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 * This function MUST be called with the consumer_data lock acquired.
260 static void destroy_relayd(struct consumer_relayd_sock_pair
*relayd
)
263 struct lttng_ht_iter iter
;
265 if (relayd
== NULL
) {
269 DBG("Consumer destroy and close relayd socket pair");
271 iter
.iter
.node
= &relayd
->node
.node
;
272 ret
= lttng_ht_del(consumer_data
.relayd_ht
, &iter
);
274 /* We assume the relayd is being or is destroyed */
278 /* RCU free() call */
279 call_rcu(&relayd
->node
.head
, free_relayd_rcu
);
283 * Remove a channel from the global list protected by a mutex. This function is
284 * also responsible for freeing its data structures.
286 void consumer_del_channel(struct lttng_consumer_channel
*channel
)
289 struct lttng_ht_iter iter
;
290 struct lttng_consumer_stream
*stream
, *stmp
;
292 DBG("Consumer delete channel key %" PRIu64
, channel
->key
);
294 pthread_mutex_lock(&consumer_data
.lock
);
296 switch (consumer_data
.type
) {
297 case LTTNG_CONSUMER_KERNEL
:
299 case LTTNG_CONSUMER32_UST
:
300 case LTTNG_CONSUMER64_UST
:
301 /* Delete streams that might have been left in the stream list. */
302 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
304 cds_list_del(&stream
->send_node
);
305 lttng_ustconsumer_del_stream(stream
);
308 lttng_ustconsumer_del_channel(channel
);
311 ERR("Unknown consumer_data type");
317 iter
.iter
.node
= &channel
->node
.node
;
318 ret
= lttng_ht_del(consumer_data
.channel_ht
, &iter
);
322 call_rcu(&channel
->node
.head
, free_channel_rcu
);
324 pthread_mutex_unlock(&consumer_data
.lock
);
328 * Iterate over the relayd hash table and destroy each element. Finally,
329 * destroy the whole hash table.
331 static void cleanup_relayd_ht(void)
333 struct lttng_ht_iter iter
;
334 struct consumer_relayd_sock_pair
*relayd
;
338 cds_lfht_for_each_entry(consumer_data
.relayd_ht
->ht
, &iter
.iter
, relayd
,
340 destroy_relayd(relayd
);
345 lttng_ht_destroy(consumer_data
.relayd_ht
);
349 * Update the end point status of all streams having the given network sequence
350 * index (relayd index).
352 * It's atomically set without having the stream mutex locked which is fine
353 * because we handle the write/read race with a pipe wakeup for each thread.
355 static void update_endpoint_status_by_netidx(int net_seq_idx
,
356 enum consumer_endpoint_status status
)
358 struct lttng_ht_iter iter
;
359 struct lttng_consumer_stream
*stream
;
361 DBG("Consumer set delete flag on stream by idx %d", net_seq_idx
);
365 /* Let's begin with metadata */
366 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
367 if (stream
->net_seq_idx
== net_seq_idx
) {
368 uatomic_set(&stream
->endpoint_status
, status
);
369 DBG("Delete flag set to metadata stream %d", stream
->wait_fd
);
373 /* Follow up by the data streams */
374 cds_lfht_for_each_entry(data_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
375 if (stream
->net_seq_idx
== net_seq_idx
) {
376 uatomic_set(&stream
->endpoint_status
, status
);
377 DBG("Delete flag set to data stream %d", stream
->wait_fd
);
384 * Cleanup a relayd object by flagging every associated streams for deletion,
385 * destroying the object meaning removing it from the relayd hash table,
386 * closing the sockets and freeing the memory in a RCU call.
388 * If a local data context is available, notify the threads that the streams'
389 * state have changed.
391 static void cleanup_relayd(struct consumer_relayd_sock_pair
*relayd
,
392 struct lttng_consumer_local_data
*ctx
)
398 DBG("Cleaning up relayd sockets");
400 /* Save the net sequence index before destroying the object */
401 netidx
= relayd
->net_seq_idx
;
404 * Delete the relayd from the relayd hash table, close the sockets and free
405 * the object in a RCU call.
407 destroy_relayd(relayd
);
409 /* Set inactive endpoint to all streams */
410 update_endpoint_status_by_netidx(netidx
, CONSUMER_ENDPOINT_INACTIVE
);
413 * With a local data context, notify the threads that the streams' state
414 * have changed. The write() action on the pipe acts as an "implicit"
415 * memory barrier ordering the updates of the end point status from the
416 * read of this status which happens AFTER receiving this notify.
419 notify_thread_lttng_pipe(ctx
->consumer_data_pipe
);
420 notify_thread_lttng_pipe(ctx
->consumer_metadata_pipe
);
425 * Flag a relayd socket pair for destruction. Destroy it if the refcount
428 * RCU read side lock MUST be aquired before calling this function.
430 void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair
*relayd
)
434 /* Set destroy flag for this object */
435 uatomic_set(&relayd
->destroy_flag
, 1);
437 /* Destroy the relayd if refcount is 0 */
438 if (uatomic_read(&relayd
->refcount
) == 0) {
439 destroy_relayd(relayd
);
444 * Remove a stream from the global list protected by a mutex. This
445 * function is also responsible for freeing its data structures.
447 void consumer_del_stream(struct lttng_consumer_stream
*stream
,
451 struct lttng_ht_iter iter
;
452 struct lttng_consumer_channel
*free_chan
= NULL
;
453 struct consumer_relayd_sock_pair
*relayd
;
457 DBG("Consumer del stream %d", stream
->wait_fd
);
460 /* Means the stream was allocated but not successfully added */
461 goto free_stream_rcu
;
464 pthread_mutex_lock(&consumer_data
.lock
);
465 pthread_mutex_lock(&stream
->lock
);
467 switch (consumer_data
.type
) {
468 case LTTNG_CONSUMER_KERNEL
:
469 if (stream
->mmap_base
!= NULL
) {
470 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
476 if (stream
->wait_fd
>= 0) {
477 ret
= close(stream
->wait_fd
);
483 case LTTNG_CONSUMER32_UST
:
484 case LTTNG_CONSUMER64_UST
:
485 lttng_ustconsumer_del_stream(stream
);
488 ERR("Unknown consumer_data type");
494 iter
.iter
.node
= &stream
->node
.node
;
495 ret
= lttng_ht_del(ht
, &iter
);
498 iter
.iter
.node
= &stream
->node_channel_id
.node
;
499 ret
= lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
502 iter
.iter
.node
= &stream
->node_session_id
.node
;
503 ret
= lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
507 assert(consumer_data
.stream_count
> 0);
508 consumer_data
.stream_count
--;
510 if (stream
->out_fd
>= 0) {
511 ret
= close(stream
->out_fd
);
517 /* Check and cleanup relayd */
519 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
520 if (relayd
!= NULL
) {
521 uatomic_dec(&relayd
->refcount
);
522 assert(uatomic_read(&relayd
->refcount
) >= 0);
524 /* Closing streams requires to lock the control socket. */
525 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
526 ret
= relayd_send_close_stream(&relayd
->control_sock
,
527 stream
->relayd_stream_id
,
528 stream
->next_net_seq_num
- 1);
529 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
531 DBG("Unable to close stream on the relayd. Continuing");
533 * Continue here. There is nothing we can do for the relayd.
534 * Chances are that the relayd has closed the socket so we just
535 * continue cleaning up.
539 /* Both conditions are met, we destroy the relayd. */
540 if (uatomic_read(&relayd
->refcount
) == 0 &&
541 uatomic_read(&relayd
->destroy_flag
)) {
542 destroy_relayd(relayd
);
547 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
548 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
549 free_chan
= stream
->chan
;
553 consumer_data
.need_update
= 1;
554 pthread_mutex_unlock(&stream
->lock
);
555 pthread_mutex_unlock(&consumer_data
.lock
);
558 consumer_del_channel(free_chan
);
562 call_rcu(&stream
->node
.head
, free_stream_rcu
);
565 struct lttng_consumer_stream
*consumer_allocate_stream(uint64_t channel_key
,
567 enum lttng_consumer_stream_state state
,
568 const char *channel_name
,
575 enum consumer_channel_type type
)
578 struct lttng_consumer_stream
*stream
;
580 stream
= zmalloc(sizeof(*stream
));
581 if (stream
== NULL
) {
582 PERROR("malloc struct lttng_consumer_stream");
589 stream
->key
= stream_key
;
591 stream
->out_fd_offset
= 0;
592 stream
->state
= state
;
595 stream
->net_seq_idx
= relayd_id
;
596 stream
->session_id
= session_id
;
597 pthread_mutex_init(&stream
->lock
, NULL
);
599 /* If channel is the metadata, flag this stream as metadata. */
600 if (type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
601 stream
->metadata_flag
= 1;
602 /* Metadata is flat out. */
603 strncpy(stream
->name
, DEFAULT_METADATA_NAME
, sizeof(stream
->name
));
605 /* Format stream name to <channel_name>_<cpu_number> */
606 ret
= snprintf(stream
->name
, sizeof(stream
->name
), "%s_%d",
609 PERROR("snprintf stream name");
614 /* Key is always the wait_fd for streams. */
615 lttng_ht_node_init_u64(&stream
->node
, stream
->key
);
617 /* Init node per channel id key */
618 lttng_ht_node_init_u64(&stream
->node_channel_id
, channel_key
);
620 /* Init session id node with the stream session id */
621 lttng_ht_node_init_u64(&stream
->node_session_id
, stream
->session_id
);
623 DBG3("Allocated stream %s (key %" PRIu64
", chan_key %" PRIu64
" relayd_id %" PRIu64
", session_id %" PRIu64
,
624 stream
->name
, stream
->key
, channel_key
, stream
->net_seq_idx
, stream
->session_id
);
640 * Add a stream to the global list protected by a mutex.
642 static int add_stream(struct lttng_consumer_stream
*stream
,
646 struct consumer_relayd_sock_pair
*relayd
;
651 DBG3("Adding consumer stream %" PRIu64
, stream
->key
);
653 pthread_mutex_lock(&consumer_data
.lock
);
654 pthread_mutex_lock(&stream
->lock
);
657 /* Steal stream identifier to avoid having streams with the same key */
658 steal_stream_key(stream
->key
, ht
);
660 lttng_ht_add_unique_u64(ht
, &stream
->node
);
662 lttng_ht_add_u64(consumer_data
.stream_per_chan_id_ht
,
663 &stream
->node_channel_id
);
666 * Add stream to the stream_list_ht of the consumer data. No need to steal
667 * the key since the HT does not use it and we allow to add redundant keys
670 lttng_ht_add_u64(consumer_data
.stream_list_ht
, &stream
->node_session_id
);
672 /* Check and cleanup relayd */
673 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
674 if (relayd
!= NULL
) {
675 uatomic_inc(&relayd
->refcount
);
679 * When nb_init_stream_left reaches 0, we don't need to trigger any action
680 * in terms of destroying the associated channel, because the action that
681 * causes the count to become 0 also causes a stream to be added. The
682 * channel deletion will thus be triggered by the following removal of this
685 if (uatomic_read(&stream
->chan
->nb_init_stream_left
) > 0) {
686 /* Increment refcount before decrementing nb_init_stream_left */
688 uatomic_dec(&stream
->chan
->nb_init_stream_left
);
691 /* Update consumer data once the node is inserted. */
692 consumer_data
.stream_count
++;
693 consumer_data
.need_update
= 1;
696 pthread_mutex_unlock(&stream
->lock
);
697 pthread_mutex_unlock(&consumer_data
.lock
);
703 * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
704 * be acquired before calling this.
706 static int add_relayd(struct consumer_relayd_sock_pair
*relayd
)
709 struct lttng_ht_node_u64
*node
;
710 struct lttng_ht_iter iter
;
714 lttng_ht_lookup(consumer_data
.relayd_ht
,
715 &relayd
->net_seq_idx
, &iter
);
716 node
= lttng_ht_iter_get_node_u64(&iter
);
720 lttng_ht_add_unique_u64(consumer_data
.relayd_ht
, &relayd
->node
);
727 * Allocate and return a consumer relayd socket.
729 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
732 struct consumer_relayd_sock_pair
*obj
= NULL
;
734 /* Negative net sequence index is a failure */
735 if (net_seq_idx
< 0) {
739 obj
= zmalloc(sizeof(struct consumer_relayd_sock_pair
));
741 PERROR("zmalloc relayd sock");
745 obj
->net_seq_idx
= net_seq_idx
;
747 obj
->destroy_flag
= 0;
748 obj
->control_sock
.sock
.fd
= -1;
749 obj
->data_sock
.sock
.fd
= -1;
750 lttng_ht_node_init_u64(&obj
->node
, obj
->net_seq_idx
);
751 pthread_mutex_init(&obj
->ctrl_sock_mutex
, NULL
);
758 * Find a relayd socket pair in the global consumer data.
760 * Return the object if found else NULL.
761 * RCU read-side lock must be held across this call and while using the
764 struct consumer_relayd_sock_pair
*consumer_find_relayd(uint64_t key
)
766 struct lttng_ht_iter iter
;
767 struct lttng_ht_node_u64
*node
;
768 struct consumer_relayd_sock_pair
*relayd
= NULL
;
770 /* Negative keys are lookup failures */
771 if (key
== (uint64_t) -1ULL) {
775 lttng_ht_lookup(consumer_data
.relayd_ht
, &key
,
777 node
= lttng_ht_iter_get_node_u64(&iter
);
779 relayd
= caa_container_of(node
, struct consumer_relayd_sock_pair
, node
);
787 * Handle stream for relayd transmission if the stream applies for network
788 * streaming where the net sequence index is set.
790 * Return destination file descriptor or negative value on error.
792 static int write_relayd_stream_header(struct lttng_consumer_stream
*stream
,
793 size_t data_size
, unsigned long padding
,
794 struct consumer_relayd_sock_pair
*relayd
)
797 struct lttcomm_relayd_data_hdr data_hdr
;
803 /* Reset data header */
804 memset(&data_hdr
, 0, sizeof(data_hdr
));
806 if (stream
->metadata_flag
) {
807 /* Caller MUST acquire the relayd control socket lock */
808 ret
= relayd_send_metadata(&relayd
->control_sock
, data_size
);
813 /* Metadata are always sent on the control socket. */
814 outfd
= relayd
->control_sock
.sock
.fd
;
816 /* Set header with stream information */
817 data_hdr
.stream_id
= htobe64(stream
->relayd_stream_id
);
818 data_hdr
.data_size
= htobe32(data_size
);
819 data_hdr
.padding_size
= htobe32(padding
);
821 * Note that net_seq_num below is assigned with the *current* value of
822 * next_net_seq_num and only after that the next_net_seq_num will be
823 * increment. This is why when issuing a command on the relayd using
824 * this next value, 1 should always be substracted in order to compare
825 * the last seen sequence number on the relayd side to the last sent.
827 data_hdr
.net_seq_num
= htobe64(stream
->next_net_seq_num
);
828 /* Other fields are zeroed previously */
830 ret
= relayd_send_data_hdr(&relayd
->data_sock
, &data_hdr
,
836 ++stream
->next_net_seq_num
;
838 /* Set to go on data socket */
839 outfd
= relayd
->data_sock
.sock
.fd
;
847 * Allocate and return a new lttng_consumer_channel object using the given key
848 * to initialize the hash table node.
850 * On error, return NULL.
852 struct lttng_consumer_channel
*consumer_allocate_channel(uint64_t key
,
854 const char *pathname
,
859 enum lttng_event_output output
,
860 uint64_t tracefile_size
,
861 uint64_t tracefile_count
)
863 struct lttng_consumer_channel
*channel
;
865 channel
= zmalloc(sizeof(*channel
));
866 if (channel
== NULL
) {
867 PERROR("malloc struct lttng_consumer_channel");
872 channel
->refcount
= 0;
873 channel
->session_id
= session_id
;
876 channel
->relayd_id
= relayd_id
;
877 channel
->output
= output
;
878 channel
->tracefile_size
= tracefile_size
;
879 channel
->tracefile_count
= tracefile_count
;
881 strncpy(channel
->pathname
, pathname
, sizeof(channel
->pathname
));
882 channel
->pathname
[sizeof(channel
->pathname
) - 1] = '\0';
884 strncpy(channel
->name
, name
, sizeof(channel
->name
));
885 channel
->name
[sizeof(channel
->name
) - 1] = '\0';
887 lttng_ht_node_init_u64(&channel
->node
, channel
->key
);
889 channel
->wait_fd
= -1;
891 CDS_INIT_LIST_HEAD(&channel
->streams
.head
);
893 DBG("Allocated channel (key %" PRIu64
")", channel
->key
)
900 * Add a channel to the global list protected by a mutex.
902 * On success 0 is returned else a negative value.
904 int consumer_add_channel(struct lttng_consumer_channel
*channel
,
905 struct lttng_consumer_local_data
*ctx
)
908 struct lttng_ht_node_u64
*node
;
909 struct lttng_ht_iter iter
;
911 pthread_mutex_lock(&consumer_data
.lock
);
914 lttng_ht_lookup(consumer_data
.channel_ht
, &channel
->key
, &iter
);
915 node
= lttng_ht_iter_get_node_u64(&iter
);
917 /* Channel already exist. Ignore the insertion */
918 ERR("Consumer add channel key %" PRIu64
" already exists!",
924 lttng_ht_add_unique_u64(consumer_data
.channel_ht
, &channel
->node
);
928 pthread_mutex_unlock(&consumer_data
.lock
);
930 if (!ret
&& channel
->wait_fd
!= -1 &&
931 channel
->metadata_stream
== NULL
) {
932 notify_channel_pipe(ctx
, channel
, -1, CONSUMER_CHANNEL_ADD
);
938 * Allocate the pollfd structure and the local view of the out fds to avoid
939 * doing a lookup in the linked list and concurrency issues when writing is
940 * needed. Called with consumer_data.lock held.
942 * Returns the number of fds in the structures.
944 static int update_poll_array(struct lttng_consumer_local_data
*ctx
,
945 struct pollfd
**pollfd
, struct lttng_consumer_stream
**local_stream
,
949 struct lttng_ht_iter iter
;
950 struct lttng_consumer_stream
*stream
;
955 assert(local_stream
);
957 DBG("Updating poll fd array");
959 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
961 * Only active streams with an active end point can be added to the
962 * poll set and local stream storage of the thread.
964 * There is a potential race here for endpoint_status to be updated
965 * just after the check. However, this is OK since the stream(s) will
966 * be deleted once the thread is notified that the end point state has
967 * changed where this function will be called back again.
969 if (stream
->state
!= LTTNG_CONSUMER_ACTIVE_STREAM
||
970 stream
->endpoint_status
== CONSUMER_ENDPOINT_INACTIVE
) {
974 * This clobbers way too much the debug output. Uncomment that if you
975 * need it for debugging purposes.
977 * DBG("Active FD %d", stream->wait_fd);
979 (*pollfd
)[i
].fd
= stream
->wait_fd
;
980 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
981 local_stream
[i
] = stream
;
987 * Insert the consumer_data_pipe at the end of the array and don't
988 * increment i so nb_fd is the number of real FD.
990 (*pollfd
)[i
].fd
= lttng_pipe_get_readfd(ctx
->consumer_data_pipe
);
991 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
996 * Poll on the should_quit pipe and the command socket return -1 on error and
997 * should exit, 0 if data is available on the command socket
999 int lttng_consumer_poll_socket(struct pollfd
*consumer_sockpoll
)
1004 num_rdy
= poll(consumer_sockpoll
, 2, -1);
1005 if (num_rdy
== -1) {
1007 * Restart interrupted system call.
1009 if (errno
== EINTR
) {
1012 PERROR("Poll error");
1015 if (consumer_sockpoll
[0].revents
& (POLLIN
| POLLPRI
)) {
1016 DBG("consumer_should_quit wake up");
1026 * Set the error socket.
1028 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data
*ctx
,
1031 ctx
->consumer_error_socket
= sock
;
1035 * Set the command socket path.
1037 void lttng_consumer_set_command_sock_path(
1038 struct lttng_consumer_local_data
*ctx
, char *sock
)
1040 ctx
->consumer_command_sock_path
= sock
;
1044 * Send return code to the session daemon.
1045 * If the socket is not defined, we return 0, it is not a fatal error
1047 int lttng_consumer_send_error(struct lttng_consumer_local_data
*ctx
, int cmd
)
1049 if (ctx
->consumer_error_socket
> 0) {
1050 return lttcomm_send_unix_sock(ctx
->consumer_error_socket
, &cmd
,
1051 sizeof(enum lttcomm_sessiond_command
));
1058 * Close all the tracefiles and stream fds and MUST be called when all
1059 * instances are destroyed i.e. when all threads were joined and are ended.
1061 void lttng_consumer_cleanup(void)
1063 struct lttng_ht_iter iter
;
1064 struct lttng_consumer_channel
*channel
;
1068 cds_lfht_for_each_entry(consumer_data
.channel_ht
->ht
, &iter
.iter
, channel
,
1070 consumer_del_channel(channel
);
1075 lttng_ht_destroy(consumer_data
.channel_ht
);
1077 cleanup_relayd_ht();
1079 lttng_ht_destroy(consumer_data
.stream_per_chan_id_ht
);
1082 * This HT contains streams that are freed by either the metadata thread or
1083 * the data thread so we do *nothing* on the hash table and simply destroy
1086 lttng_ht_destroy(consumer_data
.stream_list_ht
);
1090 * Called from signal handler.
1092 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
)
1097 ret
= write(ctx
->consumer_should_quit
[1], "4", 1);
1098 } while (ret
< 0 && errno
== EINTR
);
1099 if (ret
< 0 || ret
!= 1) {
1100 PERROR("write consumer quit");
1103 DBG("Consumer flag that it should quit");
1106 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream
*stream
,
1109 int outfd
= stream
->out_fd
;
1112 * This does a blocking write-and-wait on any page that belongs to the
1113 * subbuffer prior to the one we just wrote.
1114 * Don't care about error values, as these are just hints and ways to
1115 * limit the amount of page cache used.
1117 if (orig_offset
< stream
->max_sb_size
) {
1120 lttng_sync_file_range(outfd
, orig_offset
- stream
->max_sb_size
,
1121 stream
->max_sb_size
,
1122 SYNC_FILE_RANGE_WAIT_BEFORE
1123 | SYNC_FILE_RANGE_WRITE
1124 | SYNC_FILE_RANGE_WAIT_AFTER
);
1126 * Give hints to the kernel about how we access the file:
1127 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
1130 * We need to call fadvise again after the file grows because the
1131 * kernel does not seem to apply fadvise to non-existing parts of the
1134 * Call fadvise _after_ having waited for the page writeback to
1135 * complete because the dirty page writeback semantic is not well
1136 * defined. So it can be expected to lead to lower throughput in
1139 posix_fadvise(outfd
, orig_offset
- stream
->max_sb_size
,
1140 stream
->max_sb_size
, POSIX_FADV_DONTNEED
);
1144 * Initialise the necessary environnement :
1145 * - create a new context
1146 * - create the poll_pipe
1147 * - create the should_quit pipe (for signal handler)
1148 * - create the thread pipe (for splice)
1150 * Takes a function pointer as argument, this function is called when data is
1151 * available on a buffer. This function is responsible to do the
1152 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
1153 * buffer configuration and then kernctl_put_next_subbuf at the end.
1155 * Returns a pointer to the new context or NULL on error.
1157 struct lttng_consumer_local_data
*lttng_consumer_create(
1158 enum lttng_consumer_type type
,
1159 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
1160 struct lttng_consumer_local_data
*ctx
),
1161 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
1162 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
1163 int (*update_stream
)(int stream_key
, uint32_t state
))
1166 struct lttng_consumer_local_data
*ctx
;
1168 assert(consumer_data
.type
== LTTNG_CONSUMER_UNKNOWN
||
1169 consumer_data
.type
== type
);
1170 consumer_data
.type
= type
;
1172 ctx
= zmalloc(sizeof(struct lttng_consumer_local_data
));
1174 PERROR("allocating context");
1178 ctx
->consumer_error_socket
= -1;
1179 ctx
->consumer_metadata_socket
= -1;
1180 /* assign the callbacks */
1181 ctx
->on_buffer_ready
= buffer_ready
;
1182 ctx
->on_recv_channel
= recv_channel
;
1183 ctx
->on_recv_stream
= recv_stream
;
1184 ctx
->on_update_stream
= update_stream
;
1186 ctx
->consumer_data_pipe
= lttng_pipe_open(0);
1187 if (!ctx
->consumer_data_pipe
) {
1188 goto error_poll_pipe
;
1191 ret
= pipe(ctx
->consumer_should_quit
);
1193 PERROR("Error creating recv pipe");
1194 goto error_quit_pipe
;
1197 ret
= pipe(ctx
->consumer_thread_pipe
);
1199 PERROR("Error creating thread pipe");
1200 goto error_thread_pipe
;
1203 ret
= pipe(ctx
->consumer_channel_pipe
);
1205 PERROR("Error creating channel pipe");
1206 goto error_channel_pipe
;
1209 ctx
->consumer_metadata_pipe
= lttng_pipe_open(0);
1210 if (!ctx
->consumer_metadata_pipe
) {
1211 goto error_metadata_pipe
;
1214 ret
= utils_create_pipe(ctx
->consumer_splice_metadata_pipe
);
1216 goto error_splice_pipe
;
1222 lttng_pipe_destroy(ctx
->consumer_metadata_pipe
);
1223 error_metadata_pipe
:
1224 utils_close_pipe(ctx
->consumer_channel_pipe
);
1226 utils_close_pipe(ctx
->consumer_thread_pipe
);
1228 utils_close_pipe(ctx
->consumer_should_quit
);
1230 lttng_pipe_destroy(ctx
->consumer_data_pipe
);
1238 * Close all fds associated with the instance and free the context.
1240 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
)
1244 DBG("Consumer destroying it. Closing everything.");
1246 ret
= close(ctx
->consumer_error_socket
);
1250 ret
= close(ctx
->consumer_metadata_socket
);
1254 utils_close_pipe(ctx
->consumer_thread_pipe
);
1255 utils_close_pipe(ctx
->consumer_channel_pipe
);
1256 lttng_pipe_destroy(ctx
->consumer_data_pipe
);
1257 lttng_pipe_destroy(ctx
->consumer_metadata_pipe
);
1258 utils_close_pipe(ctx
->consumer_should_quit
);
1259 utils_close_pipe(ctx
->consumer_splice_metadata_pipe
);
1261 unlink(ctx
->consumer_command_sock_path
);
1266 * Write the metadata stream id on the specified file descriptor.
1268 static int write_relayd_metadata_id(int fd
,
1269 struct lttng_consumer_stream
*stream
,
1270 struct consumer_relayd_sock_pair
*relayd
, unsigned long padding
)
1273 struct lttcomm_relayd_metadata_payload hdr
;
1275 hdr
.stream_id
= htobe64(stream
->relayd_stream_id
);
1276 hdr
.padding_size
= htobe32(padding
);
1278 ret
= write(fd
, (void *) &hdr
, sizeof(hdr
));
1279 } while (ret
< 0 && errno
== EINTR
);
1280 if (ret
< 0 || ret
!= sizeof(hdr
)) {
1282 * This error means that the fd's end is closed so ignore the perror
1283 * not to clubber the error output since this can happen in a normal
1286 if (errno
!= EPIPE
) {
1287 PERROR("write metadata stream id");
1289 DBG3("Consumer failed to write relayd metadata id (errno: %d)", errno
);
1291 * Set ret to a negative value because if ret != sizeof(hdr), we don't
1292 * handle writting the missing part so report that as an error and
1293 * don't lie to the caller.
1298 DBG("Metadata stream id %" PRIu64
" with padding %lu written before data",
1299 stream
->relayd_stream_id
, padding
);
1306 * Mmap the ring buffer, read it and write the data to the tracefile. This is a
1307 * core function for writing trace buffers to either the local filesystem or
1310 * It must be called with the stream lock held.
1312 * Careful review MUST be put if any changes occur!
1314 * Returns the number of bytes written
1316 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
1317 struct lttng_consumer_local_data
*ctx
,
1318 struct lttng_consumer_stream
*stream
, unsigned long len
,
1319 unsigned long padding
)
1321 unsigned long mmap_offset
;
1323 ssize_t ret
= 0, written
= 0;
1324 off_t orig_offset
= stream
->out_fd_offset
;
1325 /* Default is on the disk */
1326 int outfd
= stream
->out_fd
;
1327 struct consumer_relayd_sock_pair
*relayd
= NULL
;
1328 unsigned int relayd_hang_up
= 0;
1330 /* RCU lock for the relayd pointer */
1333 /* Flag that the current stream if set for network streaming. */
1334 if (stream
->net_seq_idx
!= -1) {
1335 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1336 if (relayd
== NULL
) {
1341 /* get the offset inside the fd to mmap */
1342 switch (consumer_data
.type
) {
1343 case LTTNG_CONSUMER_KERNEL
:
1344 mmap_base
= stream
->mmap_base
;
1345 ret
= kernctl_get_mmap_read_offset(stream
->wait_fd
, &mmap_offset
);
1347 case LTTNG_CONSUMER32_UST
:
1348 case LTTNG_CONSUMER64_UST
:
1349 mmap_base
= lttng_ustctl_get_mmap_base(stream
);
1351 ERR("read mmap get mmap base for stream %s", stream
->name
);
1355 ret
= lttng_ustctl_get_mmap_read_offset(stream
, &mmap_offset
);
1359 ERR("Unknown consumer_data type");
1364 PERROR("tracer ctl get_mmap_read_offset");
1369 /* Handle stream on the relayd if the output is on the network */
1371 unsigned long netlen
= len
;
1374 * Lock the control socket for the complete duration of the function
1375 * since from this point on we will use the socket.
1377 if (stream
->metadata_flag
) {
1378 /* Metadata requires the control socket. */
1379 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1380 netlen
+= sizeof(struct lttcomm_relayd_metadata_payload
);
1383 ret
= write_relayd_stream_header(stream
, netlen
, padding
, relayd
);
1385 /* Use the returned socket. */
1388 /* Write metadata stream id before payload */
1389 if (stream
->metadata_flag
) {
1390 ret
= write_relayd_metadata_id(outfd
, stream
, relayd
, padding
);
1393 /* Socket operation failed. We consider the relayd dead */
1394 if (ret
== -EPIPE
|| ret
== -EINVAL
) {
1402 /* Socket operation failed. We consider the relayd dead */
1403 if (ret
== -EPIPE
|| ret
== -EINVAL
) {
1407 /* Else, use the default set before which is the filesystem. */
1410 /* No streaming, we have to set the len with the full padding */
1414 * Check if we need to change the tracefile before writing the packet.
1416 if (stream
->chan
->tracefile_size
> 0 &&
1417 (stream
->tracefile_size_current
+ len
) >
1418 stream
->chan
->tracefile_size
) {
1419 ret
= utils_rotate_stream_file(stream
->chan
->pathname
,
1420 stream
->name
, stream
->chan
->tracefile_size
,
1421 stream
->chan
->tracefile_count
, stream
->uid
, stream
->gid
,
1422 stream
->out_fd
, &(stream
->tracefile_count_current
));
1424 ERR("Rotating output file");
1427 outfd
= stream
->out_fd
= ret
;
1428 /* Reset current size because we just perform a rotation. */
1429 stream
->tracefile_size_current
= 0;
1431 stream
->tracefile_size_current
+= len
;
1436 ret
= write(outfd
, mmap_base
+ mmap_offset
, len
);
1437 } while (ret
< 0 && errno
== EINTR
);
1438 DBG("Consumer mmap write() ret %zd (len %lu)", ret
, len
);
1441 * This is possible if the fd is closed on the other side (outfd)
1442 * or any write problem. It can be verbose a bit for a normal
1443 * execution if for instance the relayd is stopped abruptly. This
1444 * can happen so set this to a DBG statement.
1446 DBG("Error in file write mmap");
1450 /* Socket operation failed. We consider the relayd dead */
1451 if (errno
== EPIPE
|| errno
== EINVAL
) {
1456 } else if (ret
> len
) {
1457 PERROR("Error in file write (ret %zd > len %lu)", ret
, len
);
1465 /* This call is useless on a socket so better save a syscall. */
1467 /* This won't block, but will start writeout asynchronously */
1468 lttng_sync_file_range(outfd
, stream
->out_fd_offset
, ret
,
1469 SYNC_FILE_RANGE_WRITE
);
1470 stream
->out_fd_offset
+= ret
;
1474 lttng_consumer_sync_trace_file(stream
, orig_offset
);
1478 * This is a special case that the relayd has closed its socket. Let's
1479 * cleanup the relayd object and all associated streams.
1481 if (relayd
&& relayd_hang_up
) {
1482 cleanup_relayd(relayd
, ctx
);
1486 /* Unlock only if ctrl socket used */
1487 if (relayd
&& stream
->metadata_flag
) {
1488 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1496 * Splice the data from the ring buffer to the tracefile.
1498 * It must be called with the stream lock held.
1500 * Returns the number of bytes spliced.
1502 ssize_t
lttng_consumer_on_read_subbuffer_splice(
1503 struct lttng_consumer_local_data
*ctx
,
1504 struct lttng_consumer_stream
*stream
, unsigned long len
,
1505 unsigned long padding
)
1507 ssize_t ret
= 0, written
= 0, ret_splice
= 0;
1509 off_t orig_offset
= stream
->out_fd_offset
;
1510 int fd
= stream
->wait_fd
;
1511 /* Default is on the disk */
1512 int outfd
= stream
->out_fd
;
1513 struct consumer_relayd_sock_pair
*relayd
= NULL
;
1515 unsigned int relayd_hang_up
= 0;
1517 switch (consumer_data
.type
) {
1518 case LTTNG_CONSUMER_KERNEL
:
1520 case LTTNG_CONSUMER32_UST
:
1521 case LTTNG_CONSUMER64_UST
:
1522 /* Not supported for user space tracing */
1525 ERR("Unknown consumer_data type");
1529 /* RCU lock for the relayd pointer */
1532 /* Flag that the current stream if set for network streaming. */
1533 if (stream
->net_seq_idx
!= -1) {
1534 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1535 if (relayd
== NULL
) {
1541 * Choose right pipe for splice. Metadata and trace data are handled by
1542 * different threads hence the use of two pipes in order not to race or
1543 * corrupt the written data.
1545 if (stream
->metadata_flag
) {
1546 splice_pipe
= ctx
->consumer_splice_metadata_pipe
;
1548 splice_pipe
= ctx
->consumer_thread_pipe
;
1551 /* Write metadata stream id before payload */
1553 int total_len
= len
;
1555 if (stream
->metadata_flag
) {
1557 * Lock the control socket for the complete duration of the function
1558 * since from this point on we will use the socket.
1560 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1562 ret
= write_relayd_metadata_id(splice_pipe
[1], stream
, relayd
,
1566 /* Socket operation failed. We consider the relayd dead */
1567 if (ret
== -EBADF
) {
1568 WARN("Remote relayd disconnected. Stopping");
1575 total_len
+= sizeof(struct lttcomm_relayd_metadata_payload
);
1578 ret
= write_relayd_stream_header(stream
, total_len
, padding
, relayd
);
1580 /* Use the returned socket. */
1583 /* Socket operation failed. We consider the relayd dead */
1584 if (ret
== -EBADF
) {
1585 WARN("Remote relayd disconnected. Stopping");
1592 /* No streaming, we have to set the len with the full padding */
1596 * Check if we need to change the tracefile before writing the packet.
1598 if (stream
->chan
->tracefile_size
> 0 &&
1599 (stream
->tracefile_size_current
+ len
) >
1600 stream
->chan
->tracefile_size
) {
1601 ret
= utils_rotate_stream_file(stream
->chan
->pathname
,
1602 stream
->name
, stream
->chan
->tracefile_size
,
1603 stream
->chan
->tracefile_count
, stream
->uid
, stream
->gid
,
1604 stream
->out_fd
, &(stream
->tracefile_count_current
));
1606 ERR("Rotating output file");
1609 outfd
= stream
->out_fd
= ret
;
1610 /* Reset current size because we just perform a rotation. */
1611 stream
->tracefile_size_current
= 0;
1613 stream
->tracefile_size_current
+= len
;
1617 DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)",
1618 (unsigned long)offset
, len
, fd
, splice_pipe
[1]);
1619 ret_splice
= splice(fd
, &offset
, splice_pipe
[1], NULL
, len
,
1620 SPLICE_F_MOVE
| SPLICE_F_MORE
);
1621 DBG("splice chan to pipe, ret %zd", ret_splice
);
1622 if (ret_splice
< 0) {
1623 PERROR("Error in relay splice");
1625 written
= ret_splice
;
1631 /* Handle stream on the relayd if the output is on the network */
1633 if (stream
->metadata_flag
) {
1634 size_t metadata_payload_size
=
1635 sizeof(struct lttcomm_relayd_metadata_payload
);
1637 /* Update counter to fit the spliced data */
1638 ret_splice
+= metadata_payload_size
;
1639 len
+= metadata_payload_size
;
1641 * We do this so the return value can match the len passed as
1642 * argument to this function.
1644 written
-= metadata_payload_size
;
1648 /* Splice data out */
1649 ret_splice
= splice(splice_pipe
[0], NULL
, outfd
, NULL
,
1650 ret_splice
, SPLICE_F_MOVE
| SPLICE_F_MORE
);
1651 DBG("Consumer splice pipe to file, ret %zd", ret_splice
);
1652 if (ret_splice
< 0) {
1653 PERROR("Error in file splice");
1655 written
= ret_splice
;
1657 /* Socket operation failed. We consider the relayd dead */
1658 if (errno
== EBADF
|| errno
== EPIPE
) {
1659 WARN("Remote relayd disconnected. Stopping");
1665 } else if (ret_splice
> len
) {
1667 PERROR("Wrote more data than requested %zd (len: %lu)",
1669 written
+= ret_splice
;
1675 /* This call is useless on a socket so better save a syscall. */
1677 /* This won't block, but will start writeout asynchronously */
1678 lttng_sync_file_range(outfd
, stream
->out_fd_offset
, ret_splice
,
1679 SYNC_FILE_RANGE_WRITE
);
1680 stream
->out_fd_offset
+= ret_splice
;
1682 written
+= ret_splice
;
1684 lttng_consumer_sync_trace_file(stream
, orig_offset
);
1692 * This is a special case that the relayd has closed its socket. Let's
1693 * cleanup the relayd object and all associated streams.
1695 if (relayd
&& relayd_hang_up
) {
1696 cleanup_relayd(relayd
, ctx
);
1697 /* Skip splice error so the consumer does not fail */
1702 /* send the appropriate error description to sessiond */
1705 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_EINVAL
);
1708 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_ENOMEM
);
1711 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_SPLICE_ESPIPE
);
1716 if (relayd
&& stream
->metadata_flag
) {
1717 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1725 * Take a snapshot for a specific fd
1727 * Returns 0 on success, < 0 on error
1729 int lttng_consumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1731 switch (consumer_data
.type
) {
1732 case LTTNG_CONSUMER_KERNEL
:
1733 return lttng_kconsumer_take_snapshot(stream
);
1734 case LTTNG_CONSUMER32_UST
:
1735 case LTTNG_CONSUMER64_UST
:
1736 return lttng_ustconsumer_take_snapshot(stream
);
1738 ERR("Unknown consumer_data type");
1745 * Get the produced position
1747 * Returns 0 on success, < 0 on error
1749 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
1752 switch (consumer_data
.type
) {
1753 case LTTNG_CONSUMER_KERNEL
:
1754 return lttng_kconsumer_get_produced_snapshot(stream
, pos
);
1755 case LTTNG_CONSUMER32_UST
:
1756 case LTTNG_CONSUMER64_UST
:
1757 return lttng_ustconsumer_get_produced_snapshot(stream
, pos
);
1759 ERR("Unknown consumer_data type");
1765 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1766 int sock
, struct pollfd
*consumer_sockpoll
)
1768 switch (consumer_data
.type
) {
1769 case LTTNG_CONSUMER_KERNEL
:
1770 return lttng_kconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1771 case LTTNG_CONSUMER32_UST
:
1772 case LTTNG_CONSUMER64_UST
:
1773 return lttng_ustconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1775 ERR("Unknown consumer_data type");
1782 * Iterate over all streams of the hashtable and free them properly.
1784 * WARNING: *MUST* be used with data stream only.
1786 static void destroy_data_stream_ht(struct lttng_ht
*ht
)
1788 struct lttng_ht_iter iter
;
1789 struct lttng_consumer_stream
*stream
;
1796 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
1798 * Ignore return value since we are currently cleaning up so any error
1801 (void) consumer_del_stream(stream
, ht
);
1805 lttng_ht_destroy(ht
);
1809 * Iterate over all streams of the hashtable and free them properly.
1811 * XXX: Should not be only for metadata stream or else use an other name.
1813 static void destroy_stream_ht(struct lttng_ht
*ht
)
1815 struct lttng_ht_iter iter
;
1816 struct lttng_consumer_stream
*stream
;
1823 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, stream
, node
.node
) {
1825 * Ignore return value since we are currently cleaning up so any error
1828 (void) consumer_del_metadata_stream(stream
, ht
);
1832 lttng_ht_destroy(ht
);
1835 void lttng_consumer_close_metadata(void)
1837 switch (consumer_data
.type
) {
1838 case LTTNG_CONSUMER_KERNEL
:
1840 * The Kernel consumer has a different metadata scheme so we don't
1841 * close anything because the stream will be closed by the session
1845 case LTTNG_CONSUMER32_UST
:
1846 case LTTNG_CONSUMER64_UST
:
1848 * Close all metadata streams. The metadata hash table is passed and
1849 * this call iterates over it by closing all wakeup fd. This is safe
1850 * because at this point we are sure that the metadata producer is
1851 * either dead or blocked.
1853 lttng_ustconsumer_close_metadata(metadata_ht
);
1856 ERR("Unknown consumer_data type");
1862 * Clean up a metadata stream and free its memory.
1864 void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
1865 struct lttng_ht
*ht
)
1868 struct lttng_ht_iter iter
;
1869 struct lttng_consumer_channel
*free_chan
= NULL
;
1870 struct consumer_relayd_sock_pair
*relayd
;
1874 * This call should NEVER receive regular stream. It must always be
1875 * metadata stream and this is crucial for data structure synchronization.
1877 assert(stream
->metadata_flag
);
1879 DBG3("Consumer delete metadata stream %d", stream
->wait_fd
);
1882 /* Means the stream was allocated but not successfully added */
1883 goto free_stream_rcu
;
1886 pthread_mutex_lock(&consumer_data
.lock
);
1887 pthread_mutex_lock(&stream
->lock
);
1889 switch (consumer_data
.type
) {
1890 case LTTNG_CONSUMER_KERNEL
:
1891 if (stream
->mmap_base
!= NULL
) {
1892 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
1894 PERROR("munmap metadata stream");
1898 if (stream
->wait_fd
>= 0) {
1899 ret
= close(stream
->wait_fd
);
1901 PERROR("close kernel metadata wait_fd");
1905 case LTTNG_CONSUMER32_UST
:
1906 case LTTNG_CONSUMER64_UST
:
1907 lttng_ustconsumer_del_stream(stream
);
1910 ERR("Unknown consumer_data type");
1916 iter
.iter
.node
= &stream
->node
.node
;
1917 ret
= lttng_ht_del(ht
, &iter
);
1920 iter
.iter
.node
= &stream
->node_channel_id
.node
;
1921 ret
= lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
1924 iter
.iter
.node
= &stream
->node_session_id
.node
;
1925 ret
= lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
1929 if (stream
->out_fd
>= 0) {
1930 ret
= close(stream
->out_fd
);
1936 /* Check and cleanup relayd */
1938 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
1939 if (relayd
!= NULL
) {
1940 uatomic_dec(&relayd
->refcount
);
1941 assert(uatomic_read(&relayd
->refcount
) >= 0);
1943 /* Closing streams requires to lock the control socket. */
1944 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
1945 ret
= relayd_send_close_stream(&relayd
->control_sock
,
1946 stream
->relayd_stream_id
, stream
->next_net_seq_num
- 1);
1947 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
1949 DBG("Unable to close stream on the relayd. Continuing");
1951 * Continue here. There is nothing we can do for the relayd.
1952 * Chances are that the relayd has closed the socket so we just
1953 * continue cleaning up.
1957 /* Both conditions are met, we destroy the relayd. */
1958 if (uatomic_read(&relayd
->refcount
) == 0 &&
1959 uatomic_read(&relayd
->destroy_flag
)) {
1960 destroy_relayd(relayd
);
1965 /* Atomically decrement channel refcount since other threads can use it. */
1966 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
1967 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
1968 /* Go for channel deletion! */
1969 free_chan
= stream
->chan
;
1974 * Nullify the stream reference so it is not used after deletion. The
1975 * consumer data lock MUST be acquired before being able to check for a
1976 * NULL pointer value.
1978 stream
->chan
->metadata_stream
= NULL
;
1980 pthread_mutex_unlock(&stream
->lock
);
1981 pthread_mutex_unlock(&consumer_data
.lock
);
1984 consumer_del_channel(free_chan
);
1988 call_rcu(&stream
->node
.head
, free_stream_rcu
);
1992 * Action done with the metadata stream when adding it to the consumer internal
1993 * data structures to handle it.
1995 static int add_metadata_stream(struct lttng_consumer_stream
*stream
,
1996 struct lttng_ht
*ht
)
1999 struct consumer_relayd_sock_pair
*relayd
;
2000 struct lttng_ht_iter iter
;
2001 struct lttng_ht_node_u64
*node
;
2006 DBG3("Adding metadata stream %" PRIu64
" to hash table", stream
->key
);
2008 pthread_mutex_lock(&consumer_data
.lock
);
2009 pthread_mutex_lock(&stream
->lock
);
2012 * From here, refcounts are updated so be _careful_ when returning an error
2019 * Lookup the stream just to make sure it does not exist in our internal
2020 * state. This should NEVER happen.
2022 lttng_ht_lookup(ht
, &stream
->key
, &iter
);
2023 node
= lttng_ht_iter_get_node_u64(&iter
);
2026 /* Find relayd and, if one is found, increment refcount. */
2027 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
2028 if (relayd
!= NULL
) {
2029 uatomic_inc(&relayd
->refcount
);
2033 * When nb_init_stream_left reaches 0, we don't need to trigger any action
2034 * in terms of destroying the associated channel, because the action that
2035 * causes the count to become 0 also causes a stream to be added. The
2036 * channel deletion will thus be triggered by the following removal of this
2039 if (uatomic_read(&stream
->chan
->nb_init_stream_left
) > 0) {
2040 /* Increment refcount before decrementing nb_init_stream_left */
2042 uatomic_dec(&stream
->chan
->nb_init_stream_left
);
2045 lttng_ht_add_unique_u64(ht
, &stream
->node
);
2047 lttng_ht_add_unique_u64(consumer_data
.stream_per_chan_id_ht
,
2048 &stream
->node_channel_id
);
2051 * Add stream to the stream_list_ht of the consumer data. No need to steal
2052 * the key since the HT does not use it and we allow to add redundant keys
2055 lttng_ht_add_u64(consumer_data
.stream_list_ht
, &stream
->node_session_id
);
2059 pthread_mutex_unlock(&stream
->lock
);
2060 pthread_mutex_unlock(&consumer_data
.lock
);
2065 * Delete data stream that are flagged for deletion (endpoint_status).
2067 static void validate_endpoint_status_data_stream(void)
2069 struct lttng_ht_iter iter
;
2070 struct lttng_consumer_stream
*stream
;
2072 DBG("Consumer delete flagged data stream");
2075 cds_lfht_for_each_entry(data_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
2076 /* Validate delete flag of the stream */
2077 if (stream
->endpoint_status
== CONSUMER_ENDPOINT_ACTIVE
) {
2080 /* Delete it right now */
2081 consumer_del_stream(stream
, data_ht
);
2087 * Delete metadata stream that are flagged for deletion (endpoint_status).
2089 static void validate_endpoint_status_metadata_stream(
2090 struct lttng_poll_event
*pollset
)
2092 struct lttng_ht_iter iter
;
2093 struct lttng_consumer_stream
*stream
;
2095 DBG("Consumer delete flagged metadata stream");
2100 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
, node
.node
) {
2101 /* Validate delete flag of the stream */
2102 if (stream
->endpoint_status
== CONSUMER_ENDPOINT_ACTIVE
) {
2106 * Remove from pollset so the metadata thread can continue without
2107 * blocking on a deleted stream.
2109 lttng_poll_del(pollset
, stream
->wait_fd
);
2111 /* Delete it right now */
2112 consumer_del_metadata_stream(stream
, metadata_ht
);
2118 * Thread polls on metadata file descriptor and write them on disk or on the
2121 void *consumer_thread_metadata_poll(void *data
)
2124 uint32_t revents
, nb_fd
;
2125 struct lttng_consumer_stream
*stream
= NULL
;
2126 struct lttng_ht_iter iter
;
2127 struct lttng_ht_node_u64
*node
;
2128 struct lttng_poll_event events
;
2129 struct lttng_consumer_local_data
*ctx
= data
;
2132 rcu_register_thread();
2134 metadata_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2136 /* ENOMEM at this point. Better to bail out. */
2140 DBG("Thread metadata poll started");
2142 /* Size is set to 1 for the consumer_metadata pipe */
2143 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
2145 ERR("Poll set creation failed");
2149 ret
= lttng_poll_add(&events
,
2150 lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
), LPOLLIN
);
2156 DBG("Metadata main loop started");
2159 /* Only the metadata pipe is set */
2160 if (LTTNG_POLL_GETNB(&events
) == 0 && consumer_quit
== 1) {
2165 DBG("Metadata poll wait with %d fd(s)", LTTNG_POLL_GETNB(&events
));
2166 ret
= lttng_poll_wait(&events
, -1);
2167 DBG("Metadata event catched in thread");
2169 if (errno
== EINTR
) {
2170 ERR("Poll EINTR catched");
2178 /* From here, the event is a metadata wait fd */
2179 for (i
= 0; i
< nb_fd
; i
++) {
2180 revents
= LTTNG_POLL_GETEV(&events
, i
);
2181 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
2183 /* Just don't waste time if no returned events for the fd */
2188 if (pollfd
== lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
)) {
2189 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2190 DBG("Metadata thread pipe hung up");
2192 * Remove the pipe from the poll set and continue the loop
2193 * since their might be data to consume.
2195 lttng_poll_del(&events
,
2196 lttng_pipe_get_readfd(ctx
->consumer_metadata_pipe
));
2197 lttng_pipe_read_close(ctx
->consumer_metadata_pipe
);
2199 } else if (revents
& LPOLLIN
) {
2202 pipe_len
= lttng_pipe_read(ctx
->consumer_metadata_pipe
,
2203 &stream
, sizeof(stream
));
2205 ERR("read metadata stream, ret: %ld", pipe_len
);
2207 * Continue here to handle the rest of the streams.
2212 /* A NULL stream means that the state has changed. */
2213 if (stream
== NULL
) {
2214 /* Check for deleted streams. */
2215 validate_endpoint_status_metadata_stream(&events
);
2219 DBG("Adding metadata stream %d to poll set",
2222 ret
= add_metadata_stream(stream
, metadata_ht
);
2224 ERR("Unable to add metadata stream");
2225 /* Stream was not setup properly. Continuing. */
2226 consumer_del_metadata_stream(stream
, NULL
);
2230 /* Add metadata stream to the global poll events list */
2231 lttng_poll_add(&events
, stream
->wait_fd
,
2232 LPOLLIN
| LPOLLPRI
);
2235 /* Handle other stream */
2241 uint64_t tmp_id
= (uint64_t) pollfd
;
2243 lttng_ht_lookup(metadata_ht
, &tmp_id
, &iter
);
2245 node
= lttng_ht_iter_get_node_u64(&iter
);
2248 stream
= caa_container_of(node
, struct lttng_consumer_stream
,
2251 /* Check for error event */
2252 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2253 DBG("Metadata fd %d is hup|err.", pollfd
);
2254 if (!stream
->hangup_flush_done
2255 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
2256 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
2257 DBG("Attempting to flush and consume the UST buffers");
2258 lttng_ustconsumer_on_stream_hangup(stream
);
2260 /* We just flushed the stream now read it. */
2262 len
= ctx
->on_buffer_ready(stream
, ctx
);
2264 * We don't check the return value here since if we get
2265 * a negative len, it means an error occured thus we
2266 * simply remove it from the poll set and free the
2272 lttng_poll_del(&events
, stream
->wait_fd
);
2274 * This call update the channel states, closes file descriptors
2275 * and securely free the stream.
2277 consumer_del_metadata_stream(stream
, metadata_ht
);
2278 } else if (revents
& (LPOLLIN
| LPOLLPRI
)) {
2279 /* Get the data out of the metadata file descriptor */
2280 DBG("Metadata available on fd %d", pollfd
);
2281 assert(stream
->wait_fd
== pollfd
);
2283 len
= ctx
->on_buffer_ready(stream
, ctx
);
2284 /* It's ok to have an unavailable sub-buffer */
2285 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2286 /* Clean up stream from consumer and free it. */
2287 lttng_poll_del(&events
, stream
->wait_fd
);
2288 consumer_del_metadata_stream(stream
, metadata_ht
);
2289 } else if (len
> 0) {
2290 stream
->data_read
= 1;
2294 /* Release RCU lock for the stream looked up */
2301 DBG("Metadata poll thread exiting");
2303 lttng_poll_clean(&events
);
2305 destroy_stream_ht(metadata_ht
);
2307 rcu_unregister_thread();
2312 * This thread polls the fds in the set to consume the data and write
2313 * it to tracefile if necessary.
2315 void *consumer_thread_data_poll(void *data
)
2317 int num_rdy
, num_hup
, high_prio
, ret
, i
;
2318 struct pollfd
*pollfd
= NULL
;
2319 /* local view of the streams */
2320 struct lttng_consumer_stream
**local_stream
= NULL
, *new_stream
= NULL
;
2321 /* local view of consumer_data.fds_count */
2323 struct lttng_consumer_local_data
*ctx
= data
;
2326 rcu_register_thread();
2328 data_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2329 if (data_ht
== NULL
) {
2330 /* ENOMEM at this point. Better to bail out. */
2334 local_stream
= zmalloc(sizeof(struct lttng_consumer_stream
));
2341 * the fds set has been updated, we need to update our
2342 * local array as well
2344 pthread_mutex_lock(&consumer_data
.lock
);
2345 if (consumer_data
.need_update
) {
2350 local_stream
= NULL
;
2352 /* allocate for all fds + 1 for the consumer_data_pipe */
2353 pollfd
= zmalloc((consumer_data
.stream_count
+ 1) * sizeof(struct pollfd
));
2354 if (pollfd
== NULL
) {
2355 PERROR("pollfd malloc");
2356 pthread_mutex_unlock(&consumer_data
.lock
);
2360 /* allocate for all fds + 1 for the consumer_data_pipe */
2361 local_stream
= zmalloc((consumer_data
.stream_count
+ 1) *
2362 sizeof(struct lttng_consumer_stream
*));
2363 if (local_stream
== NULL
) {
2364 PERROR("local_stream malloc");
2365 pthread_mutex_unlock(&consumer_data
.lock
);
2368 ret
= update_poll_array(ctx
, &pollfd
, local_stream
,
2371 ERR("Error in allocating pollfd or local_outfds");
2372 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
2373 pthread_mutex_unlock(&consumer_data
.lock
);
2377 consumer_data
.need_update
= 0;
2379 pthread_mutex_unlock(&consumer_data
.lock
);
2381 /* No FDs and consumer_quit, consumer_cleanup the thread */
2382 if (nb_fd
== 0 && consumer_quit
== 1) {
2385 /* poll on the array of fds */
2387 DBG("polling on %d fd", nb_fd
+ 1);
2388 num_rdy
= poll(pollfd
, nb_fd
+ 1, -1);
2389 DBG("poll num_rdy : %d", num_rdy
);
2390 if (num_rdy
== -1) {
2392 * Restart interrupted system call.
2394 if (errno
== EINTR
) {
2397 PERROR("Poll error");
2398 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
2400 } else if (num_rdy
== 0) {
2401 DBG("Polling thread timed out");
2406 * If the consumer_data_pipe triggered poll go directly to the
2407 * beginning of the loop to update the array. We want to prioritize
2408 * array update over low-priority reads.
2410 if (pollfd
[nb_fd
].revents
& (POLLIN
| POLLPRI
)) {
2411 ssize_t pipe_readlen
;
2413 DBG("consumer_data_pipe wake up");
2414 pipe_readlen
= lttng_pipe_read(ctx
->consumer_data_pipe
,
2415 &new_stream
, sizeof(new_stream
));
2416 if (pipe_readlen
< 0) {
2417 ERR("Consumer data pipe ret %ld", pipe_readlen
);
2418 /* Continue so we can at least handle the current stream(s). */
2423 * If the stream is NULL, just ignore it. It's also possible that
2424 * the sessiond poll thread changed the consumer_quit state and is
2425 * waking us up to test it.
2427 if (new_stream
== NULL
) {
2428 validate_endpoint_status_data_stream();
2432 ret
= add_stream(new_stream
, data_ht
);
2434 ERR("Consumer add stream %" PRIu64
" failed. Continuing",
2437 * At this point, if the add_stream fails, it is not in the
2438 * hash table thus passing the NULL value here.
2440 consumer_del_stream(new_stream
, NULL
);
2443 /* Continue to update the local streams and handle prio ones */
2447 /* Take care of high priority channels first. */
2448 for (i
= 0; i
< nb_fd
; i
++) {
2449 if (local_stream
[i
] == NULL
) {
2452 if (pollfd
[i
].revents
& POLLPRI
) {
2453 DBG("Urgent read on fd %d", pollfd
[i
].fd
);
2455 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
2456 /* it's ok to have an unavailable sub-buffer */
2457 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2458 /* Clean the stream and free it. */
2459 consumer_del_stream(local_stream
[i
], data_ht
);
2460 local_stream
[i
] = NULL
;
2461 } else if (len
> 0) {
2462 local_stream
[i
]->data_read
= 1;
2468 * If we read high prio channel in this loop, try again
2469 * for more high prio data.
2475 /* Take care of low priority channels. */
2476 for (i
= 0; i
< nb_fd
; i
++) {
2477 if (local_stream
[i
] == NULL
) {
2480 if ((pollfd
[i
].revents
& POLLIN
) ||
2481 local_stream
[i
]->hangup_flush_done
) {
2482 DBG("Normal read on fd %d", pollfd
[i
].fd
);
2483 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
2484 /* it's ok to have an unavailable sub-buffer */
2485 if (len
< 0 && len
!= -EAGAIN
&& len
!= -ENODATA
) {
2486 /* Clean the stream and free it. */
2487 consumer_del_stream(local_stream
[i
], data_ht
);
2488 local_stream
[i
] = NULL
;
2489 } else if (len
> 0) {
2490 local_stream
[i
]->data_read
= 1;
2495 /* Handle hangup and errors */
2496 for (i
= 0; i
< nb_fd
; i
++) {
2497 if (local_stream
[i
] == NULL
) {
2500 if (!local_stream
[i
]->hangup_flush_done
2501 && (pollfd
[i
].revents
& (POLLHUP
| POLLERR
| POLLNVAL
))
2502 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
2503 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
2504 DBG("fd %d is hup|err|nval. Attempting flush and read.",
2506 lttng_ustconsumer_on_stream_hangup(local_stream
[i
]);
2507 /* Attempt read again, for the data we just flushed. */
2508 local_stream
[i
]->data_read
= 1;
2511 * If the poll flag is HUP/ERR/NVAL and we have
2512 * read no data in this pass, we can remove the
2513 * stream from its hash table.
2515 if ((pollfd
[i
].revents
& POLLHUP
)) {
2516 DBG("Polling fd %d tells it has hung up.", pollfd
[i
].fd
);
2517 if (!local_stream
[i
]->data_read
) {
2518 consumer_del_stream(local_stream
[i
], data_ht
);
2519 local_stream
[i
] = NULL
;
2522 } else if (pollfd
[i
].revents
& POLLERR
) {
2523 ERR("Error returned in polling fd %d.", pollfd
[i
].fd
);
2524 if (!local_stream
[i
]->data_read
) {
2525 consumer_del_stream(local_stream
[i
], data_ht
);
2526 local_stream
[i
] = NULL
;
2529 } else if (pollfd
[i
].revents
& POLLNVAL
) {
2530 ERR("Polling fd %d tells fd is not open.", pollfd
[i
].fd
);
2531 if (!local_stream
[i
]->data_read
) {
2532 consumer_del_stream(local_stream
[i
], data_ht
);
2533 local_stream
[i
] = NULL
;
2537 if (local_stream
[i
] != NULL
) {
2538 local_stream
[i
]->data_read
= 0;
2543 DBG("polling thread exiting");
2548 * Close the write side of the pipe so epoll_wait() in
2549 * consumer_thread_metadata_poll can catch it. The thread is monitoring the
2550 * read side of the pipe. If we close them both, epoll_wait strangely does
2551 * not return and could create a endless wait period if the pipe is the
2552 * only tracked fd in the poll set. The thread will take care of closing
2555 (void) lttng_pipe_write_close(ctx
->consumer_metadata_pipe
);
2557 destroy_data_stream_ht(data_ht
);
2559 rcu_unregister_thread();
2564 * Close wake-up end of each stream belonging to the channel. This will
2565 * allow the poll() on the stream read-side to detect when the
2566 * write-side (application) finally closes them.
2569 void consumer_close_channel_streams(struct lttng_consumer_channel
*channel
)
2571 struct lttng_ht
*ht
;
2572 struct lttng_consumer_stream
*stream
;
2573 struct lttng_ht_iter iter
;
2575 ht
= consumer_data
.stream_per_chan_id_ht
;
2578 cds_lfht_for_each_entry_duplicate(ht
->ht
,
2579 ht
->hash_fct(&channel
->key
, lttng_ht_seed
),
2580 ht
->match_fct
, &channel
->key
,
2581 &iter
.iter
, stream
, node_channel_id
.node
) {
2583 * Protect against teardown with mutex.
2585 pthread_mutex_lock(&stream
->lock
);
2586 if (cds_lfht_is_node_deleted(&stream
->node
.node
)) {
2589 switch (consumer_data
.type
) {
2590 case LTTNG_CONSUMER_KERNEL
:
2592 case LTTNG_CONSUMER32_UST
:
2593 case LTTNG_CONSUMER64_UST
:
2595 * Note: a mutex is taken internally within
2596 * liblttng-ust-ctl to protect timer wakeup_fd
2597 * use from concurrent close.
2599 lttng_ustconsumer_close_stream_wakeup(stream
);
2602 ERR("Unknown consumer_data type");
2606 pthread_mutex_unlock(&stream
->lock
);
2611 static void destroy_channel_ht(struct lttng_ht
*ht
)
2613 struct lttng_ht_iter iter
;
2614 struct lttng_consumer_channel
*channel
;
2622 cds_lfht_for_each_entry(ht
->ht
, &iter
.iter
, channel
, wait_fd_node
.node
) {
2623 ret
= lttng_ht_del(ht
, &iter
);
2628 lttng_ht_destroy(ht
);
2632 * This thread polls the channel fds to detect when they are being
2633 * closed. It closes all related streams if the channel is detected as
2634 * closed. It is currently only used as a shim layer for UST because the
2635 * consumerd needs to keep the per-stream wakeup end of pipes open for
2638 void *consumer_thread_channel_poll(void *data
)
2641 uint32_t revents
, nb_fd
;
2642 struct lttng_consumer_channel
*chan
= NULL
;
2643 struct lttng_ht_iter iter
;
2644 struct lttng_ht_node_u64
*node
;
2645 struct lttng_poll_event events
;
2646 struct lttng_consumer_local_data
*ctx
= data
;
2647 struct lttng_ht
*channel_ht
;
2649 rcu_register_thread();
2651 channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
2653 /* ENOMEM at this point. Better to bail out. */
2657 DBG("Thread channel poll started");
2659 /* Size is set to 1 for the consumer_channel pipe */
2660 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
2662 ERR("Poll set creation failed");
2666 ret
= lttng_poll_add(&events
, ctx
->consumer_channel_pipe
[0], LPOLLIN
);
2672 DBG("Channel main loop started");
2675 /* Only the channel pipe is set */
2676 if (LTTNG_POLL_GETNB(&events
) == 0 && consumer_quit
== 1) {
2681 DBG("Channel poll wait with %d fd(s)", LTTNG_POLL_GETNB(&events
));
2682 ret
= lttng_poll_wait(&events
, -1);
2683 DBG("Channel event catched in thread");
2685 if (errno
== EINTR
) {
2686 ERR("Poll EINTR catched");
2694 /* From here, the event is a channel wait fd */
2695 for (i
= 0; i
< nb_fd
; i
++) {
2696 revents
= LTTNG_POLL_GETEV(&events
, i
);
2697 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
2699 /* Just don't waste time if no returned events for the fd */
2703 if (pollfd
== ctx
->consumer_channel_pipe
[0]) {
2704 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2705 DBG("Channel thread pipe hung up");
2707 * Remove the pipe from the poll set and continue the loop
2708 * since their might be data to consume.
2710 lttng_poll_del(&events
, ctx
->consumer_channel_pipe
[0]);
2712 } else if (revents
& LPOLLIN
) {
2713 enum consumer_channel_action action
;
2716 ret
= read_channel_pipe(ctx
, &chan
, &key
, &action
);
2718 ERR("Error reading channel pipe");
2723 case CONSUMER_CHANNEL_ADD
:
2724 DBG("Adding channel %d to poll set",
2727 lttng_ht_node_init_u64(&chan
->wait_fd_node
,
2730 lttng_ht_add_unique_u64(channel_ht
,
2731 &chan
->wait_fd_node
);
2733 /* Add channel to the global poll events list */
2734 lttng_poll_add(&events
, chan
->wait_fd
,
2735 LPOLLIN
| LPOLLPRI
);
2737 case CONSUMER_CHANNEL_DEL
:
2739 struct lttng_consumer_stream
*stream
, *stmp
;
2742 chan
= consumer_find_channel(key
);
2745 ERR("UST consumer get channel key %" PRIu64
" not found for del channel", key
);
2748 lttng_poll_del(&events
, chan
->wait_fd
);
2749 iter
.iter
.node
= &chan
->wait_fd_node
.node
;
2750 ret
= lttng_ht_del(channel_ht
, &iter
);
2752 consumer_close_channel_streams(chan
);
2754 switch (consumer_data
.type
) {
2755 case LTTNG_CONSUMER_KERNEL
:
2757 case LTTNG_CONSUMER32_UST
:
2758 case LTTNG_CONSUMER64_UST
:
2759 /* Delete streams that might have been left in the stream list. */
2760 cds_list_for_each_entry_safe(stream
, stmp
, &chan
->streams
.head
,
2762 cds_list_del(&stream
->send_node
);
2763 lttng_ustconsumer_del_stream(stream
);
2764 uatomic_sub(&stream
->chan
->refcount
, 1);
2765 assert(&chan
->refcount
);
2770 ERR("Unknown consumer_data type");
2775 * Release our own refcount. Force channel deletion even if
2776 * streams were not initialized.
2778 if (!uatomic_sub_return(&chan
->refcount
, 1)) {
2779 consumer_del_channel(chan
);
2784 case CONSUMER_CHANNEL_QUIT
:
2786 * Remove the pipe from the poll set and continue the loop
2787 * since their might be data to consume.
2789 lttng_poll_del(&events
, ctx
->consumer_channel_pipe
[0]);
2792 ERR("Unknown action");
2797 /* Handle other stream */
2803 uint64_t tmp_id
= (uint64_t) pollfd
;
2805 lttng_ht_lookup(channel_ht
, &tmp_id
, &iter
);
2807 node
= lttng_ht_iter_get_node_u64(&iter
);
2810 chan
= caa_container_of(node
, struct lttng_consumer_channel
,
2813 /* Check for error event */
2814 if (revents
& (LPOLLERR
| LPOLLHUP
)) {
2815 DBG("Channel fd %d is hup|err.", pollfd
);
2817 lttng_poll_del(&events
, chan
->wait_fd
);
2818 ret
= lttng_ht_del(channel_ht
, &iter
);
2820 assert(cds_list_empty(&chan
->streams
.head
));
2821 consumer_close_channel_streams(chan
);
2823 /* Release our own refcount */
2824 if (!uatomic_sub_return(&chan
->refcount
, 1)
2825 && !uatomic_read(&chan
->nb_init_stream_left
)) {
2826 consumer_del_channel(chan
);
2830 /* Release RCU lock for the channel looked up */
2836 lttng_poll_clean(&events
);
2838 destroy_channel_ht(channel_ht
);
2840 DBG("Channel poll thread exiting");
2841 rcu_unregister_thread();
2845 static int set_metadata_socket(struct lttng_consumer_local_data
*ctx
,
2846 struct pollfd
*sockpoll
, int client_socket
)
2853 if (lttng_consumer_poll_socket(sockpoll
) < 0) {
2857 DBG("Metadata connection on client_socket");
2859 /* Blocking call, waiting for transmission */
2860 ctx
->consumer_metadata_socket
= lttcomm_accept_unix_sock(client_socket
);
2861 if (ctx
->consumer_metadata_socket
< 0) {
2862 WARN("On accept metadata");
2873 * This thread listens on the consumerd socket and receives the file
2874 * descriptors from the session daemon.
2876 void *consumer_thread_sessiond_poll(void *data
)
2878 int sock
= -1, client_socket
, ret
;
2880 * structure to poll for incoming data on communication socket avoids
2881 * making blocking sockets.
2883 struct pollfd consumer_sockpoll
[2];
2884 struct lttng_consumer_local_data
*ctx
= data
;
2886 rcu_register_thread();
2888 DBG("Creating command socket %s", ctx
->consumer_command_sock_path
);
2889 unlink(ctx
->consumer_command_sock_path
);
2890 client_socket
= lttcomm_create_unix_sock(ctx
->consumer_command_sock_path
);
2891 if (client_socket
< 0) {
2892 ERR("Cannot create command socket");
2896 ret
= lttcomm_listen_unix_sock(client_socket
);
2901 DBG("Sending ready command to lttng-sessiond");
2902 ret
= lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY
);
2903 /* return < 0 on error, but == 0 is not fatal */
2905 ERR("Error sending ready command to lttng-sessiond");
2909 /* prepare the FDs to poll : to client socket and the should_quit pipe */
2910 consumer_sockpoll
[0].fd
= ctx
->consumer_should_quit
[0];
2911 consumer_sockpoll
[0].events
= POLLIN
| POLLPRI
;
2912 consumer_sockpoll
[1].fd
= client_socket
;
2913 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
2915 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
2918 DBG("Connection on client_socket");
2920 /* Blocking call, waiting for transmission */
2921 sock
= lttcomm_accept_unix_sock(client_socket
);
2928 * Setup metadata socket which is the second socket connection on the
2929 * command unix socket.
2931 ret
= set_metadata_socket(ctx
, consumer_sockpoll
, client_socket
);
2936 /* This socket is not useful anymore. */
2937 ret
= close(client_socket
);
2939 PERROR("close client_socket");
2943 /* update the polling structure to poll on the established socket */
2944 consumer_sockpoll
[1].fd
= sock
;
2945 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
2948 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
2951 DBG("Incoming command on sock");
2952 ret
= lttng_consumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
2953 if (ret
== -ENOENT
) {
2954 DBG("Received STOP command");
2959 * This could simply be a session daemon quitting. Don't output
2962 DBG("Communication interrupted on command socket");
2965 if (consumer_quit
) {
2966 DBG("consumer_thread_receive_fds received quit from signal");
2969 DBG("received command on sock");
2972 DBG("Consumer thread sessiond poll exiting");
2975 * Close metadata streams since the producer is the session daemon which
2978 * NOTE: for now, this only applies to the UST tracer.
2980 lttng_consumer_close_metadata();
2983 * when all fds have hung up, the polling thread
2989 * Notify the data poll thread to poll back again and test the
2990 * consumer_quit state that we just set so to quit gracefully.
2992 notify_thread_lttng_pipe(ctx
->consumer_data_pipe
);
2994 notify_channel_pipe(ctx
, NULL
, -1, CONSUMER_CHANNEL_QUIT
);
2996 /* Cleaning up possibly open sockets. */
3000 PERROR("close sock sessiond poll");
3003 if (client_socket
>= 0) {
3004 ret
= close(client_socket
);
3006 PERROR("close client_socket sessiond poll");
3010 rcu_unregister_thread();
3014 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
3015 struct lttng_consumer_local_data
*ctx
)
3019 pthread_mutex_lock(&stream
->lock
);
3021 switch (consumer_data
.type
) {
3022 case LTTNG_CONSUMER_KERNEL
:
3023 ret
= lttng_kconsumer_read_subbuffer(stream
, ctx
);
3025 case LTTNG_CONSUMER32_UST
:
3026 case LTTNG_CONSUMER64_UST
:
3027 ret
= lttng_ustconsumer_read_subbuffer(stream
, ctx
);
3030 ERR("Unknown consumer_data type");
3036 pthread_mutex_unlock(&stream
->lock
);
3040 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
3042 switch (consumer_data
.type
) {
3043 case LTTNG_CONSUMER_KERNEL
:
3044 return lttng_kconsumer_on_recv_stream(stream
);
3045 case LTTNG_CONSUMER32_UST
:
3046 case LTTNG_CONSUMER64_UST
:
3047 return lttng_ustconsumer_on_recv_stream(stream
);
3049 ERR("Unknown consumer_data type");
3056 * Allocate and set consumer data hash tables.
3058 void lttng_consumer_init(void)
3060 consumer_data
.channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3061 consumer_data
.relayd_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3062 consumer_data
.stream_list_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3063 consumer_data
.stream_per_chan_id_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
3067 * Process the ADD_RELAYD command receive by a consumer.
3069 * This will create a relayd socket pair and add it to the relayd hash table.
3070 * The caller MUST acquire a RCU read side lock before calling it.
3072 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
3073 struct lttng_consumer_local_data
*ctx
, int sock
,
3074 struct pollfd
*consumer_sockpoll
,
3075 struct lttcomm_relayd_sock
*relayd_sock
, unsigned int sessiond_id
)
3077 int fd
= -1, ret
= -1, relayd_created
= 0;
3078 enum lttng_error_code ret_code
= LTTNG_OK
;
3079 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3082 assert(relayd_sock
);
3084 DBG("Consumer adding relayd socket (idx: %d)", net_seq_idx
);
3086 /* Get relayd reference if exists. */
3087 relayd
= consumer_find_relayd(net_seq_idx
);
3088 if (relayd
== NULL
) {
3089 /* Not found. Allocate one. */
3090 relayd
= consumer_allocate_relayd_sock_pair(net_seq_idx
);
3091 if (relayd
== NULL
) {
3092 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
3095 relayd
->sessiond_session_id
= (uint64_t) sessiond_id
;
3100 * This code path MUST continue to the consumer send status message to
3101 * we can notify the session daemon and continue our work without
3102 * killing everything.
3106 /* First send a status message before receiving the fds. */
3107 ret
= consumer_send_status_msg(sock
, ret_code
);
3108 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
3109 /* Somehow, the session daemon is not responding anymore. */
3113 /* Poll on consumer socket. */
3114 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
3115 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_POLL_ERROR
);
3120 /* Get relayd socket from session daemon */
3121 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
3122 if (ret
!= sizeof(fd
)) {
3123 ret_code
= LTTCOMM_CONSUMERD_ERROR_RECV_FD
;
3125 fd
= -1; /* Just in case it gets set with an invalid value. */
3128 * Failing to receive FDs might indicate a major problem such as
3129 * reaching a fd limit during the receive where the kernel returns a
3130 * MSG_CTRUNC and fails to cleanup the fd in the queue. Any case, we
3131 * don't take any chances and stop everything.
3133 * XXX: Feature request #558 will fix that and avoid this possible
3134 * issue when reaching the fd limit.
3136 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
3139 * This code path MUST continue to the consumer send status message so
3140 * we can send the error to the thread expecting a reply. The above
3141 * call will make everything stop.
3145 /* We have the fds without error. Send status back. */
3146 ret
= consumer_send_status_msg(sock
, ret_code
);
3147 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
3148 /* Somehow, the session daemon is not responding anymore. */
3152 /* Copy socket information and received FD */
3153 switch (sock_type
) {
3154 case LTTNG_STREAM_CONTROL
:
3155 /* Copy received lttcomm socket */
3156 lttcomm_copy_sock(&relayd
->control_sock
.sock
, &relayd_sock
->sock
);
3157 ret
= lttcomm_create_sock(&relayd
->control_sock
.sock
);
3158 /* Immediately try to close the created socket if valid. */
3159 if (relayd
->control_sock
.sock
.fd
>= 0) {
3160 if (close(relayd
->control_sock
.sock
.fd
)) {
3161 PERROR("close relayd control socket");
3164 /* Handle create_sock error. */
3169 /* Assign new file descriptor */
3170 relayd
->control_sock
.sock
.fd
= fd
;
3171 /* Assign version values. */
3172 relayd
->control_sock
.major
= relayd_sock
->major
;
3173 relayd
->control_sock
.minor
= relayd_sock
->minor
;
3176 * Create a session on the relayd and store the returned id. Lock the
3177 * control socket mutex if the relayd was NOT created before.
3179 if (!relayd_created
) {
3180 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3182 ret
= relayd_create_session(&relayd
->control_sock
,
3183 &relayd
->relayd_session_id
);
3184 if (!relayd_created
) {
3185 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3189 * Close all sockets of a relayd object. It will be freed if it was
3190 * created at the error code path or else it will be garbage
3193 (void) relayd_close(&relayd
->control_sock
);
3194 (void) relayd_close(&relayd
->data_sock
);
3199 case LTTNG_STREAM_DATA
:
3200 /* Copy received lttcomm socket */
3201 lttcomm_copy_sock(&relayd
->data_sock
.sock
, &relayd_sock
->sock
);
3202 ret
= lttcomm_create_sock(&relayd
->data_sock
.sock
);
3203 /* Immediately try to close the created socket if valid. */
3204 if (relayd
->data_sock
.sock
.fd
>= 0) {
3205 if (close(relayd
->data_sock
.sock
.fd
)) {
3206 PERROR("close relayd data socket");
3209 /* Handle create_sock error. */
3214 /* Assign new file descriptor */
3215 relayd
->data_sock
.sock
.fd
= fd
;
3216 /* Assign version values. */
3217 relayd
->data_sock
.major
= relayd_sock
->major
;
3218 relayd
->data_sock
.minor
= relayd_sock
->minor
;
3221 ERR("Unknown relayd socket type (%d)", sock_type
);
3226 DBG("Consumer %s socket created successfully with net idx %" PRIu64
" (fd: %d)",
3227 sock_type
== LTTNG_STREAM_CONTROL
? "control" : "data",
3228 relayd
->net_seq_idx
, fd
);
3231 * Add relayd socket pair to consumer data hashtable. If object already
3232 * exists or on error, the function gracefully returns.
3240 /* Close received socket if valid. */
3243 PERROR("close received socket");
3247 if (relayd_created
) {
3255 * Try to lock the stream mutex.
3257 * On success, 1 is returned else 0 indicating that the mutex is NOT lock.
3259 static int stream_try_lock(struct lttng_consumer_stream
*stream
)
3266 * Try to lock the stream mutex. On failure, we know that the stream is
3267 * being used else where hence there is data still being extracted.
3269 ret
= pthread_mutex_trylock(&stream
->lock
);
3271 /* For both EBUSY and EINVAL error, the mutex is NOT locked. */
3283 * Search for a relayd associated to the session id and return the reference.
3285 * A rcu read side lock MUST be acquire before calling this function and locked
3286 * until the relayd object is no longer necessary.
3288 static struct consumer_relayd_sock_pair
*find_relayd_by_session_id(uint64_t id
)
3290 struct lttng_ht_iter iter
;
3291 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3293 /* Iterate over all relayd since they are indexed by net_seq_idx. */
3294 cds_lfht_for_each_entry(consumer_data
.relayd_ht
->ht
, &iter
.iter
, relayd
,
3297 * Check by sessiond id which is unique here where the relayd session
3298 * id might not be when having multiple relayd.
3300 if (relayd
->sessiond_session_id
== id
) {
3301 /* Found the relayd. There can be only one per id. */
3313 * Check if for a given session id there is still data needed to be extract
3316 * Return 1 if data is pending or else 0 meaning ready to be read.
3318 int consumer_data_pending(uint64_t id
)
3321 struct lttng_ht_iter iter
;
3322 struct lttng_ht
*ht
;
3323 struct lttng_consumer_stream
*stream
;
3324 struct consumer_relayd_sock_pair
*relayd
= NULL
;
3325 int (*data_pending
)(struct lttng_consumer_stream
*);
3327 DBG("Consumer data pending command on session id %" PRIu64
, id
);
3330 pthread_mutex_lock(&consumer_data
.lock
);
3332 switch (consumer_data
.type
) {
3333 case LTTNG_CONSUMER_KERNEL
:
3334 data_pending
= lttng_kconsumer_data_pending
;
3336 case LTTNG_CONSUMER32_UST
:
3337 case LTTNG_CONSUMER64_UST
:
3338 data_pending
= lttng_ustconsumer_data_pending
;
3341 ERR("Unknown consumer data type");
3345 /* Ease our life a bit */
3346 ht
= consumer_data
.stream_list_ht
;
3348 relayd
= find_relayd_by_session_id(id
);
3350 /* Send init command for data pending. */
3351 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3352 ret
= relayd_begin_data_pending(&relayd
->control_sock
,
3353 relayd
->relayd_session_id
);
3354 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3356 /* Communication error thus the relayd so no data pending. */
3357 goto data_not_pending
;
3361 cds_lfht_for_each_entry_duplicate(ht
->ht
,
3362 ht
->hash_fct(&id
, lttng_ht_seed
),
3364 &iter
.iter
, stream
, node_session_id
.node
) {
3365 /* If this call fails, the stream is being used hence data pending. */
3366 ret
= stream_try_lock(stream
);
3372 * A removed node from the hash table indicates that the stream has
3373 * been deleted thus having a guarantee that the buffers are closed
3374 * on the consumer side. However, data can still be transmitted
3375 * over the network so don't skip the relayd check.
3377 ret
= cds_lfht_is_node_deleted(&stream
->node
.node
);
3379 /* Check the stream if there is data in the buffers. */
3380 ret
= data_pending(stream
);
3382 pthread_mutex_unlock(&stream
->lock
);
3389 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3390 if (stream
->metadata_flag
) {
3391 ret
= relayd_quiescent_control(&relayd
->control_sock
,
3392 stream
->relayd_stream_id
);
3394 ret
= relayd_data_pending(&relayd
->control_sock
,
3395 stream
->relayd_stream_id
,
3396 stream
->next_net_seq_num
- 1);
3398 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3400 pthread_mutex_unlock(&stream
->lock
);
3404 pthread_mutex_unlock(&stream
->lock
);
3408 unsigned int is_data_inflight
= 0;
3410 /* Send init command for data pending. */
3411 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
3412 ret
= relayd_end_data_pending(&relayd
->control_sock
,
3413 relayd
->relayd_session_id
, &is_data_inflight
);
3414 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
3416 goto data_not_pending
;
3418 if (is_data_inflight
) {
3424 * Finding _no_ node in the hash table and no inflight data means that the
3425 * stream(s) have been removed thus data is guaranteed to be available for
3426 * analysis from the trace files.
3430 /* Data is available to be read by a viewer. */
3431 pthread_mutex_unlock(&consumer_data
.lock
);
3436 /* Data is still being extracted from buffers. */
3437 pthread_mutex_unlock(&consumer_data
.lock
);
3443 * Send a ret code status message to the sessiond daemon.
3445 * Return the sendmsg() return value.
3447 int consumer_send_status_msg(int sock
, int ret_code
)
3449 struct lttcomm_consumer_status_msg msg
;
3451 msg
.ret_code
= ret_code
;
3453 return lttcomm_send_unix_sock(sock
, &msg
, sizeof(msg
));
3457 * Send a channel status message to the sessiond daemon.
3459 * Return the sendmsg() return value.
3461 int consumer_send_status_channel(int sock
,
3462 struct lttng_consumer_channel
*channel
)
3464 struct lttcomm_consumer_status_channel msg
;
3469 msg
.ret_code
= -LTTNG_ERR_UST_CHAN_FAIL
;
3471 msg
.ret_code
= LTTNG_OK
;
3472 msg
.key
= channel
->key
;
3473 msg
.stream_count
= channel
->streams
.count
;
3476 return lttcomm_send_unix_sock(sock
, &msg
, sizeof(msg
));