2 * Copyright (C) 2011 EfficiOS Inc.
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
11 #include "kernel-consumer.hpp"
13 #include <common/buffer-view.hpp>
14 #include <common/common.hpp>
15 #include <common/compat/endian.hpp>
16 #include <common/compat/fcntl.hpp>
17 #include <common/consumer/consumer-stream.hpp>
18 #include <common/consumer/consumer-timer.hpp>
19 #include <common/consumer/consumer.hpp>
20 #include <common/consumer/metadata-bucket.hpp>
21 #include <common/index/index.hpp>
22 #include <common/kernel-ctl/kernel-ctl.hpp>
23 #include <common/optional.hpp>
24 #include <common/pipe.hpp>
25 #include <common/relayd/relayd.hpp>
26 #include <common/sessiond-comm/relayd.hpp>
27 #include <common/sessiond-comm/sessiond-comm.hpp>
28 #include <common/utils.hpp>
30 #include <bin/lttng-consumerd/health-consumerd.hpp>
38 #include <sys/socket.h>
40 #include <sys/types.h>
43 extern struct lttng_consumer_global_data the_consumer_data
;
44 extern int consumer_poll_timeout
;
47 * Take a snapshot for a specific fd
49 * Returns 0 on success, < 0 on error
51 int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
54 int infd
= stream
->wait_fd
;
56 ret
= kernctl_snapshot(infd
);
58 * -EAGAIN is not an error, it just means that there is no data to
61 if (ret
!= 0 && ret
!= -EAGAIN
) {
62 PERROR("Getting sub-buffer snapshot.");
69 * Sample consumed and produced positions for a specific fd.
71 * Returns 0 on success, < 0 on error.
73 int lttng_kconsumer_sample_snapshot_positions(struct lttng_consumer_stream
*stream
)
77 return kernctl_snapshot_sample_positions(stream
->wait_fd
);
81 * Get the produced position
83 * Returns 0 on success, < 0 on error
85 int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
, unsigned long *pos
)
88 int infd
= stream
->wait_fd
;
90 ret
= kernctl_snapshot_get_produced(infd
, pos
);
92 PERROR("kernctl_snapshot_get_produced");
99 * Get the consumerd position
101 * Returns 0 on success, < 0 on error
103 int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream
*stream
, unsigned long *pos
)
106 int infd
= stream
->wait_fd
;
108 ret
= kernctl_snapshot_get_consumed(infd
, pos
);
110 PERROR("kernctl_snapshot_get_consumed");
116 static int get_current_subbuf_addr(struct lttng_consumer_stream
*stream
, const char **addr
)
119 unsigned long mmap_offset
;
120 const char *mmap_base
= (const char *) stream
->mmap_base
;
122 ret
= kernctl_get_mmap_read_offset(stream
->wait_fd
, &mmap_offset
);
124 PERROR("Failed to get mmap read offset");
128 *addr
= mmap_base
+ mmap_offset
;
134 * Take a snapshot of all the stream of a channel
135 * RCU read-side lock must be held across this function to ensure existence of
138 * Returns 0 on success, < 0 on error
140 static int lttng_kconsumer_snapshot_channel(struct lttng_consumer_channel
*channel
,
144 uint64_t nb_packets_per_stream
)
147 struct lttng_consumer_stream
*stream
;
149 DBG("Kernel consumer snapshot channel %" PRIu64
, key
);
151 /* Prevent channel modifications while we perform the snapshot.*/
152 pthread_mutex_lock(&channel
->lock
);
156 /* Splice is not supported yet for channel snapshot. */
157 if (channel
->output
!= CONSUMER_CHANNEL_MMAP
) {
158 ERR("Unsupported output type for channel \"%s\": mmap output is required to record a snapshot",
164 cds_list_for_each_entry (stream
, &channel
->streams
.head
, send_node
) {
165 unsigned long consumed_pos
, produced_pos
;
167 health_code_update();
170 * Lock stream because we are about to change its state.
172 pthread_mutex_lock(&stream
->lock
);
174 LTTNG_ASSERT(channel
->trace_chunk
);
175 if (!lttng_trace_chunk_get(channel
->trace_chunk
)) {
177 * Can't happen barring an internal error as the channel
178 * holds a reference to the trace chunk.
180 ERR("Failed to acquire reference to channel's trace chunk");
184 LTTNG_ASSERT(!stream
->trace_chunk
);
185 stream
->trace_chunk
= channel
->trace_chunk
;
188 * Assign the received relayd ID so we can use it for streaming. The streams
189 * are not visible to anyone so this is OK to change it.
191 stream
->net_seq_idx
= relayd_id
;
192 channel
->relayd_id
= relayd_id
;
193 if (relayd_id
!= (uint64_t) -1ULL) {
194 ret
= consumer_send_relayd_stream(stream
, path
);
196 ERR("sending stream to relayd");
197 goto error_close_stream_output
;
200 ret
= consumer_stream_create_output_files(stream
, false);
202 goto error_close_stream_output
;
204 DBG("Kernel consumer snapshot stream (%" PRIu64
")", stream
->key
);
207 ret
= kernctl_buffer_flush_empty(stream
->wait_fd
);
210 * Doing a buffer flush which does not take into
211 * account empty packets. This is not perfect
212 * for stream intersection, but required as a
213 * fall-back when "flush_empty" is not
214 * implemented by lttng-modules.
216 ret
= kernctl_buffer_flush(stream
->wait_fd
);
218 ERR("Failed to flush kernel stream");
219 goto error_close_stream_output
;
224 ret
= lttng_kconsumer_take_snapshot(stream
);
226 ERR("Taking kernel snapshot");
227 goto error_close_stream_output
;
230 ret
= lttng_kconsumer_get_produced_snapshot(stream
, &produced_pos
);
232 ERR("Produced kernel snapshot position");
233 goto error_close_stream_output
;
236 ret
= lttng_kconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
238 ERR("Consumerd kernel snapshot position");
239 goto error_close_stream_output
;
242 consumed_pos
= consumer_get_consume_start_pos(
243 consumed_pos
, produced_pos
, nb_packets_per_stream
, stream
->max_sb_size
);
245 while ((long) (consumed_pos
- produced_pos
) < 0) {
247 unsigned long len
, padded_len
;
248 const char *subbuf_addr
;
249 struct lttng_buffer_view subbuf_view
;
251 health_code_update();
252 DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos
);
254 ret
= kernctl_get_subbuf(stream
->wait_fd
, &consumed_pos
);
256 if (ret
!= -EAGAIN
) {
257 PERROR("kernctl_get_subbuf snapshot");
258 goto error_close_stream_output
;
260 DBG("Kernel consumer get subbuf failed. Skipping it.");
261 consumed_pos
+= stream
->max_sb_size
;
262 stream
->chan
->lost_packets
++;
266 ret
= kernctl_get_subbuf_size(stream
->wait_fd
, &len
);
268 ERR("Snapshot kernctl_get_subbuf_size");
269 goto error_put_subbuf
;
272 ret
= kernctl_get_padded_subbuf_size(stream
->wait_fd
, &padded_len
);
274 ERR("Snapshot kernctl_get_padded_subbuf_size");
275 goto error_put_subbuf
;
278 ret
= get_current_subbuf_addr(stream
, &subbuf_addr
);
280 goto error_put_subbuf
;
283 subbuf_view
= lttng_buffer_view_init(subbuf_addr
, 0, padded_len
);
284 read_len
= lttng_consumer_on_read_subbuffer_mmap(
285 stream
, &subbuf_view
, padded_len
- len
);
287 * We write the padded len in local tracefiles but the data len
288 * when using a relay. Display the error but continue processing
289 * to try to release the subbuffer.
291 if (relayd_id
!= (uint64_t) -1ULL) {
292 if (read_len
!= len
) {
293 ERR("Error sending to the relay (ret: %zd != len: %lu)",
298 if (read_len
!= padded_len
) {
299 ERR("Error writing to tracefile (ret: %zd != len: %lu)",
305 ret
= kernctl_put_subbuf(stream
->wait_fd
);
307 ERR("Snapshot kernctl_put_subbuf");
308 goto error_close_stream_output
;
310 consumed_pos
+= stream
->max_sb_size
;
313 consumer_stream_close_output(stream
);
314 pthread_mutex_unlock(&stream
->lock
);
322 ret
= kernctl_put_subbuf(stream
->wait_fd
);
324 ERR("Snapshot kernctl_put_subbuf error path");
326 error_close_stream_output
:
327 consumer_stream_close_output(stream
);
329 pthread_mutex_unlock(&stream
->lock
);
332 pthread_mutex_unlock(&channel
->lock
);
337 * Read the whole metadata available for a snapshot.
338 * RCU read-side lock must be held across this function to ensure existence of
341 * Returns 0 on success, < 0 on error
343 static int lttng_kconsumer_snapshot_metadata(struct lttng_consumer_channel
*metadata_channel
,
347 struct lttng_consumer_local_data
*ctx
)
349 int ret
, use_relayd
= 0;
351 struct lttng_consumer_stream
*metadata_stream
;
355 DBG("Kernel consumer snapshot metadata with key %" PRIu64
" at path %s", key
, path
);
359 metadata_stream
= metadata_channel
->metadata_stream
;
360 LTTNG_ASSERT(metadata_stream
);
362 metadata_stream
->read_subbuffer_ops
.lock(metadata_stream
);
363 LTTNG_ASSERT(metadata_channel
->trace_chunk
);
364 LTTNG_ASSERT(metadata_stream
->trace_chunk
);
366 /* Flag once that we have a valid relayd for the stream. */
367 if (relayd_id
!= (uint64_t) -1ULL) {
372 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
377 ret
= consumer_stream_create_output_files(metadata_stream
, false);
384 health_code_update();
386 ret_read
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
, true);
388 ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)", ret_read
);
392 } while (ret_read
> 0);
395 close_relayd_stream(metadata_stream
);
396 metadata_stream
->net_seq_idx
= (uint64_t) -1ULL;
398 if (metadata_stream
->out_fd
>= 0) {
399 ret
= close(metadata_stream
->out_fd
);
401 PERROR("Kernel consumer snapshot metadata close out_fd");
403 * Don't go on error here since the snapshot was successful at this
404 * point but somehow the close failed.
407 metadata_stream
->out_fd
= -1;
408 lttng_trace_chunk_put(metadata_stream
->trace_chunk
);
409 metadata_stream
->trace_chunk
= nullptr;
415 metadata_stream
->read_subbuffer_ops
.unlock(metadata_stream
);
416 consumer_stream_destroy(metadata_stream
, nullptr);
417 metadata_channel
->metadata_stream
= nullptr;
423 * Receive command from session daemon and process it.
425 * Return 1 on success else a negative value or 0.
427 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
429 struct pollfd
*consumer_sockpoll
)
432 enum lttcomm_return_code ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
433 struct lttcomm_consumer_msg msg
;
435 health_code_update();
440 ret_recv
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
441 if (ret_recv
!= sizeof(msg
)) {
443 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
450 health_code_update();
452 /* Deprecated command */
453 LTTNG_ASSERT(msg
.cmd_type
!= LTTNG_CONSUMER_STOP
);
455 health_code_update();
457 /* relayd needs RCU read-side protection */
460 switch (msg
.cmd_type
) {
461 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
463 uint32_t major
= msg
.u
.relayd_sock
.major
;
464 uint32_t minor
= msg
.u
.relayd_sock
.minor
;
465 enum lttcomm_sock_proto protocol
=
466 (enum lttcomm_sock_proto
) msg
.u
.relayd_sock
.relayd_socket_protocol
;
468 /* Session daemon status message are handled in the following call. */
469 consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
470 msg
.u
.relayd_sock
.type
,
474 msg
.u
.relayd_sock
.session_id
,
475 msg
.u
.relayd_sock
.relayd_session_id
,
481 case LTTNG_CONSUMER_ADD_CHANNEL
:
483 struct lttng_consumer_channel
*new_channel
;
484 int ret_send_status
, ret_add_channel
= 0;
485 const uint64_t chunk_id
= msg
.u
.channel
.chunk_id
.value
;
487 health_code_update();
489 /* First send a status message before receiving the fds. */
490 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
491 if (ret_send_status
< 0) {
492 /* Somehow, the session daemon is not responding anymore. */
496 health_code_update();
498 DBG("consumer_add_channel %" PRIu64
, msg
.u
.channel
.channel_key
);
499 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
500 msg
.u
.channel
.session_id
,
501 msg
.u
.channel
.chunk_id
.is_set
? &chunk_id
:
503 msg
.u
.channel
.pathname
,
505 msg
.u
.channel
.relayd_id
,
506 msg
.u
.channel
.output
,
507 msg
.u
.channel
.tracefile_size
,
508 msg
.u
.channel
.tracefile_count
,
510 msg
.u
.channel
.monitor
,
511 msg
.u
.channel
.live_timer_interval
,
512 msg
.u
.channel
.is_live
,
515 if (new_channel
== nullptr) {
516 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
519 new_channel
->nb_init_stream_left
= msg
.u
.channel
.nb_init_streams
;
520 switch (msg
.u
.channel
.output
) {
521 case LTTNG_EVENT_SPLICE
:
522 new_channel
->output
= CONSUMER_CHANNEL_SPLICE
;
524 case LTTNG_EVENT_MMAP
:
525 new_channel
->output
= CONSUMER_CHANNEL_MMAP
;
528 ERR("Channel output unknown %d", msg
.u
.channel
.output
);
532 /* Translate and save channel type. */
533 switch (msg
.u
.channel
.type
) {
534 case CONSUMER_CHANNEL_TYPE_DATA
:
535 case CONSUMER_CHANNEL_TYPE_METADATA
:
536 new_channel
->type
= (consumer_channel_type
) msg
.u
.channel
.type
;
543 health_code_update();
545 if (ctx
->on_recv_channel
!= nullptr) {
546 int ret_recv_channel
= ctx
->on_recv_channel(new_channel
);
547 if (ret_recv_channel
== 0) {
548 ret_add_channel
= consumer_add_channel(new_channel
, ctx
);
549 } else if (ret_recv_channel
< 0) {
553 ret_add_channel
= consumer_add_channel(new_channel
, ctx
);
555 if (msg
.u
.channel
.type
== CONSUMER_CHANNEL_TYPE_DATA
&& !ret_add_channel
) {
556 int monitor_start_ret
;
558 DBG("Consumer starting monitor timer");
559 consumer_timer_live_start(new_channel
, msg
.u
.channel
.live_timer_interval
);
560 monitor_start_ret
= consumer_timer_monitor_start(
561 new_channel
, msg
.u
.channel
.monitor_timer_interval
);
562 if (monitor_start_ret
< 0) {
563 ERR("Starting channel monitoring timer failed");
568 health_code_update();
570 /* If we received an error in add_channel, we need to report it. */
571 if (ret_add_channel
< 0) {
572 ret_send_status
= consumer_send_status_msg(sock
, ret_add_channel
);
573 if (ret_send_status
< 0) {
581 case LTTNG_CONSUMER_ADD_STREAM
:
584 struct lttng_pipe
*stream_pipe
;
585 struct lttng_consumer_stream
*new_stream
;
586 struct lttng_consumer_channel
*channel
;
588 int ret_send_status
, ret_poll
, ret_get_max_subbuf_size
;
589 ssize_t ret_pipe_write
, ret_recv
;
592 * Get stream's channel reference. Needed when adding the stream to the
595 channel
= consumer_find_channel(msg
.u
.stream
.channel_key
);
598 * We could not find the channel. Can happen if cpu hotplug
599 * happens while tearing down.
601 ERR("Unable to find channel key %" PRIu64
, msg
.u
.stream
.channel_key
);
602 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
605 health_code_update();
607 /* First send a status message before receiving the fds. */
608 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
609 if (ret_send_status
< 0) {
610 /* Somehow, the session daemon is not responding anymore. */
611 goto error_add_stream_fatal
;
614 health_code_update();
616 if (ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
617 /* Channel was not found. */
618 goto error_add_stream_nosignal
;
623 ret_poll
= lttng_consumer_poll_socket(consumer_sockpoll
);
626 goto error_add_stream_fatal
;
629 health_code_update();
631 /* Get stream file descriptor from socket */
632 ret_recv
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
633 if (ret_recv
!= sizeof(fd
)) {
634 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
639 health_code_update();
642 * Send status code to session daemon only if the recv works. If the
643 * above recv() failed, the session daemon is notified through the
644 * error socket and the teardown is eventually done.
646 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
647 if (ret_send_status
< 0) {
648 /* Somehow, the session daemon is not responding anymore. */
649 goto error_add_stream_nosignal
;
652 health_code_update();
654 pthread_mutex_lock(&channel
->lock
);
655 new_stream
= consumer_stream_create(channel
,
661 channel
->trace_chunk
,
666 if (new_stream
== nullptr) {
671 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
674 pthread_mutex_unlock(&channel
->lock
);
675 goto error_add_stream_nosignal
;
678 new_stream
->wait_fd
= fd
;
679 ret_get_max_subbuf_size
=
680 kernctl_get_max_subbuf_size(new_stream
->wait_fd
, &new_stream
->max_sb_size
);
681 if (ret_get_max_subbuf_size
< 0) {
682 pthread_mutex_unlock(&channel
->lock
);
683 ERR("Failed to get kernel maximal subbuffer size");
684 goto error_add_stream_nosignal
;
687 consumer_stream_update_channel_attributes(new_stream
, channel
);
690 * We've just assigned the channel to the stream so increment the
691 * refcount right now. We don't need to increment the refcount for
692 * streams in no monitor because we handle manually the cleanup of
693 * those. It is very important to make sure there is NO prior
694 * consumer_del_stream() calls or else the refcount will be unbalanced.
696 if (channel
->monitor
) {
697 uatomic_inc(&new_stream
->chan
->refcount
);
701 * The buffer flush is done on the session daemon side for the kernel
702 * so no need for the stream "hangup_flush_done" variable to be
703 * tracked. This is important for a kernel stream since we don't rely
704 * on the flush state of the stream to read data. It's not the case for
705 * user space tracing.
707 new_stream
->hangup_flush_done
= 0;
709 health_code_update();
711 pthread_mutex_lock(&new_stream
->lock
);
712 if (ctx
->on_recv_stream
) {
713 int ret_recv_stream
= ctx
->on_recv_stream(new_stream
);
714 if (ret_recv_stream
< 0) {
715 pthread_mutex_unlock(&new_stream
->lock
);
716 pthread_mutex_unlock(&channel
->lock
);
717 consumer_stream_free(new_stream
);
718 goto error_add_stream_nosignal
;
721 health_code_update();
723 if (new_stream
->metadata_flag
) {
724 channel
->metadata_stream
= new_stream
;
727 /* Do not monitor this stream. */
728 if (!channel
->monitor
) {
729 DBG("Kernel consumer add stream %s in no monitor mode with "
730 "relayd id %" PRIu64
,
732 new_stream
->net_seq_idx
);
733 cds_list_add(&new_stream
->send_node
, &channel
->streams
.head
);
734 pthread_mutex_unlock(&new_stream
->lock
);
735 pthread_mutex_unlock(&channel
->lock
);
739 /* Send stream to relayd if the stream has an ID. */
740 if (new_stream
->net_seq_idx
!= (uint64_t) -1ULL) {
741 int ret_send_relayd_stream
;
743 ret_send_relayd_stream
=
744 consumer_send_relayd_stream(new_stream
, new_stream
->chan
->pathname
);
745 if (ret_send_relayd_stream
< 0) {
746 pthread_mutex_unlock(&new_stream
->lock
);
747 pthread_mutex_unlock(&channel
->lock
);
748 consumer_stream_free(new_stream
);
749 goto error_add_stream_nosignal
;
753 * If adding an extra stream to an already
754 * existing channel (e.g. cpu hotplug), we need
755 * to send the "streams_sent" command to relayd.
757 if (channel
->streams_sent_to_relayd
) {
758 int ret_send_relayd_streams_sent
;
760 ret_send_relayd_streams_sent
=
761 consumer_send_relayd_streams_sent(new_stream
->net_seq_idx
);
762 if (ret_send_relayd_streams_sent
< 0) {
763 pthread_mutex_unlock(&new_stream
->lock
);
764 pthread_mutex_unlock(&channel
->lock
);
765 goto error_add_stream_nosignal
;
769 pthread_mutex_unlock(&new_stream
->lock
);
770 pthread_mutex_unlock(&channel
->lock
);
772 /* Get the right pipe where the stream will be sent. */
773 if (new_stream
->metadata_flag
) {
774 consumer_add_metadata_stream(new_stream
);
775 stream_pipe
= ctx
->consumer_metadata_pipe
;
777 consumer_add_data_stream(new_stream
);
778 stream_pipe
= ctx
->consumer_data_pipe
;
781 /* Visible to other threads */
782 new_stream
->globally_visible
= 1;
784 health_code_update();
787 lttng_pipe_write(stream_pipe
, &new_stream
, sizeof(new_stream
)); /* NOLINT
792 if (ret_pipe_write
< 0) {
793 ERR("Consumer write %s stream to pipe %d",
794 new_stream
->metadata_flag
? "metadata" : "data",
795 lttng_pipe_get_writefd(stream_pipe
));
796 if (new_stream
->metadata_flag
) {
797 consumer_del_stream_for_metadata(new_stream
);
799 consumer_del_stream_for_data(new_stream
);
801 goto error_add_stream_nosignal
;
804 DBG("Kernel consumer ADD_STREAM %s (fd: %d) %s with relayd id %" PRIu64
,
807 new_stream
->chan
->pathname
,
808 new_stream
->relayd_stream_id
);
811 error_add_stream_nosignal
:
813 error_add_stream_fatal
:
816 case LTTNG_CONSUMER_STREAMS_SENT
:
818 struct lttng_consumer_channel
*channel
;
822 * Get stream's channel reference. Needed when adding the stream to the
825 channel
= consumer_find_channel(msg
.u
.sent_streams
.channel_key
);
828 * We could not find the channel. Can happen if cpu hotplug
829 * happens while tearing down.
831 ERR("Unable to find channel key %" PRIu64
, msg
.u
.sent_streams
.channel_key
);
832 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
835 health_code_update();
838 * Send status code to session daemon.
840 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
841 if (ret_send_status
< 0 || ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
842 /* Somehow, the session daemon is not responding anymore. */
843 goto error_streams_sent_nosignal
;
846 health_code_update();
849 * We should not send this message if we don't monitor the
850 * streams in this channel.
852 if (!channel
->monitor
) {
853 goto end_error_streams_sent
;
856 health_code_update();
857 /* Send stream to relayd if the stream has an ID. */
858 if (msg
.u
.sent_streams
.net_seq_idx
!= (uint64_t) -1ULL) {
859 int ret_send_relay_streams
;
861 ret_send_relay_streams
=
862 consumer_send_relayd_streams_sent(msg
.u
.sent_streams
.net_seq_idx
);
863 if (ret_send_relay_streams
< 0) {
864 goto error_streams_sent_nosignal
;
866 channel
->streams_sent_to_relayd
= true;
868 end_error_streams_sent
:
870 error_streams_sent_nosignal
:
873 case LTTNG_CONSUMER_UPDATE_STREAM
:
878 case LTTNG_CONSUMER_DESTROY_RELAYD
:
880 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
881 struct consumer_relayd_sock_pair
*relayd
;
884 DBG("Kernel consumer destroying relayd %" PRIu64
, index
);
886 /* Get relayd reference if exists. */
887 relayd
= consumer_find_relayd(index
);
888 if (relayd
== nullptr) {
889 DBG("Unable to find relayd %" PRIu64
, index
);
890 ret_code
= LTTCOMM_CONSUMERD_RELAYD_FAIL
;
894 * Each relayd socket pair has a refcount of stream attached to it
895 * which tells if the relayd is still active or not depending on the
898 * This will set the destroy flag of the relayd object and destroy it
899 * if the refcount reaches zero when called.
901 * The destroy can happen either here or when a stream fd hangs up.
904 consumer_flag_relayd_for_destroy(relayd
);
907 health_code_update();
909 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
910 if (ret_send_status
< 0) {
911 /* Somehow, the session daemon is not responding anymore. */
917 case LTTNG_CONSUMER_DATA_PENDING
:
919 int32_t ret_data_pending
;
920 uint64_t id
= msg
.u
.data_pending
.session_id
;
923 DBG("Kernel consumer data pending command for id %" PRIu64
, id
);
925 ret_data_pending
= consumer_data_pending(id
);
927 health_code_update();
929 /* Send back returned value to session daemon */
931 lttcomm_send_unix_sock(sock
, &ret_data_pending
, sizeof(ret_data_pending
));
933 PERROR("send data pending ret code");
938 * No need to send back a status message since the data pending
939 * returned value is the response.
943 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
945 struct lttng_consumer_channel
*channel
;
946 uint64_t key
= msg
.u
.snapshot_channel
.key
;
949 channel
= consumer_find_channel(key
);
951 ERR("Channel %" PRIu64
" not found", key
);
952 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
954 if (msg
.u
.snapshot_channel
.metadata
== 1) {
957 ret_snapshot
= lttng_kconsumer_snapshot_metadata(
960 msg
.u
.snapshot_channel
.pathname
,
961 msg
.u
.snapshot_channel
.relayd_id
,
963 if (ret_snapshot
< 0) {
964 ERR("Snapshot metadata failed");
965 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
970 ret_snapshot
= lttng_kconsumer_snapshot_channel(
973 msg
.u
.snapshot_channel
.pathname
,
974 msg
.u
.snapshot_channel
.relayd_id
,
975 msg
.u
.snapshot_channel
.nb_packets_per_stream
);
976 if (ret_snapshot
< 0) {
977 ERR("Snapshot channel failed");
978 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
982 health_code_update();
984 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
985 if (ret_send_status
< 0) {
986 /* Somehow, the session daemon is not responding anymore. */
991 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
993 uint64_t key
= msg
.u
.destroy_channel
.key
;
994 struct lttng_consumer_channel
*channel
;
997 channel
= consumer_find_channel(key
);
999 ERR("Kernel consumer destroy channel %" PRIu64
" not found", key
);
1000 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1003 health_code_update();
1005 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1006 if (ret_send_status
< 0) {
1007 /* Somehow, the session daemon is not responding anymore. */
1008 goto end_destroy_channel
;
1011 health_code_update();
1013 /* Stop right now if no channel was found. */
1015 goto end_destroy_channel
;
1019 * This command should ONLY be issued for channel with streams set in
1022 LTTNG_ASSERT(!channel
->monitor
);
1025 * The refcount should ALWAYS be 0 in the case of a channel in no
1028 LTTNG_ASSERT(!uatomic_sub_return(&channel
->refcount
, 1));
1030 consumer_del_channel(channel
);
1031 end_destroy_channel
:
1034 case LTTNG_CONSUMER_DISCARDED_EVENTS
:
1038 struct lttng_consumer_channel
*channel
;
1039 uint64_t id
= msg
.u
.discarded_events
.session_id
;
1040 uint64_t key
= msg
.u
.discarded_events
.channel_key
;
1042 DBG("Kernel consumer discarded events command for session id %" PRIu64
1043 ", channel key %" PRIu64
,
1047 channel
= consumer_find_channel(key
);
1049 ERR("Kernel consumer discarded events channel %" PRIu64
" not found", key
);
1052 count
= channel
->discarded_events
;
1055 health_code_update();
1057 /* Send back returned value to session daemon */
1058 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1060 PERROR("send discarded events");
1066 case LTTNG_CONSUMER_LOST_PACKETS
:
1070 struct lttng_consumer_channel
*channel
;
1071 uint64_t id
= msg
.u
.lost_packets
.session_id
;
1072 uint64_t key
= msg
.u
.lost_packets
.channel_key
;
1074 DBG("Kernel consumer lost packets command for session id %" PRIu64
1075 ", channel key %" PRIu64
,
1079 channel
= consumer_find_channel(key
);
1081 ERR("Kernel consumer lost packets channel %" PRIu64
" not found", key
);
1084 count
= channel
->lost_packets
;
1087 health_code_update();
1089 /* Send back returned value to session daemon */
1090 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1092 PERROR("send lost packets");
1098 case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE
:
1100 int channel_monitor_pipe
;
1101 int ret_send_status
, ret_set_channel_monitor_pipe
;
1104 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1105 /* Successfully received the command's type. */
1106 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1107 if (ret_send_status
< 0) {
1111 ret_recv
= lttcomm_recv_fds_unix_sock(sock
, &channel_monitor_pipe
, 1);
1112 if (ret_recv
!= sizeof(channel_monitor_pipe
)) {
1113 ERR("Failed to receive channel monitor pipe");
1117 DBG("Received channel monitor pipe (%d)", channel_monitor_pipe
);
1118 ret_set_channel_monitor_pipe
=
1119 consumer_timer_thread_set_channel_monitor_pipe(channel_monitor_pipe
);
1120 if (!ret_set_channel_monitor_pipe
) {
1124 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1125 /* Set the pipe as non-blocking. */
1126 ret_fcntl
= fcntl(channel_monitor_pipe
, F_GETFL
, 0);
1127 if (ret_fcntl
== -1) {
1128 PERROR("fcntl get flags of the channel monitoring pipe");
1133 ret_fcntl
= fcntl(channel_monitor_pipe
, F_SETFL
, flags
| O_NONBLOCK
);
1134 if (ret_fcntl
== -1) {
1135 PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
1138 DBG("Channel monitor pipe set as non-blocking");
1140 ret_code
= LTTCOMM_CONSUMERD_ALREADY_SET
;
1142 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1143 if (ret_send_status
< 0) {
1148 case LTTNG_CONSUMER_ROTATE_CHANNEL
:
1150 struct lttng_consumer_channel
*channel
;
1151 uint64_t key
= msg
.u
.rotate_channel
.key
;
1152 int ret_send_status
;
1154 DBG("Consumer rotate channel %" PRIu64
, key
);
1156 channel
= consumer_find_channel(key
);
1158 ERR("Channel %" PRIu64
" not found", key
);
1159 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1162 * Sample the rotate position of all the streams in this channel.
1164 int ret_rotate_channel
;
1166 ret_rotate_channel
= lttng_consumer_rotate_channel(
1167 channel
, key
, msg
.u
.rotate_channel
.relayd_id
);
1168 if (ret_rotate_channel
< 0) {
1169 ERR("Rotate channel failed");
1170 ret_code
= LTTCOMM_CONSUMERD_ROTATION_FAIL
;
1173 health_code_update();
1176 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1177 if (ret_send_status
< 0) {
1178 /* Somehow, the session daemon is not responding anymore. */
1179 goto error_rotate_channel
;
1182 /* Rotate the streams that are ready right now. */
1185 ret_rotate
= lttng_consumer_rotate_ready_streams(channel
, key
);
1186 if (ret_rotate
< 0) {
1187 ERR("Rotate ready streams failed");
1191 error_rotate_channel
:
1194 case LTTNG_CONSUMER_CLEAR_CHANNEL
:
1196 struct lttng_consumer_channel
*channel
;
1197 uint64_t key
= msg
.u
.clear_channel
.key
;
1198 int ret_send_status
;
1200 channel
= consumer_find_channel(key
);
1202 DBG("Channel %" PRIu64
" not found", key
);
1203 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1205 int ret_clear_channel
;
1207 ret_clear_channel
= lttng_consumer_clear_channel(channel
);
1208 if (ret_clear_channel
) {
1209 ERR("Clear channel failed");
1210 ret_code
= (lttcomm_return_code
) ret_clear_channel
;
1213 health_code_update();
1216 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1217 if (ret_send_status
< 0) {
1218 /* Somehow, the session daemon is not responding anymore. */
1224 case LTTNG_CONSUMER_INIT
:
1226 int ret_send_status
;
1227 lttng_uuid sessiond_uuid
;
1229 std::copy(std::begin(msg
.u
.init
.sessiond_uuid
),
1230 std::end(msg
.u
.init
.sessiond_uuid
),
1231 sessiond_uuid
.begin());
1233 ret_code
= lttng_consumer_init_command(ctx
, sessiond_uuid
);
1234 health_code_update();
1235 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1236 if (ret_send_status
< 0) {
1237 /* Somehow, the session daemon is not responding anymore. */
1242 case LTTNG_CONSUMER_CREATE_TRACE_CHUNK
:
1244 const struct lttng_credentials credentials
= {
1245 .uid
= LTTNG_OPTIONAL_INIT_VALUE(
1246 msg
.u
.create_trace_chunk
.credentials
.value
.uid
),
1247 .gid
= LTTNG_OPTIONAL_INIT_VALUE(
1248 msg
.u
.create_trace_chunk
.credentials
.value
.gid
),
1250 const bool is_local_trace
= !msg
.u
.create_trace_chunk
.relayd_id
.is_set
;
1251 const uint64_t relayd_id
= msg
.u
.create_trace_chunk
.relayd_id
.value
;
1252 const char *chunk_override_name
= *msg
.u
.create_trace_chunk
.override_name
?
1253 msg
.u
.create_trace_chunk
.override_name
:
1255 struct lttng_directory_handle
*chunk_directory_handle
= nullptr;
1258 * The session daemon will only provide a chunk directory file
1259 * descriptor for local traces.
1261 if (is_local_trace
) {
1263 int ret_send_status
;
1266 /* Acnowledge the reception of the command. */
1267 ret_send_status
= consumer_send_status_msg(sock
, LTTCOMM_CONSUMERD_SUCCESS
);
1268 if (ret_send_status
< 0) {
1269 /* Somehow, the session daemon is not responding anymore. */
1273 ret_recv
= lttcomm_recv_fds_unix_sock(sock
, &chunk_dirfd
, 1);
1274 if (ret_recv
!= sizeof(chunk_dirfd
)) {
1275 ERR("Failed to receive trace chunk directory file descriptor");
1279 DBG("Received trace chunk directory fd (%d)", chunk_dirfd
);
1280 chunk_directory_handle
=
1281 lttng_directory_handle_create_from_dirfd(chunk_dirfd
);
1282 if (!chunk_directory_handle
) {
1283 ERR("Failed to initialize chunk directory handle from directory file descriptor");
1284 if (close(chunk_dirfd
)) {
1285 PERROR("Failed to close chunk directory file descriptor");
1291 ret_code
= lttng_consumer_create_trace_chunk(
1292 !is_local_trace
? &relayd_id
: nullptr,
1293 msg
.u
.create_trace_chunk
.session_id
,
1294 msg
.u
.create_trace_chunk
.chunk_id
,
1295 (time_t) msg
.u
.create_trace_chunk
.creation_timestamp
,
1296 chunk_override_name
,
1297 msg
.u
.create_trace_chunk
.credentials
.is_set
? &credentials
: nullptr,
1298 chunk_directory_handle
);
1299 lttng_directory_handle_put(chunk_directory_handle
);
1300 goto end_msg_sessiond
;
1302 case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK
:
1304 enum lttng_trace_chunk_command_type close_command
=
1305 (lttng_trace_chunk_command_type
) msg
.u
.close_trace_chunk
.close_command
.value
;
1306 const uint64_t relayd_id
= msg
.u
.close_trace_chunk
.relayd_id
.value
;
1307 struct lttcomm_consumer_close_trace_chunk_reply reply
;
1308 char path
[LTTNG_PATH_MAX
];
1311 ret_code
= lttng_consumer_close_trace_chunk(
1312 msg
.u
.close_trace_chunk
.relayd_id
.is_set
? &relayd_id
: nullptr,
1313 msg
.u
.close_trace_chunk
.session_id
,
1314 msg
.u
.close_trace_chunk
.chunk_id
,
1315 (time_t) msg
.u
.close_trace_chunk
.close_timestamp
,
1316 msg
.u
.close_trace_chunk
.close_command
.is_set
? &close_command
: nullptr,
1318 reply
.ret_code
= ret_code
;
1319 reply
.path_length
= strlen(path
) + 1;
1320 ret_send
= lttcomm_send_unix_sock(sock
, &reply
, sizeof(reply
));
1321 if (ret_send
!= sizeof(reply
)) {
1324 ret_send
= lttcomm_send_unix_sock(sock
, path
, reply
.path_length
);
1325 if (ret_send
!= reply
.path_length
) {
1330 case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS
:
1332 const uint64_t relayd_id
= msg
.u
.trace_chunk_exists
.relayd_id
.value
;
1334 ret_code
= lttng_consumer_trace_chunk_exists(
1335 msg
.u
.trace_chunk_exists
.relayd_id
.is_set
? &relayd_id
: nullptr,
1336 msg
.u
.trace_chunk_exists
.session_id
,
1337 msg
.u
.trace_chunk_exists
.chunk_id
);
1338 goto end_msg_sessiond
;
1340 case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS
:
1342 const uint64_t key
= msg
.u
.open_channel_packets
.key
;
1343 struct lttng_consumer_channel
*channel
= consumer_find_channel(key
);
1346 pthread_mutex_lock(&channel
->lock
);
1347 ret_code
= lttng_consumer_open_channel_packets(channel
);
1348 pthread_mutex_unlock(&channel
->lock
);
1350 WARN("Channel %" PRIu64
" not found", key
);
1351 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1354 health_code_update();
1355 goto end_msg_sessiond
;
1363 * Return 1 to indicate success since the 0 value can be a socket
1364 * shutdown during the recv() or send() call.
1369 /* This will issue a consumer stop. */
1374 * The returned value here is not useful since either way we'll return 1 to
1375 * the caller because the session daemon socket management is done
1376 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1379 int ret_send_status
;
1381 ret_send_status
= consumer_send_status_msg(sock
, ret_code
);
1382 if (ret_send_status
< 0) {
1390 health_code_update();
1396 * Sync metadata meaning request them to the session daemon and snapshot to the
1397 * metadata thread can consumer them.
1399 * Metadata stream lock MUST be acquired.
1401 enum sync_metadata_status
lttng_kconsumer_sync_metadata(struct lttng_consumer_stream
*metadata
)
1404 enum sync_metadata_status status
;
1406 LTTNG_ASSERT(metadata
);
1408 ret
= kernctl_buffer_flush(metadata
->wait_fd
);
1410 ERR("Failed to flush kernel stream");
1411 status
= SYNC_METADATA_STATUS_ERROR
;
1415 ret
= kernctl_snapshot(metadata
->wait_fd
);
1417 if (errno
== EAGAIN
) {
1418 /* No new metadata, exit. */
1419 DBG("Sync metadata, no new kernel metadata");
1420 status
= SYNC_METADATA_STATUS_NO_DATA
;
1422 ERR("Sync metadata, taking kernel snapshot failed.");
1423 status
= SYNC_METADATA_STATUS_ERROR
;
1426 status
= SYNC_METADATA_STATUS_NEW_DATA
;
1433 static int extract_common_subbuffer_info(struct lttng_consumer_stream
*stream
,
1434 struct stream_subbuffer
*subbuf
)
1438 ret
= kernctl_get_subbuf_size(stream
->wait_fd
, &subbuf
->info
.data
.subbuf_size
);
1443 ret
= kernctl_get_padded_subbuf_size(stream
->wait_fd
,
1444 &subbuf
->info
.data
.padded_subbuf_size
);
1453 static int extract_metadata_subbuffer_info(struct lttng_consumer_stream
*stream
,
1454 struct stream_subbuffer
*subbuf
)
1458 ret
= extract_common_subbuffer_info(stream
, subbuf
);
1463 ret
= kernctl_get_metadata_version(stream
->wait_fd
, &subbuf
->info
.metadata
.version
);
1472 static int extract_data_subbuffer_info(struct lttng_consumer_stream
*stream
,
1473 struct stream_subbuffer
*subbuf
)
1477 ret
= extract_common_subbuffer_info(stream
, subbuf
);
1482 ret
= kernctl_get_packet_size(stream
->wait_fd
, &subbuf
->info
.data
.packet_size
);
1484 PERROR("Failed to get sub-buffer packet size");
1488 ret
= kernctl_get_content_size(stream
->wait_fd
, &subbuf
->info
.data
.content_size
);
1490 PERROR("Failed to get sub-buffer content size");
1494 ret
= kernctl_get_timestamp_begin(stream
->wait_fd
, &subbuf
->info
.data
.timestamp_begin
);
1496 PERROR("Failed to get sub-buffer begin timestamp");
1500 ret
= kernctl_get_timestamp_end(stream
->wait_fd
, &subbuf
->info
.data
.timestamp_end
);
1502 PERROR("Failed to get sub-buffer end timestamp");
1506 ret
= kernctl_get_events_discarded(stream
->wait_fd
, &subbuf
->info
.data
.events_discarded
);
1508 PERROR("Failed to get sub-buffer events discarded count");
1512 ret
= kernctl_get_sequence_number(stream
->wait_fd
,
1513 &subbuf
->info
.data
.sequence_number
.value
);
1515 /* May not be supported by older LTTng-modules. */
1516 if (ret
!= -ENOTTY
) {
1517 PERROR("Failed to get sub-buffer sequence number");
1521 subbuf
->info
.data
.sequence_number
.is_set
= true;
1524 ret
= kernctl_get_stream_id(stream
->wait_fd
, &subbuf
->info
.data
.stream_id
);
1526 PERROR("Failed to get stream id");
1530 ret
= kernctl_get_instance_id(stream
->wait_fd
, &subbuf
->info
.data
.stream_instance_id
.value
);
1532 /* May not be supported by older LTTng-modules. */
1533 if (ret
!= -ENOTTY
) {
1534 PERROR("Failed to get stream instance id");
1538 subbuf
->info
.data
.stream_instance_id
.is_set
= true;
1544 static enum get_next_subbuffer_status
get_subbuffer_common(struct lttng_consumer_stream
*stream
,
1545 struct stream_subbuffer
*subbuffer
)
1548 enum get_next_subbuffer_status status
;
1550 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1553 status
= GET_NEXT_SUBBUFFER_STATUS_OK
;
1558 * The caller only expects -ENODATA when there is no data to
1559 * read, but the kernel tracer returns -EAGAIN when there is
1560 * currently no data for a non-finalized stream, and -ENODATA
1561 * when there is no data for a finalized stream. Those can be
1562 * combined into a -ENODATA return value.
1564 status
= GET_NEXT_SUBBUFFER_STATUS_NO_DATA
;
1567 status
= GET_NEXT_SUBBUFFER_STATUS_ERROR
;
1571 ret
= stream
->read_subbuffer_ops
.extract_subbuffer_info(stream
, subbuffer
);
1573 status
= GET_NEXT_SUBBUFFER_STATUS_ERROR
;
1579 static enum get_next_subbuffer_status
1580 get_next_subbuffer_splice(struct lttng_consumer_stream
*stream
, struct stream_subbuffer
*subbuffer
)
1582 const enum get_next_subbuffer_status status
= get_subbuffer_common(stream
, subbuffer
);
1584 if (status
!= GET_NEXT_SUBBUFFER_STATUS_OK
) {
1588 subbuffer
->buffer
.fd
= stream
->wait_fd
;
1593 static enum get_next_subbuffer_status
get_next_subbuffer_mmap(struct lttng_consumer_stream
*stream
,
1594 struct stream_subbuffer
*subbuffer
)
1597 enum get_next_subbuffer_status status
;
1600 status
= get_subbuffer_common(stream
, subbuffer
);
1601 if (status
!= GET_NEXT_SUBBUFFER_STATUS_OK
) {
1605 ret
= get_current_subbuf_addr(stream
, &addr
);
1607 status
= GET_NEXT_SUBBUFFER_STATUS_ERROR
;
1611 subbuffer
->buffer
.buffer
=
1612 lttng_buffer_view_init(addr
, 0, subbuffer
->info
.data
.padded_subbuf_size
);
1617 static enum get_next_subbuffer_status
1618 get_next_subbuffer_metadata_check(struct lttng_consumer_stream
*stream
,
1619 struct stream_subbuffer
*subbuffer
)
1624 enum get_next_subbuffer_status status
;
1626 ret
= kernctl_get_next_subbuf_metadata_check(stream
->wait_fd
, &coherent
);
1631 ret
= stream
->read_subbuffer_ops
.extract_subbuffer_info(stream
, subbuffer
);
1636 LTTNG_OPTIONAL_SET(&subbuffer
->info
.metadata
.coherent
, coherent
);
1638 ret
= get_current_subbuf_addr(stream
, &addr
);
1643 subbuffer
->buffer
.buffer
=
1644 lttng_buffer_view_init(addr
, 0, subbuffer
->info
.data
.padded_subbuf_size
);
1645 DBG("Got metadata packet with padded_subbuf_size = %lu, coherent = %s",
1646 subbuffer
->info
.metadata
.padded_subbuf_size
,
1647 coherent
? "true" : "false");
1650 * The caller only expects -ENODATA when there is no data to read, but
1651 * the kernel tracer returns -EAGAIN when there is currently no data
1652 * for a non-finalized stream, and -ENODATA when there is no data for a
1653 * finalized stream. Those can be combined into a -ENODATA return value.
1657 status
= GET_NEXT_SUBBUFFER_STATUS_OK
;
1662 * The caller only expects -ENODATA when there is no data to
1663 * read, but the kernel tracer returns -EAGAIN when there is
1664 * currently no data for a non-finalized stream, and -ENODATA
1665 * when there is no data for a finalized stream. Those can be
1666 * combined into a -ENODATA return value.
1668 status
= GET_NEXT_SUBBUFFER_STATUS_NO_DATA
;
1671 status
= GET_NEXT_SUBBUFFER_STATUS_ERROR
;
1678 static int put_next_subbuffer(struct lttng_consumer_stream
*stream
,
1679 struct stream_subbuffer
*subbuffer
__attribute__((unused
)))
1681 const int ret
= kernctl_put_next_subbuf(stream
->wait_fd
);
1684 if (ret
== -EFAULT
) {
1685 PERROR("Error in unreserving sub buffer");
1686 } else if (ret
== -EIO
) {
1687 /* Should never happen with newer LTTng versions */
1688 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted");
1695 static bool is_get_next_check_metadata_available(int tracer_fd
)
1697 const int ret
= kernctl_get_next_subbuf_metadata_check(tracer_fd
, nullptr);
1698 const bool available
= ret
!= -ENOTTY
;
1701 /* get succeeded, make sure to put the subbuffer. */
1702 kernctl_put_subbuf(tracer_fd
);
1708 static int signal_metadata(struct lttng_consumer_stream
*stream
,
1709 struct lttng_consumer_local_data
*ctx
__attribute__((unused
)))
1711 ASSERT_LOCKED(stream
->metadata_rdv_lock
);
1712 return pthread_cond_broadcast(&stream
->metadata_rdv
) ? -errno
: 0;
1715 static int lttng_kconsumer_set_stream_ops(struct lttng_consumer_stream
*stream
)
1719 if (stream
->metadata_flag
&& stream
->chan
->is_live
) {
1720 DBG("Attempting to enable metadata bucketization for live consumers");
1721 if (is_get_next_check_metadata_available(stream
->wait_fd
)) {
1722 DBG("Kernel tracer supports get_next_subbuffer_metadata_check, metadata will be accumulated until a coherent state is reached");
1723 stream
->read_subbuffer_ops
.get_next_subbuffer
=
1724 get_next_subbuffer_metadata_check
;
1725 ret
= consumer_stream_enable_metadata_bucketization(stream
);
1731 * The kernel tracer version is too old to indicate
1732 * when the metadata stream has reached a "coherent"
1733 * (parseable) point.
1735 * This means that a live viewer may see an incoherent
1736 * sequence of metadata and fail to parse it.
1738 WARN("Kernel tracer does not support get_next_subbuffer_metadata_check which may cause live clients to fail to parse the metadata stream");
1739 metadata_bucket_destroy(stream
->metadata_bucket
);
1740 stream
->metadata_bucket
= nullptr;
1743 stream
->read_subbuffer_ops
.on_sleep
= signal_metadata
;
1746 if (!stream
->read_subbuffer_ops
.get_next_subbuffer
) {
1747 if (stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
) {
1748 stream
->read_subbuffer_ops
.get_next_subbuffer
= get_next_subbuffer_mmap
;
1750 stream
->read_subbuffer_ops
.get_next_subbuffer
= get_next_subbuffer_splice
;
1754 if (stream
->metadata_flag
) {
1755 stream
->read_subbuffer_ops
.extract_subbuffer_info
= extract_metadata_subbuffer_info
;
1757 stream
->read_subbuffer_ops
.extract_subbuffer_info
= extract_data_subbuffer_info
;
1758 if (stream
->chan
->is_live
) {
1759 stream
->read_subbuffer_ops
.send_live_beacon
= consumer_flush_kernel_index
;
1763 stream
->read_subbuffer_ops
.put_next_subbuffer
= put_next_subbuffer
;
1768 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1772 LTTNG_ASSERT(stream
);
1775 * Don't create anything if this is set for streaming or if there is
1776 * no current trace chunk on the parent channel.
1778 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
&&
1779 stream
->chan
->trace_chunk
) {
1780 ret
= consumer_stream_create_output_files(stream
, true);
1786 if (stream
->output
== LTTNG_EVENT_MMAP
) {
1787 /* get the len of the mmap region */
1788 unsigned long mmap_len
;
1790 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
1792 PERROR("kernctl_get_mmap_len");
1793 goto error_close_fd
;
1795 stream
->mmap_len
= (size_t) mmap_len
;
1798 mmap(nullptr, stream
->mmap_len
, PROT_READ
, MAP_PRIVATE
, stream
->wait_fd
, 0);
1799 if (stream
->mmap_base
== MAP_FAILED
) {
1800 PERROR("Error mmaping");
1802 goto error_close_fd
;
1806 ret
= lttng_kconsumer_set_stream_ops(stream
);
1808 goto error_close_fd
;
1811 /* we return 0 to let the library handle the FD internally */
1815 if (stream
->out_fd
>= 0) {
1818 err
= close(stream
->out_fd
);
1820 stream
->out_fd
= -1;
1827 * Check if data is still being extracted from the buffers for a specific
1828 * stream. Consumer data lock MUST be acquired before calling this function
1829 * and the stream lock.
1831 * Return 1 if the traced data are still getting read else 0 meaning that the
1832 * data is available for trace viewer reading.
1834 int lttng_kconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1838 LTTNG_ASSERT(stream
);
1840 if (stream
->endpoint_status
!= CONSUMER_ENDPOINT_ACTIVE
) {
1845 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1847 /* There is still data so let's put back this subbuffer. */
1848 ret
= kernctl_put_subbuf(stream
->wait_fd
);
1849 LTTNG_ASSERT(ret
== 0);
1850 ret
= 1; /* Data is pending */
1854 /* Data is NOT pending and ready to be read. */