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 ret
= consumer_add_metadata_stream(stream
);
199 ERR("Consumer add metadata stream %" PRIu64
" failed.",
203 stream_pipe
= ctx
->consumer_metadata_pipe
;
205 ret
= consumer_add_data_stream(stream
);
207 ERR("Consumer add stream %" PRIu64
" failed.",
211 stream_pipe
= ctx
->consumer_data_pipe
;
215 * From this point on, the stream's ownership has been moved away from
216 * the channel and becomes globally visible.
218 stream
->globally_visible
= 1;
220 ret
= lttng_pipe_write(stream_pipe
, &stream
, sizeof(stream
));
222 ERR("Consumer write %s stream to pipe %d",
223 stream
->metadata_flag
? "metadata" : "data",
224 lttng_pipe_get_writefd(stream_pipe
));
225 if (stream
->metadata_flag
) {
226 consumer_del_stream_for_metadata(stream
);
228 consumer_del_stream_for_data(stream
);
236 * Create streams for the given channel using liblttng-ust-ctl.
238 * Return 0 on success else a negative value.
240 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
241 struct lttng_consumer_local_data
*ctx
)
244 struct ustctl_consumer_stream
*ustream
;
245 struct lttng_consumer_stream
*stream
;
251 * While a stream is available from ustctl. When NULL is returned, we've
252 * reached the end of the possible stream for the channel.
254 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
256 int ust_metadata_pipe
[2];
258 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
&& channel
->monitor
) {
259 ret
= utils_create_pipe_cloexec_nonblock(ust_metadata_pipe
);
261 ERR("Create ust metadata poll pipe");
264 wait_fd
= ust_metadata_pipe
[0];
266 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
269 /* Allocate consumer stream object. */
270 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
274 stream
->ustream
= ustream
;
276 * Store it so we can save multiple function calls afterwards since
277 * this value is used heavily in the stream threads. This is UST
278 * specific so this is why it's done after allocation.
280 stream
->wait_fd
= wait_fd
;
283 * Increment channel refcount since the channel reference has now been
284 * assigned in the allocation process above.
286 if (stream
->chan
->monitor
) {
287 uatomic_inc(&stream
->chan
->refcount
);
291 * Order is important this is why a list is used. On error, the caller
292 * should clean this list.
294 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
296 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
297 &stream
->max_sb_size
);
299 ERR("ustctl_get_max_subbuf_size failed for stream %s",
304 /* Do actions once stream has been received. */
305 if (ctx
->on_recv_stream
) {
306 ret
= ctx
->on_recv_stream(stream
);
312 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
313 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
315 /* Set next CPU stream. */
316 channel
->streams
.count
= ++cpu
;
318 /* Keep stream reference when creating metadata. */
319 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
320 channel
->metadata_stream
= stream
;
321 stream
->ust_metadata_poll_pipe
[0] = ust_metadata_pipe
[0];
322 stream
->ust_metadata_poll_pipe
[1] = ust_metadata_pipe
[1];
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 DBG("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 if (channel
->relayd_id
!= (uint64_t) -1ULL) {
412 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
413 /* Try to send the stream to the relayd if one is available. */
414 ret
= consumer_send_relayd_stream(stream
, stream
->chan
->pathname
);
417 * Flag that the relayd was the problem here probably due to a
418 * communicaton error on the socket.
423 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
428 /* Inform sessiond that we are about to send channel and streams. */
429 ret
= consumer_send_status_msg(sock
, ret_code
);
430 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
432 * Either the session daemon is not responding or the relayd died so we
438 /* Send channel to sessiond. */
439 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
444 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
449 /* The channel was sent successfully to the sessiond at this point. */
450 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
451 /* Send stream to session daemon. */
452 ret
= send_sessiond_stream(sock
, stream
);
458 /* Tell sessiond there is no more stream. */
459 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
464 DBG("UST consumer NULL stream sent to sessiond");
469 if (ret_code
!= LTTNG_OK
) {
476 * Creates a channel and streams and add the channel it to the channel internal
477 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
480 * Return 0 on success or else, a negative value is returned and the channel
481 * MUST be destroyed by consumer_del_channel().
483 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
484 struct lttng_consumer_channel
*channel
,
485 struct ustctl_consumer_channel_attr
*attr
)
494 * This value is still used by the kernel consumer since for the kernel,
495 * the stream ownership is not IN the consumer so we need to have the
496 * number of left stream that needs to be initialized so we can know when
497 * to delete the channel (see consumer.c).
499 * As for the user space tracer now, the consumer creates and sends the
500 * stream to the session daemon which only sends them to the application
501 * once every stream of a channel is received making this value useless
502 * because we they will be added to the poll thread before the application
503 * receives them. This ensures that a stream can not hang up during
504 * initilization of a channel.
506 channel
->nb_init_stream_left
= 0;
508 /* The reply msg status is handled in the following call. */
509 ret
= create_ust_channel(attr
, &channel
->uchan
);
514 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
517 * For the snapshots (no monitor), we create the metadata streams
518 * on demand, not during the channel creation.
520 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
&& !channel
->monitor
) {
525 /* Open all streams for this channel. */
526 ret
= create_ust_streams(channel
, ctx
);
536 * Send all stream of a channel to the right thread handling it.
538 * On error, return a negative value else 0 on success.
540 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
541 struct lttng_consumer_local_data
*ctx
)
544 struct lttng_consumer_stream
*stream
, *stmp
;
549 /* Send streams to the corresponding thread. */
550 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
552 /* Sending the stream to the thread. */
553 ret
= send_stream_to_thread(stream
, ctx
);
556 * If we are unable to send the stream to the thread, there is
557 * a big problem so just stop everything.
559 /* Remove node from the channel stream list. */
560 cds_list_del(&stream
->send_node
);
564 /* Remove node from the channel stream list. */
565 cds_list_del(&stream
->send_node
);
574 * Flush channel's streams using the given key to retrieve the channel.
576 * Return 0 on success else an LTTng error code.
578 static int flush_channel(uint64_t chan_key
)
581 struct lttng_consumer_channel
*channel
;
582 struct lttng_consumer_stream
*stream
;
584 struct lttng_ht_iter iter
;
586 DBG("UST consumer flush channel key %" PRIu64
, chan_key
);
589 channel
= consumer_find_channel(chan_key
);
591 ERR("UST consumer flush channel %" PRIu64
" not found", chan_key
);
592 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
596 ht
= consumer_data
.stream_per_chan_id_ht
;
598 /* For each stream of the channel id, flush it. */
599 cds_lfht_for_each_entry_duplicate(ht
->ht
,
600 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
601 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
602 ustctl_flush_buffer(stream
->ustream
, 1);
610 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
611 * RCU read side lock MUST be acquired before calling this function.
613 * Return 0 on success else an LTTng error code.
615 static int close_metadata(uint64_t chan_key
)
618 struct lttng_consumer_channel
*channel
;
620 DBG("UST consumer close metadata key %" PRIu64
, chan_key
);
622 channel
= consumer_find_channel(chan_key
);
625 * This is possible if the metadata thread has issue a delete because
626 * the endpoint point of the stream hung up. There is no way the
627 * session daemon can know about it thus use a DBG instead of an actual
630 DBG("UST consumer close metadata %" PRIu64
" not found", chan_key
);
631 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
635 pthread_mutex_lock(&consumer_data
.lock
);
636 pthread_mutex_lock(&channel
->lock
);
638 if (cds_lfht_is_node_deleted(&channel
->node
.node
)) {
642 if (channel
->switch_timer_enabled
== 1) {
643 DBG("Deleting timer on metadata channel");
644 consumer_timer_switch_stop(channel
);
647 if (channel
->metadata_stream
) {
648 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
650 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
651 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
654 if (channel
->monitor
) {
655 /* close the read-side in consumer_del_metadata_stream */
656 ret
= close(channel
->metadata_stream
->ust_metadata_poll_pipe
[1]);
658 PERROR("Close UST metadata write-side poll pipe");
664 pthread_mutex_unlock(&channel
->lock
);
665 pthread_mutex_unlock(&consumer_data
.lock
);
671 * RCU read side lock MUST be acquired before calling this function.
673 * Return 0 on success else an LTTng error code.
675 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
678 struct lttng_consumer_channel
*metadata
;
680 DBG("UST consumer setup metadata key %" PRIu64
, key
);
682 metadata
= consumer_find_channel(key
);
684 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
685 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
690 * In no monitor mode, the metadata channel has no stream(s) so skip the
691 * ownership transfer to the metadata thread.
693 if (!metadata
->monitor
) {
694 DBG("Metadata channel in no monitor");
700 * Send metadata stream to relayd if one available. Availability is
701 * known if the stream is still in the list of the channel.
703 if (cds_list_empty(&metadata
->streams
.head
)) {
704 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
705 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
706 goto error_no_stream
;
709 /* Send metadata stream to relayd if needed. */
710 if (metadata
->metadata_stream
->net_seq_idx
!= (uint64_t) -1ULL) {
711 ret
= consumer_send_relayd_stream(metadata
->metadata_stream
,
714 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
719 ret
= send_streams_to_thread(metadata
, ctx
);
722 * If we are unable to send the stream to the thread, there is
723 * a big problem so just stop everything.
725 ret
= LTTCOMM_CONSUMERD_FATAL
;
728 /* List MUST be empty after or else it could be reused. */
729 assert(cds_list_empty(&metadata
->streams
.head
));
736 * Delete metadata channel on error. At this point, the metadata stream can
737 * NOT be monitored by the metadata thread thus having the guarantee that
738 * the stream is still in the local stream list of the channel. This call
739 * will make sure to clean that list.
741 cds_list_del(&metadata
->metadata_stream
->send_node
);
742 consumer_stream_destroy(metadata
->metadata_stream
, NULL
);
749 * Snapshot the whole metadata.
751 * Returns 0 on success, < 0 on error
753 static int snapshot_metadata(uint64_t key
, char *path
, uint64_t relayd_id
,
754 struct lttng_consumer_local_data
*ctx
)
757 struct lttng_consumer_channel
*metadata_channel
;
758 struct lttng_consumer_stream
*metadata_stream
;
763 DBG("UST consumer snapshot metadata with key %" PRIu64
" at path %s",
768 metadata_channel
= consumer_find_channel(key
);
769 if (!metadata_channel
) {
770 ERR("UST snapshot metadata channel not found for key %" PRIu64
,
775 assert(!metadata_channel
->monitor
);
778 * Ask the sessiond if we have new metadata waiting and update the
779 * consumer metadata cache.
781 ret
= lttng_ustconsumer_request_metadata(ctx
, metadata_channel
, 0);
787 * The metadata stream is NOT created in no monitor mode when the channel
788 * is created on a sessiond ask channel command.
790 ret
= create_ust_streams(metadata_channel
, ctx
);
795 metadata_stream
= metadata_channel
->metadata_stream
;
796 assert(metadata_stream
);
798 if (relayd_id
!= (uint64_t) -1ULL) {
799 metadata_stream
->net_seq_idx
= relayd_id
;
800 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
805 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
806 metadata_stream
->chan
->tracefile_size
,
807 metadata_stream
->tracefile_count_current
,
808 metadata_stream
->uid
, metadata_stream
->gid
);
812 metadata_stream
->out_fd
= ret
;
813 metadata_stream
->tracefile_size_current
= 0;
816 pthread_mutex_lock(&metadata_channel
->metadata_cache
->lock
);
819 ret
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
);
826 pthread_mutex_unlock(&metadata_channel
->metadata_cache
->lock
);
830 * Clean up the stream completly because the next snapshot will use a new
833 cds_list_del(&metadata_stream
->send_node
);
834 consumer_stream_destroy(metadata_stream
, NULL
);
835 metadata_channel
->metadata_stream
= NULL
;
843 * Take a snapshot of all the stream of a channel.
845 * Returns 0 on success, < 0 on error
847 static int snapshot_channel(uint64_t key
, char *path
, uint64_t relayd_id
,
848 uint64_t max_stream_size
, struct lttng_consumer_local_data
*ctx
)
851 unsigned use_relayd
= 0;
852 unsigned long consumed_pos
, produced_pos
;
853 struct lttng_consumer_channel
*channel
;
854 struct lttng_consumer_stream
*stream
;
861 if (relayd_id
!= (uint64_t) -1ULL) {
865 channel
= consumer_find_channel(key
);
867 ERR("UST snapshot channel not found for key %" PRIu64
, key
);
871 assert(!channel
->monitor
);
872 DBG("UST consumer snapshot channel %" PRIu64
, key
);
874 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
875 /* Lock stream because we are about to change its state. */
876 pthread_mutex_lock(&stream
->lock
);
877 stream
->net_seq_idx
= relayd_id
;
880 ret
= consumer_send_relayd_stream(stream
, path
);
885 ret
= utils_create_stream_file(path
, stream
->name
,
886 stream
->chan
->tracefile_size
,
887 stream
->tracefile_count_current
,
888 stream
->uid
, stream
->gid
);
892 stream
->out_fd
= ret
;
893 stream
->tracefile_size_current
= 0;
895 DBG("UST consumer snapshot stream %s/%s (%" PRIu64
")", path
,
896 stream
->name
, stream
->key
);
899 ustctl_flush_buffer(stream
->ustream
, 1);
901 ret
= lttng_ustconsumer_take_snapshot(stream
);
903 ERR("Taking UST snapshot");
907 ret
= lttng_ustconsumer_get_produced_snapshot(stream
, &produced_pos
);
909 ERR("Produced UST snapshot position");
913 ret
= lttng_ustconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
915 ERR("Consumerd UST snapshot position");
920 * The original value is sent back if max stream size is larger than
921 * the possible size of the snapshot. Also, we asume that the session
922 * daemon should never send a maximum stream size that is lower than
925 consumed_pos
= consumer_get_consumed_maxsize(consumed_pos
,
926 produced_pos
, max_stream_size
);
928 while (consumed_pos
< produced_pos
) {
930 unsigned long len
, padded_len
;
932 DBG("UST consumer taking snapshot at pos %lu", consumed_pos
);
934 ret
= ustctl_get_subbuf(stream
->ustream
, &consumed_pos
);
936 if (ret
!= -EAGAIN
) {
937 PERROR("ustctl_get_subbuf snapshot");
938 goto error_close_stream
;
940 DBG("UST consumer get subbuf failed. Skipping it.");
941 consumed_pos
+= stream
->max_sb_size
;
945 ret
= ustctl_get_subbuf_size(stream
->ustream
, &len
);
947 ERR("Snapshot ustctl_get_subbuf_size");
948 goto error_put_subbuf
;
951 ret
= ustctl_get_padded_subbuf_size(stream
->ustream
, &padded_len
);
953 ERR("Snapshot ustctl_get_padded_subbuf_size");
954 goto error_put_subbuf
;
957 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
960 if (read_len
!= len
) {
962 goto error_put_subbuf
;
965 if (read_len
!= padded_len
) {
967 goto error_put_subbuf
;
971 ret
= ustctl_put_subbuf(stream
->ustream
);
973 ERR("Snapshot ustctl_put_subbuf");
974 goto error_close_stream
;
976 consumed_pos
+= stream
->max_sb_size
;
979 /* Simply close the stream so we can use it on the next snapshot. */
980 consumer_stream_close(stream
);
981 pthread_mutex_unlock(&stream
->lock
);
988 if (ustctl_put_subbuf(stream
->ustream
) < 0) {
989 ERR("Snapshot ustctl_put_subbuf");
992 consumer_stream_close(stream
);
994 pthread_mutex_unlock(&stream
->lock
);
1001 * Receive the metadata updates from the sessiond.
1003 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
1004 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. */
1027 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
1028 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
1030 /* Unable to handle metadata. Notify session daemon. */
1031 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1033 * Skip metadata flush on write error since the offset and len might
1034 * not have been updated which could create an infinite loop below when
1035 * waiting for the metadata cache to be flushed.
1037 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1040 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1042 while (consumer_metadata_cache_flushed(channel
, offset
+ len
, timer
)) {
1043 DBG("Waiting for metadata to be flushed");
1044 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
1054 * Receive command from session daemon and process it.
1056 * Return 1 on success else a negative value or 0.
1058 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1059 int sock
, struct pollfd
*consumer_sockpoll
)
1062 enum lttng_error_code ret_code
= LTTNG_OK
;
1063 struct lttcomm_consumer_msg msg
;
1064 struct lttng_consumer_channel
*channel
= NULL
;
1066 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
1067 if (ret
!= sizeof(msg
)) {
1068 DBG("Consumer received unexpected message size %zd (expects %zu)",
1071 * The ret value might 0 meaning an orderly shutdown but this is ok
1072 * since the caller handles this.
1075 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1080 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
1082 * Notify the session daemon that the command is completed.
1084 * On transport layer error, the function call will print an error
1085 * message so handling the returned code is a bit useless since we
1086 * return an error code anyway.
1088 (void) consumer_send_status_msg(sock
, ret_code
);
1092 /* relayd needs RCU read-side lock */
1095 switch (msg
.cmd_type
) {
1096 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
1098 /* Session daemon status message are handled in the following call. */
1099 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
1100 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
1101 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
1104 case LTTNG_CONSUMER_DESTROY_RELAYD
:
1106 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
1107 struct consumer_relayd_sock_pair
*relayd
;
1109 DBG("UST consumer destroying relayd %" PRIu64
, index
);
1111 /* Get relayd reference if exists. */
1112 relayd
= consumer_find_relayd(index
);
1113 if (relayd
== NULL
) {
1114 DBG("Unable to find relayd %" PRIu64
, index
);
1115 ret_code
= LTTNG_ERR_NO_CONSUMER
;
1119 * Each relayd socket pair has a refcount of stream attached to it
1120 * which tells if the relayd is still active or not depending on the
1123 * This will set the destroy flag of the relayd object and destroy it
1124 * if the refcount reaches zero when called.
1126 * The destroy can happen either here or when a stream fd hangs up.
1129 consumer_flag_relayd_for_destroy(relayd
);
1132 goto end_msg_sessiond
;
1134 case LTTNG_CONSUMER_UPDATE_STREAM
:
1139 case LTTNG_CONSUMER_DATA_PENDING
:
1141 int ret
, is_data_pending
;
1142 uint64_t id
= msg
.u
.data_pending
.session_id
;
1144 DBG("UST consumer data pending command for id %" PRIu64
, id
);
1146 is_data_pending
= consumer_data_pending(id
);
1148 /* Send back returned value to session daemon */
1149 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
1150 sizeof(is_data_pending
));
1152 DBG("Error when sending the data pending ret code: %d", ret
);
1157 * No need to send back a status message since the data pending
1158 * returned value is the response.
1162 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
1165 struct ustctl_consumer_channel_attr attr
;
1167 /* Create a plain object and reserve a channel key. */
1168 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
1169 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
1170 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
1171 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
1172 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
1173 msg
.u
.ask_channel
.tracefile_size
,
1174 msg
.u
.ask_channel
.tracefile_count
,
1175 msg
.u
.ask_channel
.session_id_per_pid
,
1176 msg
.u
.ask_channel
.monitor
);
1178 goto end_channel_error
;
1181 /* Build channel attributes from received message. */
1182 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
1183 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
1184 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
1185 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
1186 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
1187 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
1188 attr
.output
= msg
.u
.ask_channel
.output
;
1189 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
1191 /* Translate and save channel type. */
1192 switch (msg
.u
.ask_channel
.type
) {
1193 case LTTNG_UST_CHAN_PER_CPU
:
1194 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
1195 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1197 * Set refcount to 1 for owner. Below, we will
1198 * pass ownership to the
1199 * consumer_thread_channel_poll() thread.
1201 channel
->refcount
= 1;
1203 case LTTNG_UST_CHAN_METADATA
:
1204 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
1205 attr
.type
= LTTNG_UST_CHAN_METADATA
;
1212 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
1214 goto end_channel_error
;
1217 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1218 ret
= consumer_metadata_cache_allocate(channel
);
1220 ERR("Allocating metadata cache");
1221 goto end_channel_error
;
1223 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
1224 attr
.switch_timer_interval
= 0;
1228 * Add the channel to the internal state AFTER all streams were created
1229 * and successfully sent to session daemon. This way, all streams must
1230 * be ready before this channel is visible to the threads.
1231 * If add_channel succeeds, ownership of the channel is
1232 * passed to consumer_thread_channel_poll().
1234 ret
= add_channel(channel
, ctx
);
1236 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1237 if (channel
->switch_timer_enabled
== 1) {
1238 consumer_timer_switch_stop(channel
);
1240 consumer_metadata_cache_destroy(channel
);
1242 goto end_channel_error
;
1246 * Channel and streams are now created. Inform the session daemon that
1247 * everything went well and should wait to receive the channel and
1248 * streams with ustctl API.
1250 ret
= consumer_send_status_channel(sock
, channel
);
1253 * There is probably a problem on the socket.
1260 case LTTNG_CONSUMER_GET_CHANNEL
:
1262 int ret
, relayd_err
= 0;
1263 uint64_t key
= msg
.u
.get_channel
.key
;
1264 struct lttng_consumer_channel
*channel
;
1266 channel
= consumer_find_channel(key
);
1268 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1269 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1270 goto end_msg_sessiond
;
1273 /* Send everything to sessiond. */
1274 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1278 * We were unable to send to the relayd the stream so avoid
1279 * sending back a fatal error to the thread since this is OK
1280 * and the consumer can continue its work. The above call
1281 * has sent the error status message to the sessiond.
1286 * The communicaton was broken hence there is a bad state between
1287 * the consumer and sessiond so stop everything.
1293 * In no monitor mode, the streams ownership is kept inside the channel
1294 * so don't send them to the data thread.
1296 if (!channel
->monitor
) {
1297 goto end_msg_sessiond
;
1300 ret
= send_streams_to_thread(channel
, ctx
);
1303 * If we are unable to send the stream to the thread, there is
1304 * a big problem so just stop everything.
1308 /* List MUST be empty after or else it could be reused. */
1309 assert(cds_list_empty(&channel
->streams
.head
));
1310 goto end_msg_sessiond
;
1312 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1314 uint64_t key
= msg
.u
.destroy_channel
.key
;
1317 * Only called if streams have not been sent to stream
1318 * manager thread. However, channel has been sent to
1319 * channel manager thread.
1321 notify_thread_del_channel(ctx
, key
);
1322 goto end_msg_sessiond
;
1324 case LTTNG_CONSUMER_CLOSE_METADATA
:
1328 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1333 goto end_msg_sessiond
;
1335 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1339 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1344 goto end_msg_sessiond
;
1346 case LTTNG_CONSUMER_PUSH_METADATA
:
1349 uint64_t len
= msg
.u
.push_metadata
.len
;
1350 uint64_t key
= msg
.u
.push_metadata
.key
;
1351 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1352 struct lttng_consumer_channel
*channel
;
1354 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1357 channel
= consumer_find_channel(key
);
1359 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1360 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1361 goto end_msg_sessiond
;
1364 /* Tell session daemon we are ready to receive the metadata. */
1365 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1367 /* Somehow, the session daemon is not responding anymore. */
1371 /* Wait for more data. */
1372 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1376 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1379 /* error receiving from sessiond */
1383 goto end_msg_sessiond
;
1386 case LTTNG_CONSUMER_SETUP_METADATA
:
1390 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1394 goto end_msg_sessiond
;
1396 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
1398 if (msg
.u
.snapshot_channel
.metadata
) {
1399 ret
= snapshot_metadata(msg
.u
.snapshot_channel
.key
,
1400 msg
.u
.snapshot_channel
.pathname
,
1401 msg
.u
.snapshot_channel
.relayd_id
,
1404 ERR("Snapshot metadata failed");
1405 ret_code
= LTTNG_ERR_UST_META_FAIL
;
1408 ret
= snapshot_channel(msg
.u
.snapshot_channel
.key
,
1409 msg
.u
.snapshot_channel
.pathname
,
1410 msg
.u
.snapshot_channel
.relayd_id
,
1411 msg
.u
.snapshot_channel
.max_stream_size
,
1414 ERR("Snapshot channel failed");
1415 ret_code
= LTTNG_ERR_UST_CHAN_FAIL
;
1419 ret
= consumer_send_status_msg(sock
, ret_code
);
1421 /* Somehow, the session daemon is not responding anymore. */
1434 * Return 1 to indicate success since the 0 value can be a socket
1435 * shutdown during the recv() or send() call.
1441 * The returned value here is not useful since either way we'll return 1 to
1442 * the caller because the session daemon socket management is done
1443 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1445 ret
= consumer_send_status_msg(sock
, ret_code
);
1454 * Free channel here since no one has a reference to it. We don't
1455 * free after that because a stream can store this pointer.
1457 destroy_channel(channel
);
1459 /* We have to send a status channel message indicating an error. */
1460 ret
= consumer_send_status_channel(sock
, NULL
);
1462 /* Stop everything if session daemon can not be notified. */
1469 /* This will issue a consumer stop. */
1474 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1475 * compiled out, we isolate it in this library.
1477 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1481 assert(stream
->ustream
);
1483 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1487 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1488 * compiled out, we isolate it in this library.
1490 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1493 assert(stream
->ustream
);
1495 return ustctl_get_mmap_base(stream
->ustream
);
1499 * Take a snapshot for a specific fd
1501 * Returns 0 on success, < 0 on error
1503 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1506 assert(stream
->ustream
);
1508 return ustctl_snapshot(stream
->ustream
);
1512 * Get the produced position
1514 * Returns 0 on success, < 0 on error
1516 int lttng_ustconsumer_get_produced_snapshot(
1517 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1520 assert(stream
->ustream
);
1523 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1527 * Get the consumed position
1529 * Returns 0 on success, < 0 on error
1531 int lttng_ustconsumer_get_consumed_snapshot(
1532 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1535 assert(stream
->ustream
);
1538 return ustctl_snapshot_get_consumed(stream
->ustream
, pos
);
1542 * Called when the stream signal the consumer that it has hang up.
1544 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1547 assert(stream
->ustream
);
1549 ustctl_flush_buffer(stream
->ustream
, 0);
1550 stream
->hangup_flush_done
= 1;
1553 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1556 assert(chan
->uchan
);
1558 if (chan
->switch_timer_enabled
== 1) {
1559 consumer_timer_switch_stop(chan
);
1561 consumer_metadata_cache_destroy(chan
);
1562 ustctl_destroy_channel(chan
->uchan
);
1565 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1568 assert(stream
->ustream
);
1570 if (stream
->chan
->switch_timer_enabled
== 1) {
1571 consumer_timer_switch_stop(stream
->chan
);
1573 ustctl_destroy_stream(stream
->ustream
);
1576 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1577 struct lttng_consumer_local_data
*ctx
)
1579 unsigned long len
, subbuf_size
, padding
;
1583 struct ustctl_consumer_stream
*ustream
;
1586 assert(stream
->ustream
);
1589 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1592 /* Ease our life for what's next. */
1593 ustream
= stream
->ustream
;
1595 /* We can consume the 1 byte written into the wait_fd by UST */
1596 if (stream
->monitor
&& !stream
->hangup_flush_done
) {
1600 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1601 } while (readlen
== -1 && errno
== EINTR
);
1602 if (readlen
== -1 && errno
!= EAGAIN
&& errno
!= EWOULDBLOCK
) {
1609 /* Get the next subbuffer */
1610 err
= ustctl_get_next_subbuf(ustream
);
1613 * Populate metadata info if the existing info has
1614 * already been read.
1616 if (stream
->metadata_flag
) {
1619 if (stream
->chan
->metadata_cache
->contiguous
1620 == stream
->ust_metadata_pushed
) {
1625 write_len
= ustctl_write_one_packet_to_channel(stream
->chan
->uchan
,
1626 &stream
->chan
->metadata_cache
->data
[stream
->ust_metadata_pushed
],
1627 stream
->chan
->metadata_cache
->contiguous
1628 - stream
->ust_metadata_pushed
);
1629 assert(write_len
!= 0);
1630 if (write_len
< 0) {
1631 ERR("Writing one metadata packet");
1635 stream
->ust_metadata_pushed
+= write_len
;
1636 ustctl_flush_buffer(stream
->ustream
, 1);
1640 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1642 * This is a debug message even for single-threaded consumer,
1643 * because poll() have more relaxed criterions than get subbuf,
1644 * so get_subbuf may fail for short race windows where poll()
1645 * would issue wakeups.
1647 DBG("Reserving sub buffer failed (everything is normal, "
1648 "it is due to concurrency) [ret: %d]", err
);
1651 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1652 /* Get the full padded subbuffer size */
1653 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1656 /* Get subbuffer data size (without padding) */
1657 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1660 /* Make sure we don't get a subbuffer size bigger than the padded */
1661 assert(len
>= subbuf_size
);
1663 padding
= len
- subbuf_size
;
1664 /* write the subbuffer to the tracefile */
1665 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1667 * The mmap operation should write subbuf_size amount of data when network
1668 * streaming or the full padding (len) size when we are _not_ streaming.
1670 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1671 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1673 * Display the error but continue processing to try to release the
1674 * subbuffer. This is a DBG statement since any unexpected kill or
1675 * signal, the application gets unregistered, relayd gets closed or
1676 * anything that affects the buffer lifetime will trigger this error.
1677 * So, for the sake of the user, don't print this error since it can
1678 * happen and it is OK with the code flow.
1680 DBG("Error writing to tracefile "
1681 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1682 ret
, len
, subbuf_size
);
1684 err
= ustctl_put_next_subbuf(ustream
);
1692 * Called when a stream is created.
1694 * Return 0 on success or else a negative value.
1696 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1702 /* Don't create anything if this is set for streaming. */
1703 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
1704 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1705 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1706 stream
->uid
, stream
->gid
);
1710 stream
->out_fd
= ret
;
1711 stream
->tracefile_size_current
= 0;
1720 * Check if data is still being extracted from the buffers for a specific
1721 * stream. Consumer data lock MUST be acquired before calling this function
1722 * and the stream lock.
1724 * Return 1 if the traced data are still getting read else 0 meaning that the
1725 * data is available for trace viewer reading.
1727 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1732 assert(stream
->ustream
);
1734 DBG("UST consumer checking data pending");
1736 if (stream
->endpoint_status
!= CONSUMER_ENDPOINT_ACTIVE
) {
1741 if (stream
->chan
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
1743 * We can simply check whether all contiguously available data
1744 * has been pushed to the ring buffer, since the push operation
1745 * is performed within get_next_subbuf(), and because both
1746 * get_next_subbuf() and put_next_subbuf() are issued atomically
1747 * thanks to the stream lock within
1748 * lttng_ustconsumer_read_subbuffer(). This basically means that
1749 * whetnever ust_metadata_pushed is incremented, the associated
1750 * metadata has been consumed from the metadata stream.
1752 DBG("UST consumer metadata pending check: contiguous %" PRIu64
" vs pushed %" PRIu64
,
1753 stream
->chan
->metadata_cache
->contiguous
,
1754 stream
->ust_metadata_pushed
);
1755 if (stream
->chan
->metadata_cache
->contiguous
1756 != stream
->ust_metadata_pushed
) {
1757 ret
= 1; /* Data is pending */
1761 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1764 * There is still data so let's put back this
1767 ret
= ustctl_put_subbuf(stream
->ustream
);
1769 ret
= 1; /* Data is pending */
1774 /* Data is NOT pending so ready to be read. */
1782 * Close every metadata stream wait fd of the metadata hash table. This
1783 * function MUST be used very carefully so not to run into a race between the
1784 * metadata thread handling streams and this function closing their wait fd.
1786 * For UST, this is used when the session daemon hangs up. Its the metadata
1787 * producer so calling this is safe because we are assured that no state change
1788 * can occur in the metadata thread for the streams in the hash table.
1790 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1793 struct lttng_ht_iter iter
;
1794 struct lttng_consumer_stream
*stream
;
1796 assert(metadata_ht
);
1797 assert(metadata_ht
->ht
);
1799 DBG("UST consumer closing all metadata streams");
1802 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1804 int fd
= stream
->wait_fd
;
1807 * Whatever happens here we have to continue to try to close every
1808 * streams. Let's report at least the error on failure.
1810 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1812 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1814 DBG("Metadata wait fd %d closed", fd
);
1819 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1823 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1825 ERR("Unable to close wakeup fd");
1830 * Please refer to consumer-timer.c before adding any lock within this
1831 * function or any of its callees. Timers have a very strict locking
1832 * semantic with respect to teardown. Failure to respect this semantic
1833 * introduces deadlocks.
1835 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1836 struct lttng_consumer_channel
*channel
, int timer
)
1838 struct lttcomm_metadata_request_msg request
;
1839 struct lttcomm_consumer_msg msg
;
1840 enum lttng_error_code ret_code
= LTTNG_OK
;
1841 uint64_t len
, key
, offset
;
1845 assert(channel
->metadata_cache
);
1847 /* send the metadata request to sessiond */
1848 switch (consumer_data
.type
) {
1849 case LTTNG_CONSUMER64_UST
:
1850 request
.bits_per_long
= 64;
1852 case LTTNG_CONSUMER32_UST
:
1853 request
.bits_per_long
= 32;
1856 request
.bits_per_long
= 0;
1860 request
.session_id
= channel
->session_id
;
1861 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1862 request
.uid
= channel
->uid
;
1863 request
.key
= channel
->key
;
1864 DBG("Sending metadata request to sessiond, session id %" PRIu64
1865 ", per-pid %" PRIu64
,
1866 channel
->session_id
,
1867 channel
->session_id_per_pid
);
1869 pthread_mutex_lock(&ctx
->metadata_socket_lock
);
1870 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1873 ERR("Asking metadata to sessiond");
1877 /* Receive the metadata from sessiond */
1878 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1880 if (ret
!= sizeof(msg
)) {
1881 DBG("Consumer received unexpected message size %d (expects %zu)",
1883 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1885 * The ret value might 0 meaning an orderly shutdown but this is ok
1886 * since the caller handles this.
1891 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1892 /* No registry found */
1893 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1897 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1898 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1903 len
= msg
.u
.push_metadata
.len
;
1904 key
= msg
.u
.push_metadata
.key
;
1905 offset
= msg
.u
.push_metadata
.target_offset
;
1907 assert(key
== channel
->key
);
1909 DBG("No new metadata to receive for key %" PRIu64
, key
);
1912 /* Tell session daemon we are ready to receive the metadata. */
1913 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1915 if (ret
< 0 || len
== 0) {
1917 * Somehow, the session daemon is not responding anymore or there is
1918 * nothing to receive.
1923 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1924 key
, offset
, len
, channel
, timer
);
1925 if (ret_code
>= 0) {
1927 * Only send the status msg if the sessiond is alive meaning a positive
1930 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);
1935 pthread_mutex_unlock(&ctx
->metadata_socket_lock
);