2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <sys/socket.h>
28 #include <sys/types.h>
33 #include <bin/lttng-consumerd/health-consumerd.h>
34 #include <common/common.h>
35 #include <common/kernel-ctl/kernel-ctl.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/sessiond-comm/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/compat/endian.h>
40 #include <common/pipe.h>
41 #include <common/relayd/relayd.h>
42 #include <common/utils.h>
43 #include <common/consumer/consumer-stream.h>
44 #include <common/index/index.h>
45 #include <common/consumer/consumer-timer.h>
46 #include <common/optional.h>
48 #include "kernel-consumer.h"
50 extern struct lttng_consumer_global_data consumer_data
;
51 extern int consumer_poll_timeout
;
54 * Take a snapshot for a specific fd
56 * Returns 0 on success, < 0 on error
58 int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
61 int infd
= stream
->wait_fd
;
63 ret
= kernctl_snapshot(infd
);
65 * -EAGAIN is not an error, it just means that there is no data to
68 if (ret
!= 0 && ret
!= -EAGAIN
) {
69 PERROR("Getting sub-buffer snapshot.");
76 * Sample consumed and produced positions for a specific fd.
78 * Returns 0 on success, < 0 on error.
80 int lttng_kconsumer_sample_snapshot_positions(
81 struct lttng_consumer_stream
*stream
)
85 return kernctl_snapshot_sample_positions(stream
->wait_fd
);
89 * Get the produced position
91 * Returns 0 on success, < 0 on error
93 int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
97 int infd
= stream
->wait_fd
;
99 ret
= kernctl_snapshot_get_produced(infd
, pos
);
101 PERROR("kernctl_snapshot_get_produced");
108 * Get the consumerd position
110 * Returns 0 on success, < 0 on error
112 int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream
*stream
,
116 int infd
= stream
->wait_fd
;
118 ret
= kernctl_snapshot_get_consumed(infd
, pos
);
120 PERROR("kernctl_snapshot_get_consumed");
127 * Take a snapshot of all the stream of a channel
128 * RCU read-side lock must be held across this function to ensure existence of
129 * channel. The channel lock must be held by the caller.
131 * Returns 0 on success, < 0 on error
133 static int lttng_kconsumer_snapshot_channel(
134 struct lttng_consumer_channel
*channel
,
135 uint64_t key
, char *path
, uint64_t relayd_id
,
136 uint64_t nb_packets_per_stream
,
137 struct lttng_consumer_local_data
*ctx
)
140 struct lttng_consumer_stream
*stream
;
142 DBG("Kernel consumer snapshot channel %" PRIu64
, key
);
146 /* Splice is not supported yet for channel snapshot. */
147 if (channel
->output
!= CONSUMER_CHANNEL_MMAP
) {
148 ERR("Unsupported output type for channel \"%s\": mmap output is required to record a snapshot",
154 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
155 unsigned long consumed_pos
, produced_pos
;
157 health_code_update();
160 * Lock stream because we are about to change its state.
162 pthread_mutex_lock(&stream
->lock
);
164 assert(channel
->trace_chunk
);
165 if (!lttng_trace_chunk_get(channel
->trace_chunk
)) {
167 * Can't happen barring an internal error as the channel
168 * holds a reference to the trace chunk.
170 ERR("Failed to acquire reference to channel's trace chunk");
174 assert(!stream
->trace_chunk
);
175 stream
->trace_chunk
= channel
->trace_chunk
;
178 * Assign the received relayd ID so we can use it for streaming. The streams
179 * are not visible to anyone so this is OK to change it.
181 stream
->net_seq_idx
= relayd_id
;
182 channel
->relayd_id
= relayd_id
;
183 if (relayd_id
!= (uint64_t) -1ULL) {
184 ret
= consumer_send_relayd_stream(stream
, path
);
186 ERR("sending stream to relayd");
190 ret
= consumer_stream_create_output_files(stream
,
195 DBG("Kernel consumer snapshot stream (%" PRIu64
")",
199 ret
= kernctl_buffer_flush_empty(stream
->wait_fd
);
202 * Doing a buffer flush which does not take into
203 * account empty packets. This is not perfect
204 * for stream intersection, but required as a
205 * fall-back when "flush_empty" is not
206 * implemented by lttng-modules.
208 ret
= kernctl_buffer_flush(stream
->wait_fd
);
210 ERR("Failed to flush kernel stream");
216 ret
= lttng_kconsumer_take_snapshot(stream
);
218 ERR("Taking kernel snapshot");
222 ret
= lttng_kconsumer_get_produced_snapshot(stream
, &produced_pos
);
224 ERR("Produced kernel snapshot position");
228 ret
= lttng_kconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
230 ERR("Consumerd kernel snapshot position");
234 consumed_pos
= consumer_get_consume_start_pos(consumed_pos
,
235 produced_pos
, nb_packets_per_stream
,
236 stream
->max_sb_size
);
238 while ((long) (consumed_pos
- produced_pos
) < 0) {
240 unsigned long len
, padded_len
;
242 health_code_update();
244 DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos
);
246 ret
= kernctl_get_subbuf(stream
->wait_fd
, &consumed_pos
);
248 if (ret
!= -EAGAIN
) {
249 PERROR("kernctl_get_subbuf snapshot");
252 DBG("Kernel consumer get subbuf failed. Skipping it.");
253 consumed_pos
+= stream
->max_sb_size
;
254 stream
->chan
->lost_packets
++;
258 ret
= kernctl_get_subbuf_size(stream
->wait_fd
, &len
);
260 ERR("Snapshot kernctl_get_subbuf_size");
261 goto error_put_subbuf
;
264 ret
= kernctl_get_padded_subbuf_size(stream
->wait_fd
, &padded_len
);
266 ERR("Snapshot kernctl_get_padded_subbuf_size");
267 goto error_put_subbuf
;
270 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
271 padded_len
- len
, NULL
);
273 * We write the padded len in local tracefiles but the data len
274 * when using a relay. Display the error but continue processing
275 * to try to release the subbuffer.
277 if (relayd_id
!= (uint64_t) -1ULL) {
278 if (read_len
!= len
) {
279 ERR("Error sending to the relay (ret: %zd != len: %lu)",
283 if (read_len
!= padded_len
) {
284 ERR("Error writing to tracefile (ret: %zd != len: %lu)",
285 read_len
, padded_len
);
289 ret
= kernctl_put_subbuf(stream
->wait_fd
);
291 ERR("Snapshot kernctl_put_subbuf");
294 consumed_pos
+= stream
->max_sb_size
;
297 if (relayd_id
== (uint64_t) -1ULL) {
298 if (stream
->out_fd
>= 0) {
299 ret
= close(stream
->out_fd
);
301 PERROR("Kernel consumer snapshot close out_fd");
307 close_relayd_stream(stream
);
308 stream
->net_seq_idx
= (uint64_t) -1ULL;
310 lttng_trace_chunk_put(stream
->trace_chunk
);
311 stream
->trace_chunk
= NULL
;
312 pthread_mutex_unlock(&stream
->lock
);
320 ret
= kernctl_put_subbuf(stream
->wait_fd
);
322 ERR("Snapshot kernctl_put_subbuf error path");
325 pthread_mutex_unlock(&stream
->lock
);
332 * Read the whole metadata available for a snapshot.
333 * RCU read-side lock must be held across this function to ensure existence of
334 * metadata_channel. The channel lock must be held by the caller.
336 * Returns 0 on success, < 0 on error
338 static int lttng_kconsumer_snapshot_metadata(
339 struct lttng_consumer_channel
*metadata_channel
,
340 uint64_t key
, char *path
, uint64_t relayd_id
,
341 struct lttng_consumer_local_data
*ctx
)
343 int ret
, use_relayd
= 0;
345 struct lttng_consumer_stream
*metadata_stream
;
349 DBG("Kernel consumer snapshot metadata with key %" PRIu64
" at path %s",
354 metadata_stream
= metadata_channel
->metadata_stream
;
355 assert(metadata_stream
);
357 pthread_mutex_lock(&metadata_stream
->lock
);
358 assert(metadata_channel
->trace_chunk
);
359 assert(metadata_stream
->trace_chunk
);
361 /* Flag once that we have a valid relayd for the stream. */
362 if (relayd_id
!= (uint64_t) -1ULL) {
367 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
372 ret
= consumer_stream_create_output_files(metadata_stream
,
380 health_code_update();
382 ret_read
= lttng_kconsumer_read_subbuffer(metadata_stream
, ctx
);
384 if (ret_read
!= -EAGAIN
) {
385 ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
390 /* ret_read is negative at this point so we will exit the loop. */
393 } while (ret_read
>= 0);
396 close_relayd_stream(metadata_stream
);
397 metadata_stream
->net_seq_idx
= (uint64_t) -1ULL;
399 if (metadata_stream
->out_fd
>= 0) {
400 ret
= close(metadata_stream
->out_fd
);
402 PERROR("Kernel consumer snapshot metadata close out_fd");
404 * Don't go on error here since the snapshot was successful at this
405 * point but somehow the close failed.
408 metadata_stream
->out_fd
= -1;
409 lttng_trace_chunk_put(metadata_stream
->trace_chunk
);
410 metadata_stream
->trace_chunk
= NULL
;
416 pthread_mutex_unlock(&metadata_stream
->lock
);
417 cds_list_del(&metadata_stream
->send_node
);
418 consumer_stream_destroy(metadata_stream
, NULL
);
419 metadata_channel
->metadata_stream
= NULL
;
425 * Receive command from session daemon and process it.
427 * Return 1 on success else a negative value or 0.
429 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
430 int sock
, struct pollfd
*consumer_sockpoll
)
433 enum lttcomm_return_code ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
434 struct lttcomm_consumer_msg msg
;
436 health_code_update();
438 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
439 if (ret
!= sizeof(msg
)) {
441 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
447 health_code_update();
449 /* Deprecated command */
450 assert(msg
.cmd_type
!= LTTNG_CONSUMER_STOP
);
452 health_code_update();
454 /* relayd needs RCU read-side protection */
457 switch (msg
.cmd_type
) {
458 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
460 /* Session daemon status message are handled in the following call. */
461 consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
462 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
463 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
,
464 msg
.u
.relayd_sock
.relayd_session_id
);
467 case LTTNG_CONSUMER_ADD_CHANNEL
:
469 struct lttng_consumer_channel
*new_channel
;
471 const uint64_t chunk_id
= msg
.u
.channel
.chunk_id
.value
;
473 health_code_update();
475 /* First send a status message before receiving the fds. */
476 ret
= consumer_send_status_msg(sock
, ret_code
);
478 /* Somehow, the session daemon is not responding anymore. */
482 health_code_update();
484 DBG("consumer_add_channel %" PRIu64
, msg
.u
.channel
.channel_key
);
485 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
486 msg
.u
.channel
.session_id
,
487 msg
.u
.channel
.chunk_id
.is_set
?
489 msg
.u
.channel
.pathname
,
491 msg
.u
.channel
.relayd_id
, msg
.u
.channel
.output
,
492 msg
.u
.channel
.tracefile_size
,
493 msg
.u
.channel
.tracefile_count
, 0,
494 msg
.u
.channel
.monitor
,
495 msg
.u
.channel
.live_timer_interval
,
497 if (new_channel
== NULL
) {
498 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
501 new_channel
->nb_init_stream_left
= msg
.u
.channel
.nb_init_streams
;
502 switch (msg
.u
.channel
.output
) {
503 case LTTNG_EVENT_SPLICE
:
504 new_channel
->output
= CONSUMER_CHANNEL_SPLICE
;
506 case LTTNG_EVENT_MMAP
:
507 new_channel
->output
= CONSUMER_CHANNEL_MMAP
;
510 ERR("Channel output unknown %d", msg
.u
.channel
.output
);
514 /* Translate and save channel type. */
515 switch (msg
.u
.channel
.type
) {
516 case CONSUMER_CHANNEL_TYPE_DATA
:
517 case CONSUMER_CHANNEL_TYPE_METADATA
:
518 new_channel
->type
= msg
.u
.channel
.type
;
525 health_code_update();
527 if (ctx
->on_recv_channel
!= NULL
) {
528 ret_recv
= ctx
->on_recv_channel(new_channel
);
530 ret
= consumer_add_channel(new_channel
, ctx
);
531 } else if (ret_recv
< 0) {
535 ret
= consumer_add_channel(new_channel
, ctx
);
537 if (msg
.u
.channel
.type
== CONSUMER_CHANNEL_TYPE_DATA
&& !ret
) {
538 int monitor_start_ret
;
540 DBG("Consumer starting monitor timer");
541 consumer_timer_live_start(new_channel
,
542 msg
.u
.channel
.live_timer_interval
);
543 monitor_start_ret
= consumer_timer_monitor_start(
545 msg
.u
.channel
.monitor_timer_interval
);
546 if (monitor_start_ret
< 0) {
547 ERR("Starting channel monitoring timer failed");
553 health_code_update();
555 /* If we received an error in add_channel, we need to report it. */
557 ret
= consumer_send_status_msg(sock
, ret
);
566 case LTTNG_CONSUMER_ADD_STREAM
:
569 struct lttng_pipe
*stream_pipe
;
570 struct lttng_consumer_stream
*new_stream
;
571 struct lttng_consumer_channel
*channel
;
575 * Get stream's channel reference. Needed when adding the stream to the
578 channel
= consumer_find_channel(msg
.u
.stream
.channel_key
);
581 * We could not find the channel. Can happen if cpu hotplug
582 * happens while tearing down.
584 ERR("Unable to find channel key %" PRIu64
, msg
.u
.stream
.channel_key
);
585 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
588 health_code_update();
590 /* First send a status message before receiving the fds. */
591 ret
= consumer_send_status_msg(sock
, ret_code
);
593 /* Somehow, the session daemon is not responding anymore. */
597 health_code_update();
599 if (ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
600 /* Channel was not found. */
606 ret
= lttng_consumer_poll_socket(consumer_sockpoll
);
612 health_code_update();
614 /* Get stream file descriptor from socket */
615 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
616 if (ret
!= sizeof(fd
)) {
617 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
622 health_code_update();
625 * Send status code to session daemon only if the recv works. If the
626 * above recv() failed, the session daemon is notified through the
627 * error socket and the teardown is eventually done.
629 ret
= consumer_send_status_msg(sock
, ret_code
);
631 /* Somehow, the session daemon is not responding anymore. */
635 health_code_update();
637 pthread_mutex_lock(&channel
->lock
);
638 new_stream
= consumer_allocate_stream(channel
->key
,
643 channel
->trace_chunk
,
648 if (new_stream
== NULL
) {
653 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
656 pthread_mutex_unlock(&channel
->lock
);
660 new_stream
->chan
= channel
;
661 new_stream
->wait_fd
= fd
;
662 ret
= kernctl_get_max_subbuf_size(new_stream
->wait_fd
,
663 &new_stream
->max_sb_size
);
665 pthread_mutex_unlock(&channel
->lock
);
666 ERR("Failed to get kernel maximal subbuffer size");
670 consumer_stream_update_channel_attributes(new_stream
,
672 switch (channel
->output
) {
673 case CONSUMER_CHANNEL_SPLICE
:
674 new_stream
->output
= LTTNG_EVENT_SPLICE
;
675 ret
= utils_create_pipe(new_stream
->splice_pipe
);
677 pthread_mutex_unlock(&channel
->lock
);
681 case CONSUMER_CHANNEL_MMAP
:
682 new_stream
->output
= LTTNG_EVENT_MMAP
;
685 ERR("Stream output unknown %d", channel
->output
);
686 pthread_mutex_unlock(&channel
->lock
);
691 * We've just assigned the channel to the stream so increment the
692 * refcount right now. We don't need to increment the refcount for
693 * streams in no monitor because we handle manually the cleanup of
694 * those. It is very important to make sure there is NO prior
695 * consumer_del_stream() calls or else the refcount will be unbalanced.
697 if (channel
->monitor
) {
698 uatomic_inc(&new_stream
->chan
->refcount
);
702 * The buffer flush is done on the session daemon side for the kernel
703 * so no need for the stream "hangup_flush_done" variable to be
704 * tracked. This is important for a kernel stream since we don't rely
705 * on the flush state of the stream to read data. It's not the case for
706 * user space tracing.
708 new_stream
->hangup_flush_done
= 0;
710 health_code_update();
712 pthread_mutex_lock(&new_stream
->lock
);
713 if (ctx
->on_recv_stream
) {
714 ret
= ctx
->on_recv_stream(new_stream
);
716 pthread_mutex_unlock(&new_stream
->lock
);
717 pthread_mutex_unlock(&channel
->lock
);
718 consumer_stream_free(new_stream
);
722 health_code_update();
724 if (new_stream
->metadata_flag
) {
725 channel
->metadata_stream
= new_stream
;
728 /* Do not monitor this stream. */
729 if (!channel
->monitor
) {
730 DBG("Kernel consumer add stream %s in no monitor mode with "
731 "relayd id %" PRIu64
, new_stream
->name
,
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 ret
= consumer_send_relayd_stream(new_stream
,
742 new_stream
->chan
->pathname
);
744 pthread_mutex_unlock(&new_stream
->lock
);
745 pthread_mutex_unlock(&channel
->lock
);
746 consumer_stream_free(new_stream
);
751 * If adding an extra stream to an already
752 * existing channel (e.g. cpu hotplug), we need
753 * to send the "streams_sent" command to relayd.
755 if (channel
->streams_sent_to_relayd
) {
756 ret
= consumer_send_relayd_streams_sent(
757 new_stream
->net_seq_idx
);
759 pthread_mutex_unlock(&new_stream
->lock
);
760 pthread_mutex_unlock(&channel
->lock
);
765 pthread_mutex_unlock(&new_stream
->lock
);
766 pthread_mutex_unlock(&channel
->lock
);
768 /* Get the right pipe where the stream will be sent. */
769 if (new_stream
->metadata_flag
) {
770 consumer_add_metadata_stream(new_stream
);
771 stream_pipe
= ctx
->consumer_metadata_pipe
;
773 consumer_add_data_stream(new_stream
);
774 stream_pipe
= ctx
->consumer_data_pipe
;
777 /* Visible to other threads */
778 new_stream
->globally_visible
= 1;
780 health_code_update();
782 ret
= lttng_pipe_write(stream_pipe
, &new_stream
, sizeof(new_stream
));
784 ERR("Consumer write %s stream to pipe %d",
785 new_stream
->metadata_flag
? "metadata" : "data",
786 lttng_pipe_get_writefd(stream_pipe
));
787 if (new_stream
->metadata_flag
) {
788 consumer_del_stream_for_metadata(new_stream
);
790 consumer_del_stream_for_data(new_stream
);
795 DBG("Kernel consumer ADD_STREAM %s (fd: %d) %s with relayd id %" PRIu64
,
796 new_stream
->name
, fd
, new_stream
->chan
->pathname
, new_stream
->relayd_stream_id
);
799 case LTTNG_CONSUMER_STREAMS_SENT
:
801 struct lttng_consumer_channel
*channel
;
804 * Get stream's channel reference. Needed when adding the stream to the
807 channel
= consumer_find_channel(msg
.u
.sent_streams
.channel_key
);
810 * We could not find the channel. Can happen if cpu hotplug
811 * happens while tearing down.
813 ERR("Unable to find channel key %" PRIu64
,
814 msg
.u
.sent_streams
.channel_key
);
815 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
818 health_code_update();
821 * Send status code to session daemon.
823 ret
= consumer_send_status_msg(sock
, ret_code
);
824 if (ret
< 0 || ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
825 /* Somehow, the session daemon is not responding anymore. */
829 health_code_update();
832 * We should not send this message if we don't monitor the
833 * streams in this channel.
835 if (!channel
->monitor
) {
839 health_code_update();
840 /* Send stream to relayd if the stream has an ID. */
841 if (msg
.u
.sent_streams
.net_seq_idx
!= (uint64_t) -1ULL) {
842 ret
= consumer_send_relayd_streams_sent(
843 msg
.u
.sent_streams
.net_seq_idx
);
847 channel
->streams_sent_to_relayd
= true;
851 case LTTNG_CONSUMER_UPDATE_STREAM
:
856 case LTTNG_CONSUMER_DESTROY_RELAYD
:
858 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
859 struct consumer_relayd_sock_pair
*relayd
;
861 DBG("Kernel consumer destroying relayd %" PRIu64
, index
);
863 /* Get relayd reference if exists. */
864 relayd
= consumer_find_relayd(index
);
865 if (relayd
== NULL
) {
866 DBG("Unable to find relayd %" PRIu64
, index
);
867 ret_code
= LTTCOMM_CONSUMERD_RELAYD_FAIL
;
871 * Each relayd socket pair has a refcount of stream attached to it
872 * which tells if the relayd is still active or not depending on the
875 * This will set the destroy flag of the relayd object and destroy it
876 * if the refcount reaches zero when called.
878 * The destroy can happen either here or when a stream fd hangs up.
881 consumer_flag_relayd_for_destroy(relayd
);
884 health_code_update();
886 ret
= consumer_send_status_msg(sock
, ret_code
);
888 /* Somehow, the session daemon is not responding anymore. */
894 case LTTNG_CONSUMER_DATA_PENDING
:
897 uint64_t id
= msg
.u
.data_pending
.session_id
;
899 DBG("Kernel consumer data pending command for id %" PRIu64
, id
);
901 ret
= consumer_data_pending(id
);
903 health_code_update();
905 /* Send back returned value to session daemon */
906 ret
= lttcomm_send_unix_sock(sock
, &ret
, sizeof(ret
));
908 PERROR("send data pending ret code");
913 * No need to send back a status message since the data pending
914 * returned value is the response.
918 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
920 struct lttng_consumer_channel
*channel
;
921 uint64_t key
= msg
.u
.snapshot_channel
.key
;
923 channel
= consumer_find_channel(key
);
925 ERR("Channel %" PRIu64
" not found", key
);
926 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
928 pthread_mutex_lock(&channel
->lock
);
929 if (msg
.u
.snapshot_channel
.metadata
== 1) {
930 ret
= lttng_kconsumer_snapshot_metadata(channel
, key
,
931 msg
.u
.snapshot_channel
.pathname
,
932 msg
.u
.snapshot_channel
.relayd_id
, ctx
);
934 ERR("Snapshot metadata failed");
935 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
938 ret
= lttng_kconsumer_snapshot_channel(channel
, key
,
939 msg
.u
.snapshot_channel
.pathname
,
940 msg
.u
.snapshot_channel
.relayd_id
,
941 msg
.u
.snapshot_channel
.nb_packets_per_stream
,
944 ERR("Snapshot channel failed");
945 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
948 pthread_mutex_unlock(&channel
->lock
);
950 health_code_update();
952 ret
= consumer_send_status_msg(sock
, ret_code
);
954 /* Somehow, the session daemon is not responding anymore. */
959 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
961 uint64_t key
= msg
.u
.destroy_channel
.key
;
962 struct lttng_consumer_channel
*channel
;
964 channel
= consumer_find_channel(key
);
966 ERR("Kernel consumer destroy channel %" PRIu64
" not found", key
);
967 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
970 health_code_update();
972 ret
= consumer_send_status_msg(sock
, ret_code
);
974 /* Somehow, the session daemon is not responding anymore. */
978 health_code_update();
980 /* Stop right now if no channel was found. */
986 * This command should ONLY be issued for channel with streams set in
989 assert(!channel
->monitor
);
992 * The refcount should ALWAYS be 0 in the case of a channel in no
995 assert(!uatomic_sub_return(&channel
->refcount
, 1));
997 consumer_del_channel(channel
);
1001 case LTTNG_CONSUMER_DISCARDED_EVENTS
:
1005 struct lttng_consumer_channel
*channel
;
1006 uint64_t id
= msg
.u
.discarded_events
.session_id
;
1007 uint64_t key
= msg
.u
.discarded_events
.channel_key
;
1009 DBG("Kernel consumer discarded events command for session id %"
1010 PRIu64
", channel key %" PRIu64
, id
, key
);
1012 channel
= consumer_find_channel(key
);
1014 ERR("Kernel consumer discarded events channel %"
1015 PRIu64
" not found", key
);
1018 count
= channel
->discarded_events
;
1021 health_code_update();
1023 /* Send back returned value to session daemon */
1024 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1026 PERROR("send discarded events");
1032 case LTTNG_CONSUMER_LOST_PACKETS
:
1036 struct lttng_consumer_channel
*channel
;
1037 uint64_t id
= msg
.u
.lost_packets
.session_id
;
1038 uint64_t key
= msg
.u
.lost_packets
.channel_key
;
1040 DBG("Kernel consumer lost packets command for session id %"
1041 PRIu64
", channel key %" PRIu64
, id
, key
);
1043 channel
= consumer_find_channel(key
);
1045 ERR("Kernel consumer lost packets channel %"
1046 PRIu64
" not found", key
);
1049 count
= channel
->lost_packets
;
1052 health_code_update();
1054 /* Send back returned value to session daemon */
1055 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1057 PERROR("send lost packets");
1063 case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE
:
1065 int channel_monitor_pipe
;
1067 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1068 /* Successfully received the command's type. */
1069 ret
= consumer_send_status_msg(sock
, ret_code
);
1074 ret
= lttcomm_recv_fds_unix_sock(sock
, &channel_monitor_pipe
,
1076 if (ret
!= sizeof(channel_monitor_pipe
)) {
1077 ERR("Failed to receive channel monitor pipe");
1081 DBG("Received channel monitor pipe (%d)", channel_monitor_pipe
);
1082 ret
= consumer_timer_thread_set_channel_monitor_pipe(
1083 channel_monitor_pipe
);
1087 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1088 /* Set the pipe as non-blocking. */
1089 ret
= fcntl(channel_monitor_pipe
, F_GETFL
, 0);
1091 PERROR("fcntl get flags of the channel monitoring pipe");
1096 ret
= fcntl(channel_monitor_pipe
, F_SETFL
,
1097 flags
| O_NONBLOCK
);
1099 PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
1102 DBG("Channel monitor pipe set as non-blocking");
1104 ret_code
= LTTCOMM_CONSUMERD_ALREADY_SET
;
1106 ret
= consumer_send_status_msg(sock
, ret_code
);
1112 case LTTNG_CONSUMER_ROTATE_CHANNEL
:
1114 struct lttng_consumer_channel
*channel
;
1115 uint64_t key
= msg
.u
.rotate_channel
.key
;
1117 DBG("Consumer rotate channel %" PRIu64
, key
);
1119 channel
= consumer_find_channel(key
);
1121 ERR("Channel %" PRIu64
" not found", key
);
1122 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1125 * Sample the rotate position of all the streams in this channel.
1127 ret
= lttng_consumer_rotate_channel(channel
, key
,
1128 msg
.u
.rotate_channel
.relayd_id
,
1129 msg
.u
.rotate_channel
.metadata
,
1132 ERR("Rotate channel failed");
1133 ret_code
= LTTCOMM_CONSUMERD_ROTATION_FAIL
;
1136 health_code_update();
1138 ret
= consumer_send_status_msg(sock
, ret_code
);
1140 /* Somehow, the session daemon is not responding anymore. */
1144 /* Rotate the streams that are ready right now. */
1145 ret
= lttng_consumer_rotate_ready_streams(
1148 ERR("Rotate ready streams failed");
1154 case LTTNG_CONSUMER_INIT
:
1156 ret_code
= lttng_consumer_init_command(ctx
,
1157 msg
.u
.init
.sessiond_uuid
);
1158 health_code_update();
1159 ret
= consumer_send_status_msg(sock
, ret_code
);
1161 /* Somehow, the session daemon is not responding anymore. */
1166 case LTTNG_CONSUMER_CREATE_TRACE_CHUNK
:
1168 const struct lttng_credentials credentials
= {
1169 .uid
= msg
.u
.create_trace_chunk
.credentials
.value
.uid
,
1170 .gid
= msg
.u
.create_trace_chunk
.credentials
.value
.gid
,
1172 const bool is_local_trace
=
1173 !msg
.u
.create_trace_chunk
.relayd_id
.is_set
;
1174 const uint64_t relayd_id
=
1175 msg
.u
.create_trace_chunk
.relayd_id
.value
;
1176 const char *chunk_override_name
=
1177 *msg
.u
.create_trace_chunk
.override_name
?
1178 msg
.u
.create_trace_chunk
.override_name
:
1180 LTTNG_OPTIONAL(struct lttng_directory_handle
) chunk_directory_handle
=
1181 LTTNG_OPTIONAL_INIT
;
1184 * The session daemon will only provide a chunk directory file
1185 * descriptor for local traces.
1187 if (is_local_trace
) {
1190 /* Acnowledge the reception of the command. */
1191 ret
= consumer_send_status_msg(sock
,
1192 LTTCOMM_CONSUMERD_SUCCESS
);
1194 /* Somehow, the session daemon is not responding anymore. */
1198 ret
= lttcomm_recv_fds_unix_sock(sock
, &chunk_dirfd
, 1);
1199 if (ret
!= sizeof(chunk_dirfd
)) {
1200 ERR("Failed to receive trace chunk directory file descriptor");
1204 DBG("Received trace chunk directory fd (%d)",
1206 ret
= lttng_directory_handle_init_from_dirfd(
1207 &chunk_directory_handle
.value
,
1210 ERR("Failed to initialize chunk directory handle from directory file descriptor");
1211 if (close(chunk_dirfd
)) {
1212 PERROR("Failed to close chunk directory file descriptor");
1216 chunk_directory_handle
.is_set
= true;
1219 ret_code
= lttng_consumer_create_trace_chunk(
1220 !is_local_trace
? &relayd_id
: NULL
,
1221 msg
.u
.create_trace_chunk
.session_id
,
1222 msg
.u
.create_trace_chunk
.chunk_id
,
1223 (time_t) msg
.u
.create_trace_chunk
1224 .creation_timestamp
,
1225 chunk_override_name
,
1226 msg
.u
.create_trace_chunk
.credentials
.is_set
?
1229 chunk_directory_handle
.is_set
?
1230 &chunk_directory_handle
.value
:
1233 if (chunk_directory_handle
.is_set
) {
1234 lttng_directory_handle_fini(
1235 &chunk_directory_handle
.value
);
1237 goto end_msg_sessiond
;
1239 case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK
:
1241 enum lttng_trace_chunk_command_type close_command
=
1242 msg
.u
.close_trace_chunk
.close_command
.value
;
1243 const uint64_t relayd_id
=
1244 msg
.u
.close_trace_chunk
.relayd_id
.value
;
1246 ret_code
= lttng_consumer_close_trace_chunk(
1247 msg
.u
.close_trace_chunk
.relayd_id
.is_set
?
1250 msg
.u
.close_trace_chunk
.session_id
,
1251 msg
.u
.close_trace_chunk
.chunk_id
,
1252 (time_t) msg
.u
.close_trace_chunk
.close_timestamp
,
1253 msg
.u
.close_trace_chunk
.close_command
.is_set
?
1256 goto end_msg_sessiond
;
1258 case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS
:
1260 const uint64_t relayd_id
=
1261 msg
.u
.trace_chunk_exists
.relayd_id
.value
;
1263 ret_code
= lttng_consumer_trace_chunk_exists(
1264 msg
.u
.trace_chunk_exists
.relayd_id
.is_set
?
1266 msg
.u
.trace_chunk_exists
.session_id
,
1267 msg
.u
.trace_chunk_exists
.chunk_id
);
1268 goto end_msg_sessiond
;
1278 * Return 1 to indicate success since the 0 value can be a socket
1279 * shutdown during the recv() or send() call.
1281 health_code_update();
1286 * The returned value here is not useful since either way we'll return 1 to
1287 * the caller because the session daemon socket management is done
1288 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1290 ret
= consumer_send_status_msg(sock
, ret_code
);
1296 health_code_update();
1302 /* This will issue a consumer stop. */
1307 * Populate index values of a kernel stream. Values are set in big endian order.
1309 * Return 0 on success or else a negative value.
1311 static int get_index_values(struct ctf_packet_index
*index
, int infd
)
1315 ret
= kernctl_get_timestamp_begin(infd
, &index
->timestamp_begin
);
1317 PERROR("kernctl_get_timestamp_begin");
1320 index
->timestamp_begin
= htobe64(index
->timestamp_begin
);
1322 ret
= kernctl_get_timestamp_end(infd
, &index
->timestamp_end
);
1324 PERROR("kernctl_get_timestamp_end");
1327 index
->timestamp_end
= htobe64(index
->timestamp_end
);
1329 ret
= kernctl_get_events_discarded(infd
, &index
->events_discarded
);
1331 PERROR("kernctl_get_events_discarded");
1334 index
->events_discarded
= htobe64(index
->events_discarded
);
1336 ret
= kernctl_get_content_size(infd
, &index
->content_size
);
1338 PERROR("kernctl_get_content_size");
1341 index
->content_size
= htobe64(index
->content_size
);
1343 ret
= kernctl_get_packet_size(infd
, &index
->packet_size
);
1345 PERROR("kernctl_get_packet_size");
1348 index
->packet_size
= htobe64(index
->packet_size
);
1350 ret
= kernctl_get_stream_id(infd
, &index
->stream_id
);
1352 PERROR("kernctl_get_stream_id");
1355 index
->stream_id
= htobe64(index
->stream_id
);
1357 ret
= kernctl_get_instance_id(infd
, &index
->stream_instance_id
);
1359 if (ret
== -ENOTTY
) {
1360 /* Command not implemented by lttng-modules. */
1361 index
->stream_instance_id
= -1ULL;
1363 PERROR("kernctl_get_instance_id");
1367 index
->stream_instance_id
= htobe64(index
->stream_instance_id
);
1369 ret
= kernctl_get_sequence_number(infd
, &index
->packet_seq_num
);
1371 if (ret
== -ENOTTY
) {
1372 /* Command not implemented by lttng-modules. */
1373 index
->packet_seq_num
= -1ULL;
1376 PERROR("kernctl_get_sequence_number");
1380 index
->packet_seq_num
= htobe64(index
->packet_seq_num
);
1386 * Sync metadata meaning request them to the session daemon and snapshot to the
1387 * metadata thread can consumer them.
1389 * Metadata stream lock MUST be acquired.
1391 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
1392 * is empty or a negative value on error.
1394 int lttng_kconsumer_sync_metadata(struct lttng_consumer_stream
*metadata
)
1400 ret
= kernctl_buffer_flush(metadata
->wait_fd
);
1402 ERR("Failed to flush kernel stream");
1406 ret
= kernctl_snapshot(metadata
->wait_fd
);
1408 if (ret
!= -EAGAIN
) {
1409 ERR("Sync metadata, taking kernel snapshot failed.");
1412 DBG("Sync metadata, no new kernel metadata");
1413 /* No new metadata, exit. */
1423 int update_stream_stats(struct lttng_consumer_stream
*stream
)
1426 uint64_t seq
, discarded
;
1428 ret
= kernctl_get_sequence_number(stream
->wait_fd
, &seq
);
1430 if (ret
== -ENOTTY
) {
1431 /* Command not implemented by lttng-modules. */
1434 PERROR("kernctl_get_sequence_number");
1440 * Start the sequence when we extract the first packet in case we don't
1441 * start at 0 (for example if a consumer is not connected to the
1442 * session immediately after the beginning).
1444 if (stream
->last_sequence_number
== -1ULL) {
1445 stream
->last_sequence_number
= seq
;
1446 } else if (seq
> stream
->last_sequence_number
) {
1447 stream
->chan
->lost_packets
+= seq
-
1448 stream
->last_sequence_number
- 1;
1450 /* seq <= last_sequence_number */
1451 ERR("Sequence number inconsistent : prev = %" PRIu64
1452 ", current = %" PRIu64
,
1453 stream
->last_sequence_number
, seq
);
1457 stream
->last_sequence_number
= seq
;
1459 ret
= kernctl_get_events_discarded(stream
->wait_fd
, &discarded
);
1461 PERROR("kernctl_get_events_discarded");
1464 if (discarded
< stream
->last_discarded_events
) {
1466 * Overflow has occurred. We assume only one wrap-around
1469 stream
->chan
->discarded_events
+= (1ULL << (CAA_BITS_PER_LONG
- 1)) -
1470 stream
->last_discarded_events
+ discarded
;
1472 stream
->chan
->discarded_events
+= discarded
-
1473 stream
->last_discarded_events
;
1475 stream
->last_discarded_events
= discarded
;
1483 * Check if the local version of the metadata stream matches with the version
1484 * of the metadata stream in the kernel. If it was updated, set the reset flag
1488 int metadata_stream_check_version(int infd
, struct lttng_consumer_stream
*stream
)
1491 uint64_t cur_version
;
1493 ret
= kernctl_get_metadata_version(infd
, &cur_version
);
1495 if (ret
== -ENOTTY
) {
1497 * LTTng-modules does not implement this
1503 ERR("Failed to get the metadata version");
1507 if (stream
->metadata_version
== cur_version
) {
1512 DBG("New metadata version detected");
1513 stream
->metadata_version
= cur_version
;
1514 stream
->reset_metadata_flag
= 1;
1522 * Consume data on a file descriptor and write it on a trace file.
1523 * The stream and channel locks must be held by the caller.
1525 ssize_t
lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1526 struct lttng_consumer_local_data
*ctx
)
1528 unsigned long len
, subbuf_size
, padding
;
1529 int err
, write_index
= 1, rotation_ret
;
1531 int infd
= stream
->wait_fd
;
1532 struct ctf_packet_index index
;
1534 DBG("In read_subbuffer (infd : %d)", infd
);
1537 * If the stream was flagged to be ready for rotation before we extract the
1538 * next packet, rotate it now.
1540 if (stream
->rotate_ready
) {
1541 DBG("Rotate stream before extracting data");
1542 rotation_ret
= lttng_consumer_rotate_stream(ctx
, stream
);
1543 if (rotation_ret
< 0) {
1544 ERR("Stream rotation error");
1550 /* Get the next subbuffer */
1551 err
= kernctl_get_next_subbuf(infd
);
1554 * This is a debug message even for single-threaded consumer,
1555 * because poll() have more relaxed criterions than get subbuf,
1556 * so get_subbuf may fail for short race windows where poll()
1557 * would issue wakeups.
1559 DBG("Reserving sub buffer failed (everything is normal, "
1560 "it is due to concurrency)");
1565 /* Get the full subbuffer size including padding */
1566 err
= kernctl_get_padded_subbuf_size(infd
, &len
);
1568 PERROR("Getting sub-buffer len failed.");
1569 err
= kernctl_put_subbuf(infd
);
1571 if (err
== -EFAULT
) {
1572 PERROR("Error in unreserving sub buffer\n");
1573 } else if (err
== -EIO
) {
1574 /* Should never happen with newer LTTng versions */
1575 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1584 if (!stream
->metadata_flag
) {
1585 ret
= get_index_values(&index
, infd
);
1587 err
= kernctl_put_subbuf(infd
);
1589 if (err
== -EFAULT
) {
1590 PERROR("Error in unreserving sub buffer\n");
1591 } else if (err
== -EIO
) {
1592 /* Should never happen with newer LTTng versions */
1593 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1600 ret
= update_stream_stats(stream
);
1602 err
= kernctl_put_subbuf(infd
);
1604 if (err
== -EFAULT
) {
1605 PERROR("Error in unreserving sub buffer\n");
1606 } else if (err
== -EIO
) {
1607 /* Should never happen with newer LTTng versions */
1608 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1617 ret
= metadata_stream_check_version(infd
, stream
);
1619 err
= kernctl_put_subbuf(infd
);
1621 if (err
== -EFAULT
) {
1622 PERROR("Error in unreserving sub buffer\n");
1623 } else if (err
== -EIO
) {
1624 /* Should never happen with newer LTTng versions */
1625 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1634 switch (stream
->chan
->output
) {
1635 case CONSUMER_CHANNEL_SPLICE
:
1637 * XXX: The lttng-modules splice "actor" does not handle copying
1638 * partial pages hence only using the subbuffer size without the
1639 * padding makes the splice fail.
1644 /* splice the subbuffer to the tracefile */
1645 ret
= lttng_consumer_on_read_subbuffer_splice(ctx
, stream
, subbuf_size
,
1648 * XXX: Splice does not support network streaming so the return value
1649 * is simply checked against subbuf_size and not like the mmap() op.
1651 if (ret
!= subbuf_size
) {
1653 * display the error but continue processing to try
1654 * to release the subbuffer
1656 ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
1661 case CONSUMER_CHANNEL_MMAP
:
1662 /* Get subbuffer size without padding */
1663 err
= kernctl_get_subbuf_size(infd
, &subbuf_size
);
1665 PERROR("Getting sub-buffer len failed.");
1666 err
= kernctl_put_subbuf(infd
);
1668 if (err
== -EFAULT
) {
1669 PERROR("Error in unreserving sub buffer\n");
1670 } else if (err
== -EIO
) {
1671 /* Should never happen with newer LTTng versions */
1672 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1681 /* Make sure the tracer is not gone mad on us! */
1682 assert(len
>= subbuf_size
);
1684 padding
= len
- subbuf_size
;
1686 /* write the subbuffer to the tracefile */
1687 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
,
1690 * The mmap operation should write subbuf_size amount of data when
1691 * network streaming or the full padding (len) size when we are _not_
1694 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1695 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1697 * Display the error but continue processing to try to release the
1698 * subbuffer. This is a DBG statement since this is possible to
1699 * happen without being a critical error.
1701 DBG("Error writing to tracefile "
1702 "(ret: %zd != len: %lu != subbuf_size: %lu)",
1703 ret
, len
, subbuf_size
);
1708 ERR("Unknown output method");
1712 err
= kernctl_put_next_subbuf(infd
);
1714 if (err
== -EFAULT
) {
1715 PERROR("Error in unreserving sub buffer\n");
1716 } else if (err
== -EIO
) {
1717 /* Should never happen with newer LTTng versions */
1718 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
1724 /* Write index if needed. */
1729 if (stream
->chan
->live_timer_interval
&& !stream
->metadata_flag
) {
1731 * In live, block until all the metadata is sent.
1733 pthread_mutex_lock(&stream
->metadata_timer_lock
);
1734 assert(!stream
->missed_metadata_flush
);
1735 stream
->waiting_on_metadata
= true;
1736 pthread_mutex_unlock(&stream
->metadata_timer_lock
);
1738 err
= consumer_stream_sync_metadata(ctx
, stream
->session_id
);
1740 pthread_mutex_lock(&stream
->metadata_timer_lock
);
1741 stream
->waiting_on_metadata
= false;
1742 if (stream
->missed_metadata_flush
) {
1743 stream
->missed_metadata_flush
= false;
1744 pthread_mutex_unlock(&stream
->metadata_timer_lock
);
1745 (void) consumer_flush_kernel_index(stream
);
1747 pthread_mutex_unlock(&stream
->metadata_timer_lock
);
1754 err
= consumer_stream_write_index(stream
, &index
);
1761 * After extracting the packet, we check if the stream is now ready to be
1762 * rotated and perform the action immediately.
1764 rotation_ret
= lttng_consumer_stream_is_rotate_ready(stream
);
1765 if (rotation_ret
== 1) {
1766 rotation_ret
= lttng_consumer_rotate_stream(ctx
, stream
);
1767 if (rotation_ret
< 0) {
1768 ERR("Stream rotation error");
1772 } else if (rotation_ret
< 0) {
1773 ERR("Checking if stream is ready to rotate");
1782 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1789 * Don't create anything if this is set for streaming or if there is
1790 * no current trace chunk on the parent channel.
1792 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
&&
1793 stream
->chan
->trace_chunk
) {
1794 ret
= consumer_stream_create_output_files(stream
, true);
1800 if (stream
->output
== LTTNG_EVENT_MMAP
) {
1801 /* get the len of the mmap region */
1802 unsigned long mmap_len
;
1804 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
1806 PERROR("kernctl_get_mmap_len");
1807 goto error_close_fd
;
1809 stream
->mmap_len
= (size_t) mmap_len
;
1811 stream
->mmap_base
= mmap(NULL
, stream
->mmap_len
, PROT_READ
,
1812 MAP_PRIVATE
, stream
->wait_fd
, 0);
1813 if (stream
->mmap_base
== MAP_FAILED
) {
1814 PERROR("Error mmaping");
1816 goto error_close_fd
;
1820 /* we return 0 to let the library handle the FD internally */
1824 if (stream
->out_fd
>= 0) {
1827 err
= close(stream
->out_fd
);
1829 stream
->out_fd
= -1;
1836 * Check if data is still being extracted from the buffers for a specific
1837 * stream. Consumer data lock MUST be acquired before calling this function
1838 * and the stream lock.
1840 * Return 1 if the traced data are still getting read else 0 meaning that the
1841 * data is available for trace viewer reading.
1843 int lttng_kconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1849 if (stream
->endpoint_status
!= CONSUMER_ENDPOINT_ACTIVE
) {
1854 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1856 /* There is still data so let's put back this subbuffer. */
1857 ret
= kernctl_put_subbuf(stream
->wait_fd
);
1859 ret
= 1; /* Data is pending */
1863 /* Data is NOT pending and ready to be read. */