2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <sys/socket.h>
28 #include <sys/types.h>
33 #include <common/common.h>
34 #include <common/utils.h>
35 #include <common/compat/poll.h>
36 #include <common/kernel-ctl/kernel-ctl.h>
37 #include <common/sessiond-comm/relayd.h>
38 #include <common/sessiond-comm/sessiond-comm.h>
39 #include <common/kernel-consumer/kernel-consumer.h>
40 #include <common/relayd/relayd.h>
41 #include <common/ust-consumer/ust-consumer.h>
45 struct lttng_consumer_global_data consumer_data
= {
48 .type
= LTTNG_CONSUMER_UNKNOWN
,
51 enum consumer_channel_action
{
54 CONSUMER_CHANNEL_QUIT
,
57 struct consumer_channel_msg
{
58 enum consumer_channel_action action
;
59 struct lttng_consumer_channel
*chan
; /* add */
60 uint64_t key
; /* del */
64 * Flag to inform the polling thread to quit when all fd hung up. Updated by
65 * the consumer_thread_receive_fds when it notices that all fds has hung up.
66 * Also updated by the signal handler (consumer_should_exit()). Read by the
69 volatile int consumer_quit
;
72 * Global hash table containing respectively metadata and data streams. The
73 * stream element in this ht should only be updated by the metadata poll thread
74 * for the metadata and the data poll thread for the data.
76 static struct lttng_ht
*metadata_ht
;
77 static struct lttng_ht
*data_ht
;
80 * Notify a thread lttng pipe to poll back again. This usually means that some
81 * global state has changed so we just send back the thread in a poll wait
84 static void notify_thread_lttng_pipe(struct lttng_pipe
*pipe
)
86 struct lttng_consumer_stream
*null_stream
= NULL
;
90 (void) lttng_pipe_write(pipe
, &null_stream
, sizeof(null_stream
));
93 static void notify_channel_pipe(struct lttng_consumer_local_data
*ctx
,
94 struct lttng_consumer_channel
*chan
,
96 enum consumer_channel_action action
)
98 struct consumer_channel_msg msg
;
101 memset(&msg
, 0, sizeof(msg
));
107 ret
= write(ctx
->consumer_channel_pipe
[1], &msg
, sizeof(msg
));
108 } while (ret
< 0 && errno
== EINTR
);
111 void notify_thread_del_channel(struct lttng_consumer_local_data
*ctx
,
114 notify_channel_pipe(ctx
, NULL
, key
, CONSUMER_CHANNEL_DEL
);
117 static int read_channel_pipe(struct lttng_consumer_local_data
*ctx
,
118 struct lttng_consumer_channel
**chan
,
120 enum consumer_channel_action
*action
)
122 struct consumer_channel_msg msg
;
126 ret
= read(ctx
->consumer_channel_pipe
[0], &msg
, sizeof(msg
));
127 } while (ret
< 0 && errno
== EINTR
);
129 *action
= msg
.action
;
137 * Find a stream. The consumer_data.lock must be locked during this
140 static struct lttng_consumer_stream
*find_stream(uint64_t key
,
143 struct lttng_ht_iter iter
;
144 struct lttng_ht_node_u64
*node
;
145 struct lttng_consumer_stream
*stream
= NULL
;
149 /* -1ULL keys are lookup failures */
150 if (key
== (uint64_t) -1ULL) {
156 lttng_ht_lookup(ht
, &key
, &iter
);
157 node
= lttng_ht_iter_get_node_u64(&iter
);
159 stream
= caa_container_of(node
, struct lttng_consumer_stream
, node
);
167 static void steal_stream_key(int key
, struct lttng_ht
*ht
)
169 struct lttng_consumer_stream
*stream
;
172 stream
= find_stream(key
, ht
);
176 * We don't want the lookup to match, but we still need
177 * to iterate on this stream when iterating over the hash table. Just
178 * change the node key.
180 stream
->node
.key
= -1ULL;
186 * Return a channel object for the given key.
188 * RCU read side lock MUST be acquired before calling this function and
189 * protects the channel ptr.
191 struct lttng_consumer_channel
*consumer_find_channel(uint64_t key
)
193 struct lttng_ht_iter iter
;
194 struct lttng_ht_node_u64
*node
;
195 struct lttng_consumer_channel
*channel
= NULL
;
197 /* -1ULL keys are lookup failures */
198 if (key
== (uint64_t) -1ULL) {
202 lttng_ht_lookup(consumer_data
.channel_ht
, &key
, &iter
);
203 node
= lttng_ht_iter_get_node_u64(&iter
);
205 channel
= caa_container_of(node
, struct lttng_consumer_channel
, node
);
211 static void free_stream_rcu(struct rcu_head
*head
)
213 struct lttng_ht_node_u64
*node
=
214 caa_container_of(head
, struct lttng_ht_node_u64
, head
);
215 struct lttng_consumer_stream
*stream
=
216 caa_container_of(node
, struct lttng_consumer_stream
, node
);
221 static void free_channel_rcu(struct rcu_head
*head
)
223 struct lttng_ht_node_u64
*node
=
224 caa_container_of(head
, struct lttng_ht_node_u64
, head
);
225 struct lttng_consumer_channel
*channel
=
226 caa_container_of(node
, struct lttng_consumer_channel
, node
);
232 * RCU protected relayd socket pair free.
234 static void free_relayd_rcu(struct rcu_head
*head
)
236 struct lttng_ht_node_u64
*node
=
237 caa_container_of(head
, struct lttng_ht_node_u64
, head
);
238 struct consumer_relayd_sock_pair
*relayd
=
239 caa_container_of(node
, struct consumer_relayd_sock_pair
, node
);
242 * Close all sockets. This is done in the call RCU since we don't want the
243 * socket fds to be reassigned thus potentially creating bad state of the
246 * We do not have to lock the control socket mutex here since at this stage
247 * there is no one referencing to this relayd object.
249 (void) relayd_close(&relayd
->control_sock
);
250 (void) relayd_close(&relayd
->data_sock
);
256 * Destroy and free relayd socket pair object.
258 void consumer_destroy_relayd(struct consumer_relayd_sock_pair
*relayd
)
261 struct lttng_ht_iter iter
;
263 if (relayd
== NULL
) {
267 DBG("Consumer destroy and close relayd socket pair");
269 iter
.iter
.node
= &relayd
->node
.node
;
270 ret
= lttng_ht_del(consumer_data
.relayd_ht
, &iter
);
272 /* We assume the relayd is being or is destroyed */
276 /* RCU free() call */
277 call_rcu(&relayd
->node
.head
, free_relayd_rcu
);
281 * Remove a channel from the global list protected by a mutex. This function is
282 * also responsible for freeing its data structures.
284 void consumer_del_channel(struct lttng_consumer_channel
*channel
)
287 struct lttng_ht_iter iter
;
288 struct lttng_consumer_stream
*stream
, *stmp
;
290 DBG("Consumer delete channel key %" PRIu64
, channel
->key
);
292 pthread_mutex_lock(&consumer_data
.lock
);
294 switch (consumer_data
.type
) {
295 case LTTNG_CONSUMER_KERNEL
:
297 case LTTNG_CONSUMER32_UST
:
298 case LTTNG_CONSUMER64_UST
:
299 /* Delete streams that might have been left in the stream list. */
300 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
302 cds_list_del(&stream
->send_node
);
303 lttng_ustconsumer_del_stream(stream
);
306 lttng_ustconsumer_del_channel(channel
);
309 ERR("Unknown consumer_data type");
315 iter
.iter
.node
= &channel
->node
.node
;
316 ret
= lttng_ht_del(consumer_data
.channel_ht
, &iter
);
320 call_rcu(&channel
->node
.head
, free_channel_rcu
);
322 pthread_mutex_unlock(&consumer_data
.lock
);
326 * Iterate over the relayd hash table and destroy each element. Finally,
327 * destroy the whole hash table.
329 static void cleanup_relayd_ht(void)
331 struct lttng_ht_iter iter
;
332 struct consumer_relayd_sock_pair
*relayd
;
336 cds_lfht_for_each_entry(consumer_data
.relayd_ht
->ht
, &iter
.iter
, relayd
,
338 consumer_destroy_relayd(relayd
);
343 lttng_ht_destroy(consumer_data
.relayd_ht
);
347 * Update the end point status of all streams having the given network sequence
348 * index (relayd index).
350 * It's atomically set without having the stream mutex locked which is fine
351 * because we handle the write/read race with a pipe wakeup for each thread.
353 static void update_endpoint_status_by_netidx(int net_seq_idx
,
354 enum consumer_endpoint_status status
)
356 struct lttng_ht_iter iter
;
357 struct lttng_consumer_stream
*stream
;
359 DBG("Consumer set delete flag on stream by idx %d", net_seq_idx
);
363 /* Let's begin with metadata */
364 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
365 if (stream
->net_seq_idx
== net_seq_idx
) {
366 uatomic_set(&stream
->endpoint_status
, status
);
367 DBG("Delete flag set to metadata stream %d", stream
->wait_fd
);
371 /* Follow up by the data streams */
372 cds_lfht_for_each_entry(data_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
373 if (stream
->net_seq_idx
== net_seq_idx
) {
374 uatomic_set(&stream
->endpoint_status
, status
);
375 DBG("Delete flag set to data stream %d", stream
->wait_fd
);
382 * Cleanup a relayd object by flagging every associated streams for deletion,
383 * destroying the object meaning removing it from the relayd hash table,
384 * closing the sockets and freeing the memory in a RCU call.
386 * If a local data context is available, notify the threads that the streams'
387 * state have changed.
389 static void cleanup_relayd(struct consumer_relayd_sock_pair
*relayd
,
390 struct lttng_consumer_local_data
*ctx
)
396 DBG("Cleaning up relayd sockets");
398 /* Save the net sequence index before destroying the object */
399 netidx
= relayd
->net_seq_idx
;
402 * Delete the relayd from the relayd hash table, close the sockets and free
403 * the object in a RCU call.
405 consumer_destroy_relayd(relayd
);
407 /* Set inactive endpoint to all streams */
408 update_endpoint_status_by_netidx(netidx
, CONSUMER_ENDPOINT_INACTIVE
);
411 * With a local data context, notify the threads that the streams' state
412 * have changed. The write() action on the pipe acts as an "implicit"
413 * memory barrier ordering the updates of the end point status from the
414 * read of this status which happens AFTER receiving this notify.
417 notify_thread_lttng_pipe(ctx
->consumer_data_pipe
);
418 notify_thread_lttng_pipe(ctx
->consumer_metadata_pipe
);
423 * Flag a relayd socket pair for destruction. Destroy it if the refcount
426 * RCU read side lock MUST be aquired before calling this function.
428 void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair
*relayd
)
432 /* Set destroy flag for this object */
433 uatomic_set(&relayd
->destroy_flag
, 1);
435 /* Destroy the relayd if refcount is 0 */
436 if (uatomic_read(&relayd
->refcount
) == 0) {
437 consumer_destroy_relayd(relayd
);
442 * Remove a stream from the global list protected by a mutex. This
443 * function is also responsible for freeing its data structures.
445 void consumer_del_stream(struct lttng_consumer_stream
*stream
,
449 struct lttng_ht_iter iter
;
450 struct lttng_consumer_channel
*free_chan
= NULL
;
451 struct consumer_relayd_sock_pair
*relayd
;
455 DBG("Consumer del stream %d", stream
->wait_fd
);
458 /* Means the stream was allocated but not successfully added */
459 goto free_stream_rcu
;
462 pthread_mutex_lock(&consumer_data
.lock
);
463 pthread_mutex_lock(&stream
->lock
);
465 switch (consumer_data
.type
) {
466 case LTTNG_CONSUMER_KERNEL
:
467 if (stream
->mmap_base
!= NULL
) {
468 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
474 if (stream
->wait_fd
>= 0) {
475 ret
= close(stream
->wait_fd
);
481 case LTTNG_CONSUMER32_UST
:
482 case LTTNG_CONSUMER64_UST
:
483 lttng_ustconsumer_del_stream(stream
);
486 ERR("Unknown consumer_data type");
492 iter
.iter
.node
= &stream
->node
.node
;
493 ret
= lttng_ht_del(ht
, &iter
);
496 iter
.iter
.node
= &stream
->node_channel_id
.node
;
497 ret
= lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
500 iter
.iter
.node
= &stream
->node_session_id
.node
;
501 ret
= lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
505 assert(consumer_data
.stream_count
> 0);
506 consumer_data
.stream_count
--;
508 if (stream
->out_fd
>= 0) {
509 ret
= close(stream
->out_fd
);
515 /* Check and cleanup relayd */
517 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
518 if (relayd
!= NULL
) {
519 uatomic_dec(&relayd
->refcount
);
520 assert(uatomic_read(&relayd
->refcount
) >= 0);
522 /* Closing streams requires to lock the control socket. */
523 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
524 ret
= relayd_send_close_stream(&relayd
->control_sock
,
525 stream
->relayd_stream_id
,
526 stream
->next_net_seq_num
- 1);
527 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
529 DBG("Unable to close stream on the relayd. Continuing");
531 * Continue here. There is nothing we can do for the relayd.
532 * Chances are that the relayd has closed the socket so we just
533 * continue cleaning up.
537 /* Both conditions are met, we destroy the relayd. */
538 if (uatomic_read(&relayd
->refcount
) == 0 &&
539 uatomic_read(&relayd
->destroy_flag
)) {
540 consumer_destroy_relayd(relayd
);
545 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
546 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
547 free_chan
= stream
->chan
;
551 consumer_data
.need_update
= 1;
552 pthread_mutex_unlock(&stream
->lock
);
553 pthread_mutex_unlock(&consumer_data
.lock
);
556 consumer_del_channel(free_chan
);
560 call_rcu(&stream
->node
.head
, free_stream_rcu
);
563 struct lttng_consumer_stream
*consumer_allocate_stream(uint64_t channel_key
,
565 enum lttng_consumer_stream_state state
,
566 const char *channel_name
,
573 enum consumer_channel_type type
)
576 struct lttng_consumer_stream
*stream
;
578 stream
= zmalloc(sizeof(*stream
));
579 if (stream
== NULL
) {
580 PERROR("malloc struct lttng_consumer_stream");
587 stream
->key
= stream_key
;
589 stream
->out_fd_offset
= 0;
590 stream
->state
= state
;
593 stream
->net_seq_idx
= relayd_id
;
594 stream
->session_id
= session_id
;
595 pthread_mutex_init(&stream
->lock
, NULL
);
597 /* If channel is the metadata, flag this stream as metadata. */
598 if (type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
599 stream
->metadata_flag
= 1;
600 /* Metadata is flat out. */
601 strncpy(stream
->name
, DEFAULT_METADATA_NAME
, sizeof(stream
->name
));
603 /* Format stream name to <channel_name>_<cpu_number> */
604 ret
= snprintf(stream
->name
, sizeof(stream
->name
), "%s_%d",
607 PERROR("snprintf stream name");
612 /* Key is always the wait_fd for streams. */
613 lttng_ht_node_init_u64(&stream
->node
, stream
->key
);
615 /* Init node per channel id key */
616 lttng_ht_node_init_u64(&stream
->node_channel_id
, channel_key
);
618 /* Init session id node with the stream session id */
619 lttng_ht_node_init_u64(&stream
->node_session_id
, stream
->session_id
);
621 DBG3("Allocated stream %s (key %" PRIu64
", chan_key %" PRIu64
" relayd_id %" PRIu64
", session_id %" PRIu64
,
622 stream
->name
, stream
->key
, channel_key
, stream
->net_seq_idx
, stream
->session_id
);
638 * Add a stream to the global list protected by a mutex.
640 static int add_stream(struct lttng_consumer_stream
*stream
,
644 struct consumer_relayd_sock_pair
*relayd
;
649 DBG3("Adding consumer stream %" PRIu64
, stream
->key
);
651 pthread_mutex_lock(&consumer_data
.lock
);
652 pthread_mutex_lock(&stream
->lock
);
655 /* Steal stream identifier to avoid having streams with the same key */
656 steal_stream_key(stream
->key
, ht
);
658 lttng_ht_add_unique_u64(ht
, &stream
->node
);
660 lttng_ht_add_u64(consumer_data
.stream_per_chan_id_ht
,
661 &stream
->node_channel_id
);
664 * Add stream to the stream_list_ht of the consumer data. No need to steal
665 * the key since the HT does not use it and we allow to add redundant keys
668 lttng_ht_add_u64(consumer_data
.stream_list_ht
, &stream
->node_session_id
);
670 /* Check and cleanup relayd */
671 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
672 if (relayd
!= NULL
) {
673 uatomic_inc(&relayd
->refcount
);
677 * When nb_init_stream_left reaches 0, we don't need to trigger any action
678 * in terms of destroying the associated channel, because the action that
679 * causes the count to become 0 also causes a stream to be added. The
680 * channel deletion will thus be triggered by the following removal of this
683 if (uatomic_read(&stream
->chan
->nb_init_stream_left
) > 0) {
684 /* Increment refcount before decrementing nb_init_stream_left */
686 uatomic_dec(&stream
->chan
->nb_init_stream_left
);
689 /* Update consumer data once the node is inserted. */
690 consumer_data
.stream_count
++;
691 consumer_data
.need_update
= 1;
694 pthread_mutex_unlock(&stream
->lock
);
695 pthread_mutex_unlock(&consumer_data
.lock
);
701 * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
702 * be acquired before calling this.
704 static int add_relayd(struct consumer_relayd_sock_pair
*relayd
)
707 struct lttng_ht_node_u64
*node
;
708 struct lttng_ht_iter iter
;
712 lttng_ht_lookup(consumer_data
.relayd_ht
,
713 &relayd
->net_seq_idx
, &iter
);
714 node
= lttng_ht_iter_get_node_u64(&iter
);
718 lttng_ht_add_unique_u64(consumer_data
.relayd_ht
, &relayd
->node
);
725 * Allocate and return a consumer relayd socket.
727 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
730 struct consumer_relayd_sock_pair
*obj
= NULL
;
732 /* Negative net sequence index is a failure */
733 if (net_seq_idx
< 0) {
737 obj
= zmalloc(sizeof(struct consumer_relayd_sock_pair
));
739 PERROR("zmalloc relayd sock");
743 obj
->net_seq_idx
= net_seq_idx
;
745 obj
->destroy_flag
= 0;
746 obj
->control_sock
.sock
.fd
= -1;
747 obj
->data_sock
.sock
.fd
= -1;
748 lttng_ht_node_init_u64(&obj
->node
, obj
->net_seq_idx
);
749 pthread_mutex_init(&obj
->ctrl_sock_mutex
, NULL
);
756 * Find a relayd socket pair in the global consumer data.
758 * Return the object if found else NULL.
759 * RCU read-side lock must be held across this call and while using the
762 struct consumer_relayd_sock_pair
*consumer_find_relayd(uint64_t key
)
764 struct lttng_ht_iter iter
;
765 struct lttng_ht_node_u64
*node
;
766 struct consumer_relayd_sock_pair
*relayd
= NULL
;
768 /* Negative keys are lookup failures */
769 if (key
== (uint64_t) -1ULL) {
773 lttng_ht_lookup(consumer_data
.relayd_ht
, &key
,
775 node
= lttng_ht_iter_get_node_u64(&iter
);
777 relayd
= caa_container_of(node
, struct consumer_relayd_sock_pair
, node
);
785 * Handle stream for relayd transmission if the stream applies for network
786 * streaming where the net sequence index is set.
788 * Return destination file descriptor or negative value on error.
790 static int write_relayd_stream_header(struct lttng_consumer_stream
*stream
,
791 size_t data_size
, unsigned long padding
,
792 struct consumer_relayd_sock_pair
*relayd
)
795 struct lttcomm_relayd_data_hdr data_hdr
;
801 /* Reset data header */
802 memset(&data_hdr
, 0, sizeof(data_hdr
));
804 if (stream
->metadata_flag
) {
805 /* Caller MUST acquire the relayd control socket lock */
806 ret
= relayd_send_metadata(&relayd
->control_sock
, data_size
);
811 /* Metadata are always sent on the control socket. */
812 outfd
= relayd
->control_sock
.sock
.fd
;
814 /* Set header with stream information */
815 data_hdr
.stream_id
= htobe64(stream
->relayd_stream_id
);
816 data_hdr
.data_size
= htobe32(data_size
);
817 data_hdr
.padding_size
= htobe32(padding
);
819 * Note that net_seq_num below is assigned with the *current* value of
820 * next_net_seq_num and only after that the next_net_seq_num will be
821 * increment. This is why when issuing a command on the relayd using
822 * this next value, 1 should always be substracted in order to compare
823 * the last seen sequence number on the relayd side to the last sent.
825 data_hdr
.net_seq_num
= htobe64(stream
->next_net_seq_num
);
826 /* Other fields are zeroed previously */
828 ret
= relayd_send_data_hdr(&relayd
->data_sock
, &data_hdr
,
834 ++stream
->next_net_seq_num
;
836 /* Set to go on data socket */
837 outfd
= relayd
->data_sock
.sock
.fd
;
845 * Allocate and return a new lttng_consumer_channel object using the given key
846 * to initialize the hash table node.
848 * On error, return NULL.
850 struct lttng_consumer_channel
*consumer_allocate_channel(uint64_t key
,
852 const char *pathname
,
857 enum lttng_event_output output
,
858 uint64_t tracefile_size
,
859 uint64_t tracefile_count
)
861 struct lttng_consumer_channel
*channel
;
863 channel
= zmalloc(sizeof(*channel
));
864 if (channel
== NULL
) {
865 PERROR("malloc struct lttng_consumer_channel");
870 channel
->refcount
= 0;
871 channel
->session_id
= session_id
;
874 channel
->relayd_id
= relayd_id
;
875 channel
->output
= output
;
876 channel
->tracefile_size
= tracefile_size
;
877 channel
->tracefile_count
= tracefile_count
;
879 strncpy(channel
->pathname
, pathname
, sizeof(channel
->pathname
));
880 channel
->pathname
[sizeof(channel
->pathname
) - 1] = '\0';
882 strncpy(channel
->name
, name
, sizeof(channel
->name
));
883 channel
->name
[sizeof(channel
->name
) - 1] = '\0';
885 lttng_ht_node_init_u64(&channel
->node
, channel
->key
);
887 channel
->wait_fd
= -1;
889 CDS_INIT_LIST_HEAD(&channel
->streams
.head
);
891 DBG("Allocated channel (key %" PRIu64
")", channel
->key
)
898 * Add a channel to the global list protected by a mutex.
900 * On success 0 is returned else a negative value.
902 int consumer_add_channel(struct lttng_consumer_channel
*channel
,
903 struct lttng_consumer_local_data
*ctx
)
906 struct lttng_ht_node_u64
*node
;
907 struct lttng_ht_iter iter
;
909 pthread_mutex_lock(&consumer_data
.lock
);
912 lttng_ht_lookup(consumer_data
.channel_ht
, &channel
->key
, &iter
);
913 node
= lttng_ht_iter_get_node_u64(&iter
);
915 /* Channel already exist. Ignore the insertion */
916 ERR("Consumer add channel key %" PRIu64
" already exists!",
922 lttng_ht_add_unique_u64(consumer_data
.channel_ht
, &channel
->node
);
926 pthread_mutex_unlock(&consumer_data
.lock
);
928 if (!ret
&& channel
->wait_fd
!= -1 &&
929 channel
->metadata_stream
== NULL
) {
930 notify_channel_pipe(ctx
, channel
, -1, CONSUMER_CHANNEL_ADD
);
936 * Allocate the pollfd structure and the local view of the out fds to avoid
937 * doing a lookup in the linked list and concurrency issues when writing is
938 * needed. Called with consumer_data.lock held.
940 * Returns the number of fds in the structures.
942 static int update_poll_array(struct lttng_consumer_local_data
*ctx
,
943 struct pollfd
**pollfd
, struct lttng_consumer_stream
**local_stream
,
947 struct lttng_ht_iter iter
;
948 struct lttng_consumer_stream
*stream
;
953 assert(local_stream
);
955 DBG("Updating poll fd array");
957 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
959 * Only active streams with an active end point can be added to the
960 * poll set and local stream storage of the thread.
962 * There is a potential race here for endpoint_status to be updated
963 * just after the check. However, this is OK since the stream(s) will
964 * be deleted once the thread is notified that the end point state has
965 * changed where this function will be called back again.
967 if (stream
->state
!= LTTNG_CONSUMER_ACTIVE_STREAM
||
968 stream
->endpoint_status
== CONSUMER_ENDPOINT_INACTIVE
) {
972 * This clobbers way too much the debug output. Uncomment that if you
973 * need it for debugging purposes.
975 * DBG("Active FD %d", stream->wait_fd);
977 (*pollfd
)[i
].fd
= stream
->wait_fd
;
978 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
979 local_stream
[i
] = stream
;
985 * Insert the consumer_data_pipe at the end of the array and don't
986 * increment i so nb_fd is the number of real FD.
988 (*pollfd
)[i
].fd
= lttng_pipe_get_readfd(ctx
->consumer_data_pipe
);
989 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
994 * Poll on the should_quit pipe and the command socket return -1 on error and
995 * should exit, 0 if data is available on the command socket
997 int lttng_consumer_poll_socket(struct pollfd
*consumer_sockpoll
)
1002 num_rdy
= poll(consumer_sockpoll
, 2, -1);
1003 if (num_rdy
== -1) {
1005 * Restart interrupted system call.
1007 if (errno
== EINTR
) {
1010 PERROR("Poll error");
1013 if (consumer_sockpoll
[0].revents
& (POLLIN
| POLLPRI
)) {
1014 DBG("consumer_should_quit wake up");
1024 * Set the error socket.
1026 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data
*ctx
,
1029 ctx
->consumer_error_socket
= sock
;
1033 * Set the command socket path.
1035 void lttng_consumer_set_command_sock_path(
1036 struct lttng_consumer_local_data
*ctx
, char *sock
)
1038 ctx
->consumer_command_sock_path
= sock
;
1042 * Send return code to the session daemon.
1043 * If the socket is not defined, we return 0, it is not a fatal error
1045 int lttng_consumer_send_error(struct lttng_consumer_local_data
*ctx
, int cmd
)
1047 if (ctx
->consumer_error_socket
> 0) {
1048 return lttcomm_send_unix_sock(ctx
->consumer_error_socket
, &cmd
,
1049 sizeof(enum lttcomm_sessiond_command
));
1056 * Close all the tracefiles and stream fds and MUST be called when all
1057 * instances are destroyed i.e. when all threads were joined and are ended.
1059 void lttng_consumer_cleanup(void)
1061 struct lttng_ht_iter iter
;
1062 struct lttng_consumer_channel
*channel
;
1066 cds_lfht_for_each_entry(consumer_data
.channel_ht
->ht
, &iter
.iter
, channel
,
1068 consumer_del_channel(channel
);
1073 lttng_ht_destroy(consumer_data
.channel_ht
);
1075 cleanup_relayd_ht();
1077 lttng_ht_destroy(consumer_data
.stream_per_chan_id_ht
);
1080 * This HT contains streams that are freed by either the metadata thread or
1081 * the data thread so we do *nothing* on the hash table and simply destroy
1084 lttng_ht_destroy(consumer_data
.stream_list_ht
);
1088 * Called from signal handler.
1090 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
)
1095 ret
= write(ctx
->consumer_should_quit
[1], "4", 1);
1096 } while (ret
< 0 && errno
== EINTR
);
1097 if (ret
< 0 || ret
!= 1) {
1098 PERROR("write consumer quit");
1101 DBG("Consumer flag that it should quit");
1104 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream
*stream
,
1107 int outfd
= stream
->out_fd
;
1110 * This does a blocking write-and-wait on any page that belongs to the
1111 * subbuffer prior to the one we just wrote.
1112 * Don't care about error values, as these are just hints and ways to
1113 * limit the amount of page cache used.
1115 if (orig_offset
< stream
->max_sb_size
) {
1118 lttng_sync_file_range(outfd
, orig_offset
- stream
->max_sb_size
,
1119 stream
->max_sb_size
,
1120 SYNC_FILE_RANGE_WAIT_BEFORE
1121 | SYNC_FILE_RANGE_WRITE
1122 | SYNC_FILE_RANGE_WAIT_AFTER
);
1124 * Give hints to the kernel about how we access the file:
1125 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
1128 * We need to call fadvise again after the file grows because the
1129 * kernel does not seem to apply fadvise to non-existing parts of the
1132 * Call fadvise _after_ having waited for the page writeback to
1133 * complete because the dirty page writeback semantic is not well
1134 * defined. So it can be expected to lead to lower throughput in
1137 posix_fadvise(outfd
, orig_offset
- stream
->max_sb_size
,
1138 stream
->max_sb_size
, POSIX_FADV_DONTNEED
);
1142 * Initialise the necessary environnement :
1143 * - create a new context
1144 * - create the poll_pipe
1145 * - create the should_quit pipe (for signal handler)
1146 * - create the thread pipe (for splice)
1148 * Takes a function pointer as argument, this function is called when data is
1149 * available on a buffer. This function is responsible to do the
1150 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
1151 * buffer configuration and then kernctl_put_next_subbuf at the end.
1153 * Returns a pointer to the new context or NULL on error.
1155 struct lttng_consumer_local_data
*lttng_consumer_create(
1156 enum lttng_consumer_type type
,
1157 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
1158 struct lttng_consumer_local_data
*ctx
),
1159 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
1160 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
1161 int (*update_stream
)(int stream_key
, uint32_t state
))
1164 struct lttng_consumer_local_data
*ctx
;
1166 assert(consumer_data
.type
== LTTNG_CONSUMER_UNKNOWN
||
1167 consumer_data
.type
== type
);
1168 consumer_data
.type
= type
;
1170 ctx
= zmalloc(sizeof(struct lttng_consumer_local_data
));
1172 PERROR("allocating context");
1176 ctx
->consumer_error_socket
= -1;
1177 ctx
->consumer_metadata_socket
= -1;
1178 /* assign the callbacks */
1179 ctx
->on_buffer_ready
= buffer_ready
;
1180 ctx
->on_recv_channel
= recv_channel
;
1181 ctx
->on_recv_stream
= recv_stream
;
1182 ctx
->on_update_stream
= update_stream
;
1184 ctx
->consumer_data_pipe
= lttng_pipe_open(0);
1185 if (!ctx
->consumer_data_pipe
) {
1186 goto error_poll_pipe
;
1189 ret
= pipe(ctx
->consumer_should_quit
);
1191 PERROR("Error creating recv pipe");
1192 goto error_quit_pipe
;
1195 ret
= pipe(ctx
->consumer_thread_pipe
);
1197 PERROR("Error creating thread pipe");
1198 goto error_thread_pipe
;
1201 ret
= pipe(ctx
->consumer_channel_pipe
);
1203 PERROR("Error creating channel pipe");
1204 goto error_channel_pipe
;
1207 ctx
->consumer_metadata_pipe
= lttng_pipe_open(0);
1208 if (!ctx
->consumer_metadata_pipe
) {
1209 goto error_metadata_pipe
;
1212 ret
= utils_create_pipe(ctx
->consumer_splice_metadata_pipe
);
1214 goto error_splice_pipe
;
1220 lttng_pipe_destroy(ctx
->consumer_metadata_pipe
);
1221 error_metadata_pipe
:
1222 utils_close_pipe(ctx
->consumer_channel_pipe
);
1224 utils_close_pipe(ctx
->consumer_thread_pipe
);
1226 utils_close_pipe(ctx
->consumer_should_quit
);
1228 lttng_pipe_destroy(ctx
->consumer_data_pipe
);
1236 * Close all fds associated with the instance and free the context.
1238 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
)
1242 DBG("Consumer destroying it. Closing everything.");
1244 ret
= close(ctx
->consumer_error_socket
);
1248 ret
= close(ctx
->consumer_metadata_socket
);
1252 utils_close_pipe(ctx
->consumer_thread_pipe
);
1253 utils_close_pipe(ctx
->consumer_channel_pipe
);
1254 lttng_pipe_destroy(ctx
->consumer_data_pipe
);
1255 lttng_pipe_destroy(ctx
->consumer_metadata_pipe
);
1256 utils_close_pipe(ctx
->consumer_should_quit
);
1257 utils_close_pipe(ctx
->consumer_splice_metadata_pipe
);
1259 unlink(ctx
->consumer_command_sock_path
);
1264 * Write the metadata stream id on the specified file descriptor.
1266 static int write_relayd_metadata_id(int fd
,
1267 struct lttng_consumer_stream
*stream
,
1268 struct consumer_relayd_sock_pair
*relayd
, unsigned long padding
)
1271 struct lttcomm_relayd_metadata_payload hdr
;
1273 hdr
.stream_id
= htobe64(stream
->relayd_stream_id
);
1274 hdr
.padding_size
= htobe32(padding
);
1276 ret
= write(fd
, (void *) &hdr
, sizeof(hdr
));
1277 } while (ret
< 0 && errno
== EINTR
);
1278 if (ret
< 0 || ret
!= sizeof(hdr
)) {
1280 * This error means that the fd's end is closed so ignore the perror
1281 * not to clubber the error output since this can happen in a normal
1284 if (errno
!= EPIPE
) {
1285 PERROR("write metadata stream id");
1287 DBG3("Consumer failed to write relayd metadata id (errno: %d)", errno
);
1289 * Set ret to a negative value because if ret != sizeof(hdr), we don't
1290 * handle writting the missing part so report that as an error and
1291 * don't lie to the caller.
1296 DBG("Metadata stream id %" PRIu64
" with padding %lu written before data",
1297 stream
->relayd_stream_id
, padding
);
1304 * Mmap the ring buffer, read it and write the data to the tracefile. This is a
1305 * core function for writing trace buffers to either the local filesystem or
1308 * It must be called with the stream lock held.
1310 * Careful review MUST be put if any changes occur!
1312 * Returns the number of bytes written
1314 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
1315 struct lttng_consumer_local_data
*ctx
,
1316 struct lttng_consumer_stream
*stream
, unsigned long len
,
1317 unsigned long padding
)
1319 unsigned long mmap_offset
;
1321 ssize_t ret
= 0, written
= 0;
1322 off_t orig_offset
= stream
->out_fd_offset
;
1323 /* Default is on the disk */
1324 int outfd
= stream
->out_fd
;
1325 struct consumer_relayd_sock_pair
*relayd
= NULL
;
1326 unsigned int relayd_hang_up
= 0;
1328 /* RCU lock for the relayd pointer */
1331 /* Flag that the current stream if set for network streaming. */
1332 if (stream
->net_seq_idx
!= -1) {
1333 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1334 if (relayd
== NULL
) {
1339 /* get the offset inside the fd to mmap */
1340 switch (consumer_data
.type
) {
1341 case LTTNG_CONSUMER_KERNEL
:
1342 mmap_base
= stream
->mmap_base
;
1343 ret
= kernctl_get_mmap_read_offset(stream
->wait_fd
, &mmap_offset
);
1345 case LTTNG_CONSUMER32_UST
:
1346 case LTTNG_CONSUMER64_UST
:
1347 mmap_base
= lttng_ustctl_get_mmap_base(stream
);
1349 ERR("read mmap get mmap base for stream %s", stream
->name
);
1353 ret
= lttng_ustctl_get_mmap_read_offset(stream
, &mmap_offset
);
1357 ERR("Unknown consumer_data type");
1362 PERROR("tracer ctl get_mmap_read_offset");
1367 /* Handle stream on the relayd if the output is on the network */
1369 unsigned long netlen
= len
;
1372 * Lock the control socket for the complete duration of the function
1373 * since from this point on we will use the socket.
1375 if (stream
->metadata_flag
) {
1376 /* Metadata requires the control socket. */
1377 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1378 netlen
+= sizeof(struct lttcomm_relayd_metadata_payload
);
1381 ret
= write_relayd_stream_header(stream
, netlen
, padding
, relayd
);
1383 /* Use the returned socket. */
1386 /* Write metadata stream id before payload */
1387 if (stream
->metadata_flag
) {
1388 ret
= write_relayd_metadata_id(outfd
, stream
, relayd
, padding
);
1391 /* Socket operation failed. We consider the relayd dead */
1392 if (ret
== -EPIPE
|| ret
== -EINVAL
) {
1400 /* Socket operation failed. We consider the relayd dead */
1401 if (ret
== -EPIPE
|| ret
== -EINVAL
) {
1405 /* Else, use the default set before which is the filesystem. */
1408 /* No streaming, we have to set the len with the full padding */
1412 * Check if we need to change the tracefile before writing the packet.
1414 if (stream
->chan
->tracefile_size
> 0 &&
1415 (stream
->tracefile_size_current
+ len
) >
1416 stream
->chan
->tracefile_size
) {
1417 ret
= utils_rotate_stream_file(stream
->chan
->pathname
,
1418 stream
->name
, stream
->chan
->tracefile_size
,
1419 stream
->chan
->tracefile_count
, stream
->uid
, stream
->gid
,
1420 stream
->out_fd
, &(stream
->tracefile_count_current
));
1422 ERR("Rotating output file");
1425 outfd
= stream
->out_fd
= ret
;
1426 /* Reset current size because we just perform a rotation. */
1427 stream
->tracefile_size_current
= 0;
1429 stream
->tracefile_size_current
+= len
;
1434 ret
= write(outfd
, mmap_base
+ mmap_offset
, len
);
1435 } while (ret
< 0 && errno
== EINTR
);
1436 DBG("Consumer mmap write() ret %zd (len %lu)", ret
, len
);
1439 * This is possible if the fd is closed on the other side (outfd)
1440 * or any write problem. It can be verbose a bit for a normal
1441 * execution if for instance the relayd is stopped abruptly. This
1442 * can happen so set this to a DBG statement.
1444 DBG("Error in file write mmap");
1448 /* Socket operation failed. We consider the relayd dead */
1449 if (errno
== EPIPE
|| errno
== EINVAL
) {
1454 } else if (ret
> len
) {
1455 PERROR("Error in file write (ret %zd > len %lu)", ret
, len
);
1463 /* This call is useless on a socket so better save a syscall. */
1465 /* This won't block, but will start writeout asynchronously */
1466 lttng_sync_file_range(outfd
, stream
->out_fd_offset
, ret
,
1467 SYNC_FILE_RANGE_WRITE
);
1468 stream
->out_fd_offset
+= ret
;
1472 lttng_consumer_sync_trace_file(stream
, orig_offset
);
1476 * This is a special case that the relayd has closed its socket. Let's
1477 * cleanup the relayd object and all associated streams.
1479 if (relayd
&& relayd_hang_up
) {
1480 cleanup_relayd(relayd
, ctx
);
1484 /* Unlock only if ctrl socket used */
1485 if (relayd
&& stream
->metadata_flag
) {
1486 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1494 * Splice the data from the ring buffer to the tracefile.
1496 * It must be called with the stream lock held.
1498 * Returns the number of bytes spliced.
1500 ssize_t
lttng_consumer_on_read_subbuffer_splice(
1501 struct lttng_consumer_local_data
*ctx
,
1502 struct lttng_consumer_stream
*stream
, unsigned long len
,
1503 unsigned long padding
)
1505 ssize_t ret
= 0, written
= 0, ret_splice
= 0;
1507 off_t orig_offset
= stream
->out_fd_offset
;
1508 int fd
= stream
->wait_fd
;
1509 /* Default is on the disk */
1510 int outfd
= stream
->out_fd
;
1511 struct consumer_relayd_sock_pair
*relayd
= NULL
;
1513 unsigned int relayd_hang_up
= 0;
1515 switch (consumer_data
.type
) {
1516 case LTTNG_CONSUMER_KERNEL
:
1518 case LTTNG_CONSUMER32_UST
:
1519 case LTTNG_CONSUMER64_UST
:
1520 /* Not supported for user space tracing */
1523 ERR("Unknown consumer_data type");
1527 /* RCU lock for the relayd pointer */
1530 /* Flag that the current stream if set for network streaming. */
1531 if (stream
->net_seq_idx
!= -1) {
1532 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1533 if (relayd
== NULL
) {
1539 * Choose right pipe for splice. Metadata and trace data are handled by
1540 * different threads hence the use of two pipes in order not to race or
1541 * corrupt the written data.
1543 if (stream
->metadata_flag
) {
1544 splice_pipe
= ctx
->consumer_splice_metadata_pipe
;
1546 splice_pipe
= ctx
->consumer_thread_pipe
;
1549 /* Write metadata stream id before payload */
1551 int total_len
= len
;
1553 if (stream
->metadata_flag
) {
1555 * Lock the control socket for the complete duration of the function
1556 * since from this point on we will use the socket.
1558 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1560 ret
= write_relayd_metadata_id(splice_pipe
[1], stream
, relayd
,
1564 /* Socket operation failed. We consider the relayd dead */
1565 if (ret
== -EBADF
) {
1566 WARN("Remote relayd disconnected. Stopping");
1573 total_len
+= sizeof(struct lttcomm_relayd_metadata_payload
);
1576 ret
= write_relayd_stream_header(stream
, total_len
, padding
, relayd
);
1578 /* Use the returned socket. */
1581 /* Socket operation failed. We consider the relayd dead */
1582 if (ret
== -EBADF
) {
1583 WARN("Remote relayd disconnected. Stopping");
1590 /* No streaming, we have to set the len with the full padding */
1594 * Check if we need to change the tracefile before writing the packet.
1596 if (stream
->chan
->tracefile_size
> 0 &&
1597 (stream
->tracefile_size_current
+ len
) >
1598 stream
->chan
->tracefile_size
) {
1599 ret
= utils_rotate_stream_file(stream
->chan
->pathname
,
1600 stream
->name
, stream
->chan
->tracefile_size
,
1601 stream
->chan
->tracefile_count
, stream
->uid
, stream
->gid
,
1602 stream
->out_fd
, &(stream
->tracefile_count_current
));
1604 ERR("Rotating output file");
1607 outfd
= stream
->out_fd
= ret
;
1608 /* Reset current size because we just perform a rotation. */
1609 stream
->tracefile_size_current
= 0;
1611 stream
->tracefile_size_current
+= len
;
1615 DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)",
1616 (unsigned long)offset
, len
, fd
, splice_pipe
[1]);
1617 ret_splice
= splice(fd
, &offset
, splice_pipe
[1], NULL
, len
,
1618 SPLICE_F_MOVE
| SPLICE_F_MORE
);
1619 DBG("splice chan to pipe, ret %zd", ret_splice
);
1620 if (ret_splice
< 0) {
1621 PERROR("Error in relay splice");
1623 written
= ret_splice
;
1629 /* Handle stream on the relayd if the output is on the network */
1631 if (stream
->metadata_flag
) {
1632 size_t metadata_payload_size
=
1633 sizeof(struct lttcomm_relayd_metadata_payload
);
1635 /* Update counter to fit the spliced data */
1636 ret_splice
+= metadata_payload_size
;
1637 len
+= metadata_payload_size
;
1639 * We do this so the return value can match the len passed as
1640 * argument to this function.
1642 written
-= metadata_payload_size
;
1646 /* Splice data out */
1647 ret_splice
= splice(splice_pipe
[0], NULL
, outfd
, NULL
,
1648 ret_splice
, SPLICE_F_MOVE
| SPLICE_F_MORE
);
1649 DBG("Consumer splice pipe to file, ret %zd", ret_splice
);
1650 if (ret_splice
< 0) {
1651 PERROR("Error in file splice");
1653 written
= ret_splice
;
1655 /* Socket operation failed. We consider the relayd dead */
1656 if (errno
== EBADF
|| errno
== EPIPE
) {
1657 WARN("Remote relayd disconnected. Stopping");
1663 } else if (ret_splice
> len
) {
1665 PERROR("Wrote more data than requested %zd (len: %lu)",
1667 written
+= ret_splice
;
1673 /* This call is useless on a socket so better save a syscall. */
1675 /* This won't block, but will start writeout asynchronously */
1676 lttng_sync_file_range(outfd
, stream
->out_fd_offset
, ret_splice
,
1677 SYNC_FILE_RANGE_WRITE
);
1678 stream
->out_fd_offset
+= ret_splice
;
1680 written
+= ret_splice
;
1682 lttng_consumer_sync_trace_file(stream
, orig_offset
);
1690 * This is a special case that the relayd has closed its socket. Let's
1691 * cleanup the relayd object and all associated streams.
1693 if (relayd
&& relayd_hang_up
) {
1694 cleanup_relayd(relayd
, ctx
);
1695 /* Skip splice error so the consumer does not fail */
1700 /* send the appropriate error description to sessiond */
1703 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_EINVAL
);
1706 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_ENOMEM
);
1709 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_ESPIPE
);
1714 if (relayd
&& stream
->metadata_flag
) {
1715 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1723 * Take a snapshot for a specific fd
1725 * Returns 0 on success, < 0 on error
1727 int lttng_consumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1729 switch (consumer_data
.type
) {
1730 case LTTNG_CONSUMER_KERNEL
:
1731 return lttng_kconsumer_take_snapshot(stream
);
1732 case LTTNG_CONSUMER32_UST
:
1733 case LTTNG_CONSUMER64_UST
:
1734 return lttng_ustconsumer_take_snapshot(stream
);
1736 ERR("Unknown consumer_data type");
1743 * Get the produced position
1745 * Returns 0 on success, < 0 on error
1747 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
1750 switch (consumer_data
.type
) {
1751 case LTTNG_CONSUMER_KERNEL
:
1752 return lttng_kconsumer_get_produced_snapshot(stream
, pos
);
1753 case LTTNG_CONSUMER32_UST
:
1754 case LTTNG_CONSUMER64_UST
:
1755 return lttng_ustconsumer_get_produced_snapshot(stream
, pos
);
1757 ERR("Unknown consumer_data type");
1763 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1764 int sock
, struct pollfd
*consumer_sockpoll
)
1766 switch (consumer_data
.type
) {
1767 case LTTNG_CONSUMER_KERNEL
:
1768 return lttng_kconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1769 case LTTNG_CONSUMER32_UST
:
1770 case LTTNG_CONSUMER64_UST
:
1771 return lttng_ustconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1773 ERR("Unknown consumer_data type");
1780 * Iterate over all streams of the hashtable and free them properly.
1782 * WARNING: *MUST* be used with data stream only.
1784 static void destroy_data_stream_ht(struct lttng_ht
*ht
)
1786 struct lttng_ht_iter iter
;
1787 struct lttng_consumer_stream
*stream
;
1794 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
1796 * Ignore return value since we are currently cleaning up so any error
1799 (void) consumer_del_stream(stream
, ht
);
1803 lttng_ht_destroy(ht
);
1807 * Iterate over all streams of the hashtable and free them properly.
1809 * XXX: Should not be only for metadata stream or else use an other name.
1811 static void destroy_stream_ht(struct lttng_ht
*ht
)
1813 struct lttng_ht_iter iter
;
1814 struct lttng_consumer_stream
*stream
;
1821 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
1823 * Ignore return value since we are currently cleaning up so any error
1826 (void) consumer_del_metadata_stream(stream
, ht
);
1830 lttng_ht_destroy(ht
);
1833 void lttng_consumer_close_metadata(void)
1835 switch (consumer_data
.type
) {
1836 case LTTNG_CONSUMER_KERNEL
:
1838 * The Kernel consumer has a different metadata scheme so we don't
1839 * close anything because the stream will be closed by the session
1843 case LTTNG_CONSUMER32_UST
:
1844 case LTTNG_CONSUMER64_UST
:
1846 * Close all metadata streams. The metadata hash table is passed and
1847 * this call iterates over it by closing all wakeup fd. This is safe
1848 * because at this point we are sure that the metadata producer is
1849 * either dead or blocked.
1851 lttng_ustconsumer_close_metadata(metadata_ht
);
1854 ERR("Unknown consumer_data type");
1860 * Clean up a metadata stream and free its memory.
1862 void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
1863 struct lttng_ht
*ht
)
1866 struct lttng_ht_iter iter
;
1867 struct lttng_consumer_channel
*free_chan
= NULL
;
1868 struct consumer_relayd_sock_pair
*relayd
;
1872 * This call should NEVER receive regular stream. It must always be
1873 * metadata stream and this is crucial for data structure synchronization.
1875 assert(stream
->metadata_flag
);
1877 DBG3("Consumer delete metadata stream %d", stream
->wait_fd
);
1880 /* Means the stream was allocated but not successfully added */
1881 goto free_stream_rcu
;
1884 pthread_mutex_lock(&consumer_data
.lock
);
1885 pthread_mutex_lock(&stream
->lock
);
1887 switch (consumer_data
.type
) {
1888 case LTTNG_CONSUMER_KERNEL
:
1889 if (stream
->mmap_base
!= NULL
) {
1890 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
1892 PERROR("munmap metadata stream");
1896 if (stream
->wait_fd
>= 0) {
1897 ret
= close(stream
->wait_fd
);
1899 PERROR("close kernel metadata wait_fd");
1903 case LTTNG_CONSUMER32_UST
:
1904 case LTTNG_CONSUMER64_UST
:
1905 lttng_ustconsumer_del_stream(stream
);
1908 ERR("Unknown consumer_data type");
1914 iter
.iter
.node
= &stream
->node
.node
;
1915 ret
= lttng_ht_del(ht
, &iter
);
1918 iter
.iter
.node
= &stream
->node_channel_id
.node
;
1919 ret
= lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
1922 iter
.iter
.node
= &stream
->node_session_id
.node
;
1923 ret
= lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
1927 if (stream
->out_fd
>= 0) {
1928 ret
= close(stream
->out_fd
);
1934 /* Check and cleanup relayd */
1936 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1937 if (relayd
!= NULL
) {
1938 uatomic_dec(&relayd
->refcount
);
1939 assert(uatomic_read(&relayd
->refcount
) >= 0);
1941 /* Closing streams requires to lock the control socket. */
1942 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1943 ret
= relayd_send_close_stream(&relayd
->control_sock
,
1944 stream
->relayd_stream_id
, stream
->next_net_seq_num
- 1);
1945 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1947 DBG("Unable to close stream on the relayd. Continuing");
1949 * Continue here. There is nothing we can do for the relayd.
1950 * Chances are that the relayd has closed the socket so we just
1951 * continue cleaning up.
1955 /* Both conditions are met, we destroy the relayd. */
1956 if (uatomic_read(&relayd
->refcount
) == 0 &&
1957 uatomic_read(&relayd
->destroy_flag
)) {
1958 consumer_destroy_relayd(relayd
);
1963 /* Atomically decrement channel refcount since other threads can use it. */
1964 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
1965 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
1966 /* Go for channel deletion! */
1967 free_chan
= stream
->chan
;
1972 * Nullify the stream reference so it is not used after deletion. The
1973 * consumer data lock MUST be acquired before being able to check for a
1974 * NULL pointer value.
1976 stream
->chan
->metadata_stream
= NULL
;
1978 pthread_mutex_unlock(&stream
->lock
);
1979 pthread_mutex_unlock(&consumer_data
.lock
);
1982 consumer_del_channel(free_chan
);
1986 call_rcu(&stream
->node
.head
, free_stream_rcu
);
1990 * Action done with the metadata stream when adding it to the consumer internal
1991 * data structures to handle it.
1993 static int add_metadata_stream(struct lttng_consumer_stream
*stream
,
1994 struct lttng_ht
*ht
)
1997 struct consumer_relayd_sock_pair
*relayd
;
1998 struct lttng_ht_iter iter
;
1999 struct lttng_ht_node_u64
*node
;
2004 DBG3("Adding metadata stream %" PRIu64
" to hash table", stream
->key
);
2006 pthread_mutex_lock(&consumer_data
.lock
);
2007 pthread_mutex_lock(&stream
->lock
);
2010 * From here, refcounts are updated so be _careful_ when returning an error
2017 * Lookup the stream just to make sure it does not exist in our internal
2018 * state. This should NEVER happen.
2020 lttng_ht_lookup(ht
, &stream
->key
, &iter
);
2021 node
= lttng_ht_iter_get_node_u64(&iter
);
2024 /* Find relayd and, if one is found, increment refcount. */
2025 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
2026 if (relayd
!= NULL
) {
2027 uatomic_inc(&relayd
->refcount
);
2031 * When nb_init_stream_left reaches 0, we don't need to trigger any action
2032 * in terms of destroying the associated channel, because the action that
2033 * causes the count to become 0 also causes a stream to be added. The
2034 * channel deletion will thus be triggered by the following removal of this
2037 if (uatomic_read(&stream
->chan
->nb_init_stream_left
) > 0) {
2038 /* Increment refcount before decrementing nb_init_stream_left */
2040 uatomic_dec(&stream
->chan
->nb_init_stream_left
);
2043 lttng_ht_add_unique_u64(ht
, &stream
->node
);
2045 lttng_ht_add_unique_u64(consumer_data
.stream_per_chan_id_ht
,
2046 &stream
->node_channel_id
);
2049 * Add stream to the stream_list_ht of the consumer data. No need to steal
2050 * the key since the HT does not use it and we allow to add redundant keys
2053 lttng_ht_add_u64(consumer_data
.stream_list_ht
, &stream
->node_session_id
);
2057 pthread_mutex_unlock(&stream
->lock
);
2058 pthread_mutex_unlock(&consumer_data
.lock
);
2063 * Delete data stream that are flagged for deletion (endpoint_status).
2065 static void validate_endpoint_status_data_stream(void)
2067 struct lttng_ht_iter iter
;
2068 struct lttng_consumer_stream
*stream
;
2070 DBG("Consumer delete flagged data stream");
2073 cds_lfht_for_each_entry(data_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
2074 /* Validate delete flag of the stream */
2075 if (stream
->endpoint_status
== CONSUMER_ENDPOINT_ACTIVE
) {
2078 /* Delete it right now */
2079 consumer_del_stream(stream
, data_ht
);
2085 * Delete metadata stream that are flagged for deletion (endpoint_status).
2087 static void validate_endpoint_status_metadata_stream(
2088 struct lttng_poll_event
*pollset
)
2090 struct lttng_ht_iter iter
;
2091 struct lttng_consumer_stream
*stream
;
2093 DBG("Consumer delete flagged metadata stream");
2098 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
2099 /* Validate delete flag of the stream */
2100 if (stream
->endpoint_status
== CONSUMER_ENDPOINT_ACTIVE
) {
2104 * Remove from pollset so the metadata thread can continue without
2105 * blocking on a deleted stream.
2107 lttng_poll_del(pollset
, stream
->wait_fd
);
2109 /* Delete it right now */
2110 consumer_del_metadata_stream(stream
, metadata_ht
);
2116 * Thread polls on metadata file descriptor and write them on disk or on the
2119 void *consumer_thread_metadata_poll(void *data
)
2122 uint32_t revents
, nb_fd
;
2123 struct lttng_consumer_stream
*stream
= NULL
;
2124 struct lttng_ht_iter iter
;
2125 struct lttng_ht_node_u64
*node
;
2126 struct lttng_poll_event events
;
2127 struct lttng_consumer_local_data
*ctx
= data
;
2130 rcu_register_thread();
2132 metadata_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2134 /* ENOMEM at this point. Better to bail out. */
2138 DBG("Thread metadata poll started");
2140 /* Size is set to 1 for the consumer_metadata pipe */
2141 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
2143 ERR("Poll set creation failed");
2147 ret
= lttng_poll_add(&events
,
2148 lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
), LPOLLIN
);
2154 DBG("Metadata main loop started");
2157 /* Only the metadata pipe is set */
2158 if (LTTNG_POLL_GETNB(&events
) == 0 && consumer_quit
== 1) {
2163 DBG("Metadata poll wait with %d fd(s)", LTTNG_POLL_GETNB(&events
));
2164 ret
= lttng_poll_wait(&events
, -1);
2165 DBG("Metadata event catched in thread");
2167 if (errno
== EINTR
) {
2168 ERR("Poll EINTR catched");
2176 /* From here, the event is a metadata wait fd */
2177 for (i
= 0; i
< nb_fd
; i
++) {
2178 revents
= LTTNG_POLL_GETEV(&events
, i
);
2179 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
2181 /* Just don't waste time if no returned events for the fd */
2186 if (pollfd
== lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
)) {
2187 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2188 DBG("Metadata thread pipe hung up");
2190 * Remove the pipe from the poll set and continue the loop
2191 * since their might be data to consume.
2193 lttng_poll_del(&events
,
2194 lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
));
2195 lttng_pipe_read_close(ctx
->consumer_metadata_pipe
);
2197 } else if (revents
& LPOLLIN
) {
2200 pipe_len
= lttng_pipe_read(ctx
->consumer_metadata_pipe
,
2201 &stream
, sizeof(stream
));
2203 ERR("read metadata stream, ret: %ld", pipe_len
);
2205 * Continue here to handle the rest of the streams.
2210 /* A NULL stream means that the state has changed. */
2211 if (stream
== NULL
) {
2212 /* Check for deleted streams. */
2213 validate_endpoint_status_metadata_stream(&events
);
2217 DBG("Adding metadata stream %d to poll set",
2220 ret
= add_metadata_stream(stream
, metadata_ht
);
2222 ERR("Unable to add metadata stream");
2223 /* Stream was not setup properly. Continuing. */
2224 consumer_del_metadata_stream(stream
, NULL
);
2228 /* Add metadata stream to the global poll events list */
2229 lttng_poll_add(&events
, stream
->wait_fd
,
2230 LPOLLIN
| LPOLLPRI
);
2233 /* Handle other stream */
2239 uint64_t tmp_id
= (uint64_t) pollfd
;
2241 lttng_ht_lookup(metadata_ht
, &tmp_id
, &iter
);
2243 node
= lttng_ht_iter_get_node_u64(&iter
);
2246 stream
= caa_container_of(node
, struct lttng_consumer_stream
,
2249 /* Check for error event */
2250 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2251 DBG("Metadata fd %d is hup|err.", pollfd
);
2252 if (!stream
->hangup_flush_done
2253 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
2254 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
2255 DBG("Attempting to flush and consume the UST buffers");
2256 lttng_ustconsumer_on_stream_hangup(stream
);
2258 /* We just flushed the stream now read it. */
2260 len
= ctx
->on_buffer_ready(stream
, ctx
);
2262 * We don't check the return value here since if we get
2263 * a negative len, it means an error occured thus we
2264 * simply remove it from the poll set and free the
2270 lttng_poll_del(&events
, stream
->wait_fd
);
2272 * This call update the channel states, closes file descriptors
2273 * and securely free the stream.
2275 consumer_del_metadata_stream(stream
, metadata_ht
);
2276 } else if (revents
& (LPOLLIN
| LPOLLPRI
)) {
2277 /* Get the data out of the metadata file descriptor */
2278 DBG("Metadata available on fd %d", pollfd
);
2279 assert(stream
->wait_fd
== pollfd
);
2281 len
= ctx
->on_buffer_ready(stream
, ctx
);
2282 /* It's ok to have an unavailable sub-buffer */
2283 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2284 /* Clean up stream from consumer and free it. */
2285 lttng_poll_del(&events
, stream
->wait_fd
);
2286 consumer_del_metadata_stream(stream
, metadata_ht
);
2287 } else if (len
> 0) {
2288 stream
->data_read
= 1;
2292 /* Release RCU lock for the stream looked up */
2299 DBG("Metadata poll thread exiting");
2301 lttng_poll_clean(&events
);
2303 destroy_stream_ht(metadata_ht
);
2305 rcu_unregister_thread();
2310 * This thread polls the fds in the set to consume the data and write
2311 * it to tracefile if necessary.
2313 void *consumer_thread_data_poll(void *data
)
2315 int num_rdy
, num_hup
, high_prio
, ret
, i
;
2316 struct pollfd
*pollfd
= NULL
;
2317 /* local view of the streams */
2318 struct lttng_consumer_stream
**local_stream
= NULL
, *new_stream
= NULL
;
2319 /* local view of consumer_data.fds_count */
2321 struct lttng_consumer_local_data
*ctx
= data
;
2324 rcu_register_thread();
2326 data_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2327 if (data_ht
== NULL
) {
2328 /* ENOMEM at this point. Better to bail out. */
2332 local_stream
= zmalloc(sizeof(struct lttng_consumer_stream
));
2339 * the fds set has been updated, we need to update our
2340 * local array as well
2342 pthread_mutex_lock(&consumer_data
.lock
);
2343 if (consumer_data
.need_update
) {
2348 local_stream
= NULL
;
2350 /* allocate for all fds + 1 for the consumer_data_pipe */
2351 pollfd
= zmalloc((consumer_data
.stream_count
+ 1) * sizeof(struct pollfd
));
2352 if (pollfd
== NULL
) {
2353 PERROR("pollfd malloc");
2354 pthread_mutex_unlock(&consumer_data
.lock
);
2358 /* allocate for all fds + 1 for the consumer_data_pipe */
2359 local_stream
= zmalloc((consumer_data
.stream_count
+ 1) *
2360 sizeof(struct lttng_consumer_stream
*));
2361 if (local_stream
== NULL
) {
2362 PERROR("local_stream malloc");
2363 pthread_mutex_unlock(&consumer_data
.lock
);
2366 ret
= update_poll_array(ctx
, &pollfd
, local_stream
,
2369 ERR("Error in allocating pollfd or local_outfds");
2370 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
2371 pthread_mutex_unlock(&consumer_data
.lock
);
2375 consumer_data
.need_update
= 0;
2377 pthread_mutex_unlock(&consumer_data
.lock
);
2379 /* No FDs and consumer_quit, consumer_cleanup the thread */
2380 if (nb_fd
== 0 && consumer_quit
== 1) {
2383 /* poll on the array of fds */
2385 DBG("polling on %d fd", nb_fd
+ 1);
2386 num_rdy
= poll(pollfd
, nb_fd
+ 1, -1);
2387 DBG("poll num_rdy : %d", num_rdy
);
2388 if (num_rdy
== -1) {
2390 * Restart interrupted system call.
2392 if (errno
== EINTR
) {
2395 PERROR("Poll error");
2396 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
2398 } else if (num_rdy
== 0) {
2399 DBG("Polling thread timed out");
2404 * If the consumer_data_pipe triggered poll go directly to the
2405 * beginning of the loop to update the array. We want to prioritize
2406 * array update over low-priority reads.
2408 if (pollfd
[nb_fd
].revents
& (POLLIN
| POLLPRI
)) {
2409 ssize_t pipe_readlen
;
2411 DBG("consumer_data_pipe wake up");
2412 pipe_readlen
= lttng_pipe_read(ctx
->consumer_data_pipe
,
2413 &new_stream
, sizeof(new_stream
));
2414 if (pipe_readlen
< 0) {
2415 ERR("Consumer data pipe ret %ld", pipe_readlen
);
2416 /* Continue so we can at least handle the current stream(s). */
2421 * If the stream is NULL, just ignore it. It's also possible that
2422 * the sessiond poll thread changed the consumer_quit state and is
2423 * waking us up to test it.
2425 if (new_stream
== NULL
) {
2426 validate_endpoint_status_data_stream();
2430 ret
= add_stream(new_stream
, data_ht
);
2432 ERR("Consumer add stream %" PRIu64
" failed. Continuing",
2435 * At this point, if the add_stream fails, it is not in the
2436 * hash table thus passing the NULL value here.
2438 consumer_del_stream(new_stream
, NULL
);
2441 /* Continue to update the local streams and handle prio ones */
2445 /* Take care of high priority channels first. */
2446 for (i
= 0; i
< nb_fd
; i
++) {
2447 if (local_stream
[i
] == NULL
) {
2450 if (pollfd
[i
].revents
& POLLPRI
) {
2451 DBG("Urgent read on fd %d", pollfd
[i
].fd
);
2453 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
2454 /* it's ok to have an unavailable sub-buffer */
2455 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2456 /* Clean the stream and free it. */
2457 consumer_del_stream(local_stream
[i
], data_ht
);
2458 local_stream
[i
] = NULL
;
2459 } else if (len
> 0) {
2460 local_stream
[i
]->data_read
= 1;
2466 * If we read high prio channel in this loop, try again
2467 * for more high prio data.
2473 /* Take care of low priority channels. */
2474 for (i
= 0; i
< nb_fd
; i
++) {
2475 if (local_stream
[i
] == NULL
) {
2478 if ((pollfd
[i
].revents
& POLLIN
) ||
2479 local_stream
[i
]->hangup_flush_done
) {
2480 DBG("Normal read on fd %d", pollfd
[i
].fd
);
2481 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
2482 /* it's ok to have an unavailable sub-buffer */
2483 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2484 /* Clean the stream and free it. */
2485 consumer_del_stream(local_stream
[i
], data_ht
);
2486 local_stream
[i
] = NULL
;
2487 } else if (len
> 0) {
2488 local_stream
[i
]->data_read
= 1;
2493 /* Handle hangup and errors */
2494 for (i
= 0; i
< nb_fd
; i
++) {
2495 if (local_stream
[i
] == NULL
) {
2498 if (!local_stream
[i
]->hangup_flush_done
2499 && (pollfd
[i
].revents
& (POLLHUP
| POLLERR
| POLLNVAL
))
2500 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
2501 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
2502 DBG("fd %d is hup|err|nval. Attempting flush and read.",
2504 lttng_ustconsumer_on_stream_hangup(local_stream
[i
]);
2505 /* Attempt read again, for the data we just flushed. */
2506 local_stream
[i
]->data_read
= 1;
2509 * If the poll flag is HUP/ERR/NVAL and we have
2510 * read no data in this pass, we can remove the
2511 * stream from its hash table.
2513 if ((pollfd
[i
].revents
& POLLHUP
)) {
2514 DBG("Polling fd %d tells it has hung up.", pollfd
[i
].fd
);
2515 if (!local_stream
[i
]->data_read
) {
2516 consumer_del_stream(local_stream
[i
], data_ht
);
2517 local_stream
[i
] = NULL
;
2520 } else if (pollfd
[i
].revents
& POLLERR
) {
2521 ERR("Error returned in polling fd %d.", pollfd
[i
].fd
);
2522 if (!local_stream
[i
]->data_read
) {
2523 consumer_del_stream(local_stream
[i
], data_ht
);
2524 local_stream
[i
] = NULL
;
2527 } else if (pollfd
[i
].revents
& POLLNVAL
) {
2528 ERR("Polling fd %d tells fd is not open.", pollfd
[i
].fd
);
2529 if (!local_stream
[i
]->data_read
) {
2530 consumer_del_stream(local_stream
[i
], data_ht
);
2531 local_stream
[i
] = NULL
;
2535 if (local_stream
[i
] != NULL
) {
2536 local_stream
[i
]->data_read
= 0;
2541 DBG("polling thread exiting");
2546 * Close the write side of the pipe so epoll_wait() in
2547 * consumer_thread_metadata_poll can catch it. The thread is monitoring the
2548 * read side of the pipe. If we close them both, epoll_wait strangely does
2549 * not return and could create a endless wait period if the pipe is the
2550 * only tracked fd in the poll set. The thread will take care of closing
2553 (void) lttng_pipe_write_close(ctx
->consumer_metadata_pipe
);
2555 destroy_data_stream_ht(data_ht
);
2557 rcu_unregister_thread();
2562 * Close wake-up end of each stream belonging to the channel. This will
2563 * allow the poll() on the stream read-side to detect when the
2564 * write-side (application) finally closes them.
2567 void consumer_close_channel_streams(struct lttng_consumer_channel
*channel
)
2569 struct lttng_ht
*ht
;
2570 struct lttng_consumer_stream
*stream
;
2571 struct lttng_ht_iter iter
;
2573 ht
= consumer_data
.stream_per_chan_id_ht
;
2576 cds_lfht_for_each_entry_duplicate(ht
->ht
,
2577 ht
->hash_fct(&channel
->key
, lttng_ht_seed
),
2578 ht
->match_fct
, &channel
->key
,
2579 &iter
.iter
, stream
, node_channel_id
.node
) {
2581 * Protect against teardown with mutex.
2583 pthread_mutex_lock(&stream
->lock
);
2584 if (cds_lfht_is_node_deleted(&stream
->node
.node
)) {
2587 switch (consumer_data
.type
) {
2588 case LTTNG_CONSUMER_KERNEL
:
2590 case LTTNG_CONSUMER32_UST
:
2591 case LTTNG_CONSUMER64_UST
:
2593 * Note: a mutex is taken internally within
2594 * liblttng-ust-ctl to protect timer wakeup_fd
2595 * use from concurrent close.
2597 lttng_ustconsumer_close_stream_wakeup(stream
);
2600 ERR("Unknown consumer_data type");
2604 pthread_mutex_unlock(&stream
->lock
);
2609 static void destroy_channel_ht(struct lttng_ht
*ht
)
2611 struct lttng_ht_iter iter
;
2612 struct lttng_consumer_channel
*channel
;
2620 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, channel
, wait_fd_node
.node
) {
2621 ret
= lttng_ht_del(ht
, &iter
);
2626 lttng_ht_destroy(ht
);
2630 * This thread polls the channel fds to detect when they are being
2631 * closed. It closes all related streams if the channel is detected as
2632 * closed. It is currently only used as a shim layer for UST because the
2633 * consumerd needs to keep the per-stream wakeup end of pipes open for
2636 void *consumer_thread_channel_poll(void *data
)
2639 uint32_t revents
, nb_fd
;
2640 struct lttng_consumer_channel
*chan
= NULL
;
2641 struct lttng_ht_iter iter
;
2642 struct lttng_ht_node_u64
*node
;
2643 struct lttng_poll_event events
;
2644 struct lttng_consumer_local_data
*ctx
= data
;
2645 struct lttng_ht
*channel_ht
;
2647 rcu_register_thread();
2649 channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2651 /* ENOMEM at this point. Better to bail out. */
2655 DBG("Thread channel poll started");
2657 /* Size is set to 1 for the consumer_channel pipe */
2658 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
2660 ERR("Poll set creation failed");
2664 ret
= lttng_poll_add(&events
, ctx
->consumer_channel_pipe
[0], LPOLLIN
);
2670 DBG("Channel main loop started");
2673 /* Only the channel pipe is set */
2674 if (LTTNG_POLL_GETNB(&events
) == 0 && consumer_quit
== 1) {
2679 DBG("Channel poll wait with %d fd(s)", LTTNG_POLL_GETNB(&events
));
2680 ret
= lttng_poll_wait(&events
, -1);
2681 DBG("Channel event catched in thread");
2683 if (errno
== EINTR
) {
2684 ERR("Poll EINTR catched");
2692 /* From here, the event is a channel wait fd */
2693 for (i
= 0; i
< nb_fd
; i
++) {
2694 revents
= LTTNG_POLL_GETEV(&events
, i
);
2695 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
2697 /* Just don't waste time if no returned events for the fd */
2701 if (pollfd
== ctx
->consumer_channel_pipe
[0]) {
2702 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2703 DBG("Channel thread pipe hung up");
2705 * Remove the pipe from the poll set and continue the loop
2706 * since their might be data to consume.
2708 lttng_poll_del(&events
, ctx
->consumer_channel_pipe
[0]);
2710 } else if (revents
& LPOLLIN
) {
2711 enum consumer_channel_action action
;
2714 ret
= read_channel_pipe(ctx
, &chan
, &key
, &action
);
2716 ERR("Error reading channel pipe");
2721 case CONSUMER_CHANNEL_ADD
:
2722 DBG("Adding channel %d to poll set",
2725 lttng_ht_node_init_u64(&chan
->wait_fd_node
,
2728 lttng_ht_add_unique_u64(channel_ht
,
2729 &chan
->wait_fd_node
);
2731 /* Add channel to the global poll events list */
2732 lttng_poll_add(&events
, chan
->wait_fd
,
2733 LPOLLIN
| LPOLLPRI
);
2735 case CONSUMER_CHANNEL_DEL
:
2737 struct lttng_consumer_stream
*stream
, *stmp
;
2740 chan
= consumer_find_channel(key
);
2743 ERR("UST consumer get channel key %" PRIu64
" not found for del channel", key
);
2746 lttng_poll_del(&events
, chan
->wait_fd
);
2747 iter
.iter
.node
= &chan
->wait_fd_node
.node
;
2748 ret
= lttng_ht_del(channel_ht
, &iter
);
2750 consumer_close_channel_streams(chan
);
2752 switch (consumer_data
.type
) {
2753 case LTTNG_CONSUMER_KERNEL
:
2755 case LTTNG_CONSUMER32_UST
:
2756 case LTTNG_CONSUMER64_UST
:
2757 /* Delete streams that might have been left in the stream list. */
2758 cds_list_for_each_entry_safe(stream
, stmp
, &chan
->streams
.head
,
2760 cds_list_del(&stream
->send_node
);
2761 lttng_ustconsumer_del_stream(stream
);
2762 uatomic_sub(&stream
->chan
->refcount
, 1);
2763 assert(&chan
->refcount
);
2768 ERR("Unknown consumer_data type");
2773 * Release our own refcount. Force channel deletion even if
2774 * streams were not initialized.
2776 if (!uatomic_sub_return(&chan
->refcount
, 1)) {
2777 consumer_del_channel(chan
);
2782 case CONSUMER_CHANNEL_QUIT
:
2784 * Remove the pipe from the poll set and continue the loop
2785 * since their might be data to consume.
2787 lttng_poll_del(&events
, ctx
->consumer_channel_pipe
[0]);
2790 ERR("Unknown action");
2795 /* Handle other stream */
2801 uint64_t tmp_id
= (uint64_t) pollfd
;
2803 lttng_ht_lookup(channel_ht
, &tmp_id
, &iter
);
2805 node
= lttng_ht_iter_get_node_u64(&iter
);
2808 chan
= caa_container_of(node
, struct lttng_consumer_channel
,
2811 /* Check for error event */
2812 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2813 DBG("Channel fd %d is hup|err.", pollfd
);
2815 lttng_poll_del(&events
, chan
->wait_fd
);
2816 ret
= lttng_ht_del(channel_ht
, &iter
);
2818 assert(cds_list_empty(&chan
->streams
.head
));
2819 consumer_close_channel_streams(chan
);
2821 /* Release our own refcount */
2822 if (!uatomic_sub_return(&chan
->refcount
, 1)
2823 && !uatomic_read(&chan
->nb_init_stream_left
)) {
2824 consumer_del_channel(chan
);
2828 /* Release RCU lock for the channel looked up */
2834 lttng_poll_clean(&events
);
2836 destroy_channel_ht(channel_ht
);
2838 DBG("Channel poll thread exiting");
2839 rcu_unregister_thread();
2843 static int set_metadata_socket(struct lttng_consumer_local_data
*ctx
,
2844 struct pollfd
*sockpoll
, int client_socket
)
2851 if (lttng_consumer_poll_socket(sockpoll
) < 0) {
2855 DBG("Metadata connection on client_socket");
2857 /* Blocking call, waiting for transmission */
2858 ctx
->consumer_metadata_socket
= lttcomm_accept_unix_sock(client_socket
);
2859 if (ctx
->consumer_metadata_socket
< 0) {
2860 WARN("On accept metadata");
2871 * This thread listens on the consumerd socket and receives the file
2872 * descriptors from the session daemon.
2874 void *consumer_thread_sessiond_poll(void *data
)
2876 int sock
= -1, client_socket
, ret
;
2878 * structure to poll for incoming data on communication socket avoids
2879 * making blocking sockets.
2881 struct pollfd consumer_sockpoll
[2];
2882 struct lttng_consumer_local_data
*ctx
= data
;
2884 rcu_register_thread();
2886 DBG("Creating command socket %s", ctx
->consumer_command_sock_path
);
2887 unlink(ctx
->consumer_command_sock_path
);
2888 client_socket
= lttcomm_create_unix_sock(ctx
->consumer_command_sock_path
);
2889 if (client_socket
< 0) {
2890 ERR("Cannot create command socket");
2894 ret
= lttcomm_listen_unix_sock(client_socket
);
2899 DBG("Sending ready command to lttng-sessiond");
2900 ret
= lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY
);
2901 /* return < 0 on error, but == 0 is not fatal */
2903 ERR("Error sending ready command to lttng-sessiond");
2907 /* prepare the FDs to poll : to client socket and the should_quit pipe */
2908 consumer_sockpoll
[0].fd
= ctx
->consumer_should_quit
[0];
2909 consumer_sockpoll
[0].events
= POLLIN
| POLLPRI
;
2910 consumer_sockpoll
[1].fd
= client_socket
;
2911 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
2913 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
2916 DBG("Connection on client_socket");
2918 /* Blocking call, waiting for transmission */
2919 sock
= lttcomm_accept_unix_sock(client_socket
);
2926 * Setup metadata socket which is the second socket connection on the
2927 * command unix socket.
2929 ret
= set_metadata_socket(ctx
, consumer_sockpoll
, client_socket
);
2934 /* This socket is not useful anymore. */
2935 ret
= close(client_socket
);
2937 PERROR("close client_socket");
2941 /* update the polling structure to poll on the established socket */
2942 consumer_sockpoll
[1].fd
= sock
;
2943 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
2946 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
2949 DBG("Incoming command on sock");
2950 ret
= lttng_consumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
2951 if (ret
== -ENOENT
) {
2952 DBG("Received STOP command");
2957 * This could simply be a session daemon quitting. Don't output
2960 DBG("Communication interrupted on command socket");
2963 if (consumer_quit
) {
2964 DBG("consumer_thread_receive_fds received quit from signal");
2967 DBG("received command on sock");
2970 DBG("Consumer thread sessiond poll exiting");
2973 * Close metadata streams since the producer is the session daemon which
2976 * NOTE: for now, this only applies to the UST tracer.
2978 lttng_consumer_close_metadata();
2981 * when all fds have hung up, the polling thread
2987 * Notify the data poll thread to poll back again and test the
2988 * consumer_quit state that we just set so to quit gracefully.
2990 notify_thread_lttng_pipe(ctx
->consumer_data_pipe
);
2992 notify_channel_pipe(ctx
, NULL
, -1, CONSUMER_CHANNEL_QUIT
);
2994 /* Cleaning up possibly open sockets. */
2998 PERROR("close sock sessiond poll");
3001 if (client_socket
>= 0) {
3002 ret
= close(client_socket
);
3004 PERROR("close client_socket sessiond poll");
3008 rcu_unregister_thread();
3012 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
3013 struct lttng_consumer_local_data
*ctx
)
3017 pthread_mutex_lock(&stream
->lock
);
3019 switch (consumer_data
.type
) {
3020 case LTTNG_CONSUMER_KERNEL
:
3021 ret
= lttng_kconsumer_read_subbuffer(stream
, ctx
);
3023 case LTTNG_CONSUMER32_UST
:
3024 case LTTNG_CONSUMER64_UST
:
3025 ret
= lttng_ustconsumer_read_subbuffer(stream
, ctx
);
3028 ERR("Unknown consumer_data type");
3034 pthread_mutex_unlock(&stream
->lock
);
3038 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
3040 switch (consumer_data
.type
) {
3041 case LTTNG_CONSUMER_KERNEL
:
3042 return lttng_kconsumer_on_recv_stream(stream
);
3043 case LTTNG_CONSUMER32_UST
:
3044 case LTTNG_CONSUMER64_UST
:
3045 return lttng_ustconsumer_on_recv_stream(stream
);
3047 ERR("Unknown consumer_data type");
3054 * Allocate and set consumer data hash tables.
3056 void lttng_consumer_init(void)
3058 consumer_data
.channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3059 consumer_data
.relayd_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3060 consumer_data
.stream_list_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3061 consumer_data
.stream_per_chan_id_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3065 * Process the ADD_RELAYD command receive by a consumer.
3067 * This will create a relayd socket pair and add it to the relayd hash table.
3068 * The caller MUST acquire a RCU read side lock before calling it.
3070 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
3071 struct lttng_consumer_local_data
*ctx
, int sock
,
3072 struct pollfd
*consumer_sockpoll
,
3073 struct lttcomm_relayd_sock
*relayd_sock
, unsigned int sessiond_id
)
3075 int fd
= -1, ret
= -1, relayd_created
= 0;
3076 enum lttng_error_code ret_code
= LTTNG_OK
;
3077 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3080 assert(relayd_sock
);
3082 DBG("Consumer adding relayd socket (idx: %d)", net_seq_idx
);
3084 /* Get relayd reference if exists. */
3085 relayd
= consumer_find_relayd(net_seq_idx
);
3086 if (relayd
== NULL
) {
3087 /* Not found. Allocate one. */
3088 relayd
= consumer_allocate_relayd_sock_pair(net_seq_idx
);
3089 if (relayd
== NULL
) {
3090 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
3093 relayd
->sessiond_session_id
= (uint64_t) sessiond_id
;
3098 * This code path MUST continue to the consumer send status message to
3099 * we can notify the session daemon and continue our work without
3100 * killing everything.
3104 /* First send a status message before receiving the fds. */
3105 ret
= consumer_send_status_msg(sock
, ret_code
);
3106 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
3107 /* Somehow, the session daemon is not responding anymore. */
3111 /* Poll on consumer socket. */
3112 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
3113 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
3118 /* Get relayd socket from session daemon */
3119 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
3120 if (ret
!= sizeof(fd
)) {
3121 ret_code
= LTTCOMM_CONSUMERD_ERROR_RECV_FD
;
3123 fd
= -1; /* Just in case it gets set with an invalid value. */
3126 * Failing to receive FDs might indicate a major problem such as
3127 * reaching a fd limit during the receive where the kernel returns a
3128 * MSG_CTRUNC and fails to cleanup the fd in the queue. Any case, we
3129 * don't take any chances and stop everything.
3131 * XXX: Feature request #558 will fix that and avoid this possible
3132 * issue when reaching the fd limit.
3134 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
3137 * This code path MUST continue to the consumer send status message so
3138 * we can send the error to the thread expecting a reply. The above
3139 * call will make everything stop.
3143 /* We have the fds without error. Send status back. */
3144 ret
= consumer_send_status_msg(sock
, ret_code
);
3145 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
3146 /* Somehow, the session daemon is not responding anymore. */
3150 /* Copy socket information and received FD */
3151 switch (sock_type
) {
3152 case LTTNG_STREAM_CONTROL
:
3153 /* Copy received lttcomm socket */
3154 lttcomm_copy_sock(&relayd
->control_sock
.sock
, &relayd_sock
->sock
);
3155 ret
= lttcomm_create_sock(&relayd
->control_sock
.sock
);
3156 /* Immediately try to close the created socket if valid. */
3157 if (relayd
->control_sock
.sock
.fd
>= 0) {
3158 if (close(relayd
->control_sock
.sock
.fd
)) {
3159 PERROR("close relayd control socket");
3162 /* Handle create_sock error. */
3167 /* Assign new file descriptor */
3168 relayd
->control_sock
.sock
.fd
= fd
;
3169 /* Assign version values. */
3170 relayd
->control_sock
.major
= relayd_sock
->major
;
3171 relayd
->control_sock
.minor
= relayd_sock
->minor
;
3174 * Create a session on the relayd and store the returned id. Lock the
3175 * control socket mutex if the relayd was NOT created before.
3177 if (!relayd_created
) {
3178 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3180 ret
= relayd_create_session(&relayd
->control_sock
,
3181 &relayd
->relayd_session_id
);
3182 if (!relayd_created
) {
3183 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3187 * Close all sockets of a relayd object. It will be freed if it was
3188 * created at the error code path or else it will be garbage
3191 (void) relayd_close(&relayd
->control_sock
);
3192 (void) relayd_close(&relayd
->data_sock
);
3197 case LTTNG_STREAM_DATA
:
3198 /* Copy received lttcomm socket */
3199 lttcomm_copy_sock(&relayd
->data_sock
.sock
, &relayd_sock
->sock
);
3200 ret
= lttcomm_create_sock(&relayd
->data_sock
.sock
);
3201 /* Immediately try to close the created socket if valid. */
3202 if (relayd
->data_sock
.sock
.fd
>= 0) {
3203 if (close(relayd
->data_sock
.sock
.fd
)) {
3204 PERROR("close relayd data socket");
3207 /* Handle create_sock error. */
3212 /* Assign new file descriptor */
3213 relayd
->data_sock
.sock
.fd
= fd
;
3214 /* Assign version values. */
3215 relayd
->data_sock
.major
= relayd_sock
->major
;
3216 relayd
->data_sock
.minor
= relayd_sock
->minor
;
3219 ERR("Unknown relayd socket type (%d)", sock_type
);
3224 DBG("Consumer %s socket created successfully with net idx %" PRIu64
" (fd: %d)",
3225 sock_type
== LTTNG_STREAM_CONTROL
? "control" : "data",
3226 relayd
->net_seq_idx
, fd
);
3229 * Add relayd socket pair to consumer data hashtable. If object already
3230 * exists or on error, the function gracefully returns.
3238 /* Close received socket if valid. */
3241 PERROR("close received socket");
3245 if (relayd_created
) {
3253 * Try to lock the stream mutex.
3255 * On success, 1 is returned else 0 indicating that the mutex is NOT lock.
3257 static int stream_try_lock(struct lttng_consumer_stream
*stream
)
3264 * Try to lock the stream mutex. On failure, we know that the stream is
3265 * being used else where hence there is data still being extracted.
3267 ret
= pthread_mutex_trylock(&stream
->lock
);
3269 /* For both EBUSY and EINVAL error, the mutex is NOT locked. */
3281 * Search for a relayd associated to the session id and return the reference.
3283 * A rcu read side lock MUST be acquire before calling this function and locked
3284 * until the relayd object is no longer necessary.
3286 static struct consumer_relayd_sock_pair
*find_relayd_by_session_id(uint64_t id
)
3288 struct lttng_ht_iter iter
;
3289 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3291 /* Iterate over all relayd since they are indexed by net_seq_idx. */
3292 cds_lfht_for_each_entry(consumer_data
.relayd_ht
->ht
, &iter
.iter
, relayd
,
3295 * Check by sessiond id which is unique here where the relayd session
3296 * id might not be when having multiple relayd.
3298 if (relayd
->sessiond_session_id
== id
) {
3299 /* Found the relayd. There can be only one per id. */
3311 * Check if for a given session id there is still data needed to be extract
3314 * Return 1 if data is pending or else 0 meaning ready to be read.
3316 int consumer_data_pending(uint64_t id
)
3319 struct lttng_ht_iter iter
;
3320 struct lttng_ht
*ht
;
3321 struct lttng_consumer_stream
*stream
;
3322 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3323 int (*data_pending
)(struct lttng_consumer_stream
*);
3325 DBG("Consumer data pending command on session id %" PRIu64
, id
);
3328 pthread_mutex_lock(&consumer_data
.lock
);
3330 switch (consumer_data
.type
) {
3331 case LTTNG_CONSUMER_KERNEL
:
3332 data_pending
= lttng_kconsumer_data_pending
;
3334 case LTTNG_CONSUMER32_UST
:
3335 case LTTNG_CONSUMER64_UST
:
3336 data_pending
= lttng_ustconsumer_data_pending
;
3339 ERR("Unknown consumer data type");
3343 /* Ease our life a bit */
3344 ht
= consumer_data
.stream_list_ht
;
3346 relayd
= find_relayd_by_session_id(id
);
3348 /* Send init command for data pending. */
3349 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3350 ret
= relayd_begin_data_pending(&relayd
->control_sock
,
3351 relayd
->relayd_session_id
);
3352 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3354 /* Communication error thus the relayd so no data pending. */
3355 goto data_not_pending
;
3359 cds_lfht_for_each_entry_duplicate(ht
->ht
,
3360 ht
->hash_fct(&id
, lttng_ht_seed
),
3362 &iter
.iter
, stream
, node_session_id
.node
) {
3363 /* If this call fails, the stream is being used hence data pending. */
3364 ret
= stream_try_lock(stream
);
3370 * A removed node from the hash table indicates that the stream has
3371 * been deleted thus having a guarantee that the buffers are closed
3372 * on the consumer side. However, data can still be transmitted
3373 * over the network so don't skip the relayd check.
3375 ret
= cds_lfht_is_node_deleted(&stream
->node
.node
);
3377 /* Check the stream if there is data in the buffers. */
3378 ret
= data_pending(stream
);
3380 pthread_mutex_unlock(&stream
->lock
);
3387 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3388 if (stream
->metadata_flag
) {
3389 ret
= relayd_quiescent_control(&relayd
->control_sock
,
3390 stream
->relayd_stream_id
);
3392 ret
= relayd_data_pending(&relayd
->control_sock
,
3393 stream
->relayd_stream_id
,
3394 stream
->next_net_seq_num
- 1);
3396 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3398 pthread_mutex_unlock(&stream
->lock
);
3402 pthread_mutex_unlock(&stream
->lock
);
3406 unsigned int is_data_inflight
= 0;
3408 /* Send init command for data pending. */
3409 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3410 ret
= relayd_end_data_pending(&relayd
->control_sock
,
3411 relayd
->relayd_session_id
, &is_data_inflight
);
3412 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3414 goto data_not_pending
;
3416 if (is_data_inflight
) {
3422 * Finding _no_ node in the hash table and no inflight data means that the
3423 * stream(s) have been removed thus data is guaranteed to be available for
3424 * analysis from the trace files.
3428 /* Data is available to be read by a viewer. */
3429 pthread_mutex_unlock(&consumer_data
.lock
);
3434 /* Data is still being extracted from buffers. */
3435 pthread_mutex_unlock(&consumer_data
.lock
);
3441 * Send a ret code status message to the sessiond daemon.
3443 * Return the sendmsg() return value.
3445 int consumer_send_status_msg(int sock
, int ret_code
)
3447 struct lttcomm_consumer_status_msg msg
;
3449 msg
.ret_code
= ret_code
;
3451 return lttcomm_send_unix_sock(sock
, &msg
, sizeof(msg
));
3455 * Send a channel status message to the sessiond daemon.
3457 * Return the sendmsg() return value.
3459 int consumer_send_status_channel(int sock
,
3460 struct lttng_consumer_channel
*channel
)
3462 struct lttcomm_consumer_status_channel msg
;
3467 msg
.ret_code
= -LTTNG_ERR_UST_CHAN_FAIL
;
3469 msg
.ret_code
= LTTNG_OK
;
3470 msg
.key
= channel
->key
;
3471 msg
.stream_count
= channel
->streams
.count
;
3474 return lttcomm_send_unix_sock(sock
, &msg
, sizeof(msg
));