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;
172 /** Pointer obtained from sender when the client is added. */
177 * Get the chunk time of the current audio file.
179 * \return A pointer to a struct containing the chunk time, or NULL,
180 * if currently no audio file is selected.
182 struct timeval *vss_chunk_time(void)
184 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
185 mmd->afd.afhi.chunk_tv.tv_usec == 0)
187 return &mmd->afd.afhi.chunk_tv;
191 * Write a fec header to a buffer.
193 * \param buf The buffer to write to.
194 * \param h The fec header to write.
196 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
198 char *buf = (char *)fc->enc_buf;
199 struct fec_group *g = &fc->group;
200 struct fec_client_parms *p = fc->fcp;
202 write_u32(buf, FEC_MAGIC);
204 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
205 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
206 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
208 write_u32(buf + 10, g->num);
209 write_u32(buf + 14, g->bytes);
211 write_u8(buf + 18, fc->current_slice_num);
212 write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
213 write_u8(buf + 22, g->first_chunk? 0 : 1);
214 write_u8(buf + 23, vsst->header_len? 1 : 0);
215 memset(buf + 24, 0, 7);
218 static int need_audio_header(struct fec_client *fc, struct vss_task *vsst)
220 if (!mmd->current_chunk) {
221 tv_add(now, &vsst->header_interval, &fc->next_header_time);
224 if (!vsst->header_buf)
226 if (!vsst->header_len)
228 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
230 tv_add(now, &vsst->header_interval, &fc->next_header_time);
234 static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *result)
236 unsigned long m = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
237 unsigned rv, redundant_slices = fc->fcp->slices_per_group
238 - fc->fcp->data_slices_per_group;
242 rv = (bytes + m - 1) / m;
243 if (rv + redundant_slices > 255)
249 /* set group start and group duration */
250 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
252 struct timeval *chunk_tv = vss_chunk_time();
254 tv_scale(g->num_chunks, chunk_tv, &g->duration);
255 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
256 &g->duration, &g->slice_duration);
257 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
258 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
261 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
263 int ret, i, k, data_slices;
265 const char *buf, *start_buf;
266 struct fec_group *g = &fc->group;
267 unsigned slice_bytes = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
268 uint32_t max_data_size;
270 if (fc->first_stream_chunk < 0) {
271 uint8_t hs, ds; /* needed header/data slices */
272 uint8_t rs = fc->fcp->slices_per_group
273 - fc->fcp->data_slices_per_group; /* redundant slices */
276 ret = num_slices(vsst->header_len, fc, &hs);
279 ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
286 if (k < fc->fcp->data_slices_per_group)
287 k = fc->fcp->data_slices_per_group;
289 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
290 PARA_NOTICE_LOG("fec parms %d:%d:%d (%d extra slices)\n",
291 slice_bytes, k, n, fc->num_extra_slices);
293 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
294 ret = fec_new(k, n, &fc->parms);
297 fc->stream_start = *now;
298 fc->first_stream_chunk = mmd->current_chunk;
299 g->first_chunk = mmd->current_chunk;
304 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
307 * Start and duration of this group depend only on the previous
308 * group. Compute the new group start as g->start += g->duration.
311 tv_add(&tmp, &g->duration, &g->start);
312 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
313 set_group_timing(fc, g);
314 g->first_chunk += g->num_chunks;
317 if (need_audio_header(fc, vsst)) {
318 ret = num_slices(vsst->header_len, fc, &g->num_header_slices);
322 g->num_header_slices = 0;
323 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &start_buf,
325 data_slices = k - g->num_header_slices;
327 max_data_size = slice_bytes * data_slices;
329 for (i = g->first_chunk; i < mmd->afd.afhi.chunks_total; i++) {
330 afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
331 if (g->bytes + len > max_data_size)
335 g->num_chunks = i - g->first_chunk;
336 assert(g->num_chunks);
337 fc->current_slice_num = 0;
339 set_group_timing(fc, g);
341 /* setup header slices */
342 buf = vsst->header_buf;
343 for (i = 0; i < g->num_header_slices; i++) {
344 fc->src_data[i] = (const unsigned char *)buf;
348 /* setup data slices */
350 for (i = g->num_header_slices; i < k; i++) {
351 if (buf + slice_bytes > vsst->map + mmd->size)
353 * Can not use the memory mapped audio file for this
354 * slice as it goes beyond the map. This slice will not
358 fc->src_data[i] = (const unsigned char *)buf;
362 uint32_t payload_size = vsst->map + mmd->size - buf;
363 memcpy(fc->extra_src_buf, buf, payload_size);
364 fc->src_data[i] = fc->extra_src_buf;
366 /* use arbitrary data for all remaining slices */
369 fc->src_data[i] = (const unsigned char *)buf;
371 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), "
372 "%d header slices, %d data slices\n",
373 g->num, g->num_chunks, g->first_chunk,
374 g->first_chunk + g->num_chunks - 1,
375 g->num_header_slices, data_slices
380 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
382 if (fc->first_stream_chunk < 0 || fc->current_slice_num
383 == fc->fcp->slices_per_group + fc->num_extra_slices) {
384 int ret = setup_next_fec_group(fc, vsst);
388 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
389 PARA_ERROR_LOG("FEC client temporarily disabled\n");
390 fc->state = FEC_STATE_DISABLED;
394 write_fec_header(fc, vsst);
395 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
396 fc->current_slice_num,
397 fc->fcp->max_slice_bytes - FEC_HEADER_SIZE);
402 * Return a buffer that marks the end of the stream.
404 * \param buf Result pointer.
405 * \return The length of the eof buffer.
407 * This is used for (multicast) udp streaming where closing the socket on the
408 * sender might not give rise to an eof condition at the peer.
410 size_t vss_get_fec_eof_packet(const char **buf)
412 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
413 *buf = fec_eof_packet;
414 return FEC_HEADER_SIZE;
418 * Add one entry to the list of active fec clients.
420 * \param sc Generic sender_client data of the transport layer.
421 * \param fcp FEC parameters as supplied by the transport layer.
423 * \return Newly allocated fec_client struct.
425 struct fec_client *vss_add_fec_client(struct sender_client *sc,
426 struct fec_client_parms *fcp)
428 struct fec_client *fc = para_calloc(sizeof(*fc));
432 para_list_add(&fc->node, &fec_client_list);
437 * Remove one entry from the list of active fec clients.
439 * \param fc The client to be removed.
441 void vss_del_fec_client(struct fec_client *fc)
446 free(fc->extra_src_buf);
452 * Compute if/when next slice is due. If it isn't due yet and \a diff is
453 * not \p Null, compute the time difference next - now, where
455 * next = stream_start + (first_group_chunk - first_stream_chunk)
456 * * chunk_time + slice_num * slice_time
458 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
460 struct timeval tmp, next;
463 if (fc->first_stream_chunk < 0)
465 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
466 tv_add(&tmp, &fc->group.start, &next);
467 ret = tv_diff(&next, now, diff);
468 return ret < 0? 1 : 0;
471 static void compute_slice_timeout(struct timeval *timeout)
473 struct fec_client *fc;
475 list_for_each_entry(fc, &fec_client_list, node) {
478 if (fc->state != FEC_STATE_READY_TO_RUN)
480 if (next_slice_is_due(fc, &diff)) {
482 timeout->tv_usec = 0;
485 /* timeout = min(timeout, diff) */
486 if (tv_diff(&diff, timeout, NULL) < 0)
491 static void set_eof_barrier(struct vss_task *vsst)
493 struct fec_client *fc;
494 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
498 list_for_each_entry(fc, &fec_client_list, node) {
499 struct timeval group_duration;
501 if (fc->state != FEC_STATE_READY_TO_RUN)
503 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
504 if (tv_diff(&timeout, &group_duration, NULL) < 0)
505 timeout = group_duration;
508 tv_add(now, &timeout, &vsst->eof_barrier);
512 * Check if vss status flag \a P (playing) is set.
514 * \return Greater than zero if playing, zero otherwise.
517 unsigned int vss_playing(void)
519 return mmd->new_vss_status_flags & VSS_PLAYING;
523 * Check if the \a N (next) status flag is set.
525 * \return Greater than zero if set, zero if not.
528 unsigned int vss_next(void)
530 return mmd->new_vss_status_flags & VSS_NEXT;
534 * Check if a reposition request is pending.
536 * \return Greater than zero if true, zero otherwise.
539 unsigned int vss_repos(void)
541 return mmd->new_vss_status_flags & VSS_REPOS;
545 * Check if the vss is currently paused.
547 * \return Greater than zero if paused, zero otherwise.
550 unsigned int vss_paused(void)
552 return !(mmd->new_vss_status_flags & VSS_NEXT)
553 && !(mmd->new_vss_status_flags & VSS_PLAYING);
557 * Check if the vss is currently stopped.
559 * \return Greater than zero if paused, zero otherwise.
562 unsigned int vss_stopped(void)
564 return (mmd->new_vss_status_flags & VSS_NEXT)
565 && !(mmd->new_vss_status_flags & VSS_PLAYING);
568 static int chk_barrier(const char *bname, const struct timeval *barrier,
569 struct timeval *diff, int print_log)
573 if (tv_diff(now, barrier, diff) > 0)
577 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
582 * != NULL: timeout for next chunk
583 * NULL: nothing to do
585 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
587 static struct timeval the_timeout;
588 struct timeval next_chunk;
590 if (vss_next() && vsst->map) {
591 /* only sleep a bit, nec*/
592 the_timeout.tv_sec = 0;
593 the_timeout.tv_usec = 100;
596 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
597 &the_timeout, 1) < 0)
599 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
601 if (chk_barrier("data send", &vsst->data_send_barrier,
602 &the_timeout, 1) < 0)
604 if (!vss_playing() || !vsst->map)
606 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
607 &mmd->stream_start, &next_chunk);
608 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
609 /* chunk is due or bof */
610 the_timeout.tv_sec = 0;
611 the_timeout.tv_usec = 0;
614 /* compute min of current timeout and next slice time */
615 compute_slice_timeout(&the_timeout);
619 static void vss_eof(struct vss_task *vsst)
624 if (mmd->new_vss_status_flags & VSS_NOMORE)
625 mmd->new_vss_status_flags = VSS_NEXT;
626 set_eof_barrier(vsst);
627 para_munmap(vsst->map, mmd->size);
629 mmd->chunks_sent = 0;
631 mmd->afd.afhi.seconds_total = 0;
632 mmd->afd.afhi.chunk_tv.tv_sec = 0;
633 mmd->afd.afhi.chunk_tv.tv_usec = 0;
634 free(mmd->afd.afhi.chunk_table);
635 mmd->afd.afhi.chunk_table = NULL;
642 * Get the list of all supported audio formats.
644 * \return Aa space separated list of all supported audio formats
645 * It is not allocated at runtime, i.e. there is no need to free
646 * the returned string in the caller.
648 const char *supported_audio_formats(void)
650 return SUPPORTED_AUDIO_FORMATS;
653 static int need_to_request_new_audio_file(struct vss_task *vsst)
657 if (vsst->map) /* have audio file */
659 if (!vss_playing()) /* don't need one */
661 if (mmd->new_vss_status_flags & VSS_NOMORE)
663 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
665 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
671 static void set_mmd_offset(void)
673 struct timeval offset;
674 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
675 mmd->offset = tv2ms(&offset);
679 * Compute the timeout for the main select-loop of the scheduler.
681 * \param s Pointer to the server scheduler.
682 * \param t Pointer to the vss task structure.
684 * Before the timeout is computed, the current vss status flags are evaluated
685 * and acted upon by calling appropriate functions from the lower layers.
686 * Possible actions include
688 * - request a new audio file from afs,
689 * - shutdown of all senders (stop/pause command),
690 * - reposition the stream (ff/jmp command).
692 static void vss_pre_select(struct sched *s, struct task *t)
695 struct timeval *tv, diff;
696 struct vss_task *vsst = container_of(t, struct vss_task, task);
698 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
699 struct fec_client *fc, *tmp;
700 for (i = 0; senders[i].name; i++)
701 if (senders[i].shutdown_clients)
702 senders[i].shutdown_clients();
703 list_for_each_entry_safe(fc, tmp, &fec_client_list, node) {
704 fc->first_stream_chunk = -1;
705 fc->state = FEC_STATE_NONE;
707 mmd->stream_start.tv_sec = 0;
708 mmd->stream_start.tv_usec = 0;
712 else if (vss_paused()) {
713 if (mmd->chunks_sent)
714 set_eof_barrier(vsst);
715 mmd->chunks_sent = 0;
716 } else if (vss_repos()) {
717 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
718 set_eof_barrier(vsst);
719 mmd->chunks_sent = 0;
720 mmd->current_chunk = mmd->repos_request;
721 mmd->new_vss_status_flags &= ~VSS_REPOS;
724 if (need_to_request_new_audio_file(vsst)) {
725 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
726 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
727 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
729 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
730 for (i = 0; senders[i].name; i++) {
731 if (!senders[i].pre_select)
733 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
735 tv = vss_compute_timeout(vsst);
736 if (tv && tv_diff(tv, &s->timeout, &diff) < 0)
740 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
742 char control[255], buf[8];
743 struct msghdr msg = {.msg_iov = NULL};
744 struct cmsghdr *cmsg;
750 iov.iov_len = sizeof(buf);
753 msg.msg_control = control;
754 msg.msg_controllen = sizeof(control);
755 memset(buf, 0, sizeof(buf));
756 ret = recvmsg(afs_socket, &msg, 0);
758 return -ERRNO_TO_PARA_ERROR(errno);
759 if (iov.iov_len != sizeof(buf))
760 return -E_AFS_SHORT_READ;
761 *code = *(uint32_t*)buf;
762 *data = *(uint32_t*)(buf + 4);
763 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
764 if (cmsg->cmsg_level != SOL_SOCKET
765 || cmsg->cmsg_type != SCM_RIGHTS)
767 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
769 *fd = *(int *)CMSG_DATA(cmsg);
774 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
776 int ret, passed_fd, shmid;
777 uint32_t afs_code = 0, afs_data = 0;
780 if (!FD_ISSET(vsst->afs_socket, rfds))
782 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
783 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
787 vsst->afsss = AFS_SOCKET_READY;
788 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
791 if (afs_code != NEXT_AUDIO_FILE)
796 ret = load_afd(shmid, &mmd->afd);
800 ret = fstat(passed_fd, &statbuf);
802 PARA_ERROR_LOG("fstat error:\n");
803 ret = -ERRNO_TO_PARA_ERROR(errno);
806 mmd->size = statbuf.st_size;
807 mmd->mtime = statbuf.st_mtime;
808 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
813 mmd->chunks_sent = 0;
814 mmd->current_chunk = 0;
818 mmd->new_vss_status_flags &= (~VSS_NEXT);
819 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
823 free(mmd->afd.afhi.chunk_table);
826 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
827 mmd->new_vss_status_flags = VSS_NEXT;
830 static int initialize_fec_client(struct fec_client *fc)
833 struct fec_client_parms *fcp = fc->fcp;
837 * Set the maximum slice size to the Maximum Packet Size if the
838 * transport protocol allows to determine this value. The user
839 * can specify a slice size up to this value.
841 ret = fcp->init_fec(fc->sc);
844 if (!fcp->max_slice_bytes || fcp->max_slice_bytes > ret)
845 fcp->max_slice_bytes = ret;
847 if (fcp->max_slice_bytes < FEC_HEADER_SIZE + fcp->data_slices_per_group)
848 return -ERRNO_TO_PARA_ERROR(EINVAL);
849 ret = fec_new(fcp->data_slices_per_group, fcp->slices_per_group,
853 fc->first_stream_chunk = -1; /* stream not yet started */
854 fc->src_data = para_malloc(fc->fcp->slices_per_group * sizeof(char *));
855 fc->enc_buf = para_calloc(fc->fcp->max_slice_bytes);
856 fc->num_extra_slices = 0;
857 fc->extra_src_buf = para_calloc(fc->fcp->max_slice_bytes);
858 fc->next_header_time.tv_sec = 0;
859 fc->state = FEC_STATE_READY_TO_RUN;
867 * Main sending function.
869 * This function gets called from vss_post_select(). It checks whether the next
870 * chunk of data should be pushed out. It obtains a pointer to the data to be
871 * sent out as well as its length from mmd->afd.afhi. This information is then
872 * passed to each supported sender's send() function as well as to the send()
873 * functions of each registered fec client.
875 static void vss_send(struct vss_task *vsst)
877 int ret, i, fec_active = 0;
879 struct fec_client *fc, *tmp_fc;
881 if (!vsst->map || !vss_playing())
883 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
885 if (chk_barrier("data send", &vsst->data_send_barrier,
888 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
890 case FEC_STATE_DISABLED:
893 ret = initialize_fec_client(fc);
895 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
899 case FEC_STATE_READY_TO_RUN:
902 if (!next_slice_is_due(fc, NULL)) {
906 if (compute_next_fec_slice(fc, vsst) <= 0)
908 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
909 fc->current_slice_num, fc->fcp->max_slice_bytes);
910 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
911 fc->fcp->max_slice_bytes);
912 fc->current_slice_num++;
915 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
917 mmd->new_vss_status_flags |= VSS_NEXT;
920 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
921 &mmd->stream_start, &due);
922 if (tv_diff(&due, now, NULL) <= 0) {
926 if (!mmd->chunks_sent) {
927 mmd->stream_start = *now;
932 * We call the send function also in case of empty chunks as
933 * they might have still some data queued which can be sent in
936 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
938 for (i = 0; senders[i].name; i++) {
939 if (!senders[i].send)
941 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
942 buf, len, vsst->header_buf, vsst->header_len);
945 mmd->current_chunk++;
949 static void vss_post_select(struct sched *s, struct task *t)
952 struct vss_task *vsst = container_of(t, struct vss_task, task);
955 if (mmd->sender_cmd_data.cmd_num >= 0) {
956 int num = mmd->sender_cmd_data.cmd_num,
957 sender_num = mmd->sender_cmd_data.sender_num;
959 if (senders[sender_num].client_cmds[num])
960 senders[sender_num].client_cmds[num](&mmd->sender_cmd_data);
961 mmd->sender_cmd_data.cmd_num = -1;
963 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
964 recv_afs_result(vsst, &s->rfds);
965 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
966 PARA_NOTICE_LOG("requesting new fd from afs\n");
967 ret = send_buffer(vsst->afs_socket, "new");
969 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
971 vsst->afsss = AFS_SOCKET_AFD_PENDING;
973 for (i = 0; senders[i].name; i++) {
974 if (!senders[i].post_select)
976 senders[i].post_select(&s->rfds, &s->wfds);
978 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
979 (vss_next() && vss_playing()))
980 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
985 * Initialize the virtual streaming system task.
987 * \param afs_socket The fd for communication with afs.
989 * This also initializes all supported senders and starts streaming
990 * if the --autoplay command line flag was given.
992 void init_vss_task(int afs_socket)
994 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
996 char *hn = para_hostname(), *home = para_homedir();
997 long unsigned announce_time = conf.announce_time_arg > 0?
998 conf.announce_time_arg : 300,
999 autoplay_delay = conf.autoplay_delay_arg > 0?
1000 conf.autoplay_delay_arg : 0;
1001 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1002 vsst->afs_socket = afs_socket;
1003 vsst->task.pre_select = vss_pre_select;
1004 vsst->task.post_select = vss_post_select;
1005 ms2tv(announce_time, &vsst->announce_tv);
1006 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1007 INIT_LIST_HEAD(&fec_client_list);
1008 for (i = 0; senders[i].name; i++) {
1009 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1010 senders[i].init(&senders[i]);
1014 mmd->sender_cmd_data.cmd_num = -1;
1015 if (conf.autoplay_given) {
1017 mmd->vss_status_flags |= VSS_PLAYING;
1018 mmd->new_vss_status_flags |= VSS_PLAYING;
1019 ms2tv(autoplay_delay, &tmp);
1020 tv_add(now, &tmp, &vsst->autoplay_barrier);
1021 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1022 &vsst->data_send_barrier);
1024 register_task(&vsst->task);