.afhi.chunk_tv.tv_sec = 0;
861 mmd->afd.afhi.chunk_tv.tv_usec = 0;
862 free(mmd->afd.afhi.chunk_table);
863 mmd->afd.afhi.chunk_table = NULL;
864 vsst->mapsize = 0;
865 afh_close(vsst->afh_context, mmd->afd.audio_format_id);
866 vsst->afh_context = NULL;
867 mmd->events++;
868 }
869
870 static int need_to_request_new_audio_file(struct vss_task *vsst)
871 {
872 struct timeval diff;
873
874 if (vsst->map) /* have audio file */
875 return 0;
876 if (!vss_playing()) /* don't need one */
877 return 0;
878 if (mmd->new_vss_status_flags & VSS_NOMORE)
879 return 0;
880 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
881 return 0;
882 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
883 &diff, 1) < 0)
884 return 0;
885 return 1;
886 }
887
888 static void set_mmd_offset(void)
889 {
890 struct timeval offset;
891 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
892 mmd->offset = tv2ms(&offset);
893 }
894
895 static void vss_pre_select(struct sched *s, void *context)
896 {
897 int i;
898 struct vss_task *vsst = context;
899
900 if (need_to_request_new_audio_file(vsst)) {
901 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
902 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
903 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
904 } else
905 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
906 FOR_EACH_SENDER(i) {
907 if (!senders[i]->pre_select)
908 continue;
909 senders[i]->pre_select(&s->max_fileno, &s->rfds, &s->wfds);
910 }
911 vss_compute_timeout(s, vsst);
912 }
913
914 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
915 {
916 char control[255] __a_aligned(8), buf[8];
917 struct msghdr msg = {.msg_iov = NULL};
918 struct cmsghdr *cmsg;
919 struct iovec iov;
920 int ret = 0;
921
922 *fd = -1;
923 iov.iov_base = buf;
924 iov.iov_len = sizeof(buf);
925 msg.msg_iov = &iov;
926 msg.msg_iovlen = 1;
927 msg.msg_control = control;
928 msg.msg_controllen = sizeof(control);
929 memset(buf, 0, sizeof(buf));
930 ret = recvmsg(afs_socket, &msg, 0);
931 if (ret < 0)
932 return -ERRNO_TO_PARA_ERROR(errno);
933 if (iov.iov_len != sizeof(buf))
934 return -E_AFS_SHORT_READ;
935 *code = *(uint32_t*)buf;
936 *data = *(uint32_t*)(buf + 4);
937 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
938 if (cmsg->cmsg_level != SOL_SOCKET
939 || cmsg->cmsg_type != SCM_RIGHTS)
940 continue;
941 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
942 continue;
943 *fd = *(int *)CMSG_DATA(cmsg);
944 }
945 return 1;
946 }
947
948 #ifndef MAP_POPULATE
949 /** As of 2018, neither FreeBSD-11.2 nor NetBSD-8.0 have MAP_POPULATE. */
950 #define MAP_POPULATE 0
951 #endif
952
953 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
954 {
955 int ret, passed_fd, shmid;
956 uint32_t afs_code = 0, afs_data = 0;
957 struct stat statbuf;
958
959 if (!FD_ISSET(vsst->afs_socket, rfds))
960 return;
961 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
962 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
963 return;
964 if (ret < 0)
965 goto err;
966 vsst->afsss = AFS_SOCKET_READY;
967 ret = -E_NOFD;
968 if (afs_code != NEXT_AUDIO_FILE) {
969 PARA_ERROR_LOG("afs code: %u, expected: %d\n", afs_code,
970 NEXT_AUDIO_FILE);
971 goto err;
972 }
973 if (passed_fd < 0)
974 goto err;
975 shmid = afs_data;
976 ret = load_afd(shmid, &mmd->afd);
977 if (ret < 0)
978 goto err;
979 shm_destroy(shmid);
980 ret = fstat(passed_fd, &statbuf);
981 if (ret < 0) {
982 PARA_ERROR_LOG("fstat error:\n");
983 ret = -ERRNO_TO_PARA_ERROR(errno);
984 goto err;
985 }
986 ret = para_mmap(statbuf.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
987 passed_fd, &vsst->map);
988 if (ret < 0)
989 goto err;
990 vsst->mapsize = statbuf.st_size;
991 close(passed_fd);
992 mmd->chunks_sent = 0;
993 mmd->current_chunk = 0;
994 mmd->offset = 0;
995 mmd->events++;
996 mmd->num_played++;
997 mmd->new_vss_status_flags &= (~VSS_NEXT);
998 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
999 vsst->map, vsst->mapsize, &vsst->header_buf, &vsst->header_len);
1000 return;
1001 err:
1002 free(mmd->afd.afhi.chunk_table);
1003 if (passed_fd >= 0)
1004 close(passed_fd);
1005 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1006 mmd->new_vss_status_flags = VSS_NEXT;
1007 }
1008
1009 /**
1010 * Main sending function.
1011 *
1012 * This function gets called from vss_post_select(). It checks whether the next
1013 * chunk of data should be pushed out. It obtains a pointer to the data to be
1014 * sent out as well as its length from mmd->afd.afhi. This information is then
1015 * passed to each supported sender's send() function as well as to the send()
1016 * functions of each registered fec client.
1017 */
1018 static void vss_send(struct vss_task *vsst)
1019 {
1020 int i, ret;
1021 bool fec_active = false;
1022 struct timeval due;
1023 struct fec_client *fc, *tmp_fc;
1024 char *buf;
1025 size_t len;
1026
1027 if (!vsst->map || !vss_playing())
1028 return;
1029 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1030 return;
1031 if (chk_barrier("data send", &vsst->data_send_barrier, &due, 1) < 0)
1032 return;
1033 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1034 if (fc->state == FEC_STATE_DISABLED)
1035 continue;
1036 if (!next_slice_is_due(fc, NULL)) {
1037 fec_active = true;
1038 continue;
1039 }
1040 if (compute_next_fec_slice(fc, vsst) <= 0)
1041 continue;
1042 PARA_DEBUG_LOG("sending %u:%u (%u bytes)\n", fc->group.num,
1043 fc->current_slice_num, fc->group.slice_bytes);
1044 fc->current_slice_num++;
1045 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1046 fc->group.slice_bytes + FEC_HEADER_SIZE);
1047 fec_active = true;
1048 }
1049 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1050 if (!fec_active)
1051 mmd->new_vss_status_flags |= VSS_NEXT;
1052 return;
1053 }
1054 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1055 &mmd->stream_start, &due);
1056 if (tv_diff(&due, now, NULL) > 0)
1057 return;
1058 if (!mmd->chunks_sent) {
1059 mmd->stream_start = *now;
1060 mmd->events++;
1061 set_mmd_offset();
1062 }
1063 ret = vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1064 if (ret < 0) {
1065 PARA_ERROR_LOG("could not get chunk %lu: %s\n",
1066 mmd->current_chunk, para_strerror(-ret));
1067 } else {
1068 /*
1069 * We call ->send() even if len is zero because senders might
1070 * have data queued which can be sent now.
1071 */
1072 FOR_EACH_SENDER(i) {
1073 if (!senders[i]->send)
1074 continue;
1075 senders[i]->send(mmd->current_chunk, mmd->chunks_sent,
1076 buf, len, vsst->header_buf, vsst->header_len);
1077 }
1078 }
1079 mmd->chunks_sent++;
1080 mmd->current_chunk++;
1081 }
1082
1083 static int vss_post_select(struct sched *s, void *context)
1084 {
1085 int ret, i;
1086 struct vss_task *vsst = context;
1087
1088 ret = task_get_notification(vsst->task);
1089 if (ret < 0) {
1090 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
1091 return ret;
1092 }
1093 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
1094 /* shut down senders and fec clients */
1095 struct fec_client *fc, *tmp;
1096 FOR_EACH_SENDER(i)
1097 if (senders[i]->shutdown_clients)
1098 senders[i]->shutdown_clients();
1099 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
1100 fc->state = FEC_STATE_NONE;
1101 mmd->stream_start.tv_sec = 0;
1102 mmd->stream_start.tv_usec = 0;
1103 }
1104 if (vss_next())
1105 vss_eof(vsst);
1106 else if (vss_paused()) {
1107 if (mmd->chunks_sent)
1108 set_eof_barrier(vsst);
1109 mmd->chunks_sent = 0;
1110 } else if (vss_repos()) { /* repositioning due to ff/jmp command */
1111 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1112 set_eof_barrier(vsst);
1113 mmd->chunks_sent = 0;
1114 mmd->current_chunk = afh_get_start_chunk(mmd->repos_request,
1115 &mmd->afd.afhi, mmd->afd.audio_format_id);
1116 mmd->new_vss_status_flags &= ~VSS_REPOS;
1117 set_mmd_offset();
1118 }
1119 /* If a sender command is pending, run it. */
1120 if (mmd->sender_cmd_data.cmd_num >= 0) {
1121 int num = mmd->sender_cmd_data.cmd_num,
1122 sender_num = mmd->sender_cmd_data.sender_num;
1123
1124 if (senders[sender_num]->client_cmds[num]) {
1125 ret = senders[sender_num]->client_cmds[num]
1126 (&mmd->sender_cmd_data);
1127 if (ret < 0)
1128 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1129 }
1130 mmd->sender_cmd_data.cmd_num = -1;
1131 }
1132 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1133 recv_afs_result(vsst, &s->rfds);
1134 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1135 PARA_NOTICE_LOG("requesting new fd from afs\n");
1136 ret = write_buffer(vsst->afs_socket, "new");
1137 if (ret < 0)
1138 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1139 else
1140 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1141 }
1142 FOR_EACH_SENDER(i) {
1143 if (!senders[i]->post_select)
1144 continue;
1145 senders[i]->post_select(&s->rfds, &s->wfds);
1146 }
1147 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1148 (vss_next() && vss_playing()))
1149 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1150 vss_send(vsst);
1151 return 0;
1152 }
1153
1154 /**
1155 * Initialize the virtual streaming system task.
1156 *
1157 * \param afs_socket The fd for communication with afs.
1158 * \param s The scheduler to register the vss task to.
1159 *
1160 * This also initializes all supported senders and starts streaming
1161 * if the --autoplay command line flag was given.
1162 */
1163 void vss_init(int afs_socket, struct sched *s)
1164 {
1165 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1166 int i;
1167 long unsigned announce_time = OPT_UINT32_VAL(ANNOUNCE_TIME),
1168 autoplay_delay = OPT_UINT32_VAL(AUTOPLAY_DELAY);
1169 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1170 vsst->afs_socket = afs_socket;
1171 ms2tv(announce_time, &vsst->announce_tv);
1172 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1173 INIT_LIST_HEAD(&fec_client_list);
1174 FOR_EACH_SENDER(i) {
1175 PARA_NOTICE_LOG("initializing %s sender\n", senders[i]->name);
1176 senders[i]->init();
1177 }
1178 mmd->sender_cmd_data.cmd_num = -1;
1179 if (OPT_GIVEN(AUTOPLAY)) {
1180 struct timeval tmp;
1181 mmd->vss_status_flags |= VSS_PLAYING;
1182 mmd->new_vss_status_flags |= VSS_PLAYING;
1183 ms2tv(autoplay_delay, &tmp);
1184 tv_add(clock_get_realtime(NULL), &tmp, &vsst->autoplay_barrier);
1185 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1186 &vsst->data_send_barrier);
1187 }
1188 vsst->task = task_register(&(struct task_info) {
1189 .name = "vss",
1190 .pre_select = vss_pre_select,
1191 .post_select = vss_post_select,
1192 .context = vsst,
1193 }, s);
1194 }
1195
1196 /**
1197 * Turn off the virtual streaming system.
1198 *
1199 * This is only executed on exit. It calls the ->shutdown method of all senders.
1200 */
1201 void vss_shutdown(void)
1202 {
1203 int i;
1204
1205 FOR_EACH_SENDER(i) {
1206 if (!senders[i]->shutdown)
1207 continue;
1208 PARA_NOTICE_LOG("shutting down %s sender\n", senders[i]->name);
1209 senders[i]->shutdown();
1210 }
1211 }