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
,
156 if (stream
== NULL
) {
160 * We could not find the channel. Can happen if cpu hotplug
161 * happens while tearing down.
163 DBG3("Could not find channel");
168 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
174 stream
->chan
= channel
;
178 *_alloc_ret
= alloc_ret
;
184 * Send the given stream pointer to the corresponding thread.
186 * Returns 0 on success else a negative value.
188 static int send_stream_to_thread(struct lttng_consumer_stream
*stream
,
189 struct lttng_consumer_local_data
*ctx
)
192 struct lttng_pipe
*stream_pipe
;
194 /* Get the right pipe where the stream will be sent. */
195 if (stream
->metadata_flag
) {
196 stream_pipe
= ctx
->consumer_metadata_pipe
;
198 stream_pipe
= ctx
->consumer_data_pipe
;
201 ret
= lttng_pipe_write(stream_pipe
, &stream
, sizeof(stream
));
203 ERR("Consumer write %s stream to pipe %d",
204 stream
->metadata_flag
? "metadata" : "data",
205 lttng_pipe_get_writefd(stream_pipe
));
212 * Search for a relayd object related to the stream. If found, send the stream
215 * On success, returns 0 else a negative value.
217 static int send_stream_to_relayd(struct lttng_consumer_stream
*stream
)
220 struct consumer_relayd_sock_pair
*relayd
;
224 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
225 if (relayd
!= NULL
) {
226 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
227 /* Add stream on the relayd */
228 ret
= relayd_add_stream(&relayd
->control_sock
, stream
->name
,
229 stream
->chan
->pathname
, &stream
->relayd_stream_id
,
230 stream
->chan
->tracefile_size
,
231 stream
->chan
->tracefile_count
);
232 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
236 } else if (stream
->net_seq_idx
!= (uint64_t) -1ULL) {
237 ERR("Network sequence index %" PRIu64
" unknown. Not adding stream.",
238 stream
->net_seq_idx
);
248 * Create streams for the given channel using liblttng-ust-ctl.
250 * Return 0 on success else a negative value.
252 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
253 struct lttng_consumer_local_data
*ctx
)
256 struct ustctl_consumer_stream
*ustream
;
257 struct lttng_consumer_stream
*stream
;
263 * While a stream is available from ustctl. When NULL is returned, we've
264 * reached the end of the possible stream for the channel.
266 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
269 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
271 /* Allocate consumer stream object. */
272 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
276 stream
->ustream
= ustream
;
278 * Store it so we can save multiple function calls afterwards since
279 * this value is used heavily in the stream threads. This is UST
280 * specific so this is why it's done after allocation.
282 stream
->wait_fd
= wait_fd
;
285 * Increment channel refcount since the channel reference has now been
286 * assigned in the allocation process above.
288 if (stream
->chan
->monitor
) {
289 uatomic_inc(&stream
->chan
->refcount
);
293 * Order is important this is why a list is used. On error, the caller
294 * should clean this list.
296 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
298 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
299 &stream
->max_sb_size
);
301 ERR("ustctl_get_max_subbuf_size failed for stream %s",
306 /* Do actions once stream has been received. */
307 if (ctx
->on_recv_stream
) {
308 ret
= ctx
->on_recv_stream(stream
);
314 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
315 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
317 /* Set next CPU stream. */
318 channel
->streams
.count
= ++cpu
;
320 /* Keep stream reference when creating metadata. */
321 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
322 channel
->metadata_stream
= stream
;
334 * Create an UST channel with the given attributes and send it to the session
335 * daemon using the ust ctl API.
337 * Return 0 on success or else a negative value.
339 static int create_ust_channel(struct ustctl_consumer_channel_attr
*attr
,
340 struct ustctl_consumer_channel
**chanp
)
343 struct ustctl_consumer_channel
*channel
;
348 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
349 "subbuf_size: %" PRIu64
", num_subbuf: %" PRIu64
", "
350 "switch_timer_interval: %u, read_timer_interval: %u, "
351 "output: %d, type: %d", attr
->overwrite
, attr
->subbuf_size
,
352 attr
->num_subbuf
, attr
->switch_timer_interval
,
353 attr
->read_timer_interval
, attr
->output
, attr
->type
);
355 channel
= ustctl_create_channel(attr
);
370 * Send a single given stream to the session daemon using the sock.
372 * Return 0 on success else a negative value.
374 static int send_sessiond_stream(int sock
, struct lttng_consumer_stream
*stream
)
381 DBG2("UST consumer sending stream %" PRIu64
" to sessiond", stream
->key
);
383 /* Send stream to session daemon. */
384 ret
= ustctl_send_stream_to_sessiond(sock
, stream
->ustream
);
394 * Send channel to sessiond.
396 * Return 0 on success or else a negative value.
398 static int send_sessiond_channel(int sock
,
399 struct lttng_consumer_channel
*channel
,
400 struct lttng_consumer_local_data
*ctx
, int *relayd_error
)
402 int ret
, ret_code
= LTTNG_OK
;
403 struct lttng_consumer_stream
*stream
;
409 DBG("UST consumer sending channel %s to sessiond", channel
->name
);
411 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
412 /* Try to send the stream to the relayd if one is available. */
413 ret
= send_stream_to_relayd(stream
);
416 * Flag that the relayd was the problem here probably due to a
417 * communicaton error on the socket.
422 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
426 /* Inform sessiond that we are about to send channel and streams. */
427 ret
= consumer_send_status_msg(sock
, ret_code
);
428 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
430 * Either the session daemon is not responding or the relayd died so we
436 /* Send channel to sessiond. */
437 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
442 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
447 /* The channel was sent successfully to the sessiond at this point. */
448 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
449 /* Send stream to session daemon. */
450 ret
= send_sessiond_stream(sock
, stream
);
456 /* Tell sessiond there is no more stream. */
457 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
462 DBG("UST consumer NULL stream sent to sessiond");
467 if (ret_code
!= LTTNG_OK
) {
474 * Creates a channel and streams and add the channel it to the channel internal
475 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
478 * Return 0 on success or else, a negative value is returned and the channel
479 * MUST be destroyed by consumer_del_channel().
481 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
482 struct lttng_consumer_channel
*channel
,
483 struct ustctl_consumer_channel_attr
*attr
)
492 * This value is still used by the kernel consumer since for the kernel,
493 * the stream ownership is not IN the consumer so we need to have the
494 * number of left stream that needs to be initialized so we can know when
495 * to delete the channel (see consumer.c).
497 * As for the user space tracer now, the consumer creates and sends the
498 * stream to the session daemon which only sends them to the application
499 * once every stream of a channel is received making this value useless
500 * because we they will be added to the poll thread before the application
501 * receives them. This ensures that a stream can not hang up during
502 * initilization of a channel.
504 channel
->nb_init_stream_left
= 0;
506 /* The reply msg status is handled in the following call. */
507 ret
= create_ust_channel(attr
, &channel
->uchan
);
512 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
515 * For the snapshots (no monitor), we create the metadata streams
516 * on demand, not during the channel creation.
518 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
&& !channel
->monitor
) {
523 /* Open all streams for this channel. */
524 ret
= create_ust_streams(channel
, ctx
);
534 * Send all stream of a channel to the right thread handling it.
536 * On error, return a negative value else 0 on success.
538 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
539 struct lttng_consumer_local_data
*ctx
)
542 struct lttng_consumer_stream
*stream
, *stmp
;
547 /* Send streams to the corresponding thread. */
548 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
550 /* Sending the stream to the thread. */
551 ret
= send_stream_to_thread(stream
, ctx
);
554 * If we are unable to send the stream to the thread, there is
555 * a big problem so just stop everything.
560 /* Remove node from the channel stream list. */
561 cds_list_del(&stream
->send_node
);
569 * Write metadata to the given channel using ustctl to convert the string to
571 * Called only from consumer_metadata_cache_write.
572 * The metadata cache lock MUST be acquired to write in the cache.
574 * Return 0 on success else a negative value.
576 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel
*metadata
,
577 const char *metadata_str
, uint64_t target_offset
, uint64_t len
)
582 assert(metadata_str
);
584 DBG("UST consumer writing metadata to channel %s", metadata
->name
);
586 if (!metadata
->metadata_stream
) {
591 assert(target_offset
<= metadata
->metadata_cache
->max_offset
);
592 ret
= ustctl_write_metadata_to_channel(metadata
->uchan
,
593 metadata_str
+ target_offset
, len
);
595 ERR("ustctl write metadata fail with ret %d, len %" PRIu64
, ret
, len
);
599 ustctl_flush_buffer(metadata
->metadata_stream
->ustream
, 1);
606 * Flush channel's streams using the given key to retrieve the channel.
608 * Return 0 on success else an LTTng error code.
610 static int flush_channel(uint64_t chan_key
)
613 struct lttng_consumer_channel
*channel
;
614 struct lttng_consumer_stream
*stream
;
616 struct lttng_ht_iter iter
;
618 DBG("UST consumer flush channel key %" PRIu64
, chan_key
);
621 channel
= consumer_find_channel(chan_key
);
623 ERR("UST consumer flush channel %" PRIu64
" not found", chan_key
);
624 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
628 ht
= consumer_data
.stream_per_chan_id_ht
;
630 /* For each stream of the channel id, flush it. */
631 cds_lfht_for_each_entry_duplicate(ht
->ht
,
632 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
633 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
634 ustctl_flush_buffer(stream
->ustream
, 1);
642 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
643 * RCU read side lock MUST be acquired before calling this function.
645 * Return 0 on success else an LTTng error code.
647 static int close_metadata(uint64_t chan_key
)
650 struct lttng_consumer_channel
*channel
;
652 DBG("UST consumer close metadata key %" PRIu64
, chan_key
);
654 channel
= consumer_find_channel(chan_key
);
657 * This is possible if the metadata thread has issue a delete because
658 * the endpoint point of the stream hung up. There is no way the
659 * session daemon can know about it thus use a DBG instead of an actual
662 DBG("UST consumer close metadata %" PRIu64
" not found", chan_key
);
663 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
667 pthread_mutex_lock(&consumer_data
.lock
);
669 if (cds_lfht_is_node_deleted(&channel
->node
.node
)) {
673 if (channel
->switch_timer_enabled
== 1) {
674 DBG("Deleting timer on metadata channel");
675 consumer_timer_switch_stop(channel
);
678 if (channel
->metadata_stream
) {
679 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
681 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
682 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
688 pthread_mutex_unlock(&consumer_data
.lock
);
694 * RCU read side lock MUST be acquired before calling this function.
696 * Return 0 on success else an LTTng error code.
698 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
701 struct lttng_consumer_channel
*metadata
;
703 DBG("UST consumer setup metadata key %" PRIu64
, key
);
705 metadata
= consumer_find_channel(key
);
707 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
708 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
713 * In no monitor mode, the metadata channel has no stream(s) so skip the
714 * ownership transfer to the metadata thread.
716 if (!metadata
->monitor
) {
717 DBG("Metadata channel in no monitor");
723 * Send metadata stream to relayd if one available. Availability is
724 * known if the stream is still in the list of the channel.
726 if (cds_list_empty(&metadata
->streams
.head
)) {
727 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
728 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
732 /* Send metadata stream to relayd if needed. */
733 ret
= send_stream_to_relayd(metadata
->metadata_stream
);
735 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
739 ret
= send_streams_to_thread(metadata
, ctx
);
742 * If we are unable to send the stream to the thread, there is
743 * a big problem so just stop everything.
745 ret
= LTTCOMM_CONSUMERD_FATAL
;
748 /* List MUST be empty after or else it could be reused. */
749 assert(cds_list_empty(&metadata
->streams
.head
));
756 * Delete metadata channel on error. At this point, the metadata stream can
757 * NOT be monitored by the metadata thread thus having the guarantee that
758 * the stream is still in the local stream list of the channel. This call
759 * will make sure to clean that list.
761 consumer_del_channel(metadata
);
767 * Snapshot the whole metadata.
769 * Returns 0 on success, < 0 on error
771 static int snapshot_metadata(uint64_t key
, char *path
, uint64_t relayd_id
,
772 struct lttng_consumer_local_data
*ctx
)
776 uint64_t total_len
= 0;
777 struct lttng_consumer_channel
*metadata_channel
;
778 struct lttng_consumer_stream
*metadata_stream
;
783 DBG("UST consumer snapshot metadata with key %" PRIu64
" at path %s",
788 metadata_channel
= consumer_find_channel(key
);
789 if (!metadata_channel
) {
790 ERR("UST snapshot metadata channel not found for key %lu", key
);
794 assert(!metadata_channel
->monitor
);
797 * Ask the sessiond if we have new metadata waiting and update the
798 * consumer metadata cache.
800 ret
= lttng_ustconsumer_request_metadata(ctx
, metadata_channel
);
806 * The metadata stream is NOT created in no monitor mode when the channel
807 * is created on a sessiond ask channel command.
809 ret
= create_ust_streams(metadata_channel
, ctx
);
814 metadata_stream
= metadata_channel
->metadata_stream
;
815 assert(metadata_stream
);
817 if (relayd_id
!= (uint64_t) -1ULL) {
818 metadata_stream
->net_seq_idx
= relayd_id
;
819 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
824 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
825 metadata_stream
->chan
->tracefile_size
,
826 metadata_stream
->tracefile_count_current
,
827 metadata_stream
->uid
, metadata_stream
->gid
);
831 metadata_stream
->out_fd
= ret
;
832 metadata_stream
->tracefile_size_current
= 0;
835 pthread_mutex_lock(&metadata_channel
->metadata_cache
->lock
);
836 while (total_len
< metadata_channel
->metadata_cache
->total_bytes_written
) {
838 * Write at most one packet of metadata into the channel
839 * to avoid blocking here.
841 write_len
= ustctl_write_one_packet_to_channel(metadata_channel
->uchan
,
842 metadata_channel
->metadata_cache
->data
,
843 metadata_channel
->metadata_cache
->total_bytes_written
);
845 ERR("UST consumer snapshot writing metadata packet");
849 total_len
+= write_len
;
851 DBG("Written %" PRIu64
" bytes to metadata (left: %" PRIu64
")",
853 metadata_channel
->metadata_cache
->total_bytes_written
- write_len
);
854 ustctl_flush_buffer(metadata_stream
->ustream
, 1);
855 ret
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
);
862 pthread_mutex_unlock(&metadata_channel
->metadata_cache
->lock
);
866 * Clean up the stream completly because the next snapshot will use a new
869 cds_list_del(&metadata_stream
->send_node
);
870 consumer_stream_destroy(metadata_stream
, NULL
);
871 metadata_channel
->metadata_stream
= NULL
;
879 * Take a snapshot of all the stream of a channel.
881 * Returns 0 on success, < 0 on error
883 static int snapshot_channel(uint64_t key
, char *path
, uint64_t relayd_id
,
884 struct lttng_consumer_local_data
*ctx
)
887 unsigned use_relayd
= 0;
888 unsigned long consumed_pos
, produced_pos
;
889 struct lttng_consumer_channel
*channel
;
890 struct lttng_consumer_stream
*stream
;
897 if (relayd_id
!= (uint64_t) -1ULL) {
901 channel
= consumer_find_channel(key
);
903 ERR("UST snapshot channel not found for key %lu", key
);
907 assert(!channel
->monitor
);
908 DBG("UST consumer snapshot channel %lu", key
);
910 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
911 /* Lock stream because we are about to change its state. */
912 pthread_mutex_lock(&stream
->lock
);
913 stream
->net_seq_idx
= relayd_id
;
916 ret
= consumer_send_relayd_stream(stream
, path
);
921 ret
= utils_create_stream_file(path
, stream
->name
,
922 stream
->chan
->tracefile_size
,
923 stream
->tracefile_count_current
,
924 stream
->uid
, stream
->gid
);
928 stream
->out_fd
= ret
;
929 stream
->tracefile_size_current
= 0;
931 DBG("UST consumer snapshot stream %s/%s (%" PRIu64
")", path
,
932 stream
->name
, stream
->key
);
935 ustctl_flush_buffer(stream
->ustream
, 1);
937 ret
= lttng_ustconsumer_take_snapshot(stream
);
939 ERR("Taking UST snapshot");
943 ret
= lttng_ustconsumer_get_produced_snapshot(stream
, &produced_pos
);
945 ERR("Produced UST snapshot position");
949 ret
= lttng_ustconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
951 ERR("Consumerd UST snapshot position");
955 while (consumed_pos
< produced_pos
) {
957 unsigned long len
, padded_len
;
959 DBG("UST consumer taking snapshot at pos %lu", consumed_pos
);
961 ret
= ustctl_get_subbuf(stream
->ustream
, &consumed_pos
);
963 if (ret
!= -EAGAIN
) {
964 PERROR("ustctl_get_subbuf snapshot");
965 goto error_close_stream
;
967 DBG("UST consumer get subbuf failed. Skipping it.");
968 consumed_pos
+= stream
->max_sb_size
;
972 ret
= ustctl_get_subbuf_size(stream
->ustream
, &len
);
974 ERR("Snapshot ustctl_get_subbuf_size");
975 goto error_put_subbuf
;
978 ret
= ustctl_get_padded_subbuf_size(stream
->ustream
, &padded_len
);
980 ERR("Snapshot ustctl_get_padded_subbuf_size");
981 goto error_put_subbuf
;
984 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
987 if (read_len
!= len
) {
989 goto error_put_subbuf
;
992 if (read_len
!= padded_len
) {
994 goto error_put_subbuf
;
998 ret
= ustctl_put_subbuf(stream
->ustream
);
1000 ERR("Snapshot ustctl_put_subbuf");
1001 goto error_close_stream
;
1003 consumed_pos
+= stream
->max_sb_size
;
1006 /* Simply close the stream so we can use it on the next snapshot. */
1007 consumer_stream_close(stream
);
1008 pthread_mutex_unlock(&stream
->lock
);
1015 if (ustctl_put_subbuf(stream
->ustream
) < 0) {
1016 ERR("Snapshot ustctl_put_subbuf");
1019 consumer_stream_close(stream
);
1021 pthread_mutex_unlock(&stream
->lock
);
1028 * Receive the metadata updates from the sessiond.
1030 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
1031 uint64_t len
, struct lttng_consumer_channel
*channel
)
1033 int ret
, ret_code
= LTTNG_OK
;
1036 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
, len
);
1038 metadata_str
= zmalloc(len
* sizeof(char));
1039 if (!metadata_str
) {
1040 PERROR("zmalloc metadata string");
1041 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
1045 /* Receive metadata string. */
1046 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
1048 /* Session daemon is dead so return gracefully. */
1054 * XXX: The consumer data lock is acquired before calling metadata cache
1055 * write which calls push metadata that MUST be protected by the consumer
1056 * lock in order to be able to check the validity of the metadata stream of
1059 * Note that this will be subject to change to better fine grained locking
1060 * and ultimately try to get rid of this global consumer data lock.
1062 pthread_mutex_lock(&consumer_data
.lock
);
1064 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
1065 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
1067 /* Unable to handle metadata. Notify session daemon. */
1068 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1070 * Skip metadata flush on write error since the offset and len might
1071 * not have been updated which could create an infinite loop below when
1072 * waiting for the metadata cache to be flushed.
1074 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1075 pthread_mutex_unlock(&consumer_data
.lock
);
1078 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1079 pthread_mutex_unlock(&consumer_data
.lock
);
1081 while (consumer_metadata_cache_flushed(channel
, offset
+ len
)) {
1082 DBG("Waiting for metadata to be flushed");
1083 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
1093 * Receive command from session daemon and process it.
1095 * Return 1 on success else a negative value or 0.
1097 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1098 int sock
, struct pollfd
*consumer_sockpoll
)
1101 enum lttng_error_code ret_code
= LTTNG_OK
;
1102 struct lttcomm_consumer_msg msg
;
1103 struct lttng_consumer_channel
*channel
= NULL
;
1105 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
1106 if (ret
!= sizeof(msg
)) {
1107 DBG("Consumer received unexpected message size %zd (expects %zu)",
1109 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1111 * The ret value might 0 meaning an orderly shutdown but this is ok
1112 * since the caller handles this.
1119 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
1121 * Notify the session daemon that the command is completed.
1123 * On transport layer error, the function call will print an error
1124 * message so handling the returned code is a bit useless since we
1125 * return an error code anyway.
1127 (void) consumer_send_status_msg(sock
, ret_code
);
1131 /* relayd needs RCU read-side lock */
1134 switch (msg
.cmd_type
) {
1135 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
1137 /* Session daemon status message are handled in the following call. */
1138 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
1139 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
1140 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
1143 case LTTNG_CONSUMER_DESTROY_RELAYD
:
1145 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
1146 struct consumer_relayd_sock_pair
*relayd
;
1148 DBG("UST consumer destroying relayd %" PRIu64
, index
);
1150 /* Get relayd reference if exists. */
1151 relayd
= consumer_find_relayd(index
);
1152 if (relayd
== NULL
) {
1153 DBG("Unable to find relayd %" PRIu64
, index
);
1154 ret_code
= LTTNG_ERR_NO_CONSUMER
;
1158 * Each relayd socket pair has a refcount of stream attached to it
1159 * which tells if the relayd is still active or not depending on the
1162 * This will set the destroy flag of the relayd object and destroy it
1163 * if the refcount reaches zero when called.
1165 * The destroy can happen either here or when a stream fd hangs up.
1168 consumer_flag_relayd_for_destroy(relayd
);
1171 goto end_msg_sessiond
;
1173 case LTTNG_CONSUMER_UPDATE_STREAM
:
1178 case LTTNG_CONSUMER_DATA_PENDING
:
1180 int ret
, is_data_pending
;
1181 uint64_t id
= msg
.u
.data_pending
.session_id
;
1183 DBG("UST consumer data pending command for id %" PRIu64
, id
);
1185 is_data_pending
= consumer_data_pending(id
);
1187 /* Send back returned value to session daemon */
1188 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
1189 sizeof(is_data_pending
));
1191 DBG("Error when sending the data pending ret code: %d", ret
);
1196 * No need to send back a status message since the data pending
1197 * returned value is the response.
1201 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
1204 struct ustctl_consumer_channel_attr attr
;
1206 /* Create a plain object and reserve a channel key. */
1207 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
1208 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
1209 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
1210 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
1211 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
1212 msg
.u
.ask_channel
.tracefile_size
,
1213 msg
.u
.ask_channel
.tracefile_count
,
1214 msg
.u
.ask_channel
.session_id_per_pid
,
1215 msg
.u
.ask_channel
.monitor
);
1217 goto end_channel_error
;
1220 /* Build channel attributes from received message. */
1221 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
1222 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
1223 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
1224 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
1225 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
1226 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
1227 attr
.output
= msg
.u
.ask_channel
.output
;
1228 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
1230 /* Translate and save channel type. */
1231 switch (msg
.u
.ask_channel
.type
) {
1232 case LTTNG_UST_CHAN_PER_CPU
:
1233 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
1234 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1236 * Set refcount to 1 for owner. Below, we will
1237 * pass ownership to the
1238 * consumer_thread_channel_poll() thread.
1240 channel
->refcount
= 1;
1242 case LTTNG_UST_CHAN_METADATA
:
1243 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
1244 attr
.type
= LTTNG_UST_CHAN_METADATA
;
1251 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
1253 goto end_channel_error
;
1256 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1257 ret
= consumer_metadata_cache_allocate(channel
);
1259 ERR("Allocating metadata cache");
1260 goto end_channel_error
;
1262 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
1263 attr
.switch_timer_interval
= 0;
1267 * Add the channel to the internal state AFTER all streams were created
1268 * and successfully sent to session daemon. This way, all streams must
1269 * be ready before this channel is visible to the threads.
1270 * If add_channel succeeds, ownership of the channel is
1271 * passed to consumer_thread_channel_poll().
1273 ret
= add_channel(channel
, ctx
);
1275 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1276 if (channel
->switch_timer_enabled
== 1) {
1277 consumer_timer_switch_stop(channel
);
1279 consumer_metadata_cache_destroy(channel
);
1281 goto end_channel_error
;
1285 * Channel and streams are now created. Inform the session daemon that
1286 * everything went well and should wait to receive the channel and
1287 * streams with ustctl API.
1289 ret
= consumer_send_status_channel(sock
, channel
);
1292 * There is probably a problem on the socket.
1299 case LTTNG_CONSUMER_GET_CHANNEL
:
1301 int ret
, relayd_err
= 0;
1302 uint64_t key
= msg
.u
.get_channel
.key
;
1303 struct lttng_consumer_channel
*channel
;
1305 channel
= consumer_find_channel(key
);
1307 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1308 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1309 goto end_msg_sessiond
;
1312 /* Send everything to sessiond. */
1313 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1317 * We were unable to send to the relayd the stream so avoid
1318 * sending back a fatal error to the thread since this is OK
1319 * and the consumer can continue its work. The above call
1320 * has sent the error status message to the sessiond.
1325 * The communicaton was broken hence there is a bad state between
1326 * the consumer and sessiond so stop everything.
1332 * In no monitor mode, the streams ownership is kept inside the channel
1333 * so don't send them to the data thread.
1335 if (!channel
->monitor
) {
1336 goto end_msg_sessiond
;
1339 ret
= send_streams_to_thread(channel
, ctx
);
1342 * If we are unable to send the stream to the thread, there is
1343 * a big problem so just stop everything.
1347 /* List MUST be empty after or else it could be reused. */
1348 assert(cds_list_empty(&channel
->streams
.head
));
1349 goto end_msg_sessiond
;
1351 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1353 uint64_t key
= msg
.u
.destroy_channel
.key
;
1356 * Only called if streams have not been sent to stream
1357 * manager thread. However, channel has been sent to
1358 * channel manager thread.
1360 notify_thread_del_channel(ctx
, key
);
1361 goto end_msg_sessiond
;
1363 case LTTNG_CONSUMER_CLOSE_METADATA
:
1367 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1372 goto end_msg_sessiond
;
1374 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1378 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1383 goto end_msg_sessiond
;
1385 case LTTNG_CONSUMER_PUSH_METADATA
:
1388 uint64_t len
= msg
.u
.push_metadata
.len
;
1389 uint64_t key
= msg
.u
.push_metadata
.key
;
1390 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1391 struct lttng_consumer_channel
*channel
;
1393 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1396 channel
= consumer_find_channel(key
);
1398 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1399 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1400 goto end_msg_sessiond
;
1403 /* Tell session daemon we are ready to receive the metadata. */
1404 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1406 /* Somehow, the session daemon is not responding anymore. */
1410 /* Wait for more data. */
1411 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1415 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1418 /* error receiving from sessiond */
1422 goto end_msg_sessiond
;
1425 case LTTNG_CONSUMER_SETUP_METADATA
:
1429 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1433 goto end_msg_sessiond
;
1435 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
1437 if (msg
.u
.snapshot_channel
.metadata
) {
1438 ret
= snapshot_metadata(msg
.u
.snapshot_channel
.key
,
1439 msg
.u
.snapshot_channel
.pathname
,
1440 msg
.u
.snapshot_channel
.relayd_id
,
1443 ERR("Snapshot metadata failed");
1444 ret_code
= LTTNG_ERR_UST_META_FAIL
;
1447 ret
= snapshot_channel(msg
.u
.snapshot_channel
.key
,
1448 msg
.u
.snapshot_channel
.pathname
,
1449 msg
.u
.snapshot_channel
.relayd_id
,
1452 ERR("Snapshot channel failed");
1453 ret_code
= LTTNG_ERR_UST_CHAN_FAIL
;
1457 ret
= consumer_send_status_msg(sock
, ret_code
);
1459 /* Somehow, the session daemon is not responding anymore. */
1472 * Return 1 to indicate success since the 0 value can be a socket
1473 * shutdown during the recv() or send() call.
1479 * The returned value here is not useful since either way we'll return 1 to
1480 * the caller because the session daemon socket management is done
1481 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1483 ret
= consumer_send_status_msg(sock
, ret_code
);
1492 * Free channel here since no one has a reference to it. We don't
1493 * free after that because a stream can store this pointer.
1495 destroy_channel(channel
);
1497 /* We have to send a status channel message indicating an error. */
1498 ret
= consumer_send_status_channel(sock
, NULL
);
1500 /* Stop everything if session daemon can not be notified. */
1507 /* This will issue a consumer stop. */
1512 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1513 * compiled out, we isolate it in this library.
1515 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1519 assert(stream
->ustream
);
1521 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1525 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1526 * compiled out, we isolate it in this library.
1528 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1531 assert(stream
->ustream
);
1533 return ustctl_get_mmap_base(stream
->ustream
);
1537 * Take a snapshot for a specific fd
1539 * Returns 0 on success, < 0 on error
1541 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1544 assert(stream
->ustream
);
1546 return ustctl_snapshot(stream
->ustream
);
1550 * Get the produced position
1552 * Returns 0 on success, < 0 on error
1554 int lttng_ustconsumer_get_produced_snapshot(
1555 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1558 assert(stream
->ustream
);
1561 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1565 * Get the consumed position
1567 * Returns 0 on success, < 0 on error
1569 int lttng_ustconsumer_get_consumed_snapshot(
1570 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1573 assert(stream
->ustream
);
1576 return ustctl_snapshot_get_consumed(stream
->ustream
, pos
);
1580 * Called when the stream signal the consumer that it has hang up.
1582 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1585 assert(stream
->ustream
);
1587 ustctl_flush_buffer(stream
->ustream
, 0);
1588 stream
->hangup_flush_done
= 1;
1591 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1594 assert(chan
->uchan
);
1596 if (chan
->switch_timer_enabled
== 1) {
1597 consumer_timer_switch_stop(chan
);
1599 consumer_metadata_cache_destroy(chan
);
1600 ustctl_destroy_channel(chan
->uchan
);
1603 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1606 assert(stream
->ustream
);
1608 if (stream
->chan
->switch_timer_enabled
== 1) {
1609 consumer_timer_switch_stop(stream
->chan
);
1611 ustctl_destroy_stream(stream
->ustream
);
1614 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1615 struct lttng_consumer_local_data
*ctx
)
1617 unsigned long len
, subbuf_size
, padding
;
1621 struct ustctl_consumer_stream
*ustream
;
1624 assert(stream
->ustream
);
1627 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1630 /* Ease our life for what's next. */
1631 ustream
= stream
->ustream
;
1633 /* We can consume the 1 byte written into the wait_fd by UST */
1634 if (!stream
->hangup_flush_done
) {
1638 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1639 } while (readlen
== -1 && errno
== EINTR
);
1640 if (readlen
== -1) {
1646 /* Get the next subbuffer */
1647 err
= ustctl_get_next_subbuf(ustream
);
1649 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1651 * This is a debug message even for single-threaded consumer,
1652 * because poll() have more relaxed criterions than get subbuf,
1653 * so get_subbuf may fail for short race windows where poll()
1654 * would issue wakeups.
1656 DBG("Reserving sub buffer failed (everything is normal, "
1657 "it is due to concurrency) [ret: %d]", err
);
1660 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1661 /* Get the full padded subbuffer size */
1662 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1665 /* Get subbuffer data size (without padding) */
1666 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1669 /* Make sure we don't get a subbuffer size bigger than the padded */
1670 assert(len
>= subbuf_size
);
1672 padding
= len
- subbuf_size
;
1673 /* write the subbuffer to the tracefile */
1674 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1676 * The mmap operation should write subbuf_size amount of data when network
1677 * streaming or the full padding (len) size when we are _not_ streaming.
1679 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1680 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1682 * Display the error but continue processing to try to release the
1683 * subbuffer. This is a DBG statement since any unexpected kill or
1684 * signal, the application gets unregistered, relayd gets closed or
1685 * anything that affects the buffer lifetime will trigger this error.
1686 * So, for the sake of the user, don't print this error since it can
1687 * happen and it is OK with the code flow.
1689 DBG("Error writing to tracefile "
1690 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1691 ret
, len
, subbuf_size
);
1693 err
= ustctl_put_next_subbuf(ustream
);
1701 * Called when a stream is created.
1703 * Return 0 on success or else a negative value.
1705 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1711 /* Don't create anything if this is set for streaming. */
1712 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
1713 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1714 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1715 stream
->uid
, stream
->gid
);
1719 stream
->out_fd
= ret
;
1720 stream
->tracefile_size_current
= 0;
1729 * Check if data is still being extracted from the buffers for a specific
1730 * stream. Consumer data lock MUST be acquired before calling this function
1731 * and the stream lock.
1733 * Return 1 if the traced data are still getting read else 0 meaning that the
1734 * data is available for trace viewer reading.
1736 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1741 assert(stream
->ustream
);
1743 DBG("UST consumer checking data pending");
1745 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1747 /* There is still data so let's put back this subbuffer. */
1748 ret
= ustctl_put_subbuf(stream
->ustream
);
1750 ret
= 1; /* Data is pending */
1754 /* Data is NOT pending so ready to be read. */
1762 * Close every metadata stream wait fd of the metadata hash table. This
1763 * function MUST be used very carefully so not to run into a race between the
1764 * metadata thread handling streams and this function closing their wait fd.
1766 * For UST, this is used when the session daemon hangs up. Its the metadata
1767 * producer so calling this is safe because we are assured that no state change
1768 * can occur in the metadata thread for the streams in the hash table.
1770 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1773 struct lttng_ht_iter iter
;
1774 struct lttng_consumer_stream
*stream
;
1776 assert(metadata_ht
);
1777 assert(metadata_ht
->ht
);
1779 DBG("UST consumer closing all metadata streams");
1782 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1784 int fd
= stream
->wait_fd
;
1787 * Whatever happens here we have to continue to try to close every
1788 * streams. Let's report at least the error on failure.
1790 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1792 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1794 DBG("Metadata wait fd %d closed", fd
);
1799 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1803 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1805 ERR("Unable to close wakeup fd");
1809 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1810 struct lttng_consumer_channel
*channel
)
1812 struct lttcomm_metadata_request_msg request
;
1813 struct lttcomm_consumer_msg msg
;
1814 enum lttng_error_code ret_code
= LTTNG_OK
;
1815 uint64_t len
, key
, offset
;
1819 assert(channel
->metadata_cache
);
1821 /* send the metadata request to sessiond */
1822 switch (consumer_data
.type
) {
1823 case LTTNG_CONSUMER64_UST
:
1824 request
.bits_per_long
= 64;
1826 case LTTNG_CONSUMER32_UST
:
1827 request
.bits_per_long
= 32;
1830 request
.bits_per_long
= 0;
1834 request
.session_id
= channel
->session_id
;
1835 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1836 request
.uid
= channel
->uid
;
1837 request
.key
= channel
->key
;
1838 DBG("Sending metadata request to sessiond, session id %" PRIu64
1839 ", per-pid %" PRIu64
,
1840 channel
->session_id
,
1841 channel
->session_id_per_pid
);
1843 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1846 ERR("Asking metadata to sessiond");
1850 /* Receive the metadata from sessiond */
1851 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1853 if (ret
!= sizeof(msg
)) {
1854 DBG("Consumer received unexpected message size %d (expects %zu)",
1856 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1858 * The ret value might 0 meaning an orderly shutdown but this is ok
1859 * since the caller handles this.
1864 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1865 /* No registry found */
1866 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1870 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1871 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1876 len
= msg
.u
.push_metadata
.len
;
1877 key
= msg
.u
.push_metadata
.key
;
1878 offset
= msg
.u
.push_metadata
.target_offset
;
1880 assert(key
== channel
->key
);
1882 DBG("No new metadata to receive for key %" PRIu64
, key
);
1885 /* Tell session daemon we are ready to receive the metadata. */
1886 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1888 if (ret
< 0 || len
== 0) {
1890 * Somehow, the session daemon is not responding anymore or there is
1891 * nothing to receive.
1896 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1897 key
, offset
, len
, channel
);
1898 if (ret_code
>= 0) {
1900 * Only send the status msg if the sessiond is alive meaning a positive
1903 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);