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
;
729 goto error_no_stream
;
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 cds_list_del(&metadata
->metadata_stream
->send_node
);
762 consumer_stream_destroy(metadata
->metadata_stream
, NULL
);
769 * Snapshot the whole metadata.
771 * Returns 0 on success, < 0 on error
773 static int snapshot_metadata(uint64_t key
, char *path
, uint64_t relayd_id
,
774 struct lttng_consumer_local_data
*ctx
)
778 uint64_t total_len
= 0;
779 struct lttng_consumer_channel
*metadata_channel
;
780 struct lttng_consumer_stream
*metadata_stream
;
785 DBG("UST consumer snapshot metadata with key %" PRIu64
" at path %s",
790 metadata_channel
= consumer_find_channel(key
);
791 if (!metadata_channel
) {
792 ERR("UST snapshot metadata channel not found for key %lu", key
);
796 assert(!metadata_channel
->monitor
);
799 * Ask the sessiond if we have new metadata waiting and update the
800 * consumer metadata cache.
802 ret
= lttng_ustconsumer_request_metadata(ctx
, metadata_channel
);
808 * The metadata stream is NOT created in no monitor mode when the channel
809 * is created on a sessiond ask channel command.
811 ret
= create_ust_streams(metadata_channel
, ctx
);
816 metadata_stream
= metadata_channel
->metadata_stream
;
817 assert(metadata_stream
);
819 if (relayd_id
!= (uint64_t) -1ULL) {
820 metadata_stream
->net_seq_idx
= relayd_id
;
821 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
826 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
827 metadata_stream
->chan
->tracefile_size
,
828 metadata_stream
->tracefile_count_current
,
829 metadata_stream
->uid
, metadata_stream
->gid
);
833 metadata_stream
->out_fd
= ret
;
834 metadata_stream
->tracefile_size_current
= 0;
837 pthread_mutex_lock(&metadata_channel
->metadata_cache
->lock
);
838 while (total_len
< metadata_channel
->metadata_cache
->total_bytes_written
) {
840 * Write at most one packet of metadata into the channel
841 * to avoid blocking here.
843 write_len
= ustctl_write_one_packet_to_channel(metadata_channel
->uchan
,
844 metadata_channel
->metadata_cache
->data
,
845 metadata_channel
->metadata_cache
->total_bytes_written
);
847 ERR("UST consumer snapshot writing metadata packet");
851 total_len
+= write_len
;
853 DBG("Written %" PRIu64
" bytes to metadata (left: %" PRIu64
")",
855 metadata_channel
->metadata_cache
->total_bytes_written
- write_len
);
856 ustctl_flush_buffer(metadata_stream
->ustream
, 1);
857 ret
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
);
864 pthread_mutex_unlock(&metadata_channel
->metadata_cache
->lock
);
868 * Clean up the stream completly because the next snapshot will use a new
871 cds_list_del(&metadata_stream
->send_node
);
872 consumer_stream_destroy(metadata_stream
, NULL
);
873 metadata_channel
->metadata_stream
= NULL
;
881 * Take a snapshot of all the stream of a channel.
883 * Returns 0 on success, < 0 on error
885 static int snapshot_channel(uint64_t key
, char *path
, uint64_t relayd_id
,
886 struct lttng_consumer_local_data
*ctx
)
889 unsigned use_relayd
= 0;
890 unsigned long consumed_pos
, produced_pos
;
891 struct lttng_consumer_channel
*channel
;
892 struct lttng_consumer_stream
*stream
;
899 if (relayd_id
!= (uint64_t) -1ULL) {
903 channel
= consumer_find_channel(key
);
905 ERR("UST snapshot channel not found for key %lu", key
);
909 assert(!channel
->monitor
);
910 DBG("UST consumer snapshot channel %lu", key
);
912 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
913 /* Lock stream because we are about to change its state. */
914 pthread_mutex_lock(&stream
->lock
);
915 stream
->net_seq_idx
= relayd_id
;
918 ret
= consumer_send_relayd_stream(stream
, path
);
923 ret
= utils_create_stream_file(path
, stream
->name
,
924 stream
->chan
->tracefile_size
,
925 stream
->tracefile_count_current
,
926 stream
->uid
, stream
->gid
);
930 stream
->out_fd
= ret
;
931 stream
->tracefile_size_current
= 0;
933 DBG("UST consumer snapshot stream %s/%s (%" PRIu64
")", path
,
934 stream
->name
, stream
->key
);
937 ustctl_flush_buffer(stream
->ustream
, 1);
939 ret
= lttng_ustconsumer_take_snapshot(stream
);
941 ERR("Taking UST snapshot");
945 ret
= lttng_ustconsumer_get_produced_snapshot(stream
, &produced_pos
);
947 ERR("Produced UST snapshot position");
951 ret
= lttng_ustconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
953 ERR("Consumerd UST snapshot position");
957 while (consumed_pos
< produced_pos
) {
959 unsigned long len
, padded_len
;
961 DBG("UST consumer taking snapshot at pos %lu", consumed_pos
);
963 ret
= ustctl_get_subbuf(stream
->ustream
, &consumed_pos
);
965 if (ret
!= -EAGAIN
) {
966 PERROR("ustctl_get_subbuf snapshot");
967 goto error_close_stream
;
969 DBG("UST consumer get subbuf failed. Skipping it.");
970 consumed_pos
+= stream
->max_sb_size
;
974 ret
= ustctl_get_subbuf_size(stream
->ustream
, &len
);
976 ERR("Snapshot ustctl_get_subbuf_size");
977 goto error_put_subbuf
;
980 ret
= ustctl_get_padded_subbuf_size(stream
->ustream
, &padded_len
);
982 ERR("Snapshot ustctl_get_padded_subbuf_size");
983 goto error_put_subbuf
;
986 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
989 if (read_len
!= len
) {
991 goto error_put_subbuf
;
994 if (read_len
!= padded_len
) {
996 goto error_put_subbuf
;
1000 ret
= ustctl_put_subbuf(stream
->ustream
);
1002 ERR("Snapshot ustctl_put_subbuf");
1003 goto error_close_stream
;
1005 consumed_pos
+= stream
->max_sb_size
;
1008 /* Simply close the stream so we can use it on the next snapshot. */
1009 consumer_stream_close(stream
);
1010 pthread_mutex_unlock(&stream
->lock
);
1017 if (ustctl_put_subbuf(stream
->ustream
) < 0) {
1018 ERR("Snapshot ustctl_put_subbuf");
1021 consumer_stream_close(stream
);
1023 pthread_mutex_unlock(&stream
->lock
);
1030 * Receive the metadata updates from the sessiond.
1032 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
1033 uint64_t len
, struct lttng_consumer_channel
*channel
)
1035 int ret
, ret_code
= LTTNG_OK
;
1038 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
, len
);
1040 metadata_str
= zmalloc(len
* sizeof(char));
1041 if (!metadata_str
) {
1042 PERROR("zmalloc metadata string");
1043 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
1047 /* Receive metadata string. */
1048 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
1050 /* Session daemon is dead so return gracefully. */
1056 * XXX: The consumer data lock is acquired before calling metadata cache
1057 * write which calls push metadata that MUST be protected by the consumer
1058 * lock in order to be able to check the validity of the metadata stream of
1061 * Note that this will be subject to change to better fine grained locking
1062 * and ultimately try to get rid of this global consumer data lock.
1064 pthread_mutex_lock(&consumer_data
.lock
);
1066 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
1067 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
1069 /* Unable to handle metadata. Notify session daemon. */
1070 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1072 * Skip metadata flush on write error since the offset and len might
1073 * not have been updated which could create an infinite loop below when
1074 * waiting for the metadata cache to be flushed.
1076 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1077 pthread_mutex_unlock(&consumer_data
.lock
);
1080 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1081 pthread_mutex_unlock(&consumer_data
.lock
);
1083 while (consumer_metadata_cache_flushed(channel
, offset
+ len
)) {
1084 DBG("Waiting for metadata to be flushed");
1085 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
1095 * Receive command from session daemon and process it.
1097 * Return 1 on success else a negative value or 0.
1099 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1100 int sock
, struct pollfd
*consumer_sockpoll
)
1103 enum lttng_error_code ret_code
= LTTNG_OK
;
1104 struct lttcomm_consumer_msg msg
;
1105 struct lttng_consumer_channel
*channel
= NULL
;
1107 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
1108 if (ret
!= sizeof(msg
)) {
1109 DBG("Consumer received unexpected message size %zd (expects %zu)",
1111 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1113 * The ret value might 0 meaning an orderly shutdown but this is ok
1114 * since the caller handles this.
1121 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
1123 * Notify the session daemon that the command is completed.
1125 * On transport layer error, the function call will print an error
1126 * message so handling the returned code is a bit useless since we
1127 * return an error code anyway.
1129 (void) consumer_send_status_msg(sock
, ret_code
);
1133 /* relayd needs RCU read-side lock */
1136 switch (msg
.cmd_type
) {
1137 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
1139 /* Session daemon status message are handled in the following call. */
1140 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
1141 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
1142 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
1145 case LTTNG_CONSUMER_DESTROY_RELAYD
:
1147 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
1148 struct consumer_relayd_sock_pair
*relayd
;
1150 DBG("UST consumer destroying relayd %" PRIu64
, index
);
1152 /* Get relayd reference if exists. */
1153 relayd
= consumer_find_relayd(index
);
1154 if (relayd
== NULL
) {
1155 DBG("Unable to find relayd %" PRIu64
, index
);
1156 ret_code
= LTTNG_ERR_NO_CONSUMER
;
1160 * Each relayd socket pair has a refcount of stream attached to it
1161 * which tells if the relayd is still active or not depending on the
1164 * This will set the destroy flag of the relayd object and destroy it
1165 * if the refcount reaches zero when called.
1167 * The destroy can happen either here or when a stream fd hangs up.
1170 consumer_flag_relayd_for_destroy(relayd
);
1173 goto end_msg_sessiond
;
1175 case LTTNG_CONSUMER_UPDATE_STREAM
:
1180 case LTTNG_CONSUMER_DATA_PENDING
:
1182 int ret
, is_data_pending
;
1183 uint64_t id
= msg
.u
.data_pending
.session_id
;
1185 DBG("UST consumer data pending command for id %" PRIu64
, id
);
1187 is_data_pending
= consumer_data_pending(id
);
1189 /* Send back returned value to session daemon */
1190 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
1191 sizeof(is_data_pending
));
1193 DBG("Error when sending the data pending ret code: %d", ret
);
1198 * No need to send back a status message since the data pending
1199 * returned value is the response.
1203 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
1206 struct ustctl_consumer_channel_attr attr
;
1208 /* Create a plain object and reserve a channel key. */
1209 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
1210 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
1211 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
1212 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
1213 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
1214 msg
.u
.ask_channel
.tracefile_size
,
1215 msg
.u
.ask_channel
.tracefile_count
,
1216 msg
.u
.ask_channel
.session_id_per_pid
,
1217 msg
.u
.ask_channel
.monitor
);
1219 goto end_channel_error
;
1222 /* Build channel attributes from received message. */
1223 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
1224 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
1225 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
1226 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
1227 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
1228 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
1229 attr
.output
= msg
.u
.ask_channel
.output
;
1230 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
1232 /* Translate and save channel type. */
1233 switch (msg
.u
.ask_channel
.type
) {
1234 case LTTNG_UST_CHAN_PER_CPU
:
1235 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
1236 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1238 * Set refcount to 1 for owner. Below, we will
1239 * pass ownership to the
1240 * consumer_thread_channel_poll() thread.
1242 channel
->refcount
= 1;
1244 case LTTNG_UST_CHAN_METADATA
:
1245 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
1246 attr
.type
= LTTNG_UST_CHAN_METADATA
;
1253 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
1255 goto end_channel_error
;
1258 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1259 ret
= consumer_metadata_cache_allocate(channel
);
1261 ERR("Allocating metadata cache");
1262 goto end_channel_error
;
1264 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
1265 attr
.switch_timer_interval
= 0;
1269 * Add the channel to the internal state AFTER all streams were created
1270 * and successfully sent to session daemon. This way, all streams must
1271 * be ready before this channel is visible to the threads.
1272 * If add_channel succeeds, ownership of the channel is
1273 * passed to consumer_thread_channel_poll().
1275 ret
= add_channel(channel
, ctx
);
1277 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1278 if (channel
->switch_timer_enabled
== 1) {
1279 consumer_timer_switch_stop(channel
);
1281 consumer_metadata_cache_destroy(channel
);
1283 goto end_channel_error
;
1287 * Channel and streams are now created. Inform the session daemon that
1288 * everything went well and should wait to receive the channel and
1289 * streams with ustctl API.
1291 ret
= consumer_send_status_channel(sock
, channel
);
1294 * There is probably a problem on the socket.
1301 case LTTNG_CONSUMER_GET_CHANNEL
:
1303 int ret
, relayd_err
= 0;
1304 uint64_t key
= msg
.u
.get_channel
.key
;
1305 struct lttng_consumer_channel
*channel
;
1307 channel
= consumer_find_channel(key
);
1309 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1310 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1311 goto end_msg_sessiond
;
1314 /* Send everything to sessiond. */
1315 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1319 * We were unable to send to the relayd the stream so avoid
1320 * sending back a fatal error to the thread since this is OK
1321 * and the consumer can continue its work. The above call
1322 * has sent the error status message to the sessiond.
1327 * The communicaton was broken hence there is a bad state between
1328 * the consumer and sessiond so stop everything.
1334 * In no monitor mode, the streams ownership is kept inside the channel
1335 * so don't send them to the data thread.
1337 if (!channel
->monitor
) {
1338 goto end_msg_sessiond
;
1341 ret
= send_streams_to_thread(channel
, ctx
);
1344 * If we are unable to send the stream to the thread, there is
1345 * a big problem so just stop everything.
1349 /* List MUST be empty after or else it could be reused. */
1350 assert(cds_list_empty(&channel
->streams
.head
));
1351 goto end_msg_sessiond
;
1353 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1355 uint64_t key
= msg
.u
.destroy_channel
.key
;
1358 * Only called if streams have not been sent to stream
1359 * manager thread. However, channel has been sent to
1360 * channel manager thread.
1362 notify_thread_del_channel(ctx
, key
);
1363 goto end_msg_sessiond
;
1365 case LTTNG_CONSUMER_CLOSE_METADATA
:
1369 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1374 goto end_msg_sessiond
;
1376 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1380 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1385 goto end_msg_sessiond
;
1387 case LTTNG_CONSUMER_PUSH_METADATA
:
1390 uint64_t len
= msg
.u
.push_metadata
.len
;
1391 uint64_t key
= msg
.u
.push_metadata
.key
;
1392 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1393 struct lttng_consumer_channel
*channel
;
1395 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1398 channel
= consumer_find_channel(key
);
1400 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1401 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1402 goto end_msg_sessiond
;
1405 /* Tell session daemon we are ready to receive the metadata. */
1406 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1408 /* Somehow, the session daemon is not responding anymore. */
1412 /* Wait for more data. */
1413 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1417 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1420 /* error receiving from sessiond */
1424 goto end_msg_sessiond
;
1427 case LTTNG_CONSUMER_SETUP_METADATA
:
1431 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1435 goto end_msg_sessiond
;
1437 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
1439 if (msg
.u
.snapshot_channel
.metadata
) {
1440 ret
= snapshot_metadata(msg
.u
.snapshot_channel
.key
,
1441 msg
.u
.snapshot_channel
.pathname
,
1442 msg
.u
.snapshot_channel
.relayd_id
,
1445 ERR("Snapshot metadata failed");
1446 ret_code
= LTTNG_ERR_UST_META_FAIL
;
1449 ret
= snapshot_channel(msg
.u
.snapshot_channel
.key
,
1450 msg
.u
.snapshot_channel
.pathname
,
1451 msg
.u
.snapshot_channel
.relayd_id
,
1454 ERR("Snapshot channel failed");
1455 ret_code
= LTTNG_ERR_UST_CHAN_FAIL
;
1459 ret
= consumer_send_status_msg(sock
, ret_code
);
1461 /* Somehow, the session daemon is not responding anymore. */
1474 * Return 1 to indicate success since the 0 value can be a socket
1475 * shutdown during the recv() or send() call.
1481 * The returned value here is not useful since either way we'll return 1 to
1482 * the caller because the session daemon socket management is done
1483 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1485 ret
= consumer_send_status_msg(sock
, ret_code
);
1494 * Free channel here since no one has a reference to it. We don't
1495 * free after that because a stream can store this pointer.
1497 destroy_channel(channel
);
1499 /* We have to send a status channel message indicating an error. */
1500 ret
= consumer_send_status_channel(sock
, NULL
);
1502 /* Stop everything if session daemon can not be notified. */
1509 /* This will issue a consumer stop. */
1514 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1515 * compiled out, we isolate it in this library.
1517 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1521 assert(stream
->ustream
);
1523 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1527 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1528 * compiled out, we isolate it in this library.
1530 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1533 assert(stream
->ustream
);
1535 return ustctl_get_mmap_base(stream
->ustream
);
1539 * Take a snapshot for a specific fd
1541 * Returns 0 on success, < 0 on error
1543 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1546 assert(stream
->ustream
);
1548 return ustctl_snapshot(stream
->ustream
);
1552 * Get the produced position
1554 * Returns 0 on success, < 0 on error
1556 int lttng_ustconsumer_get_produced_snapshot(
1557 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1560 assert(stream
->ustream
);
1563 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1567 * Get the consumed position
1569 * Returns 0 on success, < 0 on error
1571 int lttng_ustconsumer_get_consumed_snapshot(
1572 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1575 assert(stream
->ustream
);
1578 return ustctl_snapshot_get_consumed(stream
->ustream
, pos
);
1582 * Called when the stream signal the consumer that it has hang up.
1584 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1587 assert(stream
->ustream
);
1589 ustctl_flush_buffer(stream
->ustream
, 0);
1590 stream
->hangup_flush_done
= 1;
1593 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1596 assert(chan
->uchan
);
1598 if (chan
->switch_timer_enabled
== 1) {
1599 consumer_timer_switch_stop(chan
);
1601 consumer_metadata_cache_destroy(chan
);
1602 ustctl_destroy_channel(chan
->uchan
);
1605 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1608 assert(stream
->ustream
);
1610 if (stream
->chan
->switch_timer_enabled
== 1) {
1611 consumer_timer_switch_stop(stream
->chan
);
1613 ustctl_destroy_stream(stream
->ustream
);
1616 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1617 struct lttng_consumer_local_data
*ctx
)
1619 unsigned long len
, subbuf_size
, padding
;
1623 struct ustctl_consumer_stream
*ustream
;
1626 assert(stream
->ustream
);
1629 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1632 /* Ease our life for what's next. */
1633 ustream
= stream
->ustream
;
1635 /* We can consume the 1 byte written into the wait_fd by UST */
1636 if (!stream
->hangup_flush_done
) {
1640 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1641 } while (readlen
== -1 && errno
== EINTR
);
1642 if (readlen
== -1) {
1648 /* Get the next subbuffer */
1649 err
= ustctl_get_next_subbuf(ustream
);
1651 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1653 * This is a debug message even for single-threaded consumer,
1654 * because poll() have more relaxed criterions than get subbuf,
1655 * so get_subbuf may fail for short race windows where poll()
1656 * would issue wakeups.
1658 DBG("Reserving sub buffer failed (everything is normal, "
1659 "it is due to concurrency) [ret: %d]", err
);
1662 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1663 /* Get the full padded subbuffer size */
1664 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1667 /* Get subbuffer data size (without padding) */
1668 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1671 /* Make sure we don't get a subbuffer size bigger than the padded */
1672 assert(len
>= subbuf_size
);
1674 padding
= len
- subbuf_size
;
1675 /* write the subbuffer to the tracefile */
1676 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1678 * The mmap operation should write subbuf_size amount of data when network
1679 * streaming or the full padding (len) size when we are _not_ streaming.
1681 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1682 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1684 * Display the error but continue processing to try to release the
1685 * subbuffer. This is a DBG statement since any unexpected kill or
1686 * signal, the application gets unregistered, relayd gets closed or
1687 * anything that affects the buffer lifetime will trigger this error.
1688 * So, for the sake of the user, don't print this error since it can
1689 * happen and it is OK with the code flow.
1691 DBG("Error writing to tracefile "
1692 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1693 ret
, len
, subbuf_size
);
1695 err
= ustctl_put_next_subbuf(ustream
);
1703 * Called when a stream is created.
1705 * Return 0 on success or else a negative value.
1707 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1713 /* Don't create anything if this is set for streaming. */
1714 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
1715 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1716 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1717 stream
->uid
, stream
->gid
);
1721 stream
->out_fd
= ret
;
1722 stream
->tracefile_size_current
= 0;
1731 * Check if data is still being extracted from the buffers for a specific
1732 * stream. Consumer data lock MUST be acquired before calling this function
1733 * and the stream lock.
1735 * Return 1 if the traced data are still getting read else 0 meaning that the
1736 * data is available for trace viewer reading.
1738 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1743 assert(stream
->ustream
);
1745 DBG("UST consumer checking data pending");
1747 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1749 /* There is still data so let's put back this subbuffer. */
1750 ret
= ustctl_put_subbuf(stream
->ustream
);
1752 ret
= 1; /* Data is pending */
1756 /* Data is NOT pending so ready to be read. */
1764 * Close every metadata stream wait fd of the metadata hash table. This
1765 * function MUST be used very carefully so not to run into a race between the
1766 * metadata thread handling streams and this function closing their wait fd.
1768 * For UST, this is used when the session daemon hangs up. Its the metadata
1769 * producer so calling this is safe because we are assured that no state change
1770 * can occur in the metadata thread for the streams in the hash table.
1772 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1775 struct lttng_ht_iter iter
;
1776 struct lttng_consumer_stream
*stream
;
1778 assert(metadata_ht
);
1779 assert(metadata_ht
->ht
);
1781 DBG("UST consumer closing all metadata streams");
1784 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1786 int fd
= stream
->wait_fd
;
1789 * Whatever happens here we have to continue to try to close every
1790 * streams. Let's report at least the error on failure.
1792 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1794 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1796 DBG("Metadata wait fd %d closed", fd
);
1801 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1805 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1807 ERR("Unable to close wakeup fd");
1811 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1812 struct lttng_consumer_channel
*channel
)
1814 struct lttcomm_metadata_request_msg request
;
1815 struct lttcomm_consumer_msg msg
;
1816 enum lttng_error_code ret_code
= LTTNG_OK
;
1817 uint64_t len
, key
, offset
;
1821 assert(channel
->metadata_cache
);
1823 /* send the metadata request to sessiond */
1824 switch (consumer_data
.type
) {
1825 case LTTNG_CONSUMER64_UST
:
1826 request
.bits_per_long
= 64;
1828 case LTTNG_CONSUMER32_UST
:
1829 request
.bits_per_long
= 32;
1832 request
.bits_per_long
= 0;
1836 request
.session_id
= channel
->session_id
;
1837 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1838 request
.uid
= channel
->uid
;
1839 request
.key
= channel
->key
;
1840 DBG("Sending metadata request to sessiond, session id %" PRIu64
1841 ", per-pid %" PRIu64
,
1842 channel
->session_id
,
1843 channel
->session_id_per_pid
);
1845 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1848 ERR("Asking metadata to sessiond");
1852 /* Receive the metadata from sessiond */
1853 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1855 if (ret
!= sizeof(msg
)) {
1856 DBG("Consumer received unexpected message size %d (expects %zu)",
1858 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1860 * The ret value might 0 meaning an orderly shutdown but this is ok
1861 * since the caller handles this.
1866 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1867 /* No registry found */
1868 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1872 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1873 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1878 len
= msg
.u
.push_metadata
.len
;
1879 key
= msg
.u
.push_metadata
.key
;
1880 offset
= msg
.u
.push_metadata
.target_offset
;
1882 assert(key
== channel
->key
);
1884 DBG("No new metadata to receive for key %" PRIu64
, key
);
1887 /* Tell session daemon we are ready to receive the metadata. */
1888 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1890 if (ret
< 0 || len
== 0) {
1892 * Somehow, the session daemon is not responding anymore or there is
1893 * nothing to receive.
1898 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1899 key
, offset
, len
, channel
);
1900 if (ret_code
>= 0) {
1902 * Only send the status msg if the sessiond is alive meaning a positive
1905 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);