2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 #include <lttng/ust-ctl.h>
27 #include <sys/socket.h>
29 #include <sys/types.h>
32 #include <urcu/list.h>
35 #include <common/common.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/relayd/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/consumer-metadata-cache.h>
40 #include <common/consumer-timer.h>
41 #include <common/utils.h>
43 #include "ust-consumer.h"
45 extern struct lttng_consumer_global_data consumer_data
;
46 extern int consumer_poll_timeout
;
47 extern volatile int consumer_quit
;
50 * Free channel object and all streams associated with it. This MUST be used
51 * only and only if the channel has _NEVER_ been added to the global channel
54 static void destroy_channel(struct lttng_consumer_channel
*channel
)
56 struct lttng_consumer_stream
*stream
, *stmp
;
60 DBG("UST consumer cleaning stream list");
62 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
64 cds_list_del(&stream
->send_node
);
65 ustctl_destroy_stream(stream
->ustream
);
70 * If a channel is available meaning that was created before the streams
74 lttng_ustconsumer_del_channel(channel
);
80 * Add channel to internal consumer state.
82 * Returns 0 on success or else a negative value.
84 static int add_channel(struct lttng_consumer_channel
*channel
,
85 struct lttng_consumer_local_data
*ctx
)
92 if (ctx
->on_recv_channel
!= NULL
) {
93 ret
= ctx
->on_recv_channel(channel
);
95 ret
= consumer_add_channel(channel
, ctx
);
97 /* Most likely an ENOMEM. */
98 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
102 ret
= consumer_add_channel(channel
, ctx
);
105 DBG("UST consumer channel added (key: %" PRIu64
")", channel
->key
);
112 * Allocate and return a consumer channel object.
114 static struct lttng_consumer_channel
*allocate_channel(uint64_t session_id
,
115 const char *pathname
, const char *name
, uid_t uid
, gid_t gid
,
116 uint64_t relayd_id
, uint64_t key
, enum lttng_event_output output
,
117 uint64_t tracefile_size
, uint64_t tracefile_count
,
118 uint64_t session_id_per_pid
)
123 return consumer_allocate_channel(key
, session_id
, pathname
, name
, uid
,
124 gid
, relayd_id
, output
, tracefile_size
,
125 tracefile_count
, session_id_per_pid
);
129 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
130 * error value if applicable is set in it else it is kept untouched.
132 * Return NULL on error else the newly allocated stream object.
134 static struct lttng_consumer_stream
*allocate_stream(int cpu
, int key
,
135 struct lttng_consumer_channel
*channel
,
136 struct lttng_consumer_local_data
*ctx
, int *_alloc_ret
)
139 struct lttng_consumer_stream
*stream
= NULL
;
144 stream
= consumer_allocate_stream(channel
->key
,
146 LTTNG_CONSUMER_ACTIVE_STREAM
,
155 if (stream
== NULL
) {
159 * We could not find the channel. Can happen if cpu hotplug
160 * happens while tearing down.
162 DBG3("Could not find channel");
167 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
173 stream
->chan
= channel
;
177 *_alloc_ret
= alloc_ret
;
183 * Send the given stream pointer to the corresponding thread.
185 * Returns 0 on success else a negative value.
187 static int send_stream_to_thread(struct lttng_consumer_stream
*stream
,
188 struct lttng_consumer_local_data
*ctx
)
191 struct lttng_pipe
*stream_pipe
;
193 /* Get the right pipe where the stream will be sent. */
194 if (stream
->metadata_flag
) {
195 stream_pipe
= ctx
->consumer_metadata_pipe
;
197 stream_pipe
= ctx
->consumer_data_pipe
;
200 ret
= lttng_pipe_write(stream_pipe
, &stream
, sizeof(stream
));
202 ERR("Consumer write %s stream to pipe %d",
203 stream
->metadata_flag
? "metadata" : "data",
204 lttng_pipe_get_writefd(stream_pipe
));
211 * Search for a relayd object related to the stream. If found, send the stream
214 * On success, returns 0 else a negative value.
216 static int send_stream_to_relayd(struct lttng_consumer_stream
*stream
)
219 struct consumer_relayd_sock_pair
*relayd
;
223 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
224 if (relayd
!= NULL
) {
225 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
226 /* Add stream on the relayd */
227 ret
= relayd_add_stream(&relayd
->control_sock
, stream
->name
,
228 stream
->chan
->pathname
, &stream
->relayd_stream_id
,
229 stream
->chan
->tracefile_size
,
230 stream
->chan
->tracefile_count
);
231 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
235 } else if (stream
->net_seq_idx
!= (uint64_t) -1ULL) {
236 ERR("Network sequence index %" PRIu64
" unknown. Not adding stream.",
237 stream
->net_seq_idx
);
247 * Create streams for the given channel using liblttng-ust-ctl.
249 * Return 0 on success else a negative value.
251 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
252 struct lttng_consumer_local_data
*ctx
)
255 struct ustctl_consumer_stream
*ustream
;
256 struct lttng_consumer_stream
*stream
;
262 * While a stream is available from ustctl. When NULL is returned, we've
263 * reached the end of the possible stream for the channel.
265 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
268 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
270 /* Allocate consumer stream object. */
271 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
275 stream
->ustream
= ustream
;
277 * Store it so we can save multiple function calls afterwards since
278 * this value is used heavily in the stream threads. This is UST
279 * specific so this is why it's done after allocation.
281 stream
->wait_fd
= wait_fd
;
284 * Increment channel refcount since the channel reference has now been
285 * assigned in the allocation process above.
287 uatomic_inc(&stream
->chan
->refcount
);
290 * Order is important this is why a list is used. On error, the caller
291 * should clean this list.
293 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
295 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
296 &stream
->max_sb_size
);
298 ERR("ustctl_get_max_subbuf_size failed for stream %s",
303 /* Do actions once stream has been received. */
304 if (ctx
->on_recv_stream
) {
305 ret
= ctx
->on_recv_stream(stream
);
311 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
312 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
314 /* Set next CPU stream. */
315 channel
->streams
.count
= ++cpu
;
317 /* Keep stream reference when creating metadata. */
318 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
319 channel
->metadata_stream
= stream
;
331 * Create an UST channel with the given attributes and send it to the session
332 * daemon using the ust ctl API.
334 * Return 0 on success or else a negative value.
336 static int create_ust_channel(struct ustctl_consumer_channel_attr
*attr
,
337 struct ustctl_consumer_channel
**chanp
)
340 struct ustctl_consumer_channel
*channel
;
345 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
346 "subbuf_size: %" PRIu64
", num_subbuf: %" PRIu64
", "
347 "switch_timer_interval: %u, read_timer_interval: %u, "
348 "output: %d, type: %d", attr
->overwrite
, attr
->subbuf_size
,
349 attr
->num_subbuf
, attr
->switch_timer_interval
,
350 attr
->read_timer_interval
, attr
->output
, attr
->type
);
352 channel
= ustctl_create_channel(attr
);
367 * Send a single given stream to the session daemon using the sock.
369 * Return 0 on success else a negative value.
371 static int send_sessiond_stream(int sock
, struct lttng_consumer_stream
*stream
)
378 DBG("UST consumer sending stream %" PRIu64
" to sessiond", stream
->key
);
380 /* Send stream to session daemon. */
381 ret
= ustctl_send_stream_to_sessiond(sock
, stream
->ustream
);
391 * Send channel to sessiond.
393 * Return 0 on success or else a negative value.
395 static int send_sessiond_channel(int sock
,
396 struct lttng_consumer_channel
*channel
,
397 struct lttng_consumer_local_data
*ctx
, int *relayd_error
)
399 int ret
, ret_code
= LTTNG_OK
;
400 struct lttng_consumer_stream
*stream
;
406 DBG("UST consumer sending channel %s to sessiond", channel
->name
);
408 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
409 /* Try to send the stream to the relayd if one is available. */
410 ret
= send_stream_to_relayd(stream
);
413 * Flag that the relayd was the problem here probably due to a
414 * communicaton error on the socket.
419 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
423 /* Inform sessiond that we are about to send channel and streams. */
424 ret
= consumer_send_status_msg(sock
, ret_code
);
425 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
427 * Either the session daemon is not responding or the relayd died so we
433 /* Send channel to sessiond. */
434 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
439 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
444 /* The channel was sent successfully to the sessiond at this point. */
445 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
446 /* Send stream to session daemon. */
447 ret
= send_sessiond_stream(sock
, stream
);
453 /* Tell sessiond there is no more stream. */
454 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
459 DBG("UST consumer NULL stream sent to sessiond");
464 if (ret_code
!= LTTNG_OK
) {
471 * Creates a channel and streams and add the channel it to the channel internal
472 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
475 * Return 0 on success or else, a negative value is returned and the channel
476 * MUST be destroyed by consumer_del_channel().
478 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
479 struct lttng_consumer_channel
*channel
,
480 struct ustctl_consumer_channel_attr
*attr
)
489 * This value is still used by the kernel consumer since for the kernel,
490 * the stream ownership is not IN the consumer so we need to have the
491 * number of left stream that needs to be initialized so we can know when
492 * to delete the channel (see consumer.c).
494 * As for the user space tracer now, the consumer creates and sends the
495 * stream to the session daemon which only sends them to the application
496 * once every stream of a channel is received making this value useless
497 * because we they will be added to the poll thread before the application
498 * receives them. This ensures that a stream can not hang up during
499 * initilization of a channel.
501 channel
->nb_init_stream_left
= 0;
503 /* The reply msg status is handled in the following call. */
504 ret
= create_ust_channel(attr
, &channel
->uchan
);
509 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
511 /* Open all streams for this channel. */
512 ret
= create_ust_streams(channel
, ctx
);
522 * Send all stream of a channel to the right thread handling it.
524 * On error, return a negative value else 0 on success.
526 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
527 struct lttng_consumer_local_data
*ctx
)
530 struct lttng_consumer_stream
*stream
, *stmp
;
535 /* Send streams to the corresponding thread. */
536 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
538 /* Sending the stream to the thread. */
539 ret
= send_stream_to_thread(stream
, ctx
);
542 * If we are unable to send the stream to the thread, there is
543 * a big problem so just stop everything.
548 /* Remove node from the channel stream list. */
549 cds_list_del(&stream
->send_node
);
557 * Write metadata to the given channel using ustctl to convert the string to
559 * Called only from consumer_metadata_cache_write.
560 * The metadata cache lock MUST be acquired to write in the cache.
562 * Return 0 on success else a negative value.
564 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel
*metadata
,
565 const char *metadata_str
, uint64_t target_offset
, uint64_t len
)
570 assert(metadata_str
);
572 DBG("UST consumer writing metadata to channel %s", metadata
->name
);
574 if (!metadata
->metadata_stream
) {
579 assert(target_offset
<= metadata
->metadata_cache
->max_offset
);
580 ret
= ustctl_write_metadata_to_channel(metadata
->uchan
,
581 metadata_str
+ target_offset
, len
);
583 ERR("ustctl write metadata fail with ret %d, len %" PRIu64
, ret
, len
);
587 ustctl_flush_buffer(metadata
->metadata_stream
->ustream
, 1);
594 * Flush channel's streams using the given key to retrieve the channel.
596 * Return 0 on success else an LTTng error code.
598 static int flush_channel(uint64_t chan_key
)
601 struct lttng_consumer_channel
*channel
;
602 struct lttng_consumer_stream
*stream
;
604 struct lttng_ht_iter iter
;
606 DBG("UST consumer flush channel key %" PRIu64
, chan_key
);
609 channel
= consumer_find_channel(chan_key
);
611 ERR("UST consumer flush channel %" PRIu64
" not found", chan_key
);
612 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
616 ht
= consumer_data
.stream_per_chan_id_ht
;
618 /* For each stream of the channel id, flush it. */
619 cds_lfht_for_each_entry_duplicate(ht
->ht
,
620 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
621 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
622 ustctl_flush_buffer(stream
->ustream
, 1);
630 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
631 * RCU read side lock MUST be acquired before calling this function.
633 * Return 0 on success else an LTTng error code.
635 static int close_metadata(uint64_t chan_key
)
638 struct lttng_consumer_channel
*channel
;
640 DBG("UST consumer close metadata key %" PRIu64
, chan_key
);
642 channel
= consumer_find_channel(chan_key
);
645 * This is possible if the metadata thread has issue a delete because
646 * the endpoint point of the stream hung up. There is no way the
647 * session daemon can know about it thus use a DBG instead of an actual
650 DBG("UST consumer close metadata %" PRIu64
" not found", chan_key
);
651 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
655 pthread_mutex_lock(&consumer_data
.lock
);
656 pthread_mutex_lock(&channel
->lock
);
658 if (cds_lfht_is_node_deleted(&channel
->node
.node
)) {
662 if (channel
->switch_timer_enabled
== 1) {
663 DBG("Deleting timer on metadata channel");
664 consumer_timer_switch_stop(channel
);
667 if (channel
->metadata_stream
) {
668 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
670 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
671 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
677 pthread_mutex_unlock(&channel
->lock
);
678 pthread_mutex_unlock(&consumer_data
.lock
);
684 * RCU read side lock MUST be acquired before calling this function.
686 * Return 0 on success else an LTTng error code.
688 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
691 struct lttng_consumer_channel
*metadata
;
693 DBG("UST consumer setup metadata key %" PRIu64
, key
);
695 metadata
= consumer_find_channel(key
);
697 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
698 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
703 * Send metadata stream to relayd if one available. Availability is
704 * known if the stream is still in the list of the channel.
706 if (cds_list_empty(&metadata
->streams
.head
)) {
707 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
708 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
712 /* Send metadata stream to relayd if needed. */
713 ret
= send_stream_to_relayd(metadata
->metadata_stream
);
715 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
719 ret
= send_streams_to_thread(metadata
, ctx
);
722 * If we are unable to send the stream to the thread, there is
723 * a big problem so just stop everything.
725 ret
= LTTCOMM_CONSUMERD_FATAL
;
728 /* List MUST be empty after or else it could be reused. */
729 assert(cds_list_empty(&metadata
->streams
.head
));
735 * Delete metadata channel on error. At this point, the metadata stream can
736 * NOT be monitored by the metadata thread thus having the guarantee that
737 * the stream is still in the local stream list of the channel. This call
738 * will make sure to clean that list.
740 consumer_del_channel(metadata
);
746 * Receive the metadata updates from the sessiond.
748 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
749 uint64_t len
, struct lttng_consumer_channel
*channel
)
751 int ret
, ret_code
= LTTNG_OK
;
754 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
, len
);
756 metadata_str
= zmalloc(len
* sizeof(char));
758 PERROR("zmalloc metadata string");
759 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
763 /* Receive metadata string. */
764 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
766 /* Session daemon is dead so return gracefully. */
772 * XXX: The consumer data lock is acquired before calling metadata cache
773 * write which calls push metadata that MUST be protected by the consumer
774 * lock in order to be able to check the validity of the metadata stream of
777 * Note that this will be subject to change to better fine grained locking
778 * and ultimately try to get rid of this global consumer data lock.
780 pthread_mutex_lock(&consumer_data
.lock
);
781 pthread_mutex_lock(&channel
->lock
);
782 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
783 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
785 /* Unable to handle metadata. Notify session daemon. */
786 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
788 * Skip metadata flush on write error since the offset and len might
789 * not have been updated which could create an infinite loop below when
790 * waiting for the metadata cache to be flushed.
792 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
793 pthread_mutex_unlock(&channel
->lock
);
794 pthread_mutex_unlock(&consumer_data
.lock
);
797 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
798 pthread_mutex_unlock(&channel
->lock
);
799 pthread_mutex_unlock(&consumer_data
.lock
);
801 while (consumer_metadata_cache_flushed(channel
, offset
+ len
)) {
802 DBG("Waiting for metadata to be flushed");
803 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
813 * Receive command from session daemon and process it.
815 * Return 1 on success else a negative value or 0.
817 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
818 int sock
, struct pollfd
*consumer_sockpoll
)
821 enum lttng_error_code ret_code
= LTTNG_OK
;
822 struct lttcomm_consumer_msg msg
;
823 struct lttng_consumer_channel
*channel
= NULL
;
825 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
826 if (ret
!= sizeof(msg
)) {
827 DBG("Consumer received unexpected message size %zd (expects %zu)",
829 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
831 * The ret value might 0 meaning an orderly shutdown but this is ok
832 * since the caller handles this.
839 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
841 * Notify the session daemon that the command is completed.
843 * On transport layer error, the function call will print an error
844 * message so handling the returned code is a bit useless since we
845 * return an error code anyway.
847 (void) consumer_send_status_msg(sock
, ret_code
);
851 /* relayd needs RCU read-side lock */
854 switch (msg
.cmd_type
) {
855 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
857 /* Session daemon status message are handled in the following call. */
858 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
859 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
860 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
863 case LTTNG_CONSUMER_DESTROY_RELAYD
:
865 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
866 struct consumer_relayd_sock_pair
*relayd
;
868 DBG("UST consumer destroying relayd %" PRIu64
, index
);
870 /* Get relayd reference if exists. */
871 relayd
= consumer_find_relayd(index
);
872 if (relayd
== NULL
) {
873 DBG("Unable to find relayd %" PRIu64
, index
);
874 ret_code
= LTTNG_ERR_NO_CONSUMER
;
878 * Each relayd socket pair has a refcount of stream attached to it
879 * which tells if the relayd is still active or not depending on the
882 * This will set the destroy flag of the relayd object and destroy it
883 * if the refcount reaches zero when called.
885 * The destroy can happen either here or when a stream fd hangs up.
888 consumer_flag_relayd_for_destroy(relayd
);
891 goto end_msg_sessiond
;
893 case LTTNG_CONSUMER_UPDATE_STREAM
:
898 case LTTNG_CONSUMER_DATA_PENDING
:
900 int ret
, is_data_pending
;
901 uint64_t id
= msg
.u
.data_pending
.session_id
;
903 DBG("UST consumer data pending command for id %" PRIu64
, id
);
905 is_data_pending
= consumer_data_pending(id
);
907 /* Send back returned value to session daemon */
908 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
909 sizeof(is_data_pending
));
911 DBG("Error when sending the data pending ret code: %d", ret
);
916 * No need to send back a status message since the data pending
917 * returned value is the response.
921 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
924 struct ustctl_consumer_channel_attr attr
;
926 /* Create a plain object and reserve a channel key. */
927 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
928 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
929 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
930 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
931 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
932 msg
.u
.ask_channel
.tracefile_size
,
933 msg
.u
.ask_channel
.tracefile_count
,
934 msg
.u
.ask_channel
.session_id_per_pid
);
936 goto end_channel_error
;
939 /* Build channel attributes from received message. */
940 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
941 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
942 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
943 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
944 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
945 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
946 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
948 /* Translate the event output type to UST. */
949 switch (channel
->output
) {
950 case LTTNG_EVENT_SPLICE
:
951 /* Splice not supported so fallback on mmap(). */
952 case LTTNG_EVENT_MMAP
:
954 attr
.output
= CONSUMER_CHANNEL_MMAP
;
958 /* Translate and save channel type. */
959 switch (msg
.u
.ask_channel
.type
) {
960 case LTTNG_UST_CHAN_PER_CPU
:
961 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
962 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
964 * Set refcount to 1 for owner. Below, we will
965 * pass ownership to the
966 * consumer_thread_channel_poll() thread.
968 channel
->refcount
= 1;
970 case LTTNG_UST_CHAN_METADATA
:
971 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
972 attr
.type
= LTTNG_UST_CHAN_METADATA
;
979 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
981 goto end_channel_error
;
984 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
985 ret
= consumer_metadata_cache_allocate(channel
);
987 ERR("Allocating metadata cache");
988 goto end_channel_error
;
990 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
991 attr
.switch_timer_interval
= 0;
995 * Add the channel to the internal state AFTER all streams were created
996 * and successfully sent to session daemon. This way, all streams must
997 * be ready before this channel is visible to the threads.
998 * If add_channel succeeds, ownership of the channel is
999 * passed to consumer_thread_channel_poll().
1001 ret
= add_channel(channel
, ctx
);
1003 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1004 if (channel
->switch_timer_enabled
== 1) {
1005 consumer_timer_switch_stop(channel
);
1007 consumer_metadata_cache_destroy(channel
);
1009 goto end_channel_error
;
1013 * Channel and streams are now created. Inform the session daemon that
1014 * everything went well and should wait to receive the channel and
1015 * streams with ustctl API.
1017 ret
= consumer_send_status_channel(sock
, channel
);
1020 * There is probably a problem on the socket.
1027 case LTTNG_CONSUMER_GET_CHANNEL
:
1029 int ret
, relayd_err
= 0;
1030 uint64_t key
= msg
.u
.get_channel
.key
;
1031 struct lttng_consumer_channel
*channel
;
1033 channel
= consumer_find_channel(key
);
1035 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1036 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1037 goto end_msg_sessiond
;
1040 /* Send everything to sessiond. */
1041 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1045 * We were unable to send to the relayd the stream so avoid
1046 * sending back a fatal error to the thread since this is OK
1047 * and the consumer can continue its work. The above call
1048 * has sent the error status message to the sessiond.
1053 * The communicaton was broken hence there is a bad state between
1054 * the consumer and sessiond so stop everything.
1059 ret
= send_streams_to_thread(channel
, ctx
);
1062 * If we are unable to send the stream to the thread, there is
1063 * a big problem so just stop everything.
1067 /* List MUST be empty after or else it could be reused. */
1068 assert(cds_list_empty(&channel
->streams
.head
));
1070 goto end_msg_sessiond
;
1072 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1074 uint64_t key
= msg
.u
.destroy_channel
.key
;
1077 * Only called if streams have not been sent to stream
1078 * manager thread. However, channel has been sent to
1079 * channel manager thread.
1081 notify_thread_del_channel(ctx
, key
);
1082 goto end_msg_sessiond
;
1084 case LTTNG_CONSUMER_CLOSE_METADATA
:
1088 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1093 goto end_msg_sessiond
;
1095 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1099 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1104 goto end_msg_sessiond
;
1106 case LTTNG_CONSUMER_PUSH_METADATA
:
1109 uint64_t len
= msg
.u
.push_metadata
.len
;
1110 uint64_t key
= msg
.u
.push_metadata
.key
;
1111 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1112 struct lttng_consumer_channel
*channel
;
1114 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1117 channel
= consumer_find_channel(key
);
1119 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1120 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1121 goto end_msg_sessiond
;
1124 /* Tell session daemon we are ready to receive the metadata. */
1125 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1127 /* Somehow, the session daemon is not responding anymore. */
1131 /* Wait for more data. */
1132 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1136 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1139 /* error receiving from sessiond */
1143 goto end_msg_sessiond
;
1146 case LTTNG_CONSUMER_SETUP_METADATA
:
1150 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1154 goto end_msg_sessiond
;
1164 * Return 1 to indicate success since the 0 value can be a socket
1165 * shutdown during the recv() or send() call.
1171 * The returned value here is not useful since either way we'll return 1 to
1172 * the caller because the session daemon socket management is done
1173 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1175 ret
= consumer_send_status_msg(sock
, ret_code
);
1184 * Free channel here since no one has a reference to it. We don't
1185 * free after that because a stream can store this pointer.
1187 destroy_channel(channel
);
1189 /* We have to send a status channel message indicating an error. */
1190 ret
= consumer_send_status_channel(sock
, NULL
);
1192 /* Stop everything if session daemon can not be notified. */
1199 /* This will issue a consumer stop. */
1204 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1205 * compiled out, we isolate it in this library.
1207 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1211 assert(stream
->ustream
);
1213 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1217 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1218 * compiled out, we isolate it in this library.
1220 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1223 assert(stream
->ustream
);
1225 return ustctl_get_mmap_base(stream
->ustream
);
1229 * Take a snapshot for a specific fd
1231 * Returns 0 on success, < 0 on error
1233 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1236 assert(stream
->ustream
);
1238 return ustctl_snapshot(stream
->ustream
);
1242 * Get the produced position
1244 * Returns 0 on success, < 0 on error
1246 int lttng_ustconsumer_get_produced_snapshot(
1247 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1250 assert(stream
->ustream
);
1253 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1257 * Called when the stream signal the consumer that it has hang up.
1259 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1262 assert(stream
->ustream
);
1264 ustctl_flush_buffer(stream
->ustream
, 0);
1265 stream
->hangup_flush_done
= 1;
1268 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1271 assert(chan
->uchan
);
1273 if (chan
->switch_timer_enabled
== 1) {
1274 consumer_timer_switch_stop(chan
);
1276 consumer_metadata_cache_destroy(chan
);
1277 ustctl_destroy_channel(chan
->uchan
);
1280 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1283 assert(stream
->ustream
);
1285 if (stream
->chan
->switch_timer_enabled
== 1) {
1286 consumer_timer_switch_stop(stream
->chan
);
1288 ustctl_destroy_stream(stream
->ustream
);
1291 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1292 struct lttng_consumer_local_data
*ctx
)
1294 unsigned long len
, subbuf_size
, padding
;
1298 struct ustctl_consumer_stream
*ustream
;
1301 assert(stream
->ustream
);
1304 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1307 /* Ease our life for what's next. */
1308 ustream
= stream
->ustream
;
1310 /* We can consume the 1 byte written into the wait_fd by UST */
1311 if (!stream
->hangup_flush_done
) {
1315 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1316 } while (readlen
== -1 && errno
== EINTR
);
1317 if (readlen
== -1) {
1323 /* Get the next subbuffer */
1324 err
= ustctl_get_next_subbuf(ustream
);
1326 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1328 * This is a debug message even for single-threaded consumer,
1329 * because poll() have more relaxed criterions than get subbuf,
1330 * so get_subbuf may fail for short race windows where poll()
1331 * would issue wakeups.
1333 DBG("Reserving sub buffer failed (everything is normal, "
1334 "it is due to concurrency) [ret: %d]", err
);
1337 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1338 /* Get the full padded subbuffer size */
1339 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1342 /* Get subbuffer data size (without padding) */
1343 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1346 /* Make sure we don't get a subbuffer size bigger than the padded */
1347 assert(len
>= subbuf_size
);
1349 padding
= len
- subbuf_size
;
1350 /* write the subbuffer to the tracefile */
1351 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1353 * The mmap operation should write subbuf_size amount of data when network
1354 * streaming or the full padding (len) size when we are _not_ streaming.
1356 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1357 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1359 * Display the error but continue processing to try to release the
1360 * subbuffer. This is a DBG statement since any unexpected kill or
1361 * signal, the application gets unregistered, relayd gets closed or
1362 * anything that affects the buffer lifetime will trigger this error.
1363 * So, for the sake of the user, don't print this error since it can
1364 * happen and it is OK with the code flow.
1366 DBG("Error writing to tracefile "
1367 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1368 ret
, len
, subbuf_size
);
1370 err
= ustctl_put_next_subbuf(ustream
);
1378 * Called when a stream is created.
1380 * Return 0 on success or else a negative value.
1382 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1386 /* Don't create anything if this is set for streaming. */
1387 if (stream
->net_seq_idx
== (uint64_t) -1ULL) {
1388 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1389 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1390 stream
->uid
, stream
->gid
);
1394 stream
->out_fd
= ret
;
1395 stream
->tracefile_size_current
= 0;
1404 * Check if data is still being extracted from the buffers for a specific
1405 * stream. Consumer data lock MUST be acquired before calling this function
1406 * and the stream lock.
1408 * Return 1 if the traced data are still getting read else 0 meaning that the
1409 * data is available for trace viewer reading.
1411 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1416 assert(stream
->ustream
);
1418 DBG("UST consumer checking data pending");
1420 if (stream
->endpoint_status
!= CONSUMER_ENDPOINT_ACTIVE
) {
1425 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1427 /* There is still data so let's put back this subbuffer. */
1428 ret
= ustctl_put_subbuf(stream
->ustream
);
1430 ret
= 1; /* Data is pending */
1434 /* Data is NOT pending so ready to be read. */
1442 * Close every metadata stream wait fd of the metadata hash table. This
1443 * function MUST be used very carefully so not to run into a race between the
1444 * metadata thread handling streams and this function closing their wait fd.
1446 * For UST, this is used when the session daemon hangs up. Its the metadata
1447 * producer so calling this is safe because we are assured that no state change
1448 * can occur in the metadata thread for the streams in the hash table.
1450 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1453 struct lttng_ht_iter iter
;
1454 struct lttng_consumer_stream
*stream
;
1456 assert(metadata_ht
);
1457 assert(metadata_ht
->ht
);
1459 DBG("UST consumer closing all metadata streams");
1462 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1464 int fd
= stream
->wait_fd
;
1467 * Whatever happens here we have to continue to try to close every
1468 * streams. Let's report at least the error on failure.
1470 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1472 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1474 DBG("Metadata wait fd %d closed", fd
);
1479 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1483 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1485 ERR("Unable to close wakeup fd");
1489 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1490 struct lttng_consumer_channel
*channel
)
1492 struct lttcomm_metadata_request_msg request
;
1493 struct lttcomm_consumer_msg msg
;
1494 enum lttng_error_code ret_code
= LTTNG_OK
;
1495 uint64_t len
, key
, offset
;
1499 assert(channel
->metadata_cache
);
1501 /* send the metadata request to sessiond */
1502 switch (consumer_data
.type
) {
1503 case LTTNG_CONSUMER64_UST
:
1504 request
.bits_per_long
= 64;
1506 case LTTNG_CONSUMER32_UST
:
1507 request
.bits_per_long
= 32;
1510 request
.bits_per_long
= 0;
1514 request
.session_id
= channel
->session_id
;
1515 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1516 request
.uid
= channel
->uid
;
1517 request
.key
= channel
->key
;
1518 DBG("Sending metadata request to sessiond, session id %" PRIu64
1519 ", per-pid %" PRIu64
,
1520 channel
->session_id
,
1521 channel
->session_id_per_pid
);
1523 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1526 ERR("Asking metadata to sessiond");
1530 /* Receive the metadata from sessiond */
1531 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1533 if (ret
!= sizeof(msg
)) {
1534 DBG("Consumer received unexpected message size %d (expects %zu)",
1536 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1538 * The ret value might 0 meaning an orderly shutdown but this is ok
1539 * since the caller handles this.
1544 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1545 /* No registry found */
1546 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1550 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1551 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1556 len
= msg
.u
.push_metadata
.len
;
1557 key
= msg
.u
.push_metadata
.key
;
1558 offset
= msg
.u
.push_metadata
.target_offset
;
1560 assert(key
== channel
->key
);
1562 DBG("No new metadata to receive for key %" PRIu64
, key
);
1565 /* Tell session daemon we are ready to receive the metadata. */
1566 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1568 if (ret
< 0 || len
== 0) {
1570 * Somehow, the session daemon is not responding anymore or there is
1571 * nothing to receive.
1576 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1577 key
, offset
, len
, channel
);
1578 if (ret_code
>= 0) {
1580 * Only send the status msg if the sessiond is alive meaning a positive
1583 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);