2 * Copyright (C) 1997-2010 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file vss.c The virtual streaming system.
9 * This contains the audio streaming code of para_server which is independent
10 * of the current audio format, audio file selector and of the activated
20 #include "portable_io.h"
27 #include "server.cmdline.h"
35 extern struct misc_meta_data *mmd;
37 extern void dccp_send_init(struct sender *);
38 extern void http_send_init(struct sender *);
39 extern void udp_send_init(struct sender *);
41 /** The list of supported senders. */
42 struct sender senders[] = {
45 .init = http_send_init,
49 .init = dccp_send_init,
53 .init = udp_send_init,
60 /** The possible states of the afs socket. */
61 enum afs_socket_status {
62 /** Socket is inactive. */
64 /** Socket fd was included in the write fd set for select(). */
65 AFS_SOCKET_CHECK_FOR_WRITE,
66 /** vss wrote a request to the socket and waits for reply from afs. */
67 AFS_SOCKET_AFD_PENDING
70 /** The task structure for the virtual streaming system. */
72 /** Copied from the -announce_time command line option. */
73 struct timeval announce_tv;
74 /** End of the announcing interval. */
75 struct timeval data_send_barrier;
76 /** End of the EOF interval. */
77 struct timeval eof_barrier;
78 /** Only used if --autoplay_delay was given. */
79 struct timeval autoplay_barrier;
80 /** Used for afs-server communication. */
82 /** The current state of \a afs_socket. */
83 enum afs_socket_status afsss;
84 /** The memory mapped audio file. */
86 /** Used by the scheduler. */
88 /** Pointer to the header of the mapped audio file. */
89 const char *header_buf;
90 /** Length of the audio file header. */
92 /** Time between audio file headers are sent. */
93 struct timeval header_interval;
97 * The list of currently connected fec clients.
99 * Senders may use \ref vss_add_fec_client() to add entries to the list.
101 static struct list_head fec_client_list;
104 * Data associated with one FEC group.
106 * A FEC group consists of a fixed number of slices and this number is given by
107 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
108 * group contains a number of chunks of the current audio file.
110 * FEC slices directly correspond to the data packages sent by the paraslash
111 * senders that use FEC. Each slice is identified by its group number and its
112 * number within the group. All slices have the same size, but the last slice
113 * of the group may not be filled entirely.
116 /** The number of the FEC group. */
118 /** Number of bytes in this group. */
120 /** The first chunk of the current audio file belonging to the group. */
121 uint32_t first_chunk;
122 /** The number of chunks contained in this group. */
124 /** When the first chunk was sent. */
125 struct timeval start;
126 /** The duration of the full group. */
127 struct timeval duration;
128 /** The group duration divided by the number of slices. */
129 struct timeval slice_duration;
130 /** Group contains the audio file header that occupies that many slices. */
131 uint8_t num_header_slices;
134 enum fec_client_state {
135 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
136 FEC_STATE_DISABLED, /**< temporarily disabled */
137 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
141 * Describes one connected FEC client.
144 /** Current state of the client */
145 enum fec_client_state state;
146 /** The connected sender client (transport layer). */
147 struct sender_client *sc;
148 /** Parameters requested by the client. */
149 struct fec_client_parms *fcp;
150 /** Used by the core FEC code. */
151 struct fec_parms *parms;
152 /** The position of this client in the fec client list. */
153 struct list_head node;
154 /** When the first slice for this client was sent. */
155 struct timeval stream_start;
156 /** The first chunk sent to this FEC client. */
157 int first_stream_chunk;
158 /** Describes the current group. */
159 struct fec_group group;
160 /** The current slice. */
161 uint8_t current_slice_num;
162 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
163 const unsigned char **src_data;
164 /** Last time an audio header was sent. */
165 struct timeval next_header_time;
166 /** Used for the last source pointer of an audio file. */
167 unsigned char *extra_src_buf;
168 /** Extra slices needed to store largest chunk + header. */
169 int num_extra_slices;
170 /** Contains the FEC-encoded data. */
171 unsigned char *enc_buf;
175 * Get the chunk time of the current audio file.
177 * \return A pointer to a struct containing the chunk time, or NULL,
178 * if currently no audio file is selected.
180 struct timeval *vss_chunk_time(void)
182 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
183 mmd->afd.afhi.chunk_tv.tv_usec == 0)
185 return &mmd->afd.afhi.chunk_tv;
189 * Write a fec header to a buffer.
191 * \param buf The buffer to write to.
192 * \param h The fec header to write.
194 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
196 char *buf = (char *)fc->enc_buf;
197 struct fec_group *g = &fc->group;
198 struct fec_client_parms *p = fc->fcp;
200 write_u32(buf, FEC_MAGIC);
202 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
203 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
204 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
206 write_u32(buf + 10, g->num);
207 write_u32(buf + 14, g->bytes);
209 write_u8(buf + 18, fc->current_slice_num);
210 write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
211 write_u8(buf + 22, g->first_chunk? 0 : 1);
212 write_u8(buf + 23, vsst->header_len? 1 : 0);
213 memset(buf + 24, 0, 7);
216 static int need_audio_header(struct fec_client *fc, struct vss_task *vsst)
218 if (!mmd->current_chunk) {
219 tv_add(now, &vsst->header_interval, &fc->next_header_time);
222 if (!vsst->header_buf)
224 if (!vsst->header_len)
226 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
228 tv_add(now, &vsst->header_interval, &fc->next_header_time);
232 static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *result)
234 unsigned long m = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
235 unsigned rv, redundant_slices = fc->fcp->slices_per_group
236 - fc->fcp->data_slices_per_group;
240 rv = (bytes + m - 1) / m;
241 if (rv + redundant_slices > 255)
247 /* set group start and group duration */
248 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
250 struct timeval *chunk_tv = vss_chunk_time();
252 tv_scale(g->num_chunks, chunk_tv, &g->duration);
253 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
254 &g->duration, &g->slice_duration);
255 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
256 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
259 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
261 int ret, i, k, data_slices;
263 const char *buf, *start_buf;
264 struct fec_group *g = &fc->group;
265 unsigned slice_bytes = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
266 uint32_t max_data_size;
268 if (fc->first_stream_chunk < 0) {
269 uint8_t hs, ds; /* needed header/data slices */
270 uint8_t rs = fc->fcp->slices_per_group
271 - fc->fcp->data_slices_per_group; /* redundant slices */
274 ret = num_slices(vsst->header_len, fc, &hs);
277 ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
284 if (k < fc->fcp->data_slices_per_group)
285 k = fc->fcp->data_slices_per_group;
287 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
288 PARA_NOTICE_LOG("fec parms %d:%d:%d (%d extra slices)\n",
289 slice_bytes, k, n, fc->num_extra_slices);
291 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
292 ret = fec_new(k, n, &fc->parms);
295 fc->stream_start = *now;
296 fc->first_stream_chunk = mmd->current_chunk;
297 g->first_chunk = mmd->current_chunk;
302 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
305 * Start and duration of this group depend only on the previous
306 * group. Compute the new group start as g->start += g->duration.
309 tv_add(&tmp, &g->duration, &g->start);
310 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
311 set_group_timing(fc, g);
312 g->first_chunk += g->num_chunks;
315 if (need_audio_header(fc, vsst)) {
316 ret = num_slices(vsst->header_len, fc, &g->num_header_slices);
320 g->num_header_slices = 0;
321 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &start_buf,
323 data_slices = k - g->num_header_slices;
325 max_data_size = slice_bytes * data_slices;
327 for (i = g->first_chunk; i < mmd->afd.afhi.chunks_total; i++) {
328 afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
329 if (g->bytes + len > max_data_size)
333 g->num_chunks = i - g->first_chunk;
334 assert(g->num_chunks);
335 fc->current_slice_num = 0;
337 set_group_timing(fc, g);
339 /* setup header slices */
340 buf = vsst->header_buf;
341 for (i = 0; i < g->num_header_slices; i++) {
342 fc->src_data[i] = (const unsigned char *)buf;
346 /* setup data slices */
348 for (i = g->num_header_slices; i < k; i++) {
349 if (buf + slice_bytes > vsst->map + mmd->size)
351 * Can not use the memory mapped audio file for this
352 * slice as it goes beyond the map. This slice will not
356 fc->src_data[i] = (const unsigned char *)buf;
360 uint32_t payload_size = vsst->map + mmd->size - buf;
361 memcpy(fc->extra_src_buf, buf, payload_size);
362 fc->src_data[i] = fc->extra_src_buf;
364 /* use arbitrary data for all remaining slices */
367 fc->src_data[i] = (const unsigned char *)buf;
369 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), "
370 "%d header slices, %d data slices\n",
371 g->num, g->num_chunks, g->first_chunk,
372 g->first_chunk + g->num_chunks - 1,
373 g->num_header_slices, data_slices
378 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
380 if (fc->first_stream_chunk < 0 || fc->current_slice_num
381 == fc->fcp->slices_per_group + fc->num_extra_slices) {
382 int ret = setup_next_fec_group(fc, vsst);
386 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
387 PARA_ERROR_LOG("FEC client temporarily disabled\n");
388 fc->state = FEC_STATE_DISABLED;
392 write_fec_header(fc, vsst);
393 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
394 fc->current_slice_num,
395 fc->fcp->max_slice_bytes - FEC_HEADER_SIZE);
400 * Return a buffer that marks the end of the stream.
402 * \param buf Result pointer.
403 * \return The length of the eof buffer.
405 * This is used for (multicast) udp streaming where closing the socket on the
406 * sender might not give rise to an eof condition at the peer.
408 size_t vss_get_fec_eof_packet(const char **buf)
410 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
411 *buf = fec_eof_packet;
412 return FEC_HEADER_SIZE;
416 * Add one entry to the list of active fec clients.
418 * \param sc Generic sender_client data of the transport layer.
419 * \param fcp FEC parameters as supplied by the transport layer.
421 * \return Newly allocated fec_client struct.
423 struct fec_client *vss_add_fec_client(struct sender_client *sc,
424 struct fec_client_parms *fcp)
426 struct fec_client *fc = para_calloc(sizeof(*fc));
430 para_list_add(&fc->node, &fec_client_list);
435 * Remove one entry from the list of active fec clients.
437 * \param fc The client to be removed.
439 void vss_del_fec_client(struct fec_client *fc)
444 free(fc->extra_src_buf);
450 * Compute if/when next slice is due. If it isn't due yet and \a diff is
451 * not \p Null, compute the time difference next - now, where
453 * next = stream_start + (first_group_chunk - first_stream_chunk)
454 * * chunk_time + slice_num * slice_time
456 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
458 struct timeval tmp, next;
461 if (fc->first_stream_chunk < 0)
463 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
464 tv_add(&tmp, &fc->group.start, &next);
465 ret = tv_diff(&next, now, diff);
466 return ret < 0? 1 : 0;
469 static void compute_slice_timeout(struct timeval *timeout)
471 struct fec_client *fc;
473 list_for_each_entry(fc, &fec_client_list, node) {
476 if (fc->state != FEC_STATE_READY_TO_RUN)
478 if (next_slice_is_due(fc, &diff)) {
480 timeout->tv_usec = 0;
483 /* timeout = min(timeout, diff) */
484 if (tv_diff(&diff, timeout, NULL) < 0)
489 static void set_eof_barrier(struct vss_task *vsst)
491 struct fec_client *fc;
492 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
496 list_for_each_entry(fc, &fec_client_list, node) {
497 struct timeval group_duration;
499 if (fc->state != FEC_STATE_READY_TO_RUN)
501 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
502 if (tv_diff(&timeout, &group_duration, NULL) < 0)
503 timeout = group_duration;
506 tv_add(now, &timeout, &vsst->eof_barrier);
510 * Check if vss status flag \a P (playing) is set.
512 * \return Greater than zero if playing, zero otherwise.
515 unsigned int vss_playing(void)
517 return mmd->new_vss_status_flags & VSS_PLAYING;
521 * Check if the \a N (next) status flag is set.
523 * \return Greater than zero if set, zero if not.
526 unsigned int vss_next(void)
528 return mmd->new_vss_status_flags & VSS_NEXT;
532 * Check if a reposition request is pending.
534 * \return Greater than zero if true, zero otherwise.
537 unsigned int vss_repos(void)
539 return mmd->new_vss_status_flags & VSS_REPOS;
543 * Check if the vss is currently paused.
545 * \return Greater than zero if paused, zero otherwise.
548 unsigned int vss_paused(void)
550 return !(mmd->new_vss_status_flags & VSS_NEXT)
551 && !(mmd->new_vss_status_flags & VSS_PLAYING);
555 * Check if the vss is currently stopped.
557 * \return Greater than zero if paused, zero otherwise.
560 unsigned int vss_stopped(void)
562 return (mmd->new_vss_status_flags & VSS_NEXT)
563 && !(mmd->new_vss_status_flags & VSS_PLAYING);
566 static int chk_barrier(const char *bname, const struct timeval *barrier,
567 struct timeval *diff, int print_log)
571 if (tv_diff(now, barrier, diff) > 0)
575 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
580 * != NULL: timeout for next chunk
581 * NULL: nothing to do
583 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
585 static struct timeval the_timeout;
586 struct timeval next_chunk;
588 if (vss_next() && vsst->map) {
589 /* only sleep a bit, nec*/
590 the_timeout.tv_sec = 0;
591 the_timeout.tv_usec = 100;
594 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
595 &the_timeout, 1) < 0)
597 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
599 if (chk_barrier("data send", &vsst->data_send_barrier,
600 &the_timeout, 1) < 0)
602 if (!vss_playing() || !vsst->map)
604 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
605 &mmd->stream_start, &next_chunk);
606 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
607 /* chunk is due or bof */
608 the_timeout.tv_sec = 0;
609 the_timeout.tv_usec = 0;
612 /* compute min of current timeout and next slice time */
613 compute_slice_timeout(&the_timeout);
617 static void vss_eof(struct vss_task *vsst)
622 if (mmd->new_vss_status_flags & VSS_NOMORE)
623 mmd->new_vss_status_flags = VSS_NEXT;
624 set_eof_barrier(vsst);
625 para_munmap(vsst->map, mmd->size);
627 mmd->chunks_sent = 0;
629 mmd->afd.afhi.seconds_total = 0;
630 mmd->afd.afhi.chunk_tv.tv_sec = 0;
631 mmd->afd.afhi.chunk_tv.tv_usec = 0;
632 free(mmd->afd.afhi.chunk_table);
633 mmd->afd.afhi.chunk_table = NULL;
640 * Get the list of all supported audio formats.
642 * \return Aa space separated list of all supported audio formats
643 * It is not allocated at runtime, i.e. there is no need to free
644 * the returned string in the caller.
646 const char *supported_audio_formats(void)
648 return SUPPORTED_AUDIO_FORMATS;
651 static int need_to_request_new_audio_file(struct vss_task *vsst)
655 if (vsst->map) /* have audio file */
657 if (!vss_playing()) /* don't need one */
659 if (mmd->new_vss_status_flags & VSS_NOMORE)
661 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
663 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
669 static void set_mmd_offset(void)
671 struct timeval offset;
672 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
673 mmd->offset = tv2ms(&offset);
677 * Compute the timeout for the main select-loop of the scheduler.
679 * \param s Pointer to the server scheduler.
680 * \param t Pointer to the vss task structure.
682 * Before the timeout is computed, the current vss status flags are evaluated
683 * and acted upon by calling appropriate functions from the lower layers.
684 * Possible actions include
686 * - request a new audio file from afs,
687 * - shutdown of all senders (stop/pause command),
688 * - reposition the stream (ff/jmp command).
690 static void vss_pre_select(struct sched *s, struct task *t)
693 struct timeval *tv, diff;
694 struct vss_task *vsst = container_of(t, struct vss_task, task);
696 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
697 struct fec_client *fc, *tmp;
698 for (i = 0; senders[i].name; i++)
699 if (senders[i].shutdown_clients)
700 senders[i].shutdown_clients();
701 list_for_each_entry_safe(fc, tmp, &fec_client_list, node) {
702 fc->first_stream_chunk = -1;
703 fc->state = FEC_STATE_NONE;
705 mmd->stream_start.tv_sec = 0;
706 mmd->stream_start.tv_usec = 0;
710 else if (vss_paused()) {
711 if (mmd->chunks_sent)
712 set_eof_barrier(vsst);
713 mmd->chunks_sent = 0;
714 } else if (vss_repos()) {
715 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
716 set_eof_barrier(vsst);
717 mmd->chunks_sent = 0;
718 mmd->current_chunk = mmd->repos_request;
719 mmd->new_vss_status_flags &= ~VSS_REPOS;
722 if (need_to_request_new_audio_file(vsst)) {
723 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
724 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
725 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
727 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
728 for (i = 0; senders[i].name; i++) {
729 if (!senders[i].pre_select)
731 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
733 tv = vss_compute_timeout(vsst);
734 if (tv && tv_diff(tv, &s->timeout, &diff) < 0)
738 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
740 char control[255], buf[8];
741 struct msghdr msg = {.msg_iov = NULL};
742 struct cmsghdr *cmsg;
748 iov.iov_len = sizeof(buf);
751 msg.msg_control = control;
752 msg.msg_controllen = sizeof(control);
753 memset(buf, 0, sizeof(buf));
754 ret = recvmsg(afs_socket, &msg, 0);
756 return -ERRNO_TO_PARA_ERROR(errno);
757 if (iov.iov_len != sizeof(buf))
758 return -E_AFS_SHORT_READ;
759 *code = *(uint32_t*)buf;
760 *data = *(uint32_t*)(buf + 4);
761 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
762 if (cmsg->cmsg_level != SOL_SOCKET
763 || cmsg->cmsg_type != SCM_RIGHTS)
765 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
767 *fd = *(int *)CMSG_DATA(cmsg);
772 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
774 int ret, passed_fd, shmid;
775 uint32_t afs_code = 0, afs_data = 0;
778 if (!FD_ISSET(vsst->afs_socket, rfds))
780 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
781 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
785 vsst->afsss = AFS_SOCKET_READY;
786 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
789 if (afs_code != NEXT_AUDIO_FILE)
794 ret = load_afd(shmid, &mmd->afd);
798 ret = fstat(passed_fd, &statbuf);
800 PARA_ERROR_LOG("fstat error:\n");
801 ret = -ERRNO_TO_PARA_ERROR(errno);
804 mmd->size = statbuf.st_size;
805 mmd->mtime = statbuf.st_mtime;
806 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
811 mmd->chunks_sent = 0;
812 mmd->current_chunk = 0;
816 mmd->new_vss_status_flags &= (~VSS_NEXT);
817 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
821 free(mmd->afd.afhi.chunk_table);
824 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
825 mmd->new_vss_status_flags = VSS_NEXT;
828 static int initialize_fec_client(struct fec_client *fc)
831 struct fec_client_parms *fcp = fc->fcp;
835 * Set the maximum slice size to the Maximum Packet Size if the
836 * transport protocol allows to determine this value. The user
837 * can specify a slice size up to this value.
839 ret = fcp->init_fec(fc->sc);
842 if (!fcp->max_slice_bytes || fcp->max_slice_bytes > ret)
843 fcp->max_slice_bytes = ret;
845 if (fcp->max_slice_bytes < FEC_HEADER_SIZE + fcp->data_slices_per_group)
846 return -ERRNO_TO_PARA_ERROR(EINVAL);
847 ret = fec_new(fcp->data_slices_per_group, fcp->slices_per_group,
851 fc->first_stream_chunk = -1; /* stream not yet started */
852 fc->src_data = para_malloc(fc->fcp->slices_per_group * sizeof(char *));
853 fc->enc_buf = para_calloc(fc->fcp->max_slice_bytes);
854 fc->num_extra_slices = 0;
855 fc->extra_src_buf = para_calloc(fc->fcp->max_slice_bytes);
856 fc->next_header_time.tv_sec = 0;
857 fc->state = FEC_STATE_READY_TO_RUN;
865 * Main sending function.
867 * This function gets called from vss_post_select(). It checks whether the next
868 * chunk of data should be pushed out. It obtains a pointer to the data to be
869 * sent out as well as its length from mmd->afd.afhi. This information is then
870 * passed to each supported sender's send() function as well as to the send()
871 * functions of each registered fec client.
873 static void vss_send(struct vss_task *vsst)
875 int ret, i, fec_active = 0;
877 struct fec_client *fc, *tmp_fc;
879 if (!vsst->map || !vss_playing())
881 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
883 if (chk_barrier("data send", &vsst->data_send_barrier,
886 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
888 case FEC_STATE_DISABLED:
891 ret = initialize_fec_client(fc);
893 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
897 case FEC_STATE_READY_TO_RUN:
900 if (!next_slice_is_due(fc, NULL)) {
904 if (compute_next_fec_slice(fc, vsst) <= 0)
906 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
907 fc->current_slice_num, fc->fcp->max_slice_bytes);
908 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
909 fc->fcp->max_slice_bytes);
910 fc->current_slice_num++;
913 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
915 mmd->new_vss_status_flags |= VSS_NEXT;
918 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
919 &mmd->stream_start, &due);
920 if (tv_diff(&due, now, NULL) <= 0) {
924 if (!mmd->chunks_sent) {
925 mmd->stream_start = *now;
930 * We call the send function also in case of empty chunks as
931 * they might have still some data queued which can be sent in
934 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
936 for (i = 0; senders[i].name; i++) {
937 if (!senders[i].send)
939 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
940 buf, len, vsst->header_buf, vsst->header_len);
943 mmd->current_chunk++;
947 static void vss_post_select(struct sched *s, struct task *t)
950 struct vss_task *vsst = container_of(t, struct vss_task, task);
953 if (mmd->sender_cmd_data.cmd_num >= 0) {
954 int num = mmd->sender_cmd_data.cmd_num,
955 sender_num = mmd->sender_cmd_data.sender_num;
957 if (senders[sender_num].client_cmds[num]) {
958 ret = senders[sender_num].client_cmds[num]
959 (&mmd->sender_cmd_data);
961 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
963 mmd->sender_cmd_data.cmd_num = -1;
965 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
966 recv_afs_result(vsst, &s->rfds);
967 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
968 PARA_NOTICE_LOG("requesting new fd from afs\n");
969 ret = send_buffer(vsst->afs_socket, "new");
971 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
973 vsst->afsss = AFS_SOCKET_AFD_PENDING;
975 for (i = 0; senders[i].name; i++) {
976 if (!senders[i].post_select)
978 senders[i].post_select(&s->rfds, &s->wfds);
980 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
981 (vss_next() && vss_playing()))
982 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
987 * Initialize the virtual streaming system task.
989 * \param afs_socket The fd for communication with afs.
991 * This also initializes all supported senders and starts streaming
992 * if the --autoplay command line flag was given.
994 void init_vss_task(int afs_socket)
996 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
998 char *hn = para_hostname(), *home = para_homedir();
999 long unsigned announce_time = conf.announce_time_arg > 0?
1000 conf.announce_time_arg : 300,
1001 autoplay_delay = conf.autoplay_delay_arg > 0?
1002 conf.autoplay_delay_arg : 0;
1003 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1004 vsst->afs_socket = afs_socket;
1005 vsst->task.pre_select = vss_pre_select;
1006 vsst->task.post_select = vss_post_select;
1007 ms2tv(announce_time, &vsst->announce_tv);
1008 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1009 INIT_LIST_HEAD(&fec_client_list);
1010 for (i = 0; senders[i].name; i++) {
1011 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1012 senders[i].init(&senders[i]);
1016 mmd->sender_cmd_data.cmd_num = -1;
1017 if (conf.autoplay_given) {
1019 mmd->vss_status_flags |= VSS_PLAYING;
1020 mmd->new_vss_status_flags |= VSS_PLAYING;
1021 ms2tv(autoplay_delay, &tmp);
1022 tv_add(now, &tmp, &vsst->autoplay_barrier);
1023 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1024 &vsst->data_send_barrier);
1026 register_task(&vsst->task);