2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 #include <lttng/ust-ctl.h>
27 #include <sys/socket.h>
29 #include <sys/types.h>
32 #include <urcu/list.h>
35 #include <common/common.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/relayd/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/consumer-metadata-cache.h>
40 #include <common/consumer-stream.h>
41 #include <common/consumer-timer.h>
42 #include <common/utils.h>
44 #include "ust-consumer.h"
46 extern struct lttng_consumer_global_data consumer_data
;
47 extern int consumer_poll_timeout
;
48 extern volatile int consumer_quit
;
51 * Free channel object and all streams associated with it. This MUST be used
52 * only and only if the channel has _NEVER_ been added to the global channel
55 static void destroy_channel(struct lttng_consumer_channel
*channel
)
57 struct lttng_consumer_stream
*stream
, *stmp
;
61 DBG("UST consumer cleaning stream list");
63 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
65 cds_list_del(&stream
->send_node
);
66 ustctl_destroy_stream(stream
->ustream
);
71 * If a channel is available meaning that was created before the streams
75 lttng_ustconsumer_del_channel(channel
);
81 * Add channel to internal consumer state.
83 * Returns 0 on success or else a negative value.
85 static int add_channel(struct lttng_consumer_channel
*channel
,
86 struct lttng_consumer_local_data
*ctx
)
93 if (ctx
->on_recv_channel
!= NULL
) {
94 ret
= ctx
->on_recv_channel(channel
);
96 ret
= consumer_add_channel(channel
, ctx
);
98 /* Most likely an ENOMEM. */
99 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
103 ret
= consumer_add_channel(channel
, ctx
);
106 DBG("UST consumer channel added (key: %" PRIu64
")", channel
->key
);
113 * Allocate and return a consumer channel object.
115 static struct lttng_consumer_channel
*allocate_channel(uint64_t session_id
,
116 const char *pathname
, const char *name
, uid_t uid
, gid_t gid
,
117 uint64_t relayd_id
, uint64_t key
, enum lttng_event_output output
,
118 uint64_t tracefile_size
, uint64_t tracefile_count
,
119 uint64_t session_id_per_pid
, unsigned int monitor
)
124 return consumer_allocate_channel(key
, session_id
, pathname
, name
, uid
,
125 gid
, relayd_id
, output
, tracefile_size
,
126 tracefile_count
, session_id_per_pid
, monitor
);
130 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
131 * error value if applicable is set in it else it is kept untouched.
133 * Return NULL on error else the newly allocated stream object.
135 static struct lttng_consumer_stream
*allocate_stream(int cpu
, int key
,
136 struct lttng_consumer_channel
*channel
,
137 struct lttng_consumer_local_data
*ctx
, int *_alloc_ret
)
140 struct lttng_consumer_stream
*stream
= NULL
;
145 stream
= consumer_allocate_stream(channel
->key
,
147 LTTNG_CONSUMER_ACTIVE_STREAM
,
157 if (stream
== NULL
) {
161 * We could not find the channel. Can happen if cpu hotplug
162 * happens while tearing down.
164 DBG3("Could not find channel");
169 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
175 stream
->chan
= channel
;
179 *_alloc_ret
= alloc_ret
;
185 * Send the given stream pointer to the corresponding thread.
187 * Returns 0 on success else a negative value.
189 static int send_stream_to_thread(struct lttng_consumer_stream
*stream
,
190 struct lttng_consumer_local_data
*ctx
)
193 struct lttng_pipe
*stream_pipe
;
195 /* Get the right pipe where the stream will be sent. */
196 if (stream
->metadata_flag
) {
197 stream_pipe
= ctx
->consumer_metadata_pipe
;
199 stream_pipe
= ctx
->consumer_data_pipe
;
202 ret
= lttng_pipe_write(stream_pipe
, &stream
, sizeof(stream
));
204 ERR("Consumer write %s stream to pipe %d",
205 stream
->metadata_flag
? "metadata" : "data",
206 lttng_pipe_get_writefd(stream_pipe
));
213 * Create streams for the given channel using liblttng-ust-ctl.
215 * Return 0 on success else a negative value.
217 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
218 struct lttng_consumer_local_data
*ctx
)
221 struct ustctl_consumer_stream
*ustream
;
222 struct lttng_consumer_stream
*stream
;
228 * While a stream is available from ustctl. When NULL is returned, we've
229 * reached the end of the possible stream for the channel.
231 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
234 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
236 /* Allocate consumer stream object. */
237 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
241 stream
->ustream
= ustream
;
243 * Store it so we can save multiple function calls afterwards since
244 * this value is used heavily in the stream threads. This is UST
245 * specific so this is why it's done after allocation.
247 stream
->wait_fd
= wait_fd
;
250 * Increment channel refcount since the channel reference has now been
251 * assigned in the allocation process above.
253 if (stream
->chan
->monitor
) {
254 uatomic_inc(&stream
->chan
->refcount
);
258 * Order is important this is why a list is used. On error, the caller
259 * should clean this list.
261 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
263 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
264 &stream
->max_sb_size
);
266 ERR("ustctl_get_max_subbuf_size failed for stream %s",
271 /* Do actions once stream has been received. */
272 if (ctx
->on_recv_stream
) {
273 ret
= ctx
->on_recv_stream(stream
);
279 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
280 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
282 /* Set next CPU stream. */
283 channel
->streams
.count
= ++cpu
;
285 /* Keep stream reference when creating metadata. */
286 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
287 channel
->metadata_stream
= stream
;
299 * Create an UST channel with the given attributes and send it to the session
300 * daemon using the ust ctl API.
302 * Return 0 on success or else a negative value.
304 static int create_ust_channel(struct ustctl_consumer_channel_attr
*attr
,
305 struct ustctl_consumer_channel
**chanp
)
308 struct ustctl_consumer_channel
*channel
;
313 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
314 "subbuf_size: %" PRIu64
", num_subbuf: %" PRIu64
", "
315 "switch_timer_interval: %u, read_timer_interval: %u, "
316 "output: %d, type: %d", attr
->overwrite
, attr
->subbuf_size
,
317 attr
->num_subbuf
, attr
->switch_timer_interval
,
318 attr
->read_timer_interval
, attr
->output
, attr
->type
);
320 channel
= ustctl_create_channel(attr
);
335 * Send a single given stream to the session daemon using the sock.
337 * Return 0 on success else a negative value.
339 static int send_sessiond_stream(int sock
, struct lttng_consumer_stream
*stream
)
346 DBG2("UST consumer sending stream %" PRIu64
" to sessiond", stream
->key
);
348 /* Send stream to session daemon. */
349 ret
= ustctl_send_stream_to_sessiond(sock
, stream
->ustream
);
359 * Send channel to sessiond.
361 * Return 0 on success or else a negative value.
363 static int send_sessiond_channel(int sock
,
364 struct lttng_consumer_channel
*channel
,
365 struct lttng_consumer_local_data
*ctx
, int *relayd_error
)
367 int ret
, ret_code
= LTTNG_OK
;
368 struct lttng_consumer_stream
*stream
;
374 DBG("UST consumer sending channel %s to sessiond", channel
->name
);
376 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
377 /* Try to send the stream to the relayd if one is available. */
378 ret
= consumer_send_relayd_stream(stream
, stream
->chan
->pathname
);
381 * Flag that the relayd was the problem here probably due to a
382 * communicaton error on the socket.
387 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
391 /* Inform sessiond that we are about to send channel and streams. */
392 ret
= consumer_send_status_msg(sock
, ret_code
);
393 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
395 * Either the session daemon is not responding or the relayd died so we
401 /* Send channel to sessiond. */
402 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
407 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
412 /* The channel was sent successfully to the sessiond at this point. */
413 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
414 /* Send stream to session daemon. */
415 ret
= send_sessiond_stream(sock
, stream
);
421 /* Tell sessiond there is no more stream. */
422 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
427 DBG("UST consumer NULL stream sent to sessiond");
432 if (ret_code
!= LTTNG_OK
) {
439 * Creates a channel and streams and add the channel it to the channel internal
440 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
443 * Return 0 on success or else, a negative value is returned and the channel
444 * MUST be destroyed by consumer_del_channel().
446 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
447 struct lttng_consumer_channel
*channel
,
448 struct ustctl_consumer_channel_attr
*attr
)
457 * This value is still used by the kernel consumer since for the kernel,
458 * the stream ownership is not IN the consumer so we need to have the
459 * number of left stream that needs to be initialized so we can know when
460 * to delete the channel (see consumer.c).
462 * As for the user space tracer now, the consumer creates and sends the
463 * stream to the session daemon which only sends them to the application
464 * once every stream of a channel is received making this value useless
465 * because we they will be added to the poll thread before the application
466 * receives them. This ensures that a stream can not hang up during
467 * initilization of a channel.
469 channel
->nb_init_stream_left
= 0;
471 /* The reply msg status is handled in the following call. */
472 ret
= create_ust_channel(attr
, &channel
->uchan
);
477 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
480 * For the snapshots (no monitor), we create the metadata streams
481 * on demand, not during the channel creation.
483 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
&& !channel
->monitor
) {
488 /* Open all streams for this channel. */
489 ret
= create_ust_streams(channel
, ctx
);
499 * Send all stream of a channel to the right thread handling it.
501 * On error, return a negative value else 0 on success.
503 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
504 struct lttng_consumer_local_data
*ctx
)
507 struct lttng_consumer_stream
*stream
, *stmp
;
512 /* Send streams to the corresponding thread. */
513 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
515 /* Sending the stream to the thread. */
516 ret
= send_stream_to_thread(stream
, ctx
);
519 * If we are unable to send the stream to the thread, there is
520 * a big problem so just stop everything.
525 /* Remove node from the channel stream list. */
526 cds_list_del(&stream
->send_node
);
529 * From this point on, the stream's ownership has been moved away from
530 * the channel and becomes globally visible.
532 stream
->globally_visible
= 1;
540 * Write metadata to the given channel using ustctl to convert the string to
542 * Called only from consumer_metadata_cache_write.
543 * The metadata cache lock MUST be acquired to write in the cache.
545 * Return 0 on success else a negative value.
547 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel
*metadata
,
548 const char *metadata_str
, uint64_t target_offset
, uint64_t len
)
553 assert(metadata_str
);
555 DBG("UST consumer writing metadata to channel %s", metadata
->name
);
557 if (!metadata
->metadata_stream
) {
562 assert(target_offset
<= metadata
->metadata_cache
->max_offset
);
563 ret
= ustctl_write_metadata_to_channel(metadata
->uchan
,
564 metadata_str
+ target_offset
, len
);
566 ERR("ustctl write metadata fail with ret %d, len %" PRIu64
, ret
, len
);
570 ustctl_flush_buffer(metadata
->metadata_stream
->ustream
, 1);
577 * Flush channel's streams using the given key to retrieve the channel.
579 * Return 0 on success else an LTTng error code.
581 static int flush_channel(uint64_t chan_key
)
584 struct lttng_consumer_channel
*channel
;
585 struct lttng_consumer_stream
*stream
;
587 struct lttng_ht_iter iter
;
589 DBG("UST consumer flush channel key %" PRIu64
, chan_key
);
592 channel
= consumer_find_channel(chan_key
);
594 ERR("UST consumer flush channel %" PRIu64
" not found", chan_key
);
595 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
599 ht
= consumer_data
.stream_per_chan_id_ht
;
601 /* For each stream of the channel id, flush it. */
602 cds_lfht_for_each_entry_duplicate(ht
->ht
,
603 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
604 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
605 ustctl_flush_buffer(stream
->ustream
, 1);
613 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
614 * RCU read side lock MUST be acquired before calling this function.
616 * Return 0 on success else an LTTng error code.
618 static int close_metadata(uint64_t chan_key
)
621 struct lttng_consumer_channel
*channel
;
623 DBG("UST consumer close metadata key %" PRIu64
, chan_key
);
625 channel
= consumer_find_channel(chan_key
);
628 * This is possible if the metadata thread has issue a delete because
629 * the endpoint point of the stream hung up. There is no way the
630 * session daemon can know about it thus use a DBG instead of an actual
633 DBG("UST consumer close metadata %" PRIu64
" not found", chan_key
);
634 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
638 pthread_mutex_lock(&consumer_data
.lock
);
640 if (cds_lfht_is_node_deleted(&channel
->node
.node
)) {
644 if (channel
->switch_timer_enabled
== 1) {
645 DBG("Deleting timer on metadata channel");
646 consumer_timer_switch_stop(channel
);
649 if (channel
->metadata_stream
) {
650 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
652 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
653 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
659 pthread_mutex_unlock(&consumer_data
.lock
);
665 * RCU read side lock MUST be acquired before calling this function.
667 * Return 0 on success else an LTTng error code.
669 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
672 struct lttng_consumer_channel
*metadata
;
674 DBG("UST consumer setup metadata key %" PRIu64
, key
);
676 metadata
= consumer_find_channel(key
);
678 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
679 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
684 * In no monitor mode, the metadata channel has no stream(s) so skip the
685 * ownership transfer to the metadata thread.
687 if (!metadata
->monitor
) {
688 DBG("Metadata channel in no monitor");
694 * Send metadata stream to relayd if one available. Availability is
695 * known if the stream is still in the list of the channel.
697 if (cds_list_empty(&metadata
->streams
.head
)) {
698 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
699 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
700 goto error_no_stream
;
703 /* Send metadata stream to relayd if needed. */
704 ret
= consumer_send_relayd_stream(metadata
->metadata_stream
,
707 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
711 ret
= send_streams_to_thread(metadata
, ctx
);
714 * If we are unable to send the stream to the thread, there is
715 * a big problem so just stop everything.
717 ret
= LTTCOMM_CONSUMERD_FATAL
;
720 /* List MUST be empty after or else it could be reused. */
721 assert(cds_list_empty(&metadata
->streams
.head
));
728 * Delete metadata channel on error. At this point, the metadata stream can
729 * NOT be monitored by the metadata thread thus having the guarantee that
730 * the stream is still in the local stream list of the channel. This call
731 * will make sure to clean that list.
733 cds_list_del(&metadata
->metadata_stream
->send_node
);
734 consumer_stream_destroy(metadata
->metadata_stream
, NULL
);
741 * Snapshot the whole metadata.
743 * Returns 0 on success, < 0 on error
745 static int snapshot_metadata(uint64_t key
, char *path
, uint64_t relayd_id
,
746 struct lttng_consumer_local_data
*ctx
)
750 uint64_t total_len
= 0;
751 struct lttng_consumer_channel
*metadata_channel
;
752 struct lttng_consumer_stream
*metadata_stream
;
757 DBG("UST consumer snapshot metadata with key %" PRIu64
" at path %s",
762 metadata_channel
= consumer_find_channel(key
);
763 if (!metadata_channel
) {
764 ERR("UST snapshot metadata channel not found for key %lu", key
);
768 assert(!metadata_channel
->monitor
);
771 * Ask the sessiond if we have new metadata waiting and update the
772 * consumer metadata cache.
774 ret
= lttng_ustconsumer_request_metadata(ctx
, metadata_channel
);
780 * The metadata stream is NOT created in no monitor mode when the channel
781 * is created on a sessiond ask channel command.
783 ret
= create_ust_streams(metadata_channel
, ctx
);
788 metadata_stream
= metadata_channel
->metadata_stream
;
789 assert(metadata_stream
);
791 if (relayd_id
!= (uint64_t) -1ULL) {
792 metadata_stream
->net_seq_idx
= relayd_id
;
793 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
798 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
799 metadata_stream
->chan
->tracefile_size
,
800 metadata_stream
->tracefile_count_current
,
801 metadata_stream
->uid
, metadata_stream
->gid
);
805 metadata_stream
->out_fd
= ret
;
806 metadata_stream
->tracefile_size_current
= 0;
809 pthread_mutex_lock(&metadata_channel
->metadata_cache
->lock
);
810 while (total_len
< metadata_channel
->metadata_cache
->total_bytes_written
) {
812 * Write at most one packet of metadata into the channel
813 * to avoid blocking here.
815 write_len
= ustctl_write_one_packet_to_channel(metadata_channel
->uchan
,
816 metadata_channel
->metadata_cache
->data
,
817 metadata_channel
->metadata_cache
->total_bytes_written
);
819 ERR("UST consumer snapshot writing metadata packet");
823 total_len
+= write_len
;
825 DBG("Written %" PRIu64
" bytes to metadata (left: %" PRIu64
")",
827 metadata_channel
->metadata_cache
->total_bytes_written
- write_len
);
828 ustctl_flush_buffer(metadata_stream
->ustream
, 1);
829 ret
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
);
836 pthread_mutex_unlock(&metadata_channel
->metadata_cache
->lock
);
840 * Clean up the stream completly because the next snapshot will use a new
843 cds_list_del(&metadata_stream
->send_node
);
844 consumer_stream_destroy(metadata_stream
, NULL
);
845 metadata_channel
->metadata_stream
= NULL
;
853 * Take a snapshot of all the stream of a channel.
855 * Returns 0 on success, < 0 on error
857 static int snapshot_channel(uint64_t key
, char *path
, uint64_t relayd_id
,
858 struct lttng_consumer_local_data
*ctx
)
861 unsigned use_relayd
= 0;
862 unsigned long consumed_pos
, produced_pos
;
863 struct lttng_consumer_channel
*channel
;
864 struct lttng_consumer_stream
*stream
;
871 if (relayd_id
!= (uint64_t) -1ULL) {
875 channel
= consumer_find_channel(key
);
877 ERR("UST snapshot channel not found for key %lu", key
);
881 assert(!channel
->monitor
);
882 DBG("UST consumer snapshot channel %lu", key
);
884 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
885 /* Lock stream because we are about to change its state. */
886 pthread_mutex_lock(&stream
->lock
);
887 stream
->net_seq_idx
= relayd_id
;
890 ret
= consumer_send_relayd_stream(stream
, path
);
895 ret
= utils_create_stream_file(path
, stream
->name
,
896 stream
->chan
->tracefile_size
,
897 stream
->tracefile_count_current
,
898 stream
->uid
, stream
->gid
);
902 stream
->out_fd
= ret
;
903 stream
->tracefile_size_current
= 0;
905 DBG("UST consumer snapshot stream %s/%s (%" PRIu64
")", path
,
906 stream
->name
, stream
->key
);
909 ustctl_flush_buffer(stream
->ustream
, 1);
911 ret
= lttng_ustconsumer_take_snapshot(stream
);
913 ERR("Taking UST snapshot");
917 ret
= lttng_ustconsumer_get_produced_snapshot(stream
, &produced_pos
);
919 ERR("Produced UST snapshot position");
923 ret
= lttng_ustconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
925 ERR("Consumerd UST snapshot position");
929 while (consumed_pos
< produced_pos
) {
931 unsigned long len
, padded_len
;
933 DBG("UST consumer taking snapshot at pos %lu", consumed_pos
);
935 ret
= ustctl_get_subbuf(stream
->ustream
, &consumed_pos
);
937 if (ret
!= -EAGAIN
) {
938 PERROR("ustctl_get_subbuf snapshot");
939 goto error_close_stream
;
941 DBG("UST consumer get subbuf failed. Skipping it.");
942 consumed_pos
+= stream
->max_sb_size
;
946 ret
= ustctl_get_subbuf_size(stream
->ustream
, &len
);
948 ERR("Snapshot ustctl_get_subbuf_size");
949 goto error_put_subbuf
;
952 ret
= ustctl_get_padded_subbuf_size(stream
->ustream
, &padded_len
);
954 ERR("Snapshot ustctl_get_padded_subbuf_size");
955 goto error_put_subbuf
;
958 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
961 if (read_len
!= len
) {
963 goto error_put_subbuf
;
966 if (read_len
!= padded_len
) {
968 goto error_put_subbuf
;
972 ret
= ustctl_put_subbuf(stream
->ustream
);
974 ERR("Snapshot ustctl_put_subbuf");
975 goto error_close_stream
;
977 consumed_pos
+= stream
->max_sb_size
;
980 /* Simply close the stream so we can use it on the next snapshot. */
981 consumer_stream_close(stream
);
982 pthread_mutex_unlock(&stream
->lock
);
989 if (ustctl_put_subbuf(stream
->ustream
) < 0) {
990 ERR("Snapshot ustctl_put_subbuf");
993 consumer_stream_close(stream
);
995 pthread_mutex_unlock(&stream
->lock
);
1002 * Receive the metadata updates from the sessiond.
1004 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
1005 uint64_t len
, struct lttng_consumer_channel
*channel
)
1007 int ret
, ret_code
= LTTNG_OK
;
1010 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
, len
);
1012 metadata_str
= zmalloc(len
* sizeof(char));
1013 if (!metadata_str
) {
1014 PERROR("zmalloc metadata string");
1015 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
1019 /* Receive metadata string. */
1020 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
1022 /* Session daemon is dead so return gracefully. */
1028 * XXX: The consumer data lock is acquired before calling metadata cache
1029 * write which calls push metadata that MUST be protected by the consumer
1030 * lock in order to be able to check the validity of the metadata stream of
1033 * Note that this will be subject to change to better fine grained locking
1034 * and ultimately try to get rid of this global consumer data lock.
1036 pthread_mutex_lock(&consumer_data
.lock
);
1038 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
1039 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
1041 /* Unable to handle metadata. Notify session daemon. */
1042 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1044 * Skip metadata flush on write error since the offset and len might
1045 * not have been updated which could create an infinite loop below when
1046 * waiting for the metadata cache to be flushed.
1048 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1049 pthread_mutex_unlock(&consumer_data
.lock
);
1052 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1053 pthread_mutex_unlock(&consumer_data
.lock
);
1055 while (consumer_metadata_cache_flushed(channel
, offset
+ len
)) {
1056 DBG("Waiting for metadata to be flushed");
1057 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
1067 * Receive command from session daemon and process it.
1069 * Return 1 on success else a negative value or 0.
1071 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1072 int sock
, struct pollfd
*consumer_sockpoll
)
1075 enum lttng_error_code ret_code
= LTTNG_OK
;
1076 struct lttcomm_consumer_msg msg
;
1077 struct lttng_consumer_channel
*channel
= NULL
;
1079 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
1080 if (ret
!= sizeof(msg
)) {
1081 DBG("Consumer received unexpected message size %zd (expects %zu)",
1084 * The ret value might 0 meaning an orderly shutdown but this is ok
1085 * since the caller handles this.
1088 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1093 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
1095 * Notify the session daemon that the command is completed.
1097 * On transport layer error, the function call will print an error
1098 * message so handling the returned code is a bit useless since we
1099 * return an error code anyway.
1101 (void) consumer_send_status_msg(sock
, ret_code
);
1105 /* relayd needs RCU read-side lock */
1108 switch (msg
.cmd_type
) {
1109 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
1111 /* Session daemon status message are handled in the following call. */
1112 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
1113 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
1114 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
1117 case LTTNG_CONSUMER_DESTROY_RELAYD
:
1119 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
1120 struct consumer_relayd_sock_pair
*relayd
;
1122 DBG("UST consumer destroying relayd %" PRIu64
, index
);
1124 /* Get relayd reference if exists. */
1125 relayd
= consumer_find_relayd(index
);
1126 if (relayd
== NULL
) {
1127 DBG("Unable to find relayd %" PRIu64
, index
);
1128 ret_code
= LTTNG_ERR_NO_CONSUMER
;
1132 * Each relayd socket pair has a refcount of stream attached to it
1133 * which tells if the relayd is still active or not depending on the
1136 * This will set the destroy flag of the relayd object and destroy it
1137 * if the refcount reaches zero when called.
1139 * The destroy can happen either here or when a stream fd hangs up.
1142 consumer_flag_relayd_for_destroy(relayd
);
1145 goto end_msg_sessiond
;
1147 case LTTNG_CONSUMER_UPDATE_STREAM
:
1152 case LTTNG_CONSUMER_DATA_PENDING
:
1154 int ret
, is_data_pending
;
1155 uint64_t id
= msg
.u
.data_pending
.session_id
;
1157 DBG("UST consumer data pending command for id %" PRIu64
, id
);
1159 is_data_pending
= consumer_data_pending(id
);
1161 /* Send back returned value to session daemon */
1162 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
1163 sizeof(is_data_pending
));
1165 DBG("Error when sending the data pending ret code: %d", ret
);
1170 * No need to send back a status message since the data pending
1171 * returned value is the response.
1175 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
1178 struct ustctl_consumer_channel_attr attr
;
1180 /* Create a plain object and reserve a channel key. */
1181 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
1182 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
1183 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
1184 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
1185 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
1186 msg
.u
.ask_channel
.tracefile_size
,
1187 msg
.u
.ask_channel
.tracefile_count
,
1188 msg
.u
.ask_channel
.session_id_per_pid
,
1189 msg
.u
.ask_channel
.monitor
);
1191 goto end_channel_error
;
1194 /* Build channel attributes from received message. */
1195 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
1196 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
1197 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
1198 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
1199 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
1200 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
1201 attr
.output
= msg
.u
.ask_channel
.output
;
1202 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
1204 /* Translate and save channel type. */
1205 switch (msg
.u
.ask_channel
.type
) {
1206 case LTTNG_UST_CHAN_PER_CPU
:
1207 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
1208 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1210 * Set refcount to 1 for owner. Below, we will
1211 * pass ownership to the
1212 * consumer_thread_channel_poll() thread.
1214 channel
->refcount
= 1;
1216 case LTTNG_UST_CHAN_METADATA
:
1217 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
1218 attr
.type
= LTTNG_UST_CHAN_METADATA
;
1225 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
1227 goto end_channel_error
;
1230 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1231 ret
= consumer_metadata_cache_allocate(channel
);
1233 ERR("Allocating metadata cache");
1234 goto end_channel_error
;
1236 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
1237 attr
.switch_timer_interval
= 0;
1241 * Add the channel to the internal state AFTER all streams were created
1242 * and successfully sent to session daemon. This way, all streams must
1243 * be ready before this channel is visible to the threads.
1244 * If add_channel succeeds, ownership of the channel is
1245 * passed to consumer_thread_channel_poll().
1247 ret
= add_channel(channel
, ctx
);
1249 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1250 if (channel
->switch_timer_enabled
== 1) {
1251 consumer_timer_switch_stop(channel
);
1253 consumer_metadata_cache_destroy(channel
);
1255 goto end_channel_error
;
1259 * Channel and streams are now created. Inform the session daemon that
1260 * everything went well and should wait to receive the channel and
1261 * streams with ustctl API.
1263 ret
= consumer_send_status_channel(sock
, channel
);
1266 * There is probably a problem on the socket.
1273 case LTTNG_CONSUMER_GET_CHANNEL
:
1275 int ret
, relayd_err
= 0;
1276 uint64_t key
= msg
.u
.get_channel
.key
;
1277 struct lttng_consumer_channel
*channel
;
1279 channel
= consumer_find_channel(key
);
1281 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1282 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1283 goto end_msg_sessiond
;
1286 /* Send everything to sessiond. */
1287 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1291 * We were unable to send to the relayd the stream so avoid
1292 * sending back a fatal error to the thread since this is OK
1293 * and the consumer can continue its work. The above call
1294 * has sent the error status message to the sessiond.
1299 * The communicaton was broken hence there is a bad state between
1300 * the consumer and sessiond so stop everything.
1306 * In no monitor mode, the streams ownership is kept inside the channel
1307 * so don't send them to the data thread.
1309 if (!channel
->monitor
) {
1310 goto end_msg_sessiond
;
1313 ret
= send_streams_to_thread(channel
, ctx
);
1316 * If we are unable to send the stream to the thread, there is
1317 * a big problem so just stop everything.
1321 /* List MUST be empty after or else it could be reused. */
1322 assert(cds_list_empty(&channel
->streams
.head
));
1323 goto end_msg_sessiond
;
1325 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1327 uint64_t key
= msg
.u
.destroy_channel
.key
;
1330 * Only called if streams have not been sent to stream
1331 * manager thread. However, channel has been sent to
1332 * channel manager thread.
1334 notify_thread_del_channel(ctx
, key
);
1335 goto end_msg_sessiond
;
1337 case LTTNG_CONSUMER_CLOSE_METADATA
:
1341 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1346 goto end_msg_sessiond
;
1348 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1352 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1357 goto end_msg_sessiond
;
1359 case LTTNG_CONSUMER_PUSH_METADATA
:
1362 uint64_t len
= msg
.u
.push_metadata
.len
;
1363 uint64_t key
= msg
.u
.push_metadata
.key
;
1364 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1365 struct lttng_consumer_channel
*channel
;
1367 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1370 channel
= consumer_find_channel(key
);
1372 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1373 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1374 goto end_msg_sessiond
;
1377 /* Tell session daemon we are ready to receive the metadata. */
1378 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1380 /* Somehow, the session daemon is not responding anymore. */
1384 /* Wait for more data. */
1385 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1389 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1392 /* error receiving from sessiond */
1396 goto end_msg_sessiond
;
1399 case LTTNG_CONSUMER_SETUP_METADATA
:
1403 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1407 goto end_msg_sessiond
;
1409 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
1411 if (msg
.u
.snapshot_channel
.metadata
) {
1412 ret
= snapshot_metadata(msg
.u
.snapshot_channel
.key
,
1413 msg
.u
.snapshot_channel
.pathname
,
1414 msg
.u
.snapshot_channel
.relayd_id
,
1417 ERR("Snapshot metadata failed");
1418 ret_code
= LTTNG_ERR_UST_META_FAIL
;
1421 ret
= snapshot_channel(msg
.u
.snapshot_channel
.key
,
1422 msg
.u
.snapshot_channel
.pathname
,
1423 msg
.u
.snapshot_channel
.relayd_id
,
1426 ERR("Snapshot channel failed");
1427 ret_code
= LTTNG_ERR_UST_CHAN_FAIL
;
1431 ret
= consumer_send_status_msg(sock
, ret_code
);
1433 /* Somehow, the session daemon is not responding anymore. */
1446 * Return 1 to indicate success since the 0 value can be a socket
1447 * shutdown during the recv() or send() call.
1453 * The returned value here is not useful since either way we'll return 1 to
1454 * the caller because the session daemon socket management is done
1455 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1457 ret
= consumer_send_status_msg(sock
, ret_code
);
1466 * Free channel here since no one has a reference to it. We don't
1467 * free after that because a stream can store this pointer.
1469 destroy_channel(channel
);
1471 /* We have to send a status channel message indicating an error. */
1472 ret
= consumer_send_status_channel(sock
, NULL
);
1474 /* Stop everything if session daemon can not be notified. */
1481 /* This will issue a consumer stop. */
1486 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1487 * compiled out, we isolate it in this library.
1489 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1493 assert(stream
->ustream
);
1495 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1499 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1500 * compiled out, we isolate it in this library.
1502 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1505 assert(stream
->ustream
);
1507 return ustctl_get_mmap_base(stream
->ustream
);
1511 * Take a snapshot for a specific fd
1513 * Returns 0 on success, < 0 on error
1515 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1518 assert(stream
->ustream
);
1520 return ustctl_snapshot(stream
->ustream
);
1524 * Get the produced position
1526 * Returns 0 on success, < 0 on error
1528 int lttng_ustconsumer_get_produced_snapshot(
1529 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1532 assert(stream
->ustream
);
1535 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1539 * Get the consumed position
1541 * Returns 0 on success, < 0 on error
1543 int lttng_ustconsumer_get_consumed_snapshot(
1544 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1547 assert(stream
->ustream
);
1550 return ustctl_snapshot_get_consumed(stream
->ustream
, pos
);
1554 * Called when the stream signal the consumer that it has hang up.
1556 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1559 assert(stream
->ustream
);
1561 ustctl_flush_buffer(stream
->ustream
, 0);
1562 stream
->hangup_flush_done
= 1;
1565 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1568 assert(chan
->uchan
);
1570 if (chan
->switch_timer_enabled
== 1) {
1571 consumer_timer_switch_stop(chan
);
1573 consumer_metadata_cache_destroy(chan
);
1574 ustctl_destroy_channel(chan
->uchan
);
1577 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1580 assert(stream
->ustream
);
1582 if (stream
->chan
->switch_timer_enabled
== 1) {
1583 consumer_timer_switch_stop(stream
->chan
);
1585 ustctl_destroy_stream(stream
->ustream
);
1588 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1589 struct lttng_consumer_local_data
*ctx
)
1591 unsigned long len
, subbuf_size
, padding
;
1595 struct ustctl_consumer_stream
*ustream
;
1598 assert(stream
->ustream
);
1601 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1604 /* Ease our life for what's next. */
1605 ustream
= stream
->ustream
;
1607 /* We can consume the 1 byte written into the wait_fd by UST */
1608 if (!stream
->hangup_flush_done
) {
1612 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1613 } while (readlen
== -1 && errno
== EINTR
);
1614 if (readlen
== -1) {
1620 /* Get the next subbuffer */
1621 err
= ustctl_get_next_subbuf(ustream
);
1623 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1625 * This is a debug message even for single-threaded consumer,
1626 * because poll() have more relaxed criterions than get subbuf,
1627 * so get_subbuf may fail for short race windows where poll()
1628 * would issue wakeups.
1630 DBG("Reserving sub buffer failed (everything is normal, "
1631 "it is due to concurrency) [ret: %d]", err
);
1634 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1635 /* Get the full padded subbuffer size */
1636 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1639 /* Get subbuffer data size (without padding) */
1640 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1643 /* Make sure we don't get a subbuffer size bigger than the padded */
1644 assert(len
>= subbuf_size
);
1646 padding
= len
- subbuf_size
;
1647 /* write the subbuffer to the tracefile */
1648 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1650 * The mmap operation should write subbuf_size amount of data when network
1651 * streaming or the full padding (len) size when we are _not_ streaming.
1653 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1654 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1656 * Display the error but continue processing to try to release the
1657 * subbuffer. This is a DBG statement since any unexpected kill or
1658 * signal, the application gets unregistered, relayd gets closed or
1659 * anything that affects the buffer lifetime will trigger this error.
1660 * So, for the sake of the user, don't print this error since it can
1661 * happen and it is OK with the code flow.
1663 DBG("Error writing to tracefile "
1664 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1665 ret
, len
, subbuf_size
);
1667 err
= ustctl_put_next_subbuf(ustream
);
1675 * Called when a stream is created.
1677 * Return 0 on success or else a negative value.
1679 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1685 /* Don't create anything if this is set for streaming. */
1686 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
1687 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1688 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1689 stream
->uid
, stream
->gid
);
1693 stream
->out_fd
= ret
;
1694 stream
->tracefile_size_current
= 0;
1703 * Check if data is still being extracted from the buffers for a specific
1704 * stream. Consumer data lock MUST be acquired before calling this function
1705 * and the stream lock.
1707 * Return 1 if the traced data are still getting read else 0 meaning that the
1708 * data is available for trace viewer reading.
1710 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1715 assert(stream
->ustream
);
1717 DBG("UST consumer checking data pending");
1719 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1721 /* There is still data so let's put back this subbuffer. */
1722 ret
= ustctl_put_subbuf(stream
->ustream
);
1724 ret
= 1; /* Data is pending */
1728 /* Data is NOT pending so ready to be read. */
1736 * Close every metadata stream wait fd of the metadata hash table. This
1737 * function MUST be used very carefully so not to run into a race between the
1738 * metadata thread handling streams and this function closing their wait fd.
1740 * For UST, this is used when the session daemon hangs up. Its the metadata
1741 * producer so calling this is safe because we are assured that no state change
1742 * can occur in the metadata thread for the streams in the hash table.
1744 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1747 struct lttng_ht_iter iter
;
1748 struct lttng_consumer_stream
*stream
;
1750 assert(metadata_ht
);
1751 assert(metadata_ht
->ht
);
1753 DBG("UST consumer closing all metadata streams");
1756 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1758 int fd
= stream
->wait_fd
;
1761 * Whatever happens here we have to continue to try to close every
1762 * streams. Let's report at least the error on failure.
1764 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1766 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1768 DBG("Metadata wait fd %d closed", fd
);
1773 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1777 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1779 ERR("Unable to close wakeup fd");
1783 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1784 struct lttng_consumer_channel
*channel
)
1786 struct lttcomm_metadata_request_msg request
;
1787 struct lttcomm_consumer_msg msg
;
1788 enum lttng_error_code ret_code
= LTTNG_OK
;
1789 uint64_t len
, key
, offset
;
1793 assert(channel
->metadata_cache
);
1795 /* send the metadata request to sessiond */
1796 switch (consumer_data
.type
) {
1797 case LTTNG_CONSUMER64_UST
:
1798 request
.bits_per_long
= 64;
1800 case LTTNG_CONSUMER32_UST
:
1801 request
.bits_per_long
= 32;
1804 request
.bits_per_long
= 0;
1808 request
.session_id
= channel
->session_id
;
1809 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1810 request
.uid
= channel
->uid
;
1811 request
.key
= channel
->key
;
1812 DBG("Sending metadata request to sessiond, session id %" PRIu64
1813 ", per-pid %" PRIu64
,
1814 channel
->session_id
,
1815 channel
->session_id_per_pid
);
1817 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1820 ERR("Asking metadata to sessiond");
1824 /* Receive the metadata from sessiond */
1825 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1827 if (ret
!= sizeof(msg
)) {
1828 DBG("Consumer received unexpected message size %d (expects %zu)",
1830 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1832 * The ret value might 0 meaning an orderly shutdown but this is ok
1833 * since the caller handles this.
1838 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1839 /* No registry found */
1840 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1844 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1845 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1850 len
= msg
.u
.push_metadata
.len
;
1851 key
= msg
.u
.push_metadata
.key
;
1852 offset
= msg
.u
.push_metadata
.target_offset
;
1854 assert(key
== channel
->key
);
1856 DBG("No new metadata to receive for key %" PRIu64
, key
);
1859 /* Tell session daemon we are ready to receive the metadata. */
1860 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1862 if (ret
< 0 || len
== 0) {
1864 * Somehow, the session daemon is not responding anymore or there is
1865 * nothing to receive.
1870 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1871 key
, offset
, len
, channel
);
1872 if (ret_code
>= 0) {
1874 * Only send the status msg if the sessiond is alive meaning a positive
1877 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);