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>
34 #include <common/common.h>
35 #include <common/sessiond-comm/sessiond-comm.h>
36 #include <common/relayd/relayd.h>
37 #include <common/compat/fcntl.h>
39 #include "ust-consumer.h"
41 extern struct lttng_consumer_global_data consumer_data
;
42 extern int consumer_poll_timeout
;
43 extern volatile int consumer_quit
;
46 * Free channel object and all streams associated with it. This MUST be used
47 * only and only if the channel has _NEVER_ been added to the global channel
50 static void destroy_channel(struct lttng_consumer_channel
*channel
)
52 struct lttng_consumer_stream
*stream
, *stmp
;
56 DBG("UST consumer cleaning stream list");
58 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
60 cds_list_del(&stream
->send_node
);
61 ustctl_destroy_stream(stream
->ustream
);
66 * If a channel is available meaning that was created before the streams
70 lttng_ustconsumer_del_channel(channel
);
76 * Add channel to internal consumer state.
78 * Returns 0 on success or else a negative value.
80 static int add_channel(struct lttng_consumer_channel
*channel
,
81 struct lttng_consumer_local_data
*ctx
)
88 if (ctx
->on_recv_channel
!= NULL
) {
89 ret
= ctx
->on_recv_channel(channel
);
91 ret
= consumer_add_channel(channel
, ctx
);
93 /* Most likely an ENOMEM. */
94 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
98 ret
= consumer_add_channel(channel
, ctx
);
101 DBG("UST consumer channel added (key: %" PRIu64
")", channel
->key
);
108 * Allocate and return a consumer channel object.
110 static struct lttng_consumer_channel
*allocate_channel(uint64_t session_id
,
111 const char *pathname
, const char *name
, uid_t uid
, gid_t gid
,
112 int relayd_id
, uint64_t key
, enum lttng_event_output output
)
117 return consumer_allocate_channel(key
, session_id
, pathname
, name
, uid
, gid
,
122 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
123 * error value if applicable is set in it else it is kept untouched.
125 * Return NULL on error else the newly allocated stream object.
127 static struct lttng_consumer_stream
*allocate_stream(int cpu
, int key
,
128 struct lttng_consumer_channel
*channel
,
129 struct lttng_consumer_local_data
*ctx
, int *_alloc_ret
)
132 struct lttng_consumer_stream
*stream
= NULL
;
137 stream
= consumer_allocate_stream(channel
->key
,
139 LTTNG_CONSUMER_ACTIVE_STREAM
,
148 if (stream
== NULL
) {
152 * We could not find the channel. Can happen if cpu hotplug
153 * happens while tearing down.
155 DBG3("Could not find channel");
160 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
166 stream
->chan
= channel
;
170 *_alloc_ret
= alloc_ret
;
176 * Send the given stream pointer to the corresponding thread.
178 * Returns 0 on success else a negative value.
180 static int send_stream_to_thread(struct lttng_consumer_stream
*stream
,
181 struct lttng_consumer_local_data
*ctx
)
183 int ret
, stream_pipe
;
185 /* Get the right pipe where the stream will be sent. */
186 if (stream
->metadata_flag
) {
187 stream_pipe
= ctx
->consumer_metadata_pipe
[1];
189 stream_pipe
= ctx
->consumer_data_pipe
[1];
193 ret
= write(stream_pipe
, &stream
, sizeof(stream
));
194 } while (ret
< 0 && errno
== EINTR
);
196 PERROR("Consumer write %s stream to pipe %d",
197 stream
->metadata_flag
? "metadata" : "data", stream_pipe
);
204 * Search for a relayd object related to the stream. If found, send the stream
207 * On success, returns 0 else a negative value.
209 static int send_stream_to_relayd(struct lttng_consumer_stream
*stream
)
212 struct consumer_relayd_sock_pair
*relayd
;
216 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
217 if (relayd
!= NULL
) {
218 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
219 /* Add stream on the relayd */
220 ret
= relayd_add_stream(&relayd
->control_sock
, stream
->name
,
221 stream
->chan
->pathname
, &stream
->relayd_stream_id
);
222 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
226 } else if (stream
->net_seq_idx
!= (uint64_t) -1ULL) {
227 ERR("Network sequence index %" PRIu64
" unknown. Not adding stream.",
228 stream
->net_seq_idx
);
238 * Create streams for the given channel using liblttng-ust-ctl.
240 * Return 0 on success else a negative value.
242 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
243 struct lttng_consumer_local_data
*ctx
)
246 struct ustctl_consumer_stream
*ustream
;
247 struct lttng_consumer_stream
*stream
;
253 * While a stream is available from ustctl. When NULL is returned, we've
254 * reached the end of the possible stream for the channel.
256 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
259 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
261 /* Allocate consumer stream object. */
262 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
266 stream
->ustream
= ustream
;
268 * Store it so we can save multiple function calls afterwards since
269 * this value is used heavily in the stream threads. This is UST
270 * specific so this is why it's done after allocation.
272 stream
->wait_fd
= wait_fd
;
275 * Order is important this is why a list is used. On error, the caller
276 * should clean this list.
278 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
280 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
281 &stream
->max_sb_size
);
283 ERR("ustctl_get_max_subbuf_size failed for stream %s",
288 /* Do actions once stream has been received. */
289 if (ctx
->on_recv_stream
) {
290 ret
= ctx
->on_recv_stream(stream
);
296 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
297 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
299 /* Set next CPU stream. */
300 channel
->streams
.count
= ++cpu
;
302 /* Keep stream reference when creating metadata. */
303 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
304 channel
->metadata_stream
= stream
;
316 * Create an UST channel with the given attributes and send it to the session
317 * daemon using the ust ctl API.
319 * Return 0 on success or else a negative value.
321 static int create_ust_channel(struct ustctl_consumer_channel_attr
*attr
,
322 struct ustctl_consumer_channel
**chanp
)
325 struct ustctl_consumer_channel
*channel
;
330 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
331 "subbuf_size: %" PRIu64
", num_subbuf: %" PRIu64
", "
332 "switch_timer_interval: %u, read_timer_interval: %u, "
333 "output: %d, type: %d", attr
->overwrite
, attr
->subbuf_size
,
334 attr
->num_subbuf
, attr
->switch_timer_interval
,
335 attr
->read_timer_interval
, attr
->output
, attr
->type
);
337 channel
= ustctl_create_channel(attr
);
352 * Send a single given stream to the session daemon using the sock.
354 * Return 0 on success else a negative value.
356 static int send_sessiond_stream(int sock
, struct lttng_consumer_stream
*stream
)
363 DBG2("UST consumer sending stream %" PRIu64
" to sessiond", stream
->key
);
365 /* Send stream to session daemon. */
366 ret
= ustctl_send_stream_to_sessiond(sock
, stream
->ustream
);
376 * Send channel to sessiond.
378 * Return 0 on success or else a negative value.
380 static int send_sessiond_channel(int sock
,
381 struct lttng_consumer_channel
*channel
,
382 struct lttng_consumer_local_data
*ctx
, int *relayd_error
)
385 struct lttng_consumer_stream
*stream
;
391 DBG("UST consumer sending channel %s to sessiond", channel
->name
);
393 /* Send channel to sessiond. */
394 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
399 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
404 /* The channel was sent successfully to the sessiond at this point. */
405 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
406 /* Try to send the stream to the relayd if one is available. */
407 ret
= send_stream_to_relayd(stream
);
410 * Flag that the relayd was the problem here probably due to a
411 * communicaton error on the socket.
419 /* Send stream to session daemon. */
420 ret
= send_sessiond_stream(sock
, stream
);
426 /* Tell sessiond there is no more stream. */
427 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
432 DBG("UST consumer NULL stream sent to sessiond");
441 * Creates a channel and streams and add the channel it to the channel internal
442 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
445 * Return 0 on success or else, a negative value is returned and the channel
446 * MUST be destroyed by consumer_del_channel().
448 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
449 struct lttng_consumer_channel
*channel
,
450 struct ustctl_consumer_channel_attr
*attr
)
459 * This value is still used by the kernel consumer since for the kernel,
460 * the stream ownership is not IN the consumer so we need to have the
461 * number of left stream that needs to be initialized so we can know when
462 * to delete the channel (see consumer.c).
464 * As for the user space tracer now, the consumer creates and sends the
465 * stream to the session daemon which only sends them to the application
466 * once every stream of a channel is received making this value useless
467 * because we they will be added to the poll thread before the application
468 * receives them. This ensures that a stream can not hang up during
469 * initilization of a channel.
471 channel
->nb_init_stream_left
= 0;
473 /* The reply msg status is handled in the following call. */
474 ret
= create_ust_channel(attr
, &channel
->uchan
);
479 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
485 /* Open all streams for this channel. */
486 ret
= create_ust_streams(channel
, ctx
);
496 * Send all stream of a channel to the right thread handling it.
498 * On error, return a negative value else 0 on success.
500 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
501 struct lttng_consumer_local_data
*ctx
)
504 struct lttng_consumer_stream
*stream
, *stmp
;
509 /* Send streams to the corresponding thread. */
510 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
512 /* Sending the stream to the thread. */
513 ret
= send_stream_to_thread(stream
, ctx
);
516 * If we are unable to send the stream to the thread, there is
517 * a big problem so just stop everything.
522 /* Remove node from the channel stream list. */
523 cds_list_del(&stream
->send_node
);
531 * Write metadata to the given channel using ustctl to convert the string to
534 * Return 0 on success else a negative value.
536 static int push_metadata(struct lttng_consumer_channel
*metadata
,
537 const char *metadata_str
, uint64_t target_offset
, uint64_t len
)
542 assert(metadata_str
);
544 DBG("UST consumer writing metadata to channel %s", metadata
->name
);
546 assert(target_offset
== metadata
->contig_metadata_written
);
547 ret
= ustctl_write_metadata_to_channel(metadata
->uchan
, metadata_str
, len
);
549 ERR("ustctl write metadata fail with ret %d, len %ld", ret
, len
);
552 metadata
->contig_metadata_written
+= len
;
554 ustctl_flush_buffer(metadata
->metadata_stream
->ustream
, 1);
561 * Flush channel's streams using the given key to retrieve the channel.
563 * Return 0 on success else an LTTng error code.
565 static int flush_channel(uint64_t chan_key
)
568 struct lttng_consumer_channel
*channel
;
569 struct lttng_consumer_stream
*stream
;
571 struct lttng_ht_iter iter
;
573 DBG("UST consumer flush channel key %lu", chan_key
);
575 channel
= consumer_find_channel(chan_key
);
577 ERR("UST consumer flush channel %lu not found", chan_key
);
578 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
582 ht
= consumer_data
.stream_per_chan_id_ht
;
584 /* For each stream of the channel id, flush it. */
586 cds_lfht_for_each_entry_duplicate(ht
->ht
,
587 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
588 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
589 ustctl_flush_buffer(stream
->ustream
, 1);
598 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
600 * Return 0 on success else an LTTng error code.
602 static int close_metadata(uint64_t chan_key
)
605 struct lttng_consumer_channel
*channel
;
607 DBG("UST consumer close metadata key %lu", chan_key
);
609 channel
= consumer_find_channel(chan_key
);
611 ERR("UST consumer close metadata %lu not found", chan_key
);
612 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
616 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
618 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
619 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
628 * RCU read side lock MUST be acquired before calling this function.
630 * Return 0 on success else an LTTng error code.
632 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
635 struct lttng_consumer_channel
*metadata
;
637 DBG("UST consumer setup metadata key %lu", key
);
639 metadata
= consumer_find_channel(key
);
641 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
642 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
647 * Send metadata stream to relayd if one available. Availability is
648 * known if the stream is still in the list of the channel.
650 if (cds_list_empty(&metadata
->streams
.head
)) {
651 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
652 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
656 /* Send metadata stream to relayd if needed. */
657 ret
= send_stream_to_relayd(metadata
->metadata_stream
);
659 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
663 ret
= send_streams_to_thread(metadata
, ctx
);
666 * If we are unable to send the stream to the thread, there is
667 * a big problem so just stop everything.
669 ret
= LTTCOMM_CONSUMERD_FATAL
;
672 /* List MUST be empty after or else it could be reused. */
673 assert(cds_list_empty(&metadata
->streams
.head
));
682 * Receive command from session daemon and process it.
684 * Return 1 on success else a negative value or 0.
686 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
687 int sock
, struct pollfd
*consumer_sockpoll
)
690 enum lttng_error_code ret_code
= LTTNG_OK
;
691 struct lttcomm_consumer_msg msg
;
692 struct lttng_consumer_channel
*channel
= NULL
;
694 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
695 if (ret
!= sizeof(msg
)) {
696 DBG("Consumer received unexpected message size %zd (expects %zu)",
698 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
700 * The ret value might 0 meaning an orderly shutdown but this is ok
701 * since the caller handles this.
705 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
707 * Notify the session daemon that the command is completed.
709 * On transport layer error, the function call will print an error
710 * message so handling the returned code is a bit useless since we
711 * return an error code anyway.
713 (void) consumer_send_status_msg(sock
, ret_code
);
717 /* relayd needs RCU read-side lock */
720 switch (msg
.cmd_type
) {
721 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
723 /* Session daemon status message are handled in the following call. */
724 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
725 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
726 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
729 case LTTNG_CONSUMER_DESTROY_RELAYD
:
731 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
732 struct consumer_relayd_sock_pair
*relayd
;
734 DBG("UST consumer destroying relayd %" PRIu64
, index
);
736 /* Get relayd reference if exists. */
737 relayd
= consumer_find_relayd(index
);
738 if (relayd
== NULL
) {
739 DBG("Unable to find relayd %" PRIu64
, index
);
740 ret_code
= LTTNG_ERR_NO_CONSUMER
;
744 * Each relayd socket pair has a refcount of stream attached to it
745 * which tells if the relayd is still active or not depending on the
748 * This will set the destroy flag of the relayd object and destroy it
749 * if the refcount reaches zero when called.
751 * The destroy can happen either here or when a stream fd hangs up.
754 consumer_flag_relayd_for_destroy(relayd
);
757 goto end_msg_sessiond
;
759 case LTTNG_CONSUMER_UPDATE_STREAM
:
764 case LTTNG_CONSUMER_DATA_PENDING
:
766 int ret
, is_data_pending
;
767 uint64_t id
= msg
.u
.data_pending
.session_id
;
769 DBG("UST consumer data pending command for id %" PRIu64
, id
);
771 is_data_pending
= consumer_data_pending(id
);
773 /* Send back returned value to session daemon */
774 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
775 sizeof(is_data_pending
));
777 DBG("Error when sending the data pending ret code: %d", ret
);
781 * No need to send back a status message since the data pending
782 * returned value is the response.
786 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
789 struct ustctl_consumer_channel_attr attr
;
791 /* Create a plain object and reserve a channel key. */
792 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
793 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
794 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
795 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
796 (enum lttng_event_output
) msg
.u
.ask_channel
.output
);
798 goto end_channel_error
;
801 /* Build channel attributes from received message. */
802 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
803 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
804 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
805 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
806 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
807 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
808 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
810 /* Translate the event output type to UST. */
811 switch (channel
->output
) {
812 case LTTNG_EVENT_SPLICE
:
813 /* Splice not supported so fallback on mmap(). */
814 case LTTNG_EVENT_MMAP
:
816 attr
.output
= CONSUMER_CHANNEL_MMAP
;
820 /* Translate and save channel type. */
821 switch (msg
.u
.ask_channel
.type
) {
822 case LTTNG_UST_CHAN_PER_CPU
:
823 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
824 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
826 case LTTNG_UST_CHAN_METADATA
:
827 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
828 attr
.type
= LTTNG_UST_CHAN_METADATA
;
835 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
837 goto end_channel_error
;
841 * Add the channel to the internal state AFTER all streams were created
842 * and successfully sent to session daemon. This way, all streams must
843 * be ready before this channel is visible to the threads.
845 ret
= add_channel(channel
, ctx
);
847 goto end_channel_error
;
851 * Channel and streams are now created. Inform the session daemon that
852 * everything went well and should wait to receive the channel and
853 * streams with ustctl API.
855 ret
= consumer_send_status_channel(sock
, channel
);
858 * There is probably a problem on the socket so the poll will get
859 * it and clean everything up.
866 case LTTNG_CONSUMER_GET_CHANNEL
:
868 int ret
, relayd_err
= 0;
869 uint64_t key
= msg
.u
.get_channel
.key
;
870 struct lttng_consumer_channel
*channel
;
872 channel
= consumer_find_channel(key
);
874 ERR("UST consumer get channel key %lu not found", key
);
875 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
876 goto end_msg_sessiond
;
879 /* Inform sessiond that we are about to send channel and streams. */
880 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
882 /* Somehow, the session daemon is not responding anymore. */
886 /* Send everything to sessiond. */
887 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
891 * We were unable to send to the relayd the stream so avoid
892 * sending back a fatal error to the thread since this is OK
893 * and the consumer can continue its work.
895 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
896 goto end_msg_sessiond
;
899 * The communicaton was broken hence there is a bad state between
900 * the consumer and sessiond so stop everything.
905 ret
= send_streams_to_thread(channel
, ctx
);
908 * If we are unable to send the stream to the thread, there is
909 * a big problem so just stop everything.
913 /* List MUST be empty after or else it could be reused. */
914 assert(cds_list_empty(&channel
->streams
.head
));
916 goto end_msg_sessiond
;
918 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
920 uint64_t key
= msg
.u
.destroy_channel
.key
;
921 struct lttng_consumer_channel
*channel
;
923 channel
= consumer_find_channel(key
);
925 ERR("UST consumer get channel key %lu not found", key
);
926 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
927 goto end_msg_sessiond
;
930 destroy_channel(channel
);
932 goto end_msg_sessiond
;
934 case LTTNG_CONSUMER_CLOSE_METADATA
:
938 ret
= close_metadata(msg
.u
.close_metadata
.key
);
943 goto end_msg_sessiond
;
945 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
949 ret
= flush_channel(msg
.u
.flush_channel
.key
);
954 goto end_msg_sessiond
;
956 case LTTNG_CONSUMER_PUSH_METADATA
:
959 uint64_t len
= msg
.u
.push_metadata
.len
;
960 uint64_t target_offset
= msg
.u
.push_metadata
.target_offset
;
961 uint64_t key
= msg
.u
.push_metadata
.key
;
962 struct lttng_consumer_channel
*channel
;
965 DBG("UST consumer push metadata key %lu of len %lu", key
, len
);
967 channel
= consumer_find_channel(key
);
969 ERR("UST consumer push metadata %lu not found", key
);
970 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
971 goto end_msg_sessiond
;
974 metadata_str
= zmalloc(len
* sizeof(char));
976 PERROR("zmalloc metadata string");
977 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
978 goto end_msg_sessiond
;
981 /* Tell session daemon we are ready to receive the metadata. */
982 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
984 /* Somehow, the session daemon is not responding anymore. */
988 /* Wait for more data. */
989 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
993 /* Receive metadata string. */
994 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
996 /* Session daemon is dead so return gracefully. */
1000 ret
= push_metadata(channel
, metadata_str
, target_offset
, len
);
1003 /* Unable to handle metadata. Notify session daemon. */
1004 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1005 goto end_msg_sessiond
;
1008 goto end_msg_sessiond
;
1010 case LTTNG_CONSUMER_SETUP_METADATA
:
1014 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1018 goto end_msg_sessiond
;
1028 * Return 1 to indicate success since the 0 value can be a socket
1029 * shutdown during the recv() or send() call.
1035 * The returned value here is not useful since either way we'll return 1 to
1036 * the caller because the session daemon socket management is done
1037 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1039 (void) consumer_send_status_msg(sock
, ret_code
);
1045 * Free channel here since no one has a reference to it. We don't
1046 * free after that because a stream can store this pointer.
1048 destroy_channel(channel
);
1050 /* We have to send a status channel message indicating an error. */
1051 ret
= consumer_send_status_channel(sock
, NULL
);
1053 /* Stop everything if session daemon can not be notified. */
1060 /* This will issue a consumer stop. */
1065 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1066 * compiled out, we isolate it in this library.
1068 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1072 assert(stream
->ustream
);
1074 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1078 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1079 * compiled out, we isolate it in this library.
1081 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1084 assert(stream
->ustream
);
1086 return ustctl_get_mmap_base(stream
->ustream
);
1090 * Take a snapshot for a specific fd
1092 * Returns 0 on success, < 0 on error
1094 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1097 assert(stream
->ustream
);
1099 return ustctl_snapshot(stream
->ustream
);
1103 * Get the produced position
1105 * Returns 0 on success, < 0 on error
1107 int lttng_ustconsumer_get_produced_snapshot(
1108 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1111 assert(stream
->ustream
);
1114 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1118 * Called when the stream signal the consumer that it has hang up.
1120 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1123 assert(stream
->ustream
);
1125 ustctl_flush_buffer(stream
->ustream
, 0);
1126 stream
->hangup_flush_done
= 1;
1129 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1132 assert(chan
->uchan
);
1134 ustctl_destroy_channel(chan
->uchan
);
1137 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1140 assert(stream
->ustream
);
1142 ustctl_destroy_stream(stream
->ustream
);
1145 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1146 struct lttng_consumer_local_data
*ctx
)
1148 unsigned long len
, subbuf_size
, padding
;
1152 struct ustctl_consumer_stream
*ustream
;
1155 assert(stream
->ustream
);
1158 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1161 /* Ease our life for what's next. */
1162 ustream
= stream
->ustream
;
1164 /* We can consume the 1 byte written into the wait_fd by UST */
1165 if (!stream
->hangup_flush_done
) {
1169 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1170 } while (readlen
== -1 && errno
== EINTR
);
1171 if (readlen
== -1) {
1177 /* Get the next subbuffer */
1178 err
= ustctl_get_next_subbuf(ustream
);
1180 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1182 * This is a debug message even for single-threaded consumer,
1183 * because poll() have more relaxed criterions than get subbuf,
1184 * so get_subbuf may fail for short race windows where poll()
1185 * would issue wakeups.
1187 DBG("Reserving sub buffer failed (everything is normal, "
1188 "it is due to concurrency) [ret: %d]", err
);
1191 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1192 /* Get the full padded subbuffer size */
1193 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1196 /* Get subbuffer data size (without padding) */
1197 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1200 /* Make sure we don't get a subbuffer size bigger than the padded */
1201 assert(len
>= subbuf_size
);
1203 padding
= len
- subbuf_size
;
1204 /* write the subbuffer to the tracefile */
1205 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1207 * The mmap operation should write subbuf_size amount of data when network
1208 * streaming or the full padding (len) size when we are _not_ streaming.
1210 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1211 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1213 * Display the error but continue processing to try to release the
1214 * subbuffer. This is a DBG statement since any unexpected kill or
1215 * signal, the application gets unregistered, relayd gets closed or
1216 * anything that affects the buffer lifetime will trigger this error.
1217 * So, for the sake of the user, don't print this error since it can
1218 * happen and it is OK with the code flow.
1220 DBG("Error writing to tracefile "
1221 "(ret: %zd != len: %lu != subbuf_size: %lu)",
1222 ret
, len
, subbuf_size
);
1224 err
= ustctl_put_next_subbuf(ustream
);
1231 * Called when a stream is created.
1233 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1236 char full_path
[PATH_MAX
];
1238 /* Opening the tracefile in write mode */
1239 if (stream
->net_seq_idx
!= (uint64_t) -1ULL) {
1243 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
1244 stream
->chan
->pathname
, stream
->name
);
1246 PERROR("snprintf on_recv_stream");
1250 ret
= run_as_open(full_path
, O_WRONLY
| O_CREAT
| O_TRUNC
,
1251 S_IRWXU
| S_IRWXG
| S_IRWXO
, stream
->uid
, stream
->gid
);
1253 PERROR("open stream path %s", full_path
);
1256 stream
->out_fd
= ret
;
1259 /* we return 0 to let the library handle the FD internally */
1267 * Check if data is still being extracted from the buffers for a specific
1268 * stream. Consumer data lock MUST be acquired before calling this function
1269 * and the stream lock.
1271 * Return 1 if the traced data are still getting read else 0 meaning that the
1272 * data is available for trace viewer reading.
1274 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1279 assert(stream
->ustream
);
1281 DBG("UST consumer checking data pending");
1283 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1285 /* There is still data so let's put back this subbuffer. */
1286 ret
= ustctl_put_subbuf(stream
->ustream
);
1288 ret
= 1; /* Data is pending */
1292 /* Data is NOT pending so ready to be read. */
1300 * Close every metadata stream wait fd of the metadata hash table. This
1301 * function MUST be used very carefully so not to run into a race between the
1302 * metadata thread handling streams and this function closing their wait fd.
1304 * For UST, this is used when the session daemon hangs up. Its the metadata
1305 * producer so calling this is safe because we are assured that no state change
1306 * can occur in the metadata thread for the streams in the hash table.
1308 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1311 struct lttng_ht_iter iter
;
1312 struct lttng_consumer_stream
*stream
;
1314 assert(metadata_ht
);
1315 assert(metadata_ht
->ht
);
1317 DBG("UST consumer closing all metadata streams");
1320 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1322 int fd
= stream
->wait_fd
;
1325 * Whatever happens here we have to continue to try to close every
1326 * streams. Let's report at least the error on failure.
1328 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1330 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1332 DBG("Metadata wait fd %d closed", fd
);
1337 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1341 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1343 ERR("Unable to close wakeup fd");