0cfbf5c7c03ef36bf1dc958601babd76e6f3d279
[lttng-tools.git] / src / common / consumer / consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
5 *
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.
9 *
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
13 * more details.
14 *
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.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <poll.h>
23 #include <pthread.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/mman.h>
27 #include <sys/socket.h>
28 #include <sys/types.h>
29 #include <unistd.h>
30 #include <inttypes.h>
31 #include <signal.h>
32
33 #include <bin/lttng-consumerd/health-consumerd.h>
34 #include <common/common.h>
35 #include <common/utils.h>
36 #include <common/compat/poll.h>
37 #include <common/compat/endian.h>
38 #include <common/index/index.h>
39 #include <common/kernel-ctl/kernel-ctl.h>
40 #include <common/sessiond-comm/relayd.h>
41 #include <common/sessiond-comm/sessiond-comm.h>
42 #include <common/kernel-consumer/kernel-consumer.h>
43 #include <common/relayd/relayd.h>
44 #include <common/ust-consumer/ust-consumer.h>
45 #include <common/consumer/consumer-timer.h>
46 #include <common/consumer/consumer.h>
47 #include <common/consumer/consumer-stream.h>
48 #include <common/consumer/consumer-testpoint.h>
49 #include <common/align.h>
50 #include <common/consumer/consumer-metadata-cache.h>
51
52 struct lttng_consumer_global_data consumer_data = {
53 .stream_count = 0,
54 .need_update = 1,
55 .type = LTTNG_CONSUMER_UNKNOWN,
56 };
57
58 enum consumer_channel_action {
59 CONSUMER_CHANNEL_ADD,
60 CONSUMER_CHANNEL_DEL,
61 CONSUMER_CHANNEL_QUIT,
62 };
63
64 struct consumer_channel_msg {
65 enum consumer_channel_action action;
66 struct lttng_consumer_channel *chan; /* add */
67 uint64_t key; /* del */
68 };
69
70 /* Flag used to temporarily pause data consumption from testpoints. */
71 int data_consumption_paused;
72
73 /*
74 * Flag to inform the polling thread to quit when all fd hung up. Updated by
75 * the consumer_thread_receive_fds when it notices that all fds has hung up.
76 * Also updated by the signal handler (consumer_should_exit()). Read by the
77 * polling threads.
78 */
79 int consumer_quit;
80
81 /*
82 * Global hash table containing respectively metadata and data streams. The
83 * stream element in this ht should only be updated by the metadata poll thread
84 * for the metadata and the data poll thread for the data.
85 */
86 static struct lttng_ht *metadata_ht;
87 static struct lttng_ht *data_ht;
88
89 /*
90 * Notify a thread lttng pipe to poll back again. This usually means that some
91 * global state has changed so we just send back the thread in a poll wait
92 * call.
93 */
94 static void notify_thread_lttng_pipe(struct lttng_pipe *pipe)
95 {
96 struct lttng_consumer_stream *null_stream = NULL;
97
98 assert(pipe);
99
100 (void) lttng_pipe_write(pipe, &null_stream, sizeof(null_stream));
101 }
102
103 static void notify_health_quit_pipe(int *pipe)
104 {
105 ssize_t ret;
106
107 ret = lttng_write(pipe[1], "4", 1);
108 if (ret < 1) {
109 PERROR("write consumer health quit");
110 }
111 }
112
113 static void notify_channel_pipe(struct lttng_consumer_local_data *ctx,
114 struct lttng_consumer_channel *chan,
115 uint64_t key,
116 enum consumer_channel_action action)
117 {
118 struct consumer_channel_msg msg;
119 ssize_t ret;
120
121 memset(&msg, 0, sizeof(msg));
122
123 msg.action = action;
124 msg.chan = chan;
125 msg.key = key;
126 ret = lttng_write(ctx->consumer_channel_pipe[1], &msg, sizeof(msg));
127 if (ret < sizeof(msg)) {
128 PERROR("notify_channel_pipe write error");
129 }
130 }
131
132 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
133 uint64_t key)
134 {
135 notify_channel_pipe(ctx, NULL, key, CONSUMER_CHANNEL_DEL);
136 }
137
138 static int read_channel_pipe(struct lttng_consumer_local_data *ctx,
139 struct lttng_consumer_channel **chan,
140 uint64_t *key,
141 enum consumer_channel_action *action)
142 {
143 struct consumer_channel_msg msg;
144 ssize_t ret;
145
146 ret = lttng_read(ctx->consumer_channel_pipe[0], &msg, sizeof(msg));
147 if (ret < sizeof(msg)) {
148 ret = -1;
149 goto error;
150 }
151 *action = msg.action;
152 *chan = msg.chan;
153 *key = msg.key;
154 error:
155 return (int) ret;
156 }
157
158 /*
159 * Cleanup the stream list of a channel. Those streams are not yet globally
160 * visible
161 */
162 static void clean_channel_stream_list(struct lttng_consumer_channel *channel)
163 {
164 struct lttng_consumer_stream *stream, *stmp;
165
166 assert(channel);
167
168 /* Delete streams that might have been left in the stream list. */
169 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
170 send_node) {
171 cds_list_del(&stream->send_node);
172 /*
173 * Once a stream is added to this list, the buffers were created so we
174 * have a guarantee that this call will succeed. Setting the monitor
175 * mode to 0 so we don't lock nor try to delete the stream from the
176 * global hash table.
177 */
178 stream->monitor = 0;
179 consumer_stream_destroy(stream, NULL);
180 }
181 }
182
183 /*
184 * Find a stream. The consumer_data.lock must be locked during this
185 * call.
186 */
187 static struct lttng_consumer_stream *find_stream(uint64_t key,
188 struct lttng_ht *ht)
189 {
190 struct lttng_ht_iter iter;
191 struct lttng_ht_node_u64 *node;
192 struct lttng_consumer_stream *stream = NULL;
193
194 assert(ht);
195
196 /* -1ULL keys are lookup failures */
197 if (key == (uint64_t) -1ULL) {
198 return NULL;
199 }
200
201 rcu_read_lock();
202
203 lttng_ht_lookup(ht, &key, &iter);
204 node = lttng_ht_iter_get_node_u64(&iter);
205 if (node != NULL) {
206 stream = caa_container_of(node, struct lttng_consumer_stream, node);
207 }
208
209 rcu_read_unlock();
210
211 return stream;
212 }
213
214 static void steal_stream_key(uint64_t key, struct lttng_ht *ht)
215 {
216 struct lttng_consumer_stream *stream;
217
218 rcu_read_lock();
219 stream = find_stream(key, ht);
220 if (stream) {
221 stream->key = (uint64_t) -1ULL;
222 /*
223 * We don't want the lookup to match, but we still need
224 * to iterate on this stream when iterating over the hash table. Just
225 * change the node key.
226 */
227 stream->node.key = (uint64_t) -1ULL;
228 }
229 rcu_read_unlock();
230 }
231
232 /*
233 * Return a channel object for the given key.
234 *
235 * RCU read side lock MUST be acquired before calling this function and
236 * protects the channel ptr.
237 */
238 struct lttng_consumer_channel *consumer_find_channel(uint64_t key)
239 {
240 struct lttng_ht_iter iter;
241 struct lttng_ht_node_u64 *node;
242 struct lttng_consumer_channel *channel = NULL;
243
244 /* -1ULL keys are lookup failures */
245 if (key == (uint64_t) -1ULL) {
246 return NULL;
247 }
248
249 lttng_ht_lookup(consumer_data.channel_ht, &key, &iter);
250 node = lttng_ht_iter_get_node_u64(&iter);
251 if (node != NULL) {
252 channel = caa_container_of(node, struct lttng_consumer_channel, node);
253 }
254
255 return channel;
256 }
257
258 /*
259 * There is a possibility that the consumer does not have enough time between
260 * the close of the channel on the session daemon and the cleanup in here thus
261 * once we have a channel add with an existing key, we know for sure that this
262 * channel will eventually get cleaned up by all streams being closed.
263 *
264 * This function just nullifies the already existing channel key.
265 */
266 static void steal_channel_key(uint64_t key)
267 {
268 struct lttng_consumer_channel *channel;
269
270 rcu_read_lock();
271 channel = consumer_find_channel(key);
272 if (channel) {
273 channel->key = (uint64_t) -1ULL;
274 /*
275 * We don't want the lookup to match, but we still need to iterate on
276 * this channel when iterating over the hash table. Just change the
277 * node key.
278 */
279 channel->node.key = (uint64_t) -1ULL;
280 }
281 rcu_read_unlock();
282 }
283
284 static void free_channel_rcu(struct rcu_head *head)
285 {
286 struct lttng_ht_node_u64 *node =
287 caa_container_of(head, struct lttng_ht_node_u64, head);
288 struct lttng_consumer_channel *channel =
289 caa_container_of(node, struct lttng_consumer_channel, node);
290
291 switch (consumer_data.type) {
292 case LTTNG_CONSUMER_KERNEL:
293 break;
294 case LTTNG_CONSUMER32_UST:
295 case LTTNG_CONSUMER64_UST:
296 lttng_ustconsumer_free_channel(channel);
297 break;
298 default:
299 ERR("Unknown consumer_data type");
300 abort();
301 }
302 free(channel);
303 }
304
305 /*
306 * RCU protected relayd socket pair free.
307 */
308 static void free_relayd_rcu(struct rcu_head *head)
309 {
310 struct lttng_ht_node_u64 *node =
311 caa_container_of(head, struct lttng_ht_node_u64, head);
312 struct consumer_relayd_sock_pair *relayd =
313 caa_container_of(node, struct consumer_relayd_sock_pair, node);
314
315 /*
316 * Close all sockets. This is done in the call RCU since we don't want the
317 * socket fds to be reassigned thus potentially creating bad state of the
318 * relayd object.
319 *
320 * We do not have to lock the control socket mutex here since at this stage
321 * there is no one referencing to this relayd object.
322 */
323 (void) relayd_close(&relayd->control_sock);
324 (void) relayd_close(&relayd->data_sock);
325
326 free(relayd);
327 }
328
329 /*
330 * Destroy and free relayd socket pair object.
331 */
332 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd)
333 {
334 int ret;
335 struct lttng_ht_iter iter;
336
337 if (relayd == NULL) {
338 return;
339 }
340
341 DBG("Consumer destroy and close relayd socket pair");
342
343 iter.iter.node = &relayd->node.node;
344 ret = lttng_ht_del(consumer_data.relayd_ht, &iter);
345 if (ret != 0) {
346 /* We assume the relayd is being or is destroyed */
347 return;
348 }
349
350 /* RCU free() call */
351 call_rcu(&relayd->node.head, free_relayd_rcu);
352 }
353
354 /*
355 * Remove a channel from the global list protected by a mutex. This function is
356 * also responsible for freeing its data structures.
357 */
358 void consumer_del_channel(struct lttng_consumer_channel *channel)
359 {
360 int ret;
361 struct lttng_ht_iter iter;
362
363 DBG("Consumer delete channel key %" PRIu64, channel->key);
364
365 pthread_mutex_lock(&consumer_data.lock);
366 pthread_mutex_lock(&channel->lock);
367
368 /* Destroy streams that might have been left in the stream list. */
369 clean_channel_stream_list(channel);
370
371 if (channel->live_timer_enabled == 1) {
372 consumer_timer_live_stop(channel);
373 }
374 if (channel->monitor_timer_enabled == 1) {
375 consumer_timer_monitor_stop(channel);
376 }
377
378 switch (consumer_data.type) {
379 case LTTNG_CONSUMER_KERNEL:
380 break;
381 case LTTNG_CONSUMER32_UST:
382 case LTTNG_CONSUMER64_UST:
383 lttng_ustconsumer_del_channel(channel);
384 break;
385 default:
386 ERR("Unknown consumer_data type");
387 assert(0);
388 goto end;
389 }
390
391 rcu_read_lock();
392 iter.iter.node = &channel->node.node;
393 ret = lttng_ht_del(consumer_data.channel_ht, &iter);
394 assert(!ret);
395 rcu_read_unlock();
396
397 call_rcu(&channel->node.head, free_channel_rcu);
398 end:
399 pthread_mutex_unlock(&channel->lock);
400 pthread_mutex_unlock(&consumer_data.lock);
401 }
402
403 /*
404 * Iterate over the relayd hash table and destroy each element. Finally,
405 * destroy the whole hash table.
406 */
407 static void cleanup_relayd_ht(void)
408 {
409 struct lttng_ht_iter iter;
410 struct consumer_relayd_sock_pair *relayd;
411
412 rcu_read_lock();
413
414 cds_lfht_for_each_entry(consumer_data.relayd_ht->ht, &iter.iter, relayd,
415 node.node) {
416 consumer_destroy_relayd(relayd);
417 }
418
419 rcu_read_unlock();
420
421 lttng_ht_destroy(consumer_data.relayd_ht);
422 }
423
424 /*
425 * Update the end point status of all streams having the given network sequence
426 * index (relayd index).
427 *
428 * It's atomically set without having the stream mutex locked which is fine
429 * because we handle the write/read race with a pipe wakeup for each thread.
430 */
431 static void update_endpoint_status_by_netidx(uint64_t net_seq_idx,
432 enum consumer_endpoint_status status)
433 {
434 struct lttng_ht_iter iter;
435 struct lttng_consumer_stream *stream;
436
437 DBG("Consumer set delete flag on stream by idx %" PRIu64, net_seq_idx);
438
439 rcu_read_lock();
440
441 /* Let's begin with metadata */
442 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) {
443 if (stream->net_seq_idx == net_seq_idx) {
444 uatomic_set(&stream->endpoint_status, status);
445 DBG("Delete flag set to metadata stream %d", stream->wait_fd);
446 }
447 }
448
449 /* Follow up by the data streams */
450 cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) {
451 if (stream->net_seq_idx == net_seq_idx) {
452 uatomic_set(&stream->endpoint_status, status);
453 DBG("Delete flag set to data stream %d", stream->wait_fd);
454 }
455 }
456 rcu_read_unlock();
457 }
458
459 /*
460 * Cleanup a relayd object by flagging every associated streams for deletion,
461 * destroying the object meaning removing it from the relayd hash table,
462 * closing the sockets and freeing the memory in a RCU call.
463 *
464 * If a local data context is available, notify the threads that the streams'
465 * state have changed.
466 */
467 static void cleanup_relayd(struct consumer_relayd_sock_pair *relayd,
468 struct lttng_consumer_local_data *ctx)
469 {
470 uint64_t netidx;
471
472 assert(relayd);
473
474 DBG("Cleaning up relayd sockets");
475
476 /* Save the net sequence index before destroying the object */
477 netidx = relayd->net_seq_idx;
478
479 /*
480 * Delete the relayd from the relayd hash table, close the sockets and free
481 * the object in a RCU call.
482 */
483 consumer_destroy_relayd(relayd);
484
485 /* Set inactive endpoint to all streams */
486 update_endpoint_status_by_netidx(netidx, CONSUMER_ENDPOINT_INACTIVE);
487
488 /*
489 * With a local data context, notify the threads that the streams' state
490 * have changed. The write() action on the pipe acts as an "implicit"
491 * memory barrier ordering the updates of the end point status from the
492 * read of this status which happens AFTER receiving this notify.
493 */
494 if (ctx) {
495 notify_thread_lttng_pipe(ctx->consumer_data_pipe);
496 notify_thread_lttng_pipe(ctx->consumer_metadata_pipe);
497 }
498 }
499
500 /*
501 * Flag a relayd socket pair for destruction. Destroy it if the refcount
502 * reaches zero.
503 *
504 * RCU read side lock MUST be aquired before calling this function.
505 */
506 void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair *relayd)
507 {
508 assert(relayd);
509
510 /* Set destroy flag for this object */
511 uatomic_set(&relayd->destroy_flag, 1);
512
513 /* Destroy the relayd if refcount is 0 */
514 if (uatomic_read(&relayd->refcount) == 0) {
515 consumer_destroy_relayd(relayd);
516 }
517 }
518
519 /*
520 * Completly destroy stream from every visiable data structure and the given
521 * hash table if one.
522 *
523 * One this call returns, the stream object is not longer usable nor visible.
524 */
525 void consumer_del_stream(struct lttng_consumer_stream *stream,
526 struct lttng_ht *ht)
527 {
528 consumer_stream_destroy(stream, ht);
529 }
530
531 /*
532 * XXX naming of del vs destroy is all mixed up.
533 */
534 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream)
535 {
536 consumer_stream_destroy(stream, data_ht);
537 }
538
539 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream)
540 {
541 consumer_stream_destroy(stream, metadata_ht);
542 }
543
544 void consumer_stream_update_channel_attributes(
545 struct lttng_consumer_stream *stream,
546 struct lttng_consumer_channel *channel)
547 {
548 stream->channel_read_only_attributes.tracefile_size =
549 channel->tracefile_size;
550 memcpy(stream->channel_read_only_attributes.path, channel->pathname,
551 sizeof(stream->channel_read_only_attributes.path));
552 }
553
554 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
555 uint64_t stream_key,
556 enum lttng_consumer_stream_state state,
557 const char *channel_name,
558 uid_t uid,
559 gid_t gid,
560 uint64_t relayd_id,
561 uint64_t session_id,
562 int cpu,
563 int *alloc_ret,
564 enum consumer_channel_type type,
565 unsigned int monitor,
566 uint64_t trace_archive_id)
567 {
568 int ret;
569 struct lttng_consumer_stream *stream;
570
571 stream = zmalloc(sizeof(*stream));
572 if (stream == NULL) {
573 PERROR("malloc struct lttng_consumer_stream");
574 ret = -ENOMEM;
575 goto end;
576 }
577
578 rcu_read_lock();
579
580 stream->key = stream_key;
581 stream->out_fd = -1;
582 stream->out_fd_offset = 0;
583 stream->output_written = 0;
584 stream->state = state;
585 stream->uid = uid;
586 stream->gid = gid;
587 stream->net_seq_idx = relayd_id;
588 stream->session_id = session_id;
589 stream->monitor = monitor;
590 stream->endpoint_status = CONSUMER_ENDPOINT_ACTIVE;
591 stream->index_file = NULL;
592 stream->last_sequence_number = -1ULL;
593 stream->trace_archive_id = trace_archive_id;
594 pthread_mutex_init(&stream->lock, NULL);
595 pthread_mutex_init(&stream->metadata_timer_lock, NULL);
596
597 /* If channel is the metadata, flag this stream as metadata. */
598 if (type == CONSUMER_CHANNEL_TYPE_METADATA) {
599 stream->metadata_flag = 1;
600 /* Metadata is flat out. */
601 strncpy(stream->name, DEFAULT_METADATA_NAME, sizeof(stream->name));
602 /* Live rendez-vous point. */
603 pthread_cond_init(&stream->metadata_rdv, NULL);
604 pthread_mutex_init(&stream->metadata_rdv_lock, NULL);
605 } else {
606 /* Format stream name to <channel_name>_<cpu_number> */
607 ret = snprintf(stream->name, sizeof(stream->name), "%s_%d",
608 channel_name, cpu);
609 if (ret < 0) {
610 PERROR("snprintf stream name");
611 goto error;
612 }
613 }
614
615 /* Key is always the wait_fd for streams. */
616 lttng_ht_node_init_u64(&stream->node, stream->key);
617
618 /* Init node per channel id key */
619 lttng_ht_node_init_u64(&stream->node_channel_id, channel_key);
620
621 /* Init session id node with the stream session id */
622 lttng_ht_node_init_u64(&stream->node_session_id, stream->session_id);
623
624 DBG3("Allocated stream %s (key %" PRIu64 ", chan_key %" PRIu64
625 " relayd_id %" PRIu64 ", session_id %" PRIu64,
626 stream->name, stream->key, channel_key,
627 stream->net_seq_idx, stream->session_id);
628
629 rcu_read_unlock();
630 return stream;
631
632 error:
633 rcu_read_unlock();
634 free(stream);
635 end:
636 if (alloc_ret) {
637 *alloc_ret = ret;
638 }
639 return NULL;
640 }
641
642 /*
643 * Add a stream to the global list protected by a mutex.
644 */
645 void consumer_add_data_stream(struct lttng_consumer_stream *stream)
646 {
647 struct lttng_ht *ht = data_ht;
648
649 assert(stream);
650 assert(ht);
651
652 DBG3("Adding consumer stream %" PRIu64, stream->key);
653
654 pthread_mutex_lock(&consumer_data.lock);
655 pthread_mutex_lock(&stream->chan->lock);
656 pthread_mutex_lock(&stream->chan->timer_lock);
657 pthread_mutex_lock(&stream->lock);
658 rcu_read_lock();
659
660 /* Steal stream identifier to avoid having streams with the same key */
661 steal_stream_key(stream->key, ht);
662
663 lttng_ht_add_unique_u64(ht, &stream->node);
664
665 lttng_ht_add_u64(consumer_data.stream_per_chan_id_ht,
666 &stream->node_channel_id);
667
668 /*
669 * Add stream to the stream_list_ht of the consumer data. No need to steal
670 * the key since the HT does not use it and we allow to add redundant keys
671 * into this table.
672 */
673 lttng_ht_add_u64(consumer_data.stream_list_ht, &stream->node_session_id);
674
675 /*
676 * When nb_init_stream_left reaches 0, we don't need to trigger any action
677 * in terms of destroying the associated channel, because the action that
678 * causes the count to become 0 also causes a stream to be added. The
679 * channel deletion will thus be triggered by the following removal of this
680 * stream.
681 */
682 if (uatomic_read(&stream->chan->nb_init_stream_left) > 0) {
683 /* Increment refcount before decrementing nb_init_stream_left */
684 cmm_smp_wmb();
685 uatomic_dec(&stream->chan->nb_init_stream_left);
686 }
687
688 /* Update consumer data once the node is inserted. */
689 consumer_data.stream_count++;
690 consumer_data.need_update = 1;
691
692 rcu_read_unlock();
693 pthread_mutex_unlock(&stream->lock);
694 pthread_mutex_unlock(&stream->chan->timer_lock);
695 pthread_mutex_unlock(&stream->chan->lock);
696 pthread_mutex_unlock(&consumer_data.lock);
697 }
698
699 void consumer_del_data_stream(struct lttng_consumer_stream *stream)
700 {
701 consumer_del_stream(stream, data_ht);
702 }
703
704 /*
705 * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
706 * be acquired before calling this.
707 */
708 static int add_relayd(struct consumer_relayd_sock_pair *relayd)
709 {
710 int ret = 0;
711 struct lttng_ht_node_u64 *node;
712 struct lttng_ht_iter iter;
713
714 assert(relayd);
715
716 lttng_ht_lookup(consumer_data.relayd_ht,
717 &relayd->net_seq_idx, &iter);
718 node = lttng_ht_iter_get_node_u64(&iter);
719 if (node != NULL) {
720 goto end;
721 }
722 lttng_ht_add_unique_u64(consumer_data.relayd_ht, &relayd->node);
723
724 end:
725 return ret;
726 }
727
728 /*
729 * Allocate and return a consumer relayd socket.
730 */
731 static struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
732 uint64_t net_seq_idx)
733 {
734 struct consumer_relayd_sock_pair *obj = NULL;
735
736 /* net sequence index of -1 is a failure */
737 if (net_seq_idx == (uint64_t) -1ULL) {
738 goto error;
739 }
740
741 obj = zmalloc(sizeof(struct consumer_relayd_sock_pair));
742 if (obj == NULL) {
743 PERROR("zmalloc relayd sock");
744 goto error;
745 }
746
747 obj->net_seq_idx = net_seq_idx;
748 obj->refcount = 0;
749 obj->destroy_flag = 0;
750 obj->control_sock.sock.fd = -1;
751 obj->data_sock.sock.fd = -1;
752 lttng_ht_node_init_u64(&obj->node, obj->net_seq_idx);
753 pthread_mutex_init(&obj->ctrl_sock_mutex, NULL);
754
755 error:
756 return obj;
757 }
758
759 /*
760 * Find a relayd socket pair in the global consumer data.
761 *
762 * Return the object if found else NULL.
763 * RCU read-side lock must be held across this call and while using the
764 * returned object.
765 */
766 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key)
767 {
768 struct lttng_ht_iter iter;
769 struct lttng_ht_node_u64 *node;
770 struct consumer_relayd_sock_pair *relayd = NULL;
771
772 /* Negative keys are lookup failures */
773 if (key == (uint64_t) -1ULL) {
774 goto error;
775 }
776
777 lttng_ht_lookup(consumer_data.relayd_ht, &key,
778 &iter);
779 node = lttng_ht_iter_get_node_u64(&iter);
780 if (node != NULL) {
781 relayd = caa_container_of(node, struct consumer_relayd_sock_pair, node);
782 }
783
784 error:
785 return relayd;
786 }
787
788 /*
789 * Find a relayd and send the stream
790 *
791 * Returns 0 on success, < 0 on error
792 */
793 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream,
794 char *path)
795 {
796 int ret = 0;
797 struct consumer_relayd_sock_pair *relayd;
798
799 assert(stream);
800 assert(stream->net_seq_idx != -1ULL);
801 assert(path);
802
803 /* The stream is not metadata. Get relayd reference if exists. */
804 rcu_read_lock();
805 relayd = consumer_find_relayd(stream->net_seq_idx);
806 if (relayd != NULL) {
807 /* Add stream on the relayd */
808 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
809 ret = relayd_add_stream(&relayd->control_sock, stream->name,
810 path, &stream->relayd_stream_id,
811 stream->chan->tracefile_size, stream->chan->tracefile_count,
812 stream->trace_archive_id);
813 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
814 if (ret < 0) {
815 goto end;
816 }
817
818 uatomic_inc(&relayd->refcount);
819 stream->sent_to_relayd = 1;
820 } else {
821 ERR("Stream %" PRIu64 " relayd ID %" PRIu64 " unknown. Can't send it.",
822 stream->key, stream->net_seq_idx);
823 ret = -1;
824 goto end;
825 }
826
827 DBG("Stream %s with key %" PRIu64 " sent to relayd id %" PRIu64,
828 stream->name, stream->key, stream->net_seq_idx);
829
830 end:
831 rcu_read_unlock();
832 return ret;
833 }
834
835 /*
836 * Find a relayd and send the streams sent message
837 *
838 * Returns 0 on success, < 0 on error
839 */
840 int consumer_send_relayd_streams_sent(uint64_t net_seq_idx)
841 {
842 int ret = 0;
843 struct consumer_relayd_sock_pair *relayd;
844
845 assert(net_seq_idx != -1ULL);
846
847 /* The stream is not metadata. Get relayd reference if exists. */
848 rcu_read_lock();
849 relayd = consumer_find_relayd(net_seq_idx);
850 if (relayd != NULL) {
851 /* Add stream on the relayd */
852 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
853 ret = relayd_streams_sent(&relayd->control_sock);
854 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
855 if (ret < 0) {
856 goto end;
857 }
858 } else {
859 ERR("Relayd ID %" PRIu64 " unknown. Can't send streams_sent.",
860 net_seq_idx);
861 ret = -1;
862 goto end;
863 }
864
865 ret = 0;
866 DBG("All streams sent relayd id %" PRIu64, net_seq_idx);
867
868 end:
869 rcu_read_unlock();
870 return ret;
871 }
872
873 /*
874 * Find a relayd and close the stream
875 */
876 void close_relayd_stream(struct lttng_consumer_stream *stream)
877 {
878 struct consumer_relayd_sock_pair *relayd;
879
880 /* The stream is not metadata. Get relayd reference if exists. */
881 rcu_read_lock();
882 relayd = consumer_find_relayd(stream->net_seq_idx);
883 if (relayd) {
884 consumer_stream_relayd_close(stream, relayd);
885 }
886 rcu_read_unlock();
887 }
888
889 /*
890 * Handle stream for relayd transmission if the stream applies for network
891 * streaming where the net sequence index is set.
892 *
893 * Return destination file descriptor or negative value on error.
894 */
895 static int write_relayd_stream_header(struct lttng_consumer_stream *stream,
896 size_t data_size, unsigned long padding,
897 struct consumer_relayd_sock_pair *relayd)
898 {
899 int outfd = -1, ret;
900 struct lttcomm_relayd_data_hdr data_hdr;
901
902 /* Safety net */
903 assert(stream);
904 assert(relayd);
905
906 /* Reset data header */
907 memset(&data_hdr, 0, sizeof(data_hdr));
908
909 if (stream->metadata_flag) {
910 /* Caller MUST acquire the relayd control socket lock */
911 ret = relayd_send_metadata(&relayd->control_sock, data_size);
912 if (ret < 0) {
913 goto error;
914 }
915
916 /* Metadata are always sent on the control socket. */
917 outfd = relayd->control_sock.sock.fd;
918 } else {
919 /* Set header with stream information */
920 data_hdr.stream_id = htobe64(stream->relayd_stream_id);
921 data_hdr.data_size = htobe32(data_size);
922 data_hdr.padding_size = htobe32(padding);
923 /*
924 * Note that net_seq_num below is assigned with the *current* value of
925 * next_net_seq_num and only after that the next_net_seq_num will be
926 * increment. This is why when issuing a command on the relayd using
927 * this next value, 1 should always be substracted in order to compare
928 * the last seen sequence number on the relayd side to the last sent.
929 */
930 data_hdr.net_seq_num = htobe64(stream->next_net_seq_num);
931 /* Other fields are zeroed previously */
932
933 ret = relayd_send_data_hdr(&relayd->data_sock, &data_hdr,
934 sizeof(data_hdr));
935 if (ret < 0) {
936 goto error;
937 }
938
939 ++stream->next_net_seq_num;
940
941 /* Set to go on data socket */
942 outfd = relayd->data_sock.sock.fd;
943 }
944
945 error:
946 return outfd;
947 }
948
949 /*
950 * Allocate and return a new lttng_consumer_channel object using the given key
951 * to initialize the hash table node.
952 *
953 * On error, return NULL.
954 */
955 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
956 uint64_t session_id,
957 const char *pathname,
958 const char *name,
959 uid_t uid,
960 gid_t gid,
961 uint64_t relayd_id,
962 enum lttng_event_output output,
963 uint64_t tracefile_size,
964 uint64_t tracefile_count,
965 uint64_t session_id_per_pid,
966 unsigned int monitor,
967 unsigned int live_timer_interval,
968 const char *root_shm_path,
969 const char *shm_path)
970 {
971 struct lttng_consumer_channel *channel;
972
973 channel = zmalloc(sizeof(*channel));
974 if (channel == NULL) {
975 PERROR("malloc struct lttng_consumer_channel");
976 goto end;
977 }
978
979 channel->key = key;
980 channel->refcount = 0;
981 channel->session_id = session_id;
982 channel->session_id_per_pid = session_id_per_pid;
983 channel->uid = uid;
984 channel->gid = gid;
985 channel->relayd_id = relayd_id;
986 channel->tracefile_size = tracefile_size;
987 channel->tracefile_count = tracefile_count;
988 channel->monitor = monitor;
989 channel->live_timer_interval = live_timer_interval;
990 pthread_mutex_init(&channel->lock, NULL);
991 pthread_mutex_init(&channel->timer_lock, NULL);
992
993 switch (output) {
994 case LTTNG_EVENT_SPLICE:
995 channel->output = CONSUMER_CHANNEL_SPLICE;
996 break;
997 case LTTNG_EVENT_MMAP:
998 channel->output = CONSUMER_CHANNEL_MMAP;
999 break;
1000 default:
1001 assert(0);
1002 free(channel);
1003 channel = NULL;
1004 goto end;
1005 }
1006
1007 /*
1008 * In monitor mode, the streams associated with the channel will be put in
1009 * a special list ONLY owned by this channel. So, the refcount is set to 1
1010 * here meaning that the channel itself has streams that are referenced.
1011 *
1012 * On a channel deletion, once the channel is no longer visible, the
1013 * refcount is decremented and checked for a zero value to delete it. With
1014 * streams in no monitor mode, it will now be safe to destroy the channel.
1015 */
1016 if (!channel->monitor) {
1017 channel->refcount = 1;
1018 }
1019
1020 strncpy(channel->pathname, pathname, sizeof(channel->pathname));
1021 channel->pathname[sizeof(channel->pathname) - 1] = '\0';
1022
1023 strncpy(channel->name, name, sizeof(channel->name));
1024 channel->name[sizeof(channel->name) - 1] = '\0';
1025
1026 if (root_shm_path) {
1027 strncpy(channel->root_shm_path, root_shm_path, sizeof(channel->root_shm_path));
1028 channel->root_shm_path[sizeof(channel->root_shm_path) - 1] = '\0';
1029 }
1030 if (shm_path) {
1031 strncpy(channel->shm_path, shm_path, sizeof(channel->shm_path));
1032 channel->shm_path[sizeof(channel->shm_path) - 1] = '\0';
1033 }
1034
1035 lttng_ht_node_init_u64(&channel->node, channel->key);
1036
1037 channel->wait_fd = -1;
1038
1039 CDS_INIT_LIST_HEAD(&channel->streams.head);
1040
1041 DBG("Allocated channel (key %" PRIu64 ")", channel->key);
1042
1043 end:
1044 return channel;
1045 }
1046
1047 /*
1048 * Add a channel to the global list protected by a mutex.
1049 *
1050 * Always return 0 indicating success.
1051 */
1052 int consumer_add_channel(struct lttng_consumer_channel *channel,
1053 struct lttng_consumer_local_data *ctx)
1054 {
1055 pthread_mutex_lock(&consumer_data.lock);
1056 pthread_mutex_lock(&channel->lock);
1057 pthread_mutex_lock(&channel->timer_lock);
1058
1059 /*
1060 * This gives us a guarantee that the channel we are about to add to the
1061 * channel hash table will be unique. See this function comment on the why
1062 * we need to steel the channel key at this stage.
1063 */
1064 steal_channel_key(channel->key);
1065
1066 rcu_read_lock();
1067 lttng_ht_add_unique_u64(consumer_data.channel_ht, &channel->node);
1068 rcu_read_unlock();
1069
1070 pthread_mutex_unlock(&channel->timer_lock);
1071 pthread_mutex_unlock(&channel->lock);
1072 pthread_mutex_unlock(&consumer_data.lock);
1073
1074 if (channel->wait_fd != -1 && channel->type == CONSUMER_CHANNEL_TYPE_DATA) {
1075 notify_channel_pipe(ctx, channel, -1, CONSUMER_CHANNEL_ADD);
1076 }
1077
1078 return 0;
1079 }
1080
1081 /*
1082 * Allocate the pollfd structure and the local view of the out fds to avoid
1083 * doing a lookup in the linked list and concurrency issues when writing is
1084 * needed. Called with consumer_data.lock held.
1085 *
1086 * Returns the number of fds in the structures.
1087 */
1088 static int update_poll_array(struct lttng_consumer_local_data *ctx,
1089 struct pollfd **pollfd, struct lttng_consumer_stream **local_stream,
1090 struct lttng_ht *ht, int *nb_inactive_fd)
1091 {
1092 int i = 0;
1093 struct lttng_ht_iter iter;
1094 struct lttng_consumer_stream *stream;
1095
1096 assert(ctx);
1097 assert(ht);
1098 assert(pollfd);
1099 assert(local_stream);
1100
1101 DBG("Updating poll fd array");
1102 *nb_inactive_fd = 0;
1103 rcu_read_lock();
1104 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1105 /*
1106 * Only active streams with an active end point can be added to the
1107 * poll set and local stream storage of the thread.
1108 *
1109 * There is a potential race here for endpoint_status to be updated
1110 * just after the check. However, this is OK since the stream(s) will
1111 * be deleted once the thread is notified that the end point state has
1112 * changed where this function will be called back again.
1113 *
1114 * We track the number of inactive FDs because they still need to be
1115 * closed by the polling thread after a wakeup on the data_pipe or
1116 * metadata_pipe.
1117 */
1118 if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM ||
1119 stream->endpoint_status == CONSUMER_ENDPOINT_INACTIVE) {
1120 (*nb_inactive_fd)++;
1121 continue;
1122 }
1123 /*
1124 * This clobbers way too much the debug output. Uncomment that if you
1125 * need it for debugging purposes.
1126 *
1127 * DBG("Active FD %d", stream->wait_fd);
1128 */
1129 (*pollfd)[i].fd = stream->wait_fd;
1130 (*pollfd)[i].events = POLLIN | POLLPRI;
1131 local_stream[i] = stream;
1132 i++;
1133 }
1134 rcu_read_unlock();
1135
1136 /*
1137 * Insert the consumer_data_pipe at the end of the array and don't
1138 * increment i so nb_fd is the number of real FD.
1139 */
1140 (*pollfd)[i].fd = lttng_pipe_get_readfd(ctx->consumer_data_pipe);
1141 (*pollfd)[i].events = POLLIN | POLLPRI;
1142
1143 (*pollfd)[i + 1].fd = lttng_pipe_get_readfd(ctx->consumer_wakeup_pipe);
1144 (*pollfd)[i + 1].events = POLLIN | POLLPRI;
1145 return i;
1146 }
1147
1148 /*
1149 * Poll on the should_quit pipe and the command socket return -1 on
1150 * error, 1 if should exit, 0 if data is available on the command socket
1151 */
1152 int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll)
1153 {
1154 int num_rdy;
1155
1156 restart:
1157 num_rdy = poll(consumer_sockpoll, 2, -1);
1158 if (num_rdy == -1) {
1159 /*
1160 * Restart interrupted system call.
1161 */
1162 if (errno == EINTR) {
1163 goto restart;
1164 }
1165 PERROR("Poll error");
1166 return -1;
1167 }
1168 if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) {
1169 DBG("consumer_should_quit wake up");
1170 return 1;
1171 }
1172 return 0;
1173 }
1174
1175 /*
1176 * Set the error socket.
1177 */
1178 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
1179 int sock)
1180 {
1181 ctx->consumer_error_socket = sock;
1182 }
1183
1184 /*
1185 * Set the command socket path.
1186 */
1187 void lttng_consumer_set_command_sock_path(
1188 struct lttng_consumer_local_data *ctx, char *sock)
1189 {
1190 ctx->consumer_command_sock_path = sock;
1191 }
1192
1193 /*
1194 * Send return code to the session daemon.
1195 * If the socket is not defined, we return 0, it is not a fatal error
1196 */
1197 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd)
1198 {
1199 if (ctx->consumer_error_socket > 0) {
1200 return lttcomm_send_unix_sock(ctx->consumer_error_socket, &cmd,
1201 sizeof(enum lttcomm_sessiond_command));
1202 }
1203
1204 return 0;
1205 }
1206
1207 /*
1208 * Close all the tracefiles and stream fds and MUST be called when all
1209 * instances are destroyed i.e. when all threads were joined and are ended.
1210 */
1211 void lttng_consumer_cleanup(void)
1212 {
1213 struct lttng_ht_iter iter;
1214 struct lttng_consumer_channel *channel;
1215
1216 rcu_read_lock();
1217
1218 cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, channel,
1219 node.node) {
1220 consumer_del_channel(channel);
1221 }
1222
1223 rcu_read_unlock();
1224
1225 lttng_ht_destroy(consumer_data.channel_ht);
1226
1227 cleanup_relayd_ht();
1228
1229 lttng_ht_destroy(consumer_data.stream_per_chan_id_ht);
1230
1231 /*
1232 * This HT contains streams that are freed by either the metadata thread or
1233 * the data thread so we do *nothing* on the hash table and simply destroy
1234 * it.
1235 */
1236 lttng_ht_destroy(consumer_data.stream_list_ht);
1237 }
1238
1239 /*
1240 * Called from signal handler.
1241 */
1242 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx)
1243 {
1244 ssize_t ret;
1245
1246 CMM_STORE_SHARED(consumer_quit, 1);
1247 ret = lttng_write(ctx->consumer_should_quit[1], "4", 1);
1248 if (ret < 1) {
1249 PERROR("write consumer quit");
1250 }
1251
1252 DBG("Consumer flag that it should quit");
1253 }
1254
1255
1256 /*
1257 * Flush pending writes to trace output disk file.
1258 */
1259 static
1260 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
1261 off_t orig_offset)
1262 {
1263 int ret;
1264 int outfd = stream->out_fd;
1265
1266 /*
1267 * This does a blocking write-and-wait on any page that belongs to the
1268 * subbuffer prior to the one we just wrote.
1269 * Don't care about error values, as these are just hints and ways to
1270 * limit the amount of page cache used.
1271 */
1272 if (orig_offset < stream->max_sb_size) {
1273 return;
1274 }
1275 lttng_sync_file_range(outfd, orig_offset - stream->max_sb_size,
1276 stream->max_sb_size,
1277 SYNC_FILE_RANGE_WAIT_BEFORE
1278 | SYNC_FILE_RANGE_WRITE
1279 | SYNC_FILE_RANGE_WAIT_AFTER);
1280 /*
1281 * Give hints to the kernel about how we access the file:
1282 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
1283 * we write it.
1284 *
1285 * We need to call fadvise again after the file grows because the
1286 * kernel does not seem to apply fadvise to non-existing parts of the
1287 * file.
1288 *
1289 * Call fadvise _after_ having waited for the page writeback to
1290 * complete because the dirty page writeback semantic is not well
1291 * defined. So it can be expected to lead to lower throughput in
1292 * streaming.
1293 */
1294 ret = posix_fadvise(outfd, orig_offset - stream->max_sb_size,
1295 stream->max_sb_size, POSIX_FADV_DONTNEED);
1296 if (ret && ret != -ENOSYS) {
1297 errno = ret;
1298 PERROR("posix_fadvise on fd %i", outfd);
1299 }
1300 }
1301
1302 /*
1303 * Initialise the necessary environnement :
1304 * - create a new context
1305 * - create the poll_pipe
1306 * - create the should_quit pipe (for signal handler)
1307 * - create the thread pipe (for splice)
1308 *
1309 * Takes a function pointer as argument, this function is called when data is
1310 * available on a buffer. This function is responsible to do the
1311 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
1312 * buffer configuration and then kernctl_put_next_subbuf at the end.
1313 *
1314 * Returns a pointer to the new context or NULL on error.
1315 */
1316 struct lttng_consumer_local_data *lttng_consumer_create(
1317 enum lttng_consumer_type type,
1318 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
1319 struct lttng_consumer_local_data *ctx),
1320 int (*recv_channel)(struct lttng_consumer_channel *channel),
1321 int (*recv_stream)(struct lttng_consumer_stream *stream),
1322 int (*update_stream)(uint64_t stream_key, uint32_t state))
1323 {
1324 int ret;
1325 struct lttng_consumer_local_data *ctx;
1326
1327 assert(consumer_data.type == LTTNG_CONSUMER_UNKNOWN ||
1328 consumer_data.type == type);
1329 consumer_data.type = type;
1330
1331 ctx = zmalloc(sizeof(struct lttng_consumer_local_data));
1332 if (ctx == NULL) {
1333 PERROR("allocating context");
1334 goto error;
1335 }
1336
1337 ctx->consumer_error_socket = -1;
1338 ctx->consumer_metadata_socket = -1;
1339 pthread_mutex_init(&ctx->metadata_socket_lock, NULL);
1340 /* assign the callbacks */
1341 ctx->on_buffer_ready = buffer_ready;
1342 ctx->on_recv_channel = recv_channel;
1343 ctx->on_recv_stream = recv_stream;
1344 ctx->on_update_stream = update_stream;
1345
1346 ctx->consumer_data_pipe = lttng_pipe_open(0);
1347 if (!ctx->consumer_data_pipe) {
1348 goto error_poll_pipe;
1349 }
1350
1351 ctx->consumer_wakeup_pipe = lttng_pipe_open(0);
1352 if (!ctx->consumer_wakeup_pipe) {
1353 goto error_wakeup_pipe;
1354 }
1355
1356 ret = pipe(ctx->consumer_should_quit);
1357 if (ret < 0) {
1358 PERROR("Error creating recv pipe");
1359 goto error_quit_pipe;
1360 }
1361
1362 ret = pipe(ctx->consumer_channel_pipe);
1363 if (ret < 0) {
1364 PERROR("Error creating channel pipe");
1365 goto error_channel_pipe;
1366 }
1367
1368 ctx->consumer_metadata_pipe = lttng_pipe_open(0);
1369 if (!ctx->consumer_metadata_pipe) {
1370 goto error_metadata_pipe;
1371 }
1372
1373 ctx->channel_monitor_pipe = -1;
1374
1375 return ctx;
1376
1377 error_metadata_pipe:
1378 utils_close_pipe(ctx->consumer_channel_pipe);
1379 error_channel_pipe:
1380 utils_close_pipe(ctx->consumer_should_quit);
1381 error_quit_pipe:
1382 lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
1383 error_wakeup_pipe:
1384 lttng_pipe_destroy(ctx->consumer_data_pipe);
1385 error_poll_pipe:
1386 free(ctx);
1387 error:
1388 return NULL;
1389 }
1390
1391 /*
1392 * Iterate over all streams of the hashtable and free them properly.
1393 */
1394 static void destroy_data_stream_ht(struct lttng_ht *ht)
1395 {
1396 struct lttng_ht_iter iter;
1397 struct lttng_consumer_stream *stream;
1398
1399 if (ht == NULL) {
1400 return;
1401 }
1402
1403 rcu_read_lock();
1404 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1405 /*
1406 * Ignore return value since we are currently cleaning up so any error
1407 * can't be handled.
1408 */
1409 (void) consumer_del_stream(stream, ht);
1410 }
1411 rcu_read_unlock();
1412
1413 lttng_ht_destroy(ht);
1414 }
1415
1416 /*
1417 * Iterate over all streams of the metadata hashtable and free them
1418 * properly.
1419 */
1420 static void destroy_metadata_stream_ht(struct lttng_ht *ht)
1421 {
1422 struct lttng_ht_iter iter;
1423 struct lttng_consumer_stream *stream;
1424
1425 if (ht == NULL) {
1426 return;
1427 }
1428
1429 rcu_read_lock();
1430 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1431 /*
1432 * Ignore return value since we are currently cleaning up so any error
1433 * can't be handled.
1434 */
1435 (void) consumer_del_metadata_stream(stream, ht);
1436 }
1437 rcu_read_unlock();
1438
1439 lttng_ht_destroy(ht);
1440 }
1441
1442 /*
1443 * Close all fds associated with the instance and free the context.
1444 */
1445 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
1446 {
1447 int ret;
1448
1449 DBG("Consumer destroying it. Closing everything.");
1450
1451 if (!ctx) {
1452 return;
1453 }
1454
1455 destroy_data_stream_ht(data_ht);
1456 destroy_metadata_stream_ht(metadata_ht);
1457
1458 ret = close(ctx->consumer_error_socket);
1459 if (ret) {
1460 PERROR("close");
1461 }
1462 ret = close(ctx->consumer_metadata_socket);
1463 if (ret) {
1464 PERROR("close");
1465 }
1466 utils_close_pipe(ctx->consumer_channel_pipe);
1467 lttng_pipe_destroy(ctx->consumer_data_pipe);
1468 lttng_pipe_destroy(ctx->consumer_metadata_pipe);
1469 lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
1470 utils_close_pipe(ctx->consumer_should_quit);
1471
1472 unlink(ctx->consumer_command_sock_path);
1473 free(ctx);
1474 }
1475
1476 /*
1477 * Write the metadata stream id on the specified file descriptor.
1478 */
1479 static int write_relayd_metadata_id(int fd,
1480 struct lttng_consumer_stream *stream,
1481 unsigned long padding)
1482 {
1483 ssize_t ret;
1484 struct lttcomm_relayd_metadata_payload hdr;
1485
1486 hdr.stream_id = htobe64(stream->relayd_stream_id);
1487 hdr.padding_size = htobe32(padding);
1488 ret = lttng_write(fd, (void *) &hdr, sizeof(hdr));
1489 if (ret < sizeof(hdr)) {
1490 /*
1491 * This error means that the fd's end is closed so ignore the PERROR
1492 * not to clubber the error output since this can happen in a normal
1493 * code path.
1494 */
1495 if (errno != EPIPE) {
1496 PERROR("write metadata stream id");
1497 }
1498 DBG3("Consumer failed to write relayd metadata id (errno: %d)", errno);
1499 /*
1500 * Set ret to a negative value because if ret != sizeof(hdr), we don't
1501 * handle writting the missing part so report that as an error and
1502 * don't lie to the caller.
1503 */
1504 ret = -1;
1505 goto end;
1506 }
1507 DBG("Metadata stream id %" PRIu64 " with padding %lu written before data",
1508 stream->relayd_stream_id, padding);
1509
1510 end:
1511 return (int) ret;
1512 }
1513
1514 /*
1515 * Mmap the ring buffer, read it and write the data to the tracefile. This is a
1516 * core function for writing trace buffers to either the local filesystem or
1517 * the network.
1518 *
1519 * It must be called with the stream lock held.
1520 *
1521 * Careful review MUST be put if any changes occur!
1522 *
1523 * Returns the number of bytes written
1524 */
1525 ssize_t lttng_consumer_on_read_subbuffer_mmap(
1526 struct lttng_consumer_local_data *ctx,
1527 struct lttng_consumer_stream *stream, unsigned long len,
1528 unsigned long padding,
1529 struct ctf_packet_index *index)
1530 {
1531 unsigned long mmap_offset;
1532 void *mmap_base;
1533 ssize_t ret = 0;
1534 off_t orig_offset = stream->out_fd_offset;
1535 /* Default is on the disk */
1536 int outfd = stream->out_fd;
1537 struct consumer_relayd_sock_pair *relayd = NULL;
1538 unsigned int relayd_hang_up = 0;
1539
1540 /* RCU lock for the relayd pointer */
1541 rcu_read_lock();
1542
1543 /* Flag that the current stream if set for network streaming. */
1544 if (stream->net_seq_idx != (uint64_t) -1ULL) {
1545 relayd = consumer_find_relayd(stream->net_seq_idx);
1546 if (relayd == NULL) {
1547 ret = -EPIPE;
1548 goto end;
1549 }
1550 }
1551
1552 /* get the offset inside the fd to mmap */
1553 switch (consumer_data.type) {
1554 case LTTNG_CONSUMER_KERNEL:
1555 mmap_base = stream->mmap_base;
1556 ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset);
1557 if (ret < 0) {
1558 PERROR("tracer ctl get_mmap_read_offset");
1559 goto end;
1560 }
1561 break;
1562 case LTTNG_CONSUMER32_UST:
1563 case LTTNG_CONSUMER64_UST:
1564 mmap_base = lttng_ustctl_get_mmap_base(stream);
1565 if (!mmap_base) {
1566 ERR("read mmap get mmap base for stream %s", stream->name);
1567 ret = -EPERM;
1568 goto end;
1569 }
1570 ret = lttng_ustctl_get_mmap_read_offset(stream, &mmap_offset);
1571 if (ret != 0) {
1572 PERROR("tracer ctl get_mmap_read_offset");
1573 ret = -EINVAL;
1574 goto end;
1575 }
1576 break;
1577 default:
1578 ERR("Unknown consumer_data type");
1579 assert(0);
1580 }
1581
1582 /* Handle stream on the relayd if the output is on the network */
1583 if (relayd) {
1584 unsigned long netlen = len;
1585
1586 /*
1587 * Lock the control socket for the complete duration of the function
1588 * since from this point on we will use the socket.
1589 */
1590 if (stream->metadata_flag) {
1591 /* Metadata requires the control socket. */
1592 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
1593 if (stream->reset_metadata_flag) {
1594 ret = relayd_reset_metadata(&relayd->control_sock,
1595 stream->relayd_stream_id,
1596 stream->metadata_version);
1597 if (ret < 0) {
1598 relayd_hang_up = 1;
1599 goto write_error;
1600 }
1601 stream->reset_metadata_flag = 0;
1602 }
1603 netlen += sizeof(struct lttcomm_relayd_metadata_payload);
1604 }
1605
1606 ret = write_relayd_stream_header(stream, netlen, padding, relayd);
1607 if (ret < 0) {
1608 relayd_hang_up = 1;
1609 goto write_error;
1610 }
1611 /* Use the returned socket. */
1612 outfd = ret;
1613
1614 /* Write metadata stream id before payload */
1615 if (stream->metadata_flag) {
1616 ret = write_relayd_metadata_id(outfd, stream, padding);
1617 if (ret < 0) {
1618 relayd_hang_up = 1;
1619 goto write_error;
1620 }
1621 }
1622 } else {
1623 /* No streaming, we have to set the len with the full padding */
1624 len += padding;
1625
1626 if (stream->metadata_flag && stream->reset_metadata_flag) {
1627 ret = utils_truncate_stream_file(stream->out_fd, 0);
1628 if (ret < 0) {
1629 ERR("Reset metadata file");
1630 goto end;
1631 }
1632 stream->reset_metadata_flag = 0;
1633 }
1634
1635 /*
1636 * Check if we need to change the tracefile before writing the packet.
1637 */
1638 if (stream->chan->tracefile_size > 0 &&
1639 (stream->tracefile_size_current + len) >
1640 stream->chan->tracefile_size) {
1641 ret = utils_rotate_stream_file(stream->chan->pathname,
1642 stream->name, stream->chan->tracefile_size,
1643 stream->chan->tracefile_count, stream->uid, stream->gid,
1644 stream->out_fd, &(stream->tracefile_count_current),
1645 &stream->out_fd);
1646 if (ret < 0) {
1647 ERR("Rotating output file");
1648 goto end;
1649 }
1650 outfd = stream->out_fd;
1651
1652 if (stream->index_file) {
1653 lttng_index_file_put(stream->index_file);
1654 stream->index_file = lttng_index_file_create(stream->chan->pathname,
1655 stream->name, stream->uid, stream->gid,
1656 stream->chan->tracefile_size,
1657 stream->tracefile_count_current,
1658 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
1659 if (!stream->index_file) {
1660 goto end;
1661 }
1662 }
1663
1664 /* Reset current size because we just perform a rotation. */
1665 stream->tracefile_size_current = 0;
1666 stream->out_fd_offset = 0;
1667 orig_offset = 0;
1668 }
1669 stream->tracefile_size_current += len;
1670 if (index) {
1671 index->offset = htobe64(stream->out_fd_offset);
1672 }
1673 }
1674
1675 /*
1676 * This call guarantee that len or less is returned. It's impossible to
1677 * receive a ret value that is bigger than len.
1678 */
1679 ret = lttng_write(outfd, mmap_base + mmap_offset, len);
1680 DBG("Consumer mmap write() ret %zd (len %lu)", ret, len);
1681 if (ret < 0 || ((size_t) ret != len)) {
1682 /*
1683 * Report error to caller if nothing was written else at least send the
1684 * amount written.
1685 */
1686 if (ret < 0) {
1687 ret = -errno;
1688 }
1689 relayd_hang_up = 1;
1690
1691 /* Socket operation failed. We consider the relayd dead */
1692 if (errno == EPIPE || errno == EINVAL || errno == EBADF) {
1693 /*
1694 * This is possible if the fd is closed on the other side
1695 * (outfd) or any write problem. It can be verbose a bit for a
1696 * normal execution if for instance the relayd is stopped
1697 * abruptly. This can happen so set this to a DBG statement.
1698 */
1699 DBG("Consumer mmap write detected relayd hang up");
1700 } else {
1701 /* Unhandled error, print it and stop function right now. */
1702 PERROR("Error in write mmap (ret %zd != len %lu)", ret, len);
1703 }
1704 goto write_error;
1705 }
1706 stream->output_written += ret;
1707
1708 /* This call is useless on a socket so better save a syscall. */
1709 if (!relayd) {
1710 /* This won't block, but will start writeout asynchronously */
1711 lttng_sync_file_range(outfd, stream->out_fd_offset, len,
1712 SYNC_FILE_RANGE_WRITE);
1713 stream->out_fd_offset += len;
1714 lttng_consumer_sync_trace_file(stream, orig_offset);
1715 }
1716
1717 write_error:
1718 /*
1719 * This is a special case that the relayd has closed its socket. Let's
1720 * cleanup the relayd object and all associated streams.
1721 */
1722 if (relayd && relayd_hang_up) {
1723 cleanup_relayd(relayd, ctx);
1724 }
1725
1726 end:
1727 /* Unlock only if ctrl socket used */
1728 if (relayd && stream->metadata_flag) {
1729 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
1730 }
1731
1732 rcu_read_unlock();
1733 return ret;
1734 }
1735
1736 /*
1737 * Splice the data from the ring buffer to the tracefile.
1738 *
1739 * It must be called with the stream lock held.
1740 *
1741 * Returns the number of bytes spliced.
1742 */
1743 ssize_t lttng_consumer_on_read_subbuffer_splice(
1744 struct lttng_consumer_local_data *ctx,
1745 struct lttng_consumer_stream *stream, unsigned long len,
1746 unsigned long padding,
1747 struct ctf_packet_index *index)
1748 {
1749 ssize_t ret = 0, written = 0, ret_splice = 0;
1750 loff_t offset = 0;
1751 off_t orig_offset = stream->out_fd_offset;
1752 int fd = stream->wait_fd;
1753 /* Default is on the disk */
1754 int outfd = stream->out_fd;
1755 struct consumer_relayd_sock_pair *relayd = NULL;
1756 int *splice_pipe;
1757 unsigned int relayd_hang_up = 0;
1758
1759 switch (consumer_data.type) {
1760 case LTTNG_CONSUMER_KERNEL:
1761 break;
1762 case LTTNG_CONSUMER32_UST:
1763 case LTTNG_CONSUMER64_UST:
1764 /* Not supported for user space tracing */
1765 return -ENOSYS;
1766 default:
1767 ERR("Unknown consumer_data type");
1768 assert(0);
1769 }
1770
1771 /* RCU lock for the relayd pointer */
1772 rcu_read_lock();
1773
1774 /* Flag that the current stream if set for network streaming. */
1775 if (stream->net_seq_idx != (uint64_t) -1ULL) {
1776 relayd = consumer_find_relayd(stream->net_seq_idx);
1777 if (relayd == NULL) {
1778 written = -ret;
1779 goto end;
1780 }
1781 }
1782 splice_pipe = stream->splice_pipe;
1783
1784 /* Write metadata stream id before payload */
1785 if (relayd) {
1786 unsigned long total_len = len;
1787
1788 if (stream->metadata_flag) {
1789 /*
1790 * Lock the control socket for the complete duration of the function
1791 * since from this point on we will use the socket.
1792 */
1793 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
1794
1795 if (stream->reset_metadata_flag) {
1796 ret = relayd_reset_metadata(&relayd->control_sock,
1797 stream->relayd_stream_id,
1798 stream->metadata_version);
1799 if (ret < 0) {
1800 relayd_hang_up = 1;
1801 goto write_error;
1802 }
1803 stream->reset_metadata_flag = 0;
1804 }
1805 ret = write_relayd_metadata_id(splice_pipe[1], stream,
1806 padding);
1807 if (ret < 0) {
1808 written = ret;
1809 relayd_hang_up = 1;
1810 goto write_error;
1811 }
1812
1813 total_len += sizeof(struct lttcomm_relayd_metadata_payload);
1814 }
1815
1816 ret = write_relayd_stream_header(stream, total_len, padding, relayd);
1817 if (ret < 0) {
1818 written = ret;
1819 relayd_hang_up = 1;
1820 goto write_error;
1821 }
1822 /* Use the returned socket. */
1823 outfd = ret;
1824 } else {
1825 /* No streaming, we have to set the len with the full padding */
1826 len += padding;
1827
1828 if (stream->metadata_flag && stream->reset_metadata_flag) {
1829 ret = utils_truncate_stream_file(stream->out_fd, 0);
1830 if (ret < 0) {
1831 ERR("Reset metadata file");
1832 goto end;
1833 }
1834 stream->reset_metadata_flag = 0;
1835 }
1836 /*
1837 * Check if we need to change the tracefile before writing the packet.
1838 */
1839 if (stream->chan->tracefile_size > 0 &&
1840 (stream->tracefile_size_current + len) >
1841 stream->chan->tracefile_size) {
1842 ret = utils_rotate_stream_file(stream->chan->pathname,
1843 stream->name, stream->chan->tracefile_size,
1844 stream->chan->tracefile_count, stream->uid, stream->gid,
1845 stream->out_fd, &(stream->tracefile_count_current),
1846 &stream->out_fd);
1847 if (ret < 0) {
1848 written = ret;
1849 ERR("Rotating output file");
1850 goto end;
1851 }
1852 outfd = stream->out_fd;
1853
1854 if (stream->index_file) {
1855 lttng_index_file_put(stream->index_file);
1856 stream->index_file = lttng_index_file_create(stream->chan->pathname,
1857 stream->name, stream->uid, stream->gid,
1858 stream->chan->tracefile_size,
1859 stream->tracefile_count_current,
1860 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
1861 if (!stream->index_file) {
1862 goto end;
1863 }
1864 }
1865
1866 /* Reset current size because we just perform a rotation. */
1867 stream->tracefile_size_current = 0;
1868 stream->out_fd_offset = 0;
1869 orig_offset = 0;
1870 }
1871 stream->tracefile_size_current += len;
1872 index->offset = htobe64(stream->out_fd_offset);
1873 }
1874
1875 while (len > 0) {
1876 DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)",
1877 (unsigned long)offset, len, fd, splice_pipe[1]);
1878 ret_splice = splice(fd, &offset, splice_pipe[1], NULL, len,
1879 SPLICE_F_MOVE | SPLICE_F_MORE);
1880 DBG("splice chan to pipe, ret %zd", ret_splice);
1881 if (ret_splice < 0) {
1882 ret = errno;
1883 written = -ret;
1884 PERROR("Error in relay splice");
1885 goto splice_error;
1886 }
1887
1888 /* Handle stream on the relayd if the output is on the network */
1889 if (relayd && stream->metadata_flag) {
1890 size_t metadata_payload_size =
1891 sizeof(struct lttcomm_relayd_metadata_payload);
1892
1893 /* Update counter to fit the spliced data */
1894 ret_splice += metadata_payload_size;
1895 len += metadata_payload_size;
1896 /*
1897 * We do this so the return value can match the len passed as
1898 * argument to this function.
1899 */
1900 written -= metadata_payload_size;
1901 }
1902
1903 /* Splice data out */
1904 ret_splice = splice(splice_pipe[0], NULL, outfd, NULL,
1905 ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE);
1906 DBG("Consumer splice pipe to file (out_fd: %d), ret %zd",
1907 outfd, ret_splice);
1908 if (ret_splice < 0) {
1909 ret = errno;
1910 written = -ret;
1911 relayd_hang_up = 1;
1912 goto write_error;
1913 } else if (ret_splice > len) {
1914 /*
1915 * We don't expect this code path to be executed but you never know
1916 * so this is an extra protection agains a buggy splice().
1917 */
1918 ret = errno;
1919 written += ret_splice;
1920 PERROR("Wrote more data than requested %zd (len: %lu)", ret_splice,
1921 len);
1922 goto splice_error;
1923 } else {
1924 /* All good, update current len and continue. */
1925 len -= ret_splice;
1926 }
1927
1928 /* This call is useless on a socket so better save a syscall. */
1929 if (!relayd) {
1930 /* This won't block, but will start writeout asynchronously */
1931 lttng_sync_file_range(outfd, stream->out_fd_offset, ret_splice,
1932 SYNC_FILE_RANGE_WRITE);
1933 stream->out_fd_offset += ret_splice;
1934 }
1935 stream->output_written += ret_splice;
1936 written += ret_splice;
1937 }
1938 if (!relayd) {
1939 lttng_consumer_sync_trace_file(stream, orig_offset);
1940 }
1941 goto end;
1942
1943 write_error:
1944 /*
1945 * This is a special case that the relayd has closed its socket. Let's
1946 * cleanup the relayd object and all associated streams.
1947 */
1948 if (relayd && relayd_hang_up) {
1949 cleanup_relayd(relayd, ctx);
1950 /* Skip splice error so the consumer does not fail */
1951 goto end;
1952 }
1953
1954 splice_error:
1955 /* send the appropriate error description to sessiond */
1956 switch (ret) {
1957 case EINVAL:
1958 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EINVAL);
1959 break;
1960 case ENOMEM:
1961 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ENOMEM);
1962 break;
1963 case ESPIPE:
1964 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ESPIPE);
1965 break;
1966 }
1967
1968 end:
1969 if (relayd && stream->metadata_flag) {
1970 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
1971 }
1972
1973 rcu_read_unlock();
1974 return written;
1975 }
1976
1977 /*
1978 * Sample the snapshot positions for a specific fd
1979 *
1980 * Returns 0 on success, < 0 on error
1981 */
1982 int lttng_consumer_sample_snapshot_positions(struct lttng_consumer_stream *stream)
1983 {
1984 switch (consumer_data.type) {
1985 case LTTNG_CONSUMER_KERNEL:
1986 return lttng_kconsumer_sample_snapshot_positions(stream);
1987 case LTTNG_CONSUMER32_UST:
1988 case LTTNG_CONSUMER64_UST:
1989 return lttng_ustconsumer_sample_snapshot_positions(stream);
1990 default:
1991 ERR("Unknown consumer_data type");
1992 assert(0);
1993 return -ENOSYS;
1994 }
1995 }
1996 /*
1997 * Take a snapshot for a specific fd
1998 *
1999 * Returns 0 on success, < 0 on error
2000 */
2001 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream)
2002 {
2003 switch (consumer_data.type) {
2004 case LTTNG_CONSUMER_KERNEL:
2005 return lttng_kconsumer_take_snapshot(stream);
2006 case LTTNG_CONSUMER32_UST:
2007 case LTTNG_CONSUMER64_UST:
2008 return lttng_ustconsumer_take_snapshot(stream);
2009 default:
2010 ERR("Unknown consumer_data type");
2011 assert(0);
2012 return -ENOSYS;
2013 }
2014 }
2015
2016 /*
2017 * Get the produced position
2018 *
2019 * Returns 0 on success, < 0 on error
2020 */
2021 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
2022 unsigned long *pos)
2023 {
2024 switch (consumer_data.type) {
2025 case LTTNG_CONSUMER_KERNEL:
2026 return lttng_kconsumer_get_produced_snapshot(stream, pos);
2027 case LTTNG_CONSUMER32_UST:
2028 case LTTNG_CONSUMER64_UST:
2029 return lttng_ustconsumer_get_produced_snapshot(stream, pos);
2030 default:
2031 ERR("Unknown consumer_data type");
2032 assert(0);
2033 return -ENOSYS;
2034 }
2035 }
2036
2037 /*
2038 * Get the consumed position (free-running counter position in bytes).
2039 *
2040 * Returns 0 on success, < 0 on error
2041 */
2042 int lttng_consumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
2043 unsigned long *pos)
2044 {
2045 switch (consumer_data.type) {
2046 case LTTNG_CONSUMER_KERNEL:
2047 return lttng_kconsumer_get_consumed_snapshot(stream, pos);
2048 case LTTNG_CONSUMER32_UST:
2049 case LTTNG_CONSUMER64_UST:
2050 return lttng_ustconsumer_get_consumed_snapshot(stream, pos);
2051 default:
2052 ERR("Unknown consumer_data type");
2053 assert(0);
2054 return -ENOSYS;
2055 }
2056 }
2057
2058 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
2059 int sock, struct pollfd *consumer_sockpoll)
2060 {
2061 switch (consumer_data.type) {
2062 case LTTNG_CONSUMER_KERNEL:
2063 return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
2064 case LTTNG_CONSUMER32_UST:
2065 case LTTNG_CONSUMER64_UST:
2066 return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
2067 default:
2068 ERR("Unknown consumer_data type");
2069 assert(0);
2070 return -ENOSYS;
2071 }
2072 }
2073
2074 void lttng_consumer_close_all_metadata(void)
2075 {
2076 switch (consumer_data.type) {
2077 case LTTNG_CONSUMER_KERNEL:
2078 /*
2079 * The Kernel consumer has a different metadata scheme so we don't
2080 * close anything because the stream will be closed by the session
2081 * daemon.
2082 */
2083 break;
2084 case LTTNG_CONSUMER32_UST:
2085 case LTTNG_CONSUMER64_UST:
2086 /*
2087 * Close all metadata streams. The metadata hash table is passed and
2088 * this call iterates over it by closing all wakeup fd. This is safe
2089 * because at this point we are sure that the metadata producer is
2090 * either dead or blocked.
2091 */
2092 lttng_ustconsumer_close_all_metadata(metadata_ht);
2093 break;
2094 default:
2095 ERR("Unknown consumer_data type");
2096 assert(0);
2097 }
2098 }
2099
2100 /*
2101 * Clean up a metadata stream and free its memory.
2102 */
2103 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
2104 struct lttng_ht *ht)
2105 {
2106 struct lttng_consumer_channel *free_chan = NULL;
2107
2108 assert(stream);
2109 /*
2110 * This call should NEVER receive regular stream. It must always be
2111 * metadata stream and this is crucial for data structure synchronization.
2112 */
2113 assert(stream->metadata_flag);
2114
2115 DBG3("Consumer delete metadata stream %d", stream->wait_fd);
2116
2117 pthread_mutex_lock(&consumer_data.lock);
2118 pthread_mutex_lock(&stream->chan->lock);
2119 pthread_mutex_lock(&stream->lock);
2120 if (stream->chan->metadata_cache) {
2121 /* Only applicable to userspace consumers. */
2122 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
2123 }
2124
2125 /* Remove any reference to that stream. */
2126 consumer_stream_delete(stream, ht);
2127
2128 /* Close down everything including the relayd if one. */
2129 consumer_stream_close(stream);
2130 /* Destroy tracer buffers of the stream. */
2131 consumer_stream_destroy_buffers(stream);
2132
2133 /* Atomically decrement channel refcount since other threads can use it. */
2134 if (!uatomic_sub_return(&stream->chan->refcount, 1)
2135 && !uatomic_read(&stream->chan->nb_init_stream_left)) {
2136 /* Go for channel deletion! */
2137 free_chan = stream->chan;
2138 }
2139
2140 /*
2141 * Nullify the stream reference so it is not used after deletion. The
2142 * channel lock MUST be acquired before being able to check for a NULL
2143 * pointer value.
2144 */
2145 stream->chan->metadata_stream = NULL;
2146
2147 if (stream->chan->metadata_cache) {
2148 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
2149 }
2150 pthread_mutex_unlock(&stream->lock);
2151 pthread_mutex_unlock(&stream->chan->lock);
2152 pthread_mutex_unlock(&consumer_data.lock);
2153
2154 if (free_chan) {
2155 consumer_del_channel(free_chan);
2156 }
2157
2158 consumer_stream_free(stream);
2159 }
2160
2161 /*
2162 * Action done with the metadata stream when adding it to the consumer internal
2163 * data structures to handle it.
2164 */
2165 void consumer_add_metadata_stream(struct lttng_consumer_stream *stream)
2166 {
2167 struct lttng_ht *ht = metadata_ht;
2168 struct lttng_ht_iter iter;
2169 struct lttng_ht_node_u64 *node;
2170
2171 assert(stream);
2172 assert(ht);
2173
2174 DBG3("Adding metadata stream %" PRIu64 " to hash table", stream->key);
2175
2176 pthread_mutex_lock(&consumer_data.lock);
2177 pthread_mutex_lock(&stream->chan->lock);
2178 pthread_mutex_lock(&stream->chan->timer_lock);
2179 pthread_mutex_lock(&stream->lock);
2180
2181 /*
2182 * From here, refcounts are updated so be _careful_ when returning an error
2183 * after this point.
2184 */
2185
2186 rcu_read_lock();
2187
2188 /*
2189 * Lookup the stream just to make sure it does not exist in our internal
2190 * state. This should NEVER happen.
2191 */
2192 lttng_ht_lookup(ht, &stream->key, &iter);
2193 node = lttng_ht_iter_get_node_u64(&iter);
2194 assert(!node);
2195
2196 /*
2197 * When nb_init_stream_left reaches 0, we don't need to trigger any action
2198 * in terms of destroying the associated channel, because the action that
2199 * causes the count to become 0 also causes a stream to be added. The
2200 * channel deletion will thus be triggered by the following removal of this
2201 * stream.
2202 */
2203 if (uatomic_read(&stream->chan->nb_init_stream_left) > 0) {
2204 /* Increment refcount before decrementing nb_init_stream_left */
2205 cmm_smp_wmb();
2206 uatomic_dec(&stream->chan->nb_init_stream_left);
2207 }
2208
2209 lttng_ht_add_unique_u64(ht, &stream->node);
2210
2211 lttng_ht_add_u64(consumer_data.stream_per_chan_id_ht,
2212 &stream->node_channel_id);
2213
2214 /*
2215 * Add stream to the stream_list_ht of the consumer data. No need to steal
2216 * the key since the HT does not use it and we allow to add redundant keys
2217 * into this table.
2218 */
2219 lttng_ht_add_u64(consumer_data.stream_list_ht, &stream->node_session_id);
2220
2221 rcu_read_unlock();
2222
2223 pthread_mutex_unlock(&stream->lock);
2224 pthread_mutex_unlock(&stream->chan->lock);
2225 pthread_mutex_unlock(&stream->chan->timer_lock);
2226 pthread_mutex_unlock(&consumer_data.lock);
2227 }
2228
2229 /*
2230 * Delete data stream that are flagged for deletion (endpoint_status).
2231 */
2232 static void validate_endpoint_status_data_stream(void)
2233 {
2234 struct lttng_ht_iter iter;
2235 struct lttng_consumer_stream *stream;
2236
2237 DBG("Consumer delete flagged data stream");
2238
2239 rcu_read_lock();
2240 cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) {
2241 /* Validate delete flag of the stream */
2242 if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) {
2243 continue;
2244 }
2245 /* Delete it right now */
2246 consumer_del_stream(stream, data_ht);
2247 }
2248 rcu_read_unlock();
2249 }
2250
2251 /*
2252 * Delete metadata stream that are flagged for deletion (endpoint_status).
2253 */
2254 static void validate_endpoint_status_metadata_stream(
2255 struct lttng_poll_event *pollset)
2256 {
2257 struct lttng_ht_iter iter;
2258 struct lttng_consumer_stream *stream;
2259
2260 DBG("Consumer delete flagged metadata stream");
2261
2262 assert(pollset);
2263
2264 rcu_read_lock();
2265 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) {
2266 /* Validate delete flag of the stream */
2267 if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) {
2268 continue;
2269 }
2270 /*
2271 * Remove from pollset so the metadata thread can continue without
2272 * blocking on a deleted stream.
2273 */
2274 lttng_poll_del(pollset, stream->wait_fd);
2275
2276 /* Delete it right now */
2277 consumer_del_metadata_stream(stream, metadata_ht);
2278 }
2279 rcu_read_unlock();
2280 }
2281
2282 static
2283 int rotate_notify_sessiond(struct lttng_consumer_local_data *ctx,
2284 uint64_t key)
2285 {
2286 ssize_t ret;
2287
2288 do {
2289 ret = write(ctx->channel_rotate_pipe, &key, sizeof(key));
2290 } while (ret == -1 && errno == EINTR);
2291 if (ret == -1) {
2292 PERROR("Failed to write to the channel rotation pipe");
2293 } else {
2294 DBG("Sent channel rotation notification for channel key %"
2295 PRIu64, key);
2296 ret = 0;
2297 }
2298
2299 return (int) ret;
2300 }
2301
2302 /*
2303 * Perform operations that need to be done after a stream has
2304 * rotated and released the stream lock.
2305 *
2306 * Multiple rotations cannot occur simultaneously, so we know the state of the
2307 * "rotated" stream flag cannot change.
2308 *
2309 * This MUST be called WITHOUT the stream lock held.
2310 */
2311 static
2312 int consumer_post_rotation(struct lttng_consumer_stream *stream,
2313 struct lttng_consumer_local_data *ctx)
2314 {
2315 int ret = 0;
2316
2317 pthread_mutex_lock(&stream->chan->lock);
2318
2319 switch (consumer_data.type) {
2320 case LTTNG_CONSUMER_KERNEL:
2321 break;
2322 case LTTNG_CONSUMER32_UST:
2323 case LTTNG_CONSUMER64_UST:
2324 /*
2325 * The ust_metadata_pushed counter has been reset to 0, so now
2326 * we can wakeup the metadata thread so it dumps the metadata
2327 * cache to the new file.
2328 */
2329 if (stream->metadata_flag) {
2330 consumer_metadata_wakeup_pipe(stream->chan);
2331 }
2332 break;
2333 default:
2334 ERR("Unknown consumer_data type");
2335 abort();
2336 }
2337
2338 if (--stream->chan->nr_stream_rotate_pending == 0) {
2339 DBG("Rotation of channel \"%s\" completed, notifying the session daemon",
2340 stream->chan->name);
2341 ret = rotate_notify_sessiond(ctx, stream->chan->key);
2342 }
2343 pthread_mutex_unlock(&stream->chan->lock);
2344
2345 return ret;
2346 }
2347
2348 /*
2349 * Thread polls on metadata file descriptor and write them on disk or on the
2350 * network.
2351 */
2352 void *consumer_thread_metadata_poll(void *data)
2353 {
2354 int ret, i, pollfd, err = -1;
2355 uint32_t revents, nb_fd;
2356 struct lttng_consumer_stream *stream = NULL;
2357 struct lttng_ht_iter iter;
2358 struct lttng_ht_node_u64 *node;
2359 struct lttng_poll_event events;
2360 struct lttng_consumer_local_data *ctx = data;
2361 ssize_t len;
2362
2363 rcu_register_thread();
2364
2365 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_METADATA);
2366
2367 if (testpoint(consumerd_thread_metadata)) {
2368 goto error_testpoint;
2369 }
2370
2371 health_code_update();
2372
2373 DBG("Thread metadata poll started");
2374
2375 /* Size is set to 1 for the consumer_metadata pipe */
2376 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2377 if (ret < 0) {
2378 ERR("Poll set creation failed");
2379 goto end_poll;
2380 }
2381
2382 ret = lttng_poll_add(&events,
2383 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe), LPOLLIN);
2384 if (ret < 0) {
2385 goto end;
2386 }
2387
2388 /* Main loop */
2389 DBG("Metadata main loop started");
2390
2391 while (1) {
2392 restart:
2393 health_code_update();
2394 health_poll_entry();
2395 DBG("Metadata poll wait");
2396 ret = lttng_poll_wait(&events, -1);
2397 DBG("Metadata poll return from wait with %d fd(s)",
2398 LTTNG_POLL_GETNB(&events));
2399 health_poll_exit();
2400 DBG("Metadata event caught in thread");
2401 if (ret < 0) {
2402 if (errno == EINTR) {
2403 ERR("Poll EINTR caught");
2404 goto restart;
2405 }
2406 if (LTTNG_POLL_GETNB(&events) == 0) {
2407 err = 0; /* All is OK */
2408 }
2409 goto end;
2410 }
2411
2412 nb_fd = ret;
2413
2414 /* From here, the event is a metadata wait fd */
2415 for (i = 0; i < nb_fd; i++) {
2416 health_code_update();
2417
2418 revents = LTTNG_POLL_GETEV(&events, i);
2419 pollfd = LTTNG_POLL_GETFD(&events, i);
2420
2421 if (!revents) {
2422 /* No activity for this FD (poll implementation). */
2423 continue;
2424 }
2425
2426 if (pollfd == lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)) {
2427 if (revents & LPOLLIN) {
2428 ssize_t pipe_len;
2429
2430 pipe_len = lttng_pipe_read(ctx->consumer_metadata_pipe,
2431 &stream, sizeof(stream));
2432 if (pipe_len < sizeof(stream)) {
2433 if (pipe_len < 0) {
2434 PERROR("read metadata stream");
2435 }
2436 /*
2437 * Remove the pipe from the poll set and continue the loop
2438 * since their might be data to consume.
2439 */
2440 lttng_poll_del(&events,
2441 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe));
2442 lttng_pipe_read_close(ctx->consumer_metadata_pipe);
2443 continue;
2444 }
2445
2446 /* A NULL stream means that the state has changed. */
2447 if (stream == NULL) {
2448 /* Check for deleted streams. */
2449 validate_endpoint_status_metadata_stream(&events);
2450 goto restart;
2451 }
2452
2453 DBG("Adding metadata stream %d to poll set",
2454 stream->wait_fd);
2455
2456 /* Add metadata stream to the global poll events list */
2457 lttng_poll_add(&events, stream->wait_fd,
2458 LPOLLIN | LPOLLPRI | LPOLLHUP);
2459 } else if (revents & (LPOLLERR | LPOLLHUP)) {
2460 DBG("Metadata thread pipe hung up");
2461 /*
2462 * Remove the pipe from the poll set and continue the loop
2463 * since their might be data to consume.
2464 */
2465 lttng_poll_del(&events,
2466 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe));
2467 lttng_pipe_read_close(ctx->consumer_metadata_pipe);
2468 continue;
2469 } else {
2470 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2471 goto end;
2472 }
2473
2474 /* Handle other stream */
2475 continue;
2476 }
2477
2478 rcu_read_lock();
2479 {
2480 uint64_t tmp_id = (uint64_t) pollfd;
2481
2482 lttng_ht_lookup(metadata_ht, &tmp_id, &iter);
2483 }
2484 node = lttng_ht_iter_get_node_u64(&iter);
2485 assert(node);
2486
2487 stream = caa_container_of(node, struct lttng_consumer_stream,
2488 node);
2489
2490 if (revents & (LPOLLIN | LPOLLPRI)) {
2491 /* Get the data out of the metadata file descriptor */
2492 DBG("Metadata available on fd %d", pollfd);
2493 assert(stream->wait_fd == pollfd);
2494
2495 do {
2496 health_code_update();
2497
2498 len = ctx->on_buffer_ready(stream, ctx);
2499 /*
2500 * We don't check the return value here since if we get
2501 * a negative len, it means an error occurred thus we
2502 * simply remove it from the poll set and free the
2503 * stream.
2504 */
2505 } while (len > 0);
2506
2507 /* It's ok to have an unavailable sub-buffer */
2508 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2509 /* Clean up stream from consumer and free it. */
2510 lttng_poll_del(&events, stream->wait_fd);
2511 consumer_del_metadata_stream(stream, metadata_ht);
2512 }
2513 } else if (revents & (LPOLLERR | LPOLLHUP)) {
2514 DBG("Metadata fd %d is hup|err.", pollfd);
2515 if (!stream->hangup_flush_done
2516 && (consumer_data.type == LTTNG_CONSUMER32_UST
2517 || consumer_data.type == LTTNG_CONSUMER64_UST)) {
2518 DBG("Attempting to flush and consume the UST buffers");
2519 lttng_ustconsumer_on_stream_hangup(stream);
2520
2521 /* We just flushed the stream now read it. */
2522 do {
2523 health_code_update();
2524
2525 len = ctx->on_buffer_ready(stream, ctx);
2526 /*
2527 * We don't check the return value here since if we get
2528 * a negative len, it means an error occurred thus we
2529 * simply remove it from the poll set and free the
2530 * stream.
2531 */
2532 } while (len > 0);
2533 }
2534
2535 lttng_poll_del(&events, stream->wait_fd);
2536 /*
2537 * This call update the channel states, closes file descriptors
2538 * and securely free the stream.
2539 */
2540 consumer_del_metadata_stream(stream, metadata_ht);
2541 } else {
2542 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2543 rcu_read_unlock();
2544 goto end;
2545 }
2546 /* Release RCU lock for the stream looked up */
2547 rcu_read_unlock();
2548 }
2549 }
2550
2551 /* All is OK */
2552 err = 0;
2553 end:
2554 DBG("Metadata poll thread exiting");
2555
2556 lttng_poll_clean(&events);
2557 end_poll:
2558 error_testpoint:
2559 if (err) {
2560 health_error();
2561 ERR("Health error occurred in %s", __func__);
2562 }
2563 health_unregister(health_consumerd);
2564 rcu_unregister_thread();
2565 return NULL;
2566 }
2567
2568 /*
2569 * This thread polls the fds in the set to consume the data and write
2570 * it to tracefile if necessary.
2571 */
2572 void *consumer_thread_data_poll(void *data)
2573 {
2574 int num_rdy, num_hup, high_prio, ret, i, err = -1;
2575 struct pollfd *pollfd = NULL;
2576 /* local view of the streams */
2577 struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL;
2578 /* local view of consumer_data.fds_count */
2579 int nb_fd = 0;
2580 /* 2 for the consumer_data_pipe and wake up pipe */
2581 const int nb_pipes_fd = 2;
2582 /* Number of FDs with CONSUMER_ENDPOINT_INACTIVE but still open. */
2583 int nb_inactive_fd = 0;
2584 struct lttng_consumer_local_data *ctx = data;
2585 ssize_t len;
2586
2587 rcu_register_thread();
2588
2589 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_DATA);
2590
2591 if (testpoint(consumerd_thread_data)) {
2592 goto error_testpoint;
2593 }
2594
2595 health_code_update();
2596
2597 local_stream = zmalloc(sizeof(struct lttng_consumer_stream *));
2598 if (local_stream == NULL) {
2599 PERROR("local_stream malloc");
2600 goto end;
2601 }
2602
2603 while (1) {
2604 health_code_update();
2605
2606 high_prio = 0;
2607 num_hup = 0;
2608
2609 /*
2610 * the fds set has been updated, we need to update our
2611 * local array as well
2612 */
2613 pthread_mutex_lock(&consumer_data.lock);
2614 if (consumer_data.need_update) {
2615 free(pollfd);
2616 pollfd = NULL;
2617
2618 free(local_stream);
2619 local_stream = NULL;
2620
2621 /* Allocate for all fds */
2622 pollfd = zmalloc((consumer_data.stream_count + nb_pipes_fd) * sizeof(struct pollfd));
2623 if (pollfd == NULL) {
2624 PERROR("pollfd malloc");
2625 pthread_mutex_unlock(&consumer_data.lock);
2626 goto end;
2627 }
2628
2629 local_stream = zmalloc((consumer_data.stream_count + nb_pipes_fd) *
2630 sizeof(struct lttng_consumer_stream *));
2631 if (local_stream == NULL) {
2632 PERROR("local_stream malloc");
2633 pthread_mutex_unlock(&consumer_data.lock);
2634 goto end;
2635 }
2636 ret = update_poll_array(ctx, &pollfd, local_stream,
2637 data_ht, &nb_inactive_fd);
2638 if (ret < 0) {
2639 ERR("Error in allocating pollfd or local_outfds");
2640 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
2641 pthread_mutex_unlock(&consumer_data.lock);
2642 goto end;
2643 }
2644 nb_fd = ret;
2645 consumer_data.need_update = 0;
2646 }
2647 pthread_mutex_unlock(&consumer_data.lock);
2648
2649 /* No FDs and consumer_quit, consumer_cleanup the thread */
2650 if (nb_fd == 0 && nb_inactive_fd == 0 &&
2651 CMM_LOAD_SHARED(consumer_quit) == 1) {
2652 err = 0; /* All is OK */
2653 goto end;
2654 }
2655 /* poll on the array of fds */
2656 restart:
2657 DBG("polling on %d fd", nb_fd + nb_pipes_fd);
2658 if (testpoint(consumerd_thread_data_poll)) {
2659 goto end;
2660 }
2661 health_poll_entry();
2662 num_rdy = poll(pollfd, nb_fd + nb_pipes_fd, -1);
2663 health_poll_exit();
2664 DBG("poll num_rdy : %d", num_rdy);
2665 if (num_rdy == -1) {
2666 /*
2667 * Restart interrupted system call.
2668 */
2669 if (errno == EINTR) {
2670 goto restart;
2671 }
2672 PERROR("Poll error");
2673 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
2674 goto end;
2675 } else if (num_rdy == 0) {
2676 DBG("Polling thread timed out");
2677 goto end;
2678 }
2679
2680 if (caa_unlikely(data_consumption_paused)) {
2681 DBG("Data consumption paused, sleeping...");
2682 sleep(1);
2683 goto restart;
2684 }
2685
2686 /*
2687 * If the consumer_data_pipe triggered poll go directly to the
2688 * beginning of the loop to update the array. We want to prioritize
2689 * array update over low-priority reads.
2690 */
2691 if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) {
2692 ssize_t pipe_readlen;
2693
2694 DBG("consumer_data_pipe wake up");
2695 pipe_readlen = lttng_pipe_read(ctx->consumer_data_pipe,
2696 &new_stream, sizeof(new_stream));
2697 if (pipe_readlen < sizeof(new_stream)) {
2698 PERROR("Consumer data pipe");
2699 /* Continue so we can at least handle the current stream(s). */
2700 continue;
2701 }
2702
2703 /*
2704 * If the stream is NULL, just ignore it. It's also possible that
2705 * the sessiond poll thread changed the consumer_quit state and is
2706 * waking us up to test it.
2707 */
2708 if (new_stream == NULL) {
2709 validate_endpoint_status_data_stream();
2710 continue;
2711 }
2712
2713 /* Continue to update the local streams and handle prio ones */
2714 continue;
2715 }
2716
2717 /* Handle wakeup pipe. */
2718 if (pollfd[nb_fd + 1].revents & (POLLIN | POLLPRI)) {
2719 char dummy;
2720 ssize_t pipe_readlen;
2721
2722 pipe_readlen = lttng_pipe_read(ctx->consumer_wakeup_pipe, &dummy,
2723 sizeof(dummy));
2724 if (pipe_readlen < 0) {
2725 PERROR("Consumer data wakeup pipe");
2726 }
2727 /* We've been awakened to handle stream(s). */
2728 ctx->has_wakeup = 0;
2729 }
2730
2731 /* Take care of high priority channels first. */
2732 for (i = 0; i < nb_fd; i++) {
2733 health_code_update();
2734
2735 if (local_stream[i] == NULL) {
2736 continue;
2737 }
2738 if (pollfd[i].revents & POLLPRI) {
2739 DBG("Urgent read on fd %d", pollfd[i].fd);
2740 high_prio = 1;
2741 len = ctx->on_buffer_ready(local_stream[i], ctx);
2742 /* it's ok to have an unavailable sub-buffer */
2743 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2744 /* Clean the stream and free it. */
2745 consumer_del_stream(local_stream[i], data_ht);
2746 local_stream[i] = NULL;
2747 } else if (len > 0) {
2748 local_stream[i]->data_read = 1;
2749 }
2750 }
2751 }
2752
2753 /*
2754 * If we read high prio channel in this loop, try again
2755 * for more high prio data.
2756 */
2757 if (high_prio) {
2758 continue;
2759 }
2760
2761 /* Take care of low priority channels. */
2762 for (i = 0; i < nb_fd; i++) {
2763 health_code_update();
2764
2765 if (local_stream[i] == NULL) {
2766 continue;
2767 }
2768 if ((pollfd[i].revents & POLLIN) ||
2769 local_stream[i]->hangup_flush_done ||
2770 local_stream[i]->has_data) {
2771 DBG("Normal read on fd %d", pollfd[i].fd);
2772 len = ctx->on_buffer_ready(local_stream[i], ctx);
2773 /* it's ok to have an unavailable sub-buffer */
2774 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2775 /* Clean the stream and free it. */
2776 consumer_del_stream(local_stream[i], data_ht);
2777 local_stream[i] = NULL;
2778 } else if (len > 0) {
2779 local_stream[i]->data_read = 1;
2780 }
2781 }
2782 }
2783
2784 /* Handle hangup and errors */
2785 for (i = 0; i < nb_fd; i++) {
2786 health_code_update();
2787
2788 if (local_stream[i] == NULL) {
2789 continue;
2790 }
2791 if (!local_stream[i]->hangup_flush_done
2792 && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL))
2793 && (consumer_data.type == LTTNG_CONSUMER32_UST
2794 || consumer_data.type == LTTNG_CONSUMER64_UST)) {
2795 DBG("fd %d is hup|err|nval. Attempting flush and read.",
2796 pollfd[i].fd);
2797 lttng_ustconsumer_on_stream_hangup(local_stream[i]);
2798 /* Attempt read again, for the data we just flushed. */
2799 local_stream[i]->data_read = 1;
2800 }
2801 /*
2802 * If the poll flag is HUP/ERR/NVAL and we have
2803 * read no data in this pass, we can remove the
2804 * stream from its hash table.
2805 */
2806 if ((pollfd[i].revents & POLLHUP)) {
2807 DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
2808 if (!local_stream[i]->data_read) {
2809 consumer_del_stream(local_stream[i], data_ht);
2810 local_stream[i] = NULL;
2811 num_hup++;
2812 }
2813 } else if (pollfd[i].revents & POLLERR) {
2814 ERR("Error returned in polling fd %d.", pollfd[i].fd);
2815 if (!local_stream[i]->data_read) {
2816 consumer_del_stream(local_stream[i], data_ht);
2817 local_stream[i] = NULL;
2818 num_hup++;
2819 }
2820 } else if (pollfd[i].revents & POLLNVAL) {
2821 ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
2822 if (!local_stream[i]->data_read) {
2823 consumer_del_stream(local_stream[i], data_ht);
2824 local_stream[i] = NULL;
2825 num_hup++;
2826 }
2827 }
2828 if (local_stream[i] != NULL) {
2829 local_stream[i]->data_read = 0;
2830 }
2831 }
2832 }
2833 /* All is OK */
2834 err = 0;
2835 end:
2836 DBG("polling thread exiting");
2837 free(pollfd);
2838 free(local_stream);
2839
2840 /*
2841 * Close the write side of the pipe so epoll_wait() in
2842 * consumer_thread_metadata_poll can catch it. The thread is monitoring the
2843 * read side of the pipe. If we close them both, epoll_wait strangely does
2844 * not return and could create a endless wait period if the pipe is the
2845 * only tracked fd in the poll set. The thread will take care of closing
2846 * the read side.
2847 */
2848 (void) lttng_pipe_write_close(ctx->consumer_metadata_pipe);
2849
2850 error_testpoint:
2851 if (err) {
2852 health_error();
2853 ERR("Health error occurred in %s", __func__);
2854 }
2855 health_unregister(health_consumerd);
2856
2857 rcu_unregister_thread();
2858 return NULL;
2859 }
2860
2861 /*
2862 * Close wake-up end of each stream belonging to the channel. This will
2863 * allow the poll() on the stream read-side to detect when the
2864 * write-side (application) finally closes them.
2865 */
2866 static
2867 void consumer_close_channel_streams(struct lttng_consumer_channel *channel)
2868 {
2869 struct lttng_ht *ht;
2870 struct lttng_consumer_stream *stream;
2871 struct lttng_ht_iter iter;
2872
2873 ht = consumer_data.stream_per_chan_id_ht;
2874
2875 rcu_read_lock();
2876 cds_lfht_for_each_entry_duplicate(ht->ht,
2877 ht->hash_fct(&channel->key, lttng_ht_seed),
2878 ht->match_fct, &channel->key,
2879 &iter.iter, stream, node_channel_id.node) {
2880 /*
2881 * Protect against teardown with mutex.
2882 */
2883 pthread_mutex_lock(&stream->lock);
2884 if (cds_lfht_is_node_deleted(&stream->node.node)) {
2885 goto next;
2886 }
2887 switch (consumer_data.type) {
2888 case LTTNG_CONSUMER_KERNEL:
2889 break;
2890 case LTTNG_CONSUMER32_UST:
2891 case LTTNG_CONSUMER64_UST:
2892 if (stream->metadata_flag) {
2893 /* Safe and protected by the stream lock. */
2894 lttng_ustconsumer_close_metadata(stream->chan);
2895 } else {
2896 /*
2897 * Note: a mutex is taken internally within
2898 * liblttng-ust-ctl to protect timer wakeup_fd
2899 * use from concurrent close.
2900 */
2901 lttng_ustconsumer_close_stream_wakeup(stream);
2902 }
2903 break;
2904 default:
2905 ERR("Unknown consumer_data type");
2906 assert(0);
2907 }
2908 next:
2909 pthread_mutex_unlock(&stream->lock);
2910 }
2911 rcu_read_unlock();
2912 }
2913
2914 static void destroy_channel_ht(struct lttng_ht *ht)
2915 {
2916 struct lttng_ht_iter iter;
2917 struct lttng_consumer_channel *channel;
2918 int ret;
2919
2920 if (ht == NULL) {
2921 return;
2922 }
2923
2924 rcu_read_lock();
2925 cds_lfht_for_each_entry(ht->ht, &iter.iter, channel, wait_fd_node.node) {
2926 ret = lttng_ht_del(ht, &iter);
2927 assert(ret != 0);
2928 }
2929 rcu_read_unlock();
2930
2931 lttng_ht_destroy(ht);
2932 }
2933
2934 /*
2935 * This thread polls the channel fds to detect when they are being
2936 * closed. It closes all related streams if the channel is detected as
2937 * closed. It is currently only used as a shim layer for UST because the
2938 * consumerd needs to keep the per-stream wakeup end of pipes open for
2939 * periodical flush.
2940 */
2941 void *consumer_thread_channel_poll(void *data)
2942 {
2943 int ret, i, pollfd, err = -1;
2944 uint32_t revents, nb_fd;
2945 struct lttng_consumer_channel *chan = NULL;
2946 struct lttng_ht_iter iter;
2947 struct lttng_ht_node_u64 *node;
2948 struct lttng_poll_event events;
2949 struct lttng_consumer_local_data *ctx = data;
2950 struct lttng_ht *channel_ht;
2951
2952 rcu_register_thread();
2953
2954 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_CHANNEL);
2955
2956 if (testpoint(consumerd_thread_channel)) {
2957 goto error_testpoint;
2958 }
2959
2960 health_code_update();
2961
2962 channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2963 if (!channel_ht) {
2964 /* ENOMEM at this point. Better to bail out. */
2965 goto end_ht;
2966 }
2967
2968 DBG("Thread channel poll started");
2969
2970 /* Size is set to 1 for the consumer_channel pipe */
2971 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2972 if (ret < 0) {
2973 ERR("Poll set creation failed");
2974 goto end_poll;
2975 }
2976
2977 ret = lttng_poll_add(&events, ctx->consumer_channel_pipe[0], LPOLLIN);
2978 if (ret < 0) {
2979 goto end;
2980 }
2981
2982 /* Main loop */
2983 DBG("Channel main loop started");
2984
2985 while (1) {
2986 restart:
2987 health_code_update();
2988 DBG("Channel poll wait");
2989 health_poll_entry();
2990 ret = lttng_poll_wait(&events, -1);
2991 DBG("Channel poll return from wait with %d fd(s)",
2992 LTTNG_POLL_GETNB(&events));
2993 health_poll_exit();
2994 DBG("Channel event caught in thread");
2995 if (ret < 0) {
2996 if (errno == EINTR) {
2997 ERR("Poll EINTR caught");
2998 goto restart;
2999 }
3000 if (LTTNG_POLL_GETNB(&events) == 0) {
3001 err = 0; /* All is OK */
3002 }
3003 goto end;
3004 }
3005
3006 nb_fd = ret;
3007
3008 /* From here, the event is a channel wait fd */
3009 for (i = 0; i < nb_fd; i++) {
3010 health_code_update();
3011
3012 revents = LTTNG_POLL_GETEV(&events, i);
3013 pollfd = LTTNG_POLL_GETFD(&events, i);
3014
3015 if (!revents) {
3016 /* No activity for this FD (poll implementation). */
3017 continue;
3018 }
3019
3020 if (pollfd == ctx->consumer_channel_pipe[0]) {
3021 if (revents & LPOLLIN) {
3022 enum consumer_channel_action action;
3023 uint64_t key;
3024
3025 ret = read_channel_pipe(ctx, &chan, &key, &action);
3026 if (ret <= 0) {
3027 if (ret < 0) {
3028 ERR("Error reading channel pipe");
3029 }
3030 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3031 continue;
3032 }
3033
3034 switch (action) {
3035 case CONSUMER_CHANNEL_ADD:
3036 DBG("Adding channel %d to poll set",
3037 chan->wait_fd);
3038
3039 lttng_ht_node_init_u64(&chan->wait_fd_node,
3040 chan->wait_fd);
3041 rcu_read_lock();
3042 lttng_ht_add_unique_u64(channel_ht,
3043 &chan->wait_fd_node);
3044 rcu_read_unlock();
3045 /* Add channel to the global poll events list */
3046 lttng_poll_add(&events, chan->wait_fd,
3047 LPOLLERR | LPOLLHUP);
3048 break;
3049 case CONSUMER_CHANNEL_DEL:
3050 {
3051 /*
3052 * This command should never be called if the channel
3053 * has streams monitored by either the data or metadata
3054 * thread. The consumer only notify this thread with a
3055 * channel del. command if it receives a destroy
3056 * channel command from the session daemon that send it
3057 * if a command prior to the GET_CHANNEL failed.
3058 */
3059
3060 rcu_read_lock();
3061 chan = consumer_find_channel(key);
3062 if (!chan) {
3063 rcu_read_unlock();
3064 ERR("UST consumer get channel key %" PRIu64 " not found for del channel", key);
3065 break;
3066 }
3067 lttng_poll_del(&events, chan->wait_fd);
3068 iter.iter.node = &chan->wait_fd_node.node;
3069 ret = lttng_ht_del(channel_ht, &iter);
3070 assert(ret == 0);
3071
3072 switch (consumer_data.type) {
3073 case LTTNG_CONSUMER_KERNEL:
3074 break;
3075 case LTTNG_CONSUMER32_UST:
3076 case LTTNG_CONSUMER64_UST:
3077 health_code_update();
3078 /* Destroy streams that might have been left in the stream list. */
3079 clean_channel_stream_list(chan);
3080 break;
3081 default:
3082 ERR("Unknown consumer_data type");
3083 assert(0);
3084 }
3085
3086 /*
3087 * Release our own refcount. Force channel deletion even if
3088 * streams were not initialized.
3089 */
3090 if (!uatomic_sub_return(&chan->refcount, 1)) {
3091 consumer_del_channel(chan);
3092 }
3093 rcu_read_unlock();
3094 goto restart;
3095 }
3096 case CONSUMER_CHANNEL_QUIT:
3097 /*
3098 * Remove the pipe from the poll set and continue the loop
3099 * since their might be data to consume.
3100 */
3101 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3102 continue;
3103 default:
3104 ERR("Unknown action");
3105 break;
3106 }
3107 } else if (revents & (LPOLLERR | LPOLLHUP)) {
3108 DBG("Channel thread pipe hung up");
3109 /*
3110 * Remove the pipe from the poll set and continue the loop
3111 * since their might be data to consume.
3112 */
3113 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3114 continue;
3115 } else {
3116 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3117 goto end;
3118 }
3119
3120 /* Handle other stream */
3121 continue;
3122 }
3123
3124 rcu_read_lock();
3125 {
3126 uint64_t tmp_id = (uint64_t) pollfd;
3127
3128 lttng_ht_lookup(channel_ht, &tmp_id, &iter);
3129 }
3130 node = lttng_ht_iter_get_node_u64(&iter);
3131 assert(node);
3132
3133 chan = caa_container_of(node, struct lttng_consumer_channel,
3134 wait_fd_node);
3135
3136 /* Check for error event */
3137 if (revents & (LPOLLERR | LPOLLHUP)) {
3138 DBG("Channel fd %d is hup|err.", pollfd);
3139
3140 lttng_poll_del(&events, chan->wait_fd);
3141 ret = lttng_ht_del(channel_ht, &iter);
3142 assert(ret == 0);
3143
3144 /*
3145 * This will close the wait fd for each stream associated to
3146 * this channel AND monitored by the data/metadata thread thus
3147 * will be clean by the right thread.
3148 */
3149 consumer_close_channel_streams(chan);
3150
3151 /* Release our own refcount */
3152 if (!uatomic_sub_return(&chan->refcount, 1)
3153 && !uatomic_read(&chan->nb_init_stream_left)) {
3154 consumer_del_channel(chan);
3155 }
3156 } else {
3157 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3158 rcu_read_unlock();
3159 goto end;
3160 }
3161
3162 /* Release RCU lock for the channel looked up */
3163 rcu_read_unlock();
3164 }
3165 }
3166
3167 /* All is OK */
3168 err = 0;
3169 end:
3170 lttng_poll_clean(&events);
3171 end_poll:
3172 destroy_channel_ht(channel_ht);
3173 end_ht:
3174 error_testpoint:
3175 DBG("Channel poll thread exiting");
3176 if (err) {
3177 health_error();
3178 ERR("Health error occurred in %s", __func__);
3179 }
3180 health_unregister(health_consumerd);
3181 rcu_unregister_thread();
3182 return NULL;
3183 }
3184
3185 static int set_metadata_socket(struct lttng_consumer_local_data *ctx,
3186 struct pollfd *sockpoll, int client_socket)
3187 {
3188 int ret;
3189
3190 assert(ctx);
3191 assert(sockpoll);
3192
3193 ret = lttng_consumer_poll_socket(sockpoll);
3194 if (ret) {
3195 goto error;
3196 }
3197 DBG("Metadata connection on client_socket");
3198
3199 /* Blocking call, waiting for transmission */
3200 ctx->consumer_metadata_socket = lttcomm_accept_unix_sock(client_socket);
3201 if (ctx->consumer_metadata_socket < 0) {
3202 WARN("On accept metadata");
3203 ret = -1;
3204 goto error;
3205 }
3206 ret = 0;
3207
3208 error:
3209 return ret;
3210 }
3211
3212 /*
3213 * This thread listens on the consumerd socket and receives the file
3214 * descriptors from the session daemon.
3215 */
3216 void *consumer_thread_sessiond_poll(void *data)
3217 {
3218 int sock = -1, client_socket, ret, err = -1;
3219 /*
3220 * structure to poll for incoming data on communication socket avoids
3221 * making blocking sockets.
3222 */
3223 struct pollfd consumer_sockpoll[2];
3224 struct lttng_consumer_local_data *ctx = data;
3225
3226 rcu_register_thread();
3227
3228 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_SESSIOND);
3229
3230 if (testpoint(consumerd_thread_sessiond)) {
3231 goto error_testpoint;
3232 }
3233
3234 health_code_update();
3235
3236 DBG("Creating command socket %s", ctx->consumer_command_sock_path);
3237 unlink(ctx->consumer_command_sock_path);
3238 client_socket = lttcomm_create_unix_sock(ctx->consumer_command_sock_path);
3239 if (client_socket < 0) {
3240 ERR("Cannot create command socket");
3241 goto end;
3242 }
3243
3244 ret = lttcomm_listen_unix_sock(client_socket);
3245 if (ret < 0) {
3246 goto end;
3247 }
3248
3249 DBG("Sending ready command to lttng-sessiond");
3250 ret = lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY);
3251 /* return < 0 on error, but == 0 is not fatal */
3252 if (ret < 0) {
3253 ERR("Error sending ready command to lttng-sessiond");
3254 goto end;
3255 }
3256
3257 /* prepare the FDs to poll : to client socket and the should_quit pipe */
3258 consumer_sockpoll[0].fd = ctx->consumer_should_quit[0];
3259 consumer_sockpoll[0].events = POLLIN | POLLPRI;
3260 consumer_sockpoll[1].fd = client_socket;
3261 consumer_sockpoll[1].events = POLLIN | POLLPRI;
3262
3263 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3264 if (ret) {
3265 if (ret > 0) {
3266 /* should exit */
3267 err = 0;
3268 }
3269 goto end;
3270 }
3271 DBG("Connection on client_socket");
3272
3273 /* Blocking call, waiting for transmission */
3274 sock = lttcomm_accept_unix_sock(client_socket);
3275 if (sock < 0) {
3276 WARN("On accept");
3277 goto end;
3278 }
3279
3280 /*
3281 * Setup metadata socket which is the second socket connection on the
3282 * command unix socket.
3283 */
3284 ret = set_metadata_socket(ctx, consumer_sockpoll, client_socket);
3285 if (ret) {
3286 if (ret > 0) {
3287 /* should exit */
3288 err = 0;
3289 }
3290 goto end;
3291 }
3292
3293 /* This socket is not useful anymore. */
3294 ret = close(client_socket);
3295 if (ret < 0) {
3296 PERROR("close client_socket");
3297 }
3298 client_socket = -1;
3299
3300 /* update the polling structure to poll on the established socket */
3301 consumer_sockpoll[1].fd = sock;
3302 consumer_sockpoll[1].events = POLLIN | POLLPRI;
3303
3304 while (1) {
3305 health_code_update();
3306
3307 health_poll_entry();
3308 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3309 health_poll_exit();
3310 if (ret) {
3311 if (ret > 0) {
3312 /* should exit */
3313 err = 0;
3314 }
3315 goto end;
3316 }
3317 DBG("Incoming command on sock");
3318 ret = lttng_consumer_recv_cmd(ctx, sock, consumer_sockpoll);
3319 if (ret <= 0) {
3320 /*
3321 * This could simply be a session daemon quitting. Don't output
3322 * ERR() here.
3323 */
3324 DBG("Communication interrupted on command socket");
3325 err = 0;
3326 goto end;
3327 }
3328 if (CMM_LOAD_SHARED(consumer_quit)) {
3329 DBG("consumer_thread_receive_fds received quit from signal");
3330 err = 0; /* All is OK */
3331 goto end;
3332 }
3333 DBG("received command on sock");
3334 }
3335 /* All is OK */
3336 err = 0;
3337
3338 end:
3339 DBG("Consumer thread sessiond poll exiting");
3340
3341 /*
3342 * Close metadata streams since the producer is the session daemon which
3343 * just died.
3344 *
3345 * NOTE: for now, this only applies to the UST tracer.
3346 */
3347 lttng_consumer_close_all_metadata();
3348
3349 /*
3350 * when all fds have hung up, the polling thread
3351 * can exit cleanly
3352 */
3353 CMM_STORE_SHARED(consumer_quit, 1);
3354
3355 /*
3356 * Notify the data poll thread to poll back again and test the
3357 * consumer_quit state that we just set so to quit gracefully.
3358 */
3359 notify_thread_lttng_pipe(ctx->consumer_data_pipe);
3360
3361 notify_channel_pipe(ctx, NULL, -1, CONSUMER_CHANNEL_QUIT);
3362
3363 notify_health_quit_pipe(health_quit_pipe);
3364
3365 /* Cleaning up possibly open sockets. */
3366 if (sock >= 0) {
3367 ret = close(sock);
3368 if (ret < 0) {
3369 PERROR("close sock sessiond poll");
3370 }
3371 }
3372 if (client_socket >= 0) {
3373 ret = close(client_socket);
3374 if (ret < 0) {
3375 PERROR("close client_socket sessiond poll");
3376 }
3377 }
3378
3379 error_testpoint:
3380 if (err) {
3381 health_error();
3382 ERR("Health error occurred in %s", __func__);
3383 }
3384 health_unregister(health_consumerd);
3385
3386 rcu_unregister_thread();
3387 return NULL;
3388 }
3389
3390 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
3391 struct lttng_consumer_local_data *ctx)
3392 {
3393 ssize_t ret;
3394 int rotate_ret;
3395 bool rotated = false;
3396
3397 pthread_mutex_lock(&stream->lock);
3398 if (stream->metadata_flag) {
3399 pthread_mutex_lock(&stream->metadata_rdv_lock);
3400 }
3401
3402 switch (consumer_data.type) {
3403 case LTTNG_CONSUMER_KERNEL:
3404 ret = lttng_kconsumer_read_subbuffer(stream, ctx, &rotated);
3405 break;
3406 case LTTNG_CONSUMER32_UST:
3407 case LTTNG_CONSUMER64_UST:
3408 ret = lttng_ustconsumer_read_subbuffer(stream, ctx, &rotated);
3409 break;
3410 default:
3411 ERR("Unknown consumer_data type");
3412 assert(0);
3413 ret = -ENOSYS;
3414 break;
3415 }
3416
3417 if (stream->metadata_flag) {
3418 pthread_cond_broadcast(&stream->metadata_rdv);
3419 pthread_mutex_unlock(&stream->metadata_rdv_lock);
3420 }
3421 pthread_mutex_unlock(&stream->lock);
3422 if (rotated) {
3423 rotate_ret = consumer_post_rotation(stream, ctx);
3424 if (rotate_ret < 0) {
3425 ERR("Failed after a rotation");
3426 ret = -1;
3427 }
3428 }
3429
3430 return ret;
3431 }
3432
3433 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream)
3434 {
3435 switch (consumer_data.type) {
3436 case LTTNG_CONSUMER_KERNEL:
3437 return lttng_kconsumer_on_recv_stream(stream);
3438 case LTTNG_CONSUMER32_UST:
3439 case LTTNG_CONSUMER64_UST:
3440 return lttng_ustconsumer_on_recv_stream(stream);
3441 default:
3442 ERR("Unknown consumer_data type");
3443 assert(0);
3444 return -ENOSYS;
3445 }
3446 }
3447
3448 /*
3449 * Allocate and set consumer data hash tables.
3450 */
3451 int lttng_consumer_init(void)
3452 {
3453 consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3454 if (!consumer_data.channel_ht) {
3455 goto error;
3456 }
3457
3458 consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3459 if (!consumer_data.relayd_ht) {
3460 goto error;
3461 }
3462
3463 consumer_data.stream_list_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3464 if (!consumer_data.stream_list_ht) {
3465 goto error;
3466 }
3467
3468 consumer_data.stream_per_chan_id_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3469 if (!consumer_data.stream_per_chan_id_ht) {
3470 goto error;
3471 }
3472
3473 data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3474 if (!data_ht) {
3475 goto error;
3476 }
3477
3478 metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3479 if (!metadata_ht) {
3480 goto error;
3481 }
3482
3483 return 0;
3484
3485 error:
3486 return -1;
3487 }
3488
3489 /*
3490 * Process the ADD_RELAYD command receive by a consumer.
3491 *
3492 * This will create a relayd socket pair and add it to the relayd hash table.
3493 * The caller MUST acquire a RCU read side lock before calling it.
3494 */
3495 void consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
3496 struct lttng_consumer_local_data *ctx, int sock,
3497 struct pollfd *consumer_sockpoll,
3498 struct lttcomm_relayd_sock *relayd_sock, uint64_t sessiond_id,
3499 uint64_t relayd_session_id)
3500 {
3501 int fd = -1, ret = -1, relayd_created = 0;
3502 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
3503 struct consumer_relayd_sock_pair *relayd = NULL;
3504
3505 assert(ctx);
3506 assert(relayd_sock);
3507
3508 DBG("Consumer adding relayd socket (idx: %" PRIu64 ")", net_seq_idx);
3509
3510 /* Get relayd reference if exists. */
3511 relayd = consumer_find_relayd(net_seq_idx);
3512 if (relayd == NULL) {
3513 assert(sock_type == LTTNG_STREAM_CONTROL);
3514 /* Not found. Allocate one. */
3515 relayd = consumer_allocate_relayd_sock_pair(net_seq_idx);
3516 if (relayd == NULL) {
3517 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3518 goto error;
3519 } else {
3520 relayd->sessiond_session_id = sessiond_id;
3521 relayd_created = 1;
3522 }
3523
3524 /*
3525 * This code path MUST continue to the consumer send status message to
3526 * we can notify the session daemon and continue our work without
3527 * killing everything.
3528 */
3529 } else {
3530 /*
3531 * relayd key should never be found for control socket.
3532 */
3533 assert(sock_type != LTTNG_STREAM_CONTROL);
3534 }
3535
3536 /* First send a status message before receiving the fds. */
3537 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
3538 if (ret < 0) {
3539 /* Somehow, the session daemon is not responding anymore. */
3540 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3541 goto error_nosignal;
3542 }
3543
3544 /* Poll on consumer socket. */
3545 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3546 if (ret) {
3547 /* Needing to exit in the middle of a command: error. */
3548 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
3549 goto error_nosignal;
3550 }
3551
3552 /* Get relayd socket from session daemon */
3553 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
3554 if (ret != sizeof(fd)) {
3555 fd = -1; /* Just in case it gets set with an invalid value. */
3556
3557 /*
3558 * Failing to receive FDs might indicate a major problem such as
3559 * reaching a fd limit during the receive where the kernel returns a
3560 * MSG_CTRUNC and fails to cleanup the fd in the queue. Any case, we
3561 * don't take any chances and stop everything.
3562 *
3563 * XXX: Feature request #558 will fix that and avoid this possible
3564 * issue when reaching the fd limit.
3565 */
3566 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
3567 ret_code = LTTCOMM_CONSUMERD_ERROR_RECV_FD;
3568 goto error;
3569 }
3570
3571 /* Copy socket information and received FD */
3572 switch (sock_type) {
3573 case LTTNG_STREAM_CONTROL:
3574 /* Copy received lttcomm socket */
3575 lttcomm_copy_sock(&relayd->control_sock.sock, &relayd_sock->sock);
3576 ret = lttcomm_create_sock(&relayd->control_sock.sock);
3577 /* Handle create_sock error. */
3578 if (ret < 0) {
3579 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3580 goto error;
3581 }
3582 /*
3583 * Close the socket created internally by
3584 * lttcomm_create_sock, so we can replace it by the one
3585 * received from sessiond.
3586 */
3587 if (close(relayd->control_sock.sock.fd)) {
3588 PERROR("close");
3589 }
3590
3591 /* Assign new file descriptor */
3592 relayd->control_sock.sock.fd = fd;
3593 fd = -1; /* For error path */
3594 /* Assign version values. */
3595 relayd->control_sock.major = relayd_sock->major;
3596 relayd->control_sock.minor = relayd_sock->minor;
3597
3598 relayd->relayd_session_id = relayd_session_id;
3599
3600 break;
3601 case LTTNG_STREAM_DATA:
3602 /* Copy received lttcomm socket */
3603 lttcomm_copy_sock(&relayd->data_sock.sock, &relayd_sock->sock);
3604 ret = lttcomm_create_sock(&relayd->data_sock.sock);
3605 /* Handle create_sock error. */
3606 if (ret < 0) {
3607 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3608 goto error;
3609 }
3610 /*
3611 * Close the socket created internally by
3612 * lttcomm_create_sock, so we can replace it by the one
3613 * received from sessiond.
3614 */
3615 if (close(relayd->data_sock.sock.fd)) {
3616 PERROR("close");
3617 }
3618
3619 /* Assign new file descriptor */
3620 relayd->data_sock.sock.fd = fd;
3621 fd = -1; /* for eventual error paths */
3622 /* Assign version values. */
3623 relayd->data_sock.major = relayd_sock->major;
3624 relayd->data_sock.minor = relayd_sock->minor;
3625 break;
3626 default:
3627 ERR("Unknown relayd socket type (%d)", sock_type);
3628 ret_code = LTTCOMM_CONSUMERD_FATAL;
3629 goto error;
3630 }
3631
3632 DBG("Consumer %s socket created successfully with net idx %" PRIu64 " (fd: %d)",
3633 sock_type == LTTNG_STREAM_CONTROL ? "control" : "data",
3634 relayd->net_seq_idx, fd);
3635
3636 /* We successfully added the socket. Send status back. */
3637 ret = consumer_send_status_msg(sock, ret_code);
3638 if (ret < 0) {
3639 /* Somehow, the session daemon is not responding anymore. */
3640 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3641 goto error_nosignal;
3642 }
3643
3644 /*
3645 * Add relayd socket pair to consumer data hashtable. If object already
3646 * exists or on error, the function gracefully returns.
3647 */
3648 add_relayd(relayd);
3649
3650 /* All good! */
3651 return;
3652
3653 error:
3654 if (consumer_send_status_msg(sock, ret_code) < 0) {
3655 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3656 }
3657
3658 error_nosignal:
3659 /* Close received socket if valid. */
3660 if (fd >= 0) {
3661 if (close(fd)) {
3662 PERROR("close received socket");
3663 }
3664 }
3665
3666 if (relayd_created) {
3667 free(relayd);
3668 }
3669 }
3670
3671 /*
3672 * Try to lock the stream mutex.
3673 *
3674 * On success, 1 is returned else 0 indicating that the mutex is NOT lock.
3675 */
3676 static int stream_try_lock(struct lttng_consumer_stream *stream)
3677 {
3678 int ret;
3679
3680 assert(stream);
3681
3682 /*
3683 * Try to lock the stream mutex. On failure, we know that the stream is
3684 * being used else where hence there is data still being extracted.
3685 */
3686 ret = pthread_mutex_trylock(&stream->lock);
3687 if (ret) {
3688 /* For both EBUSY and EINVAL error, the mutex is NOT locked. */
3689 ret = 0;
3690 goto end;
3691 }
3692
3693 ret = 1;
3694
3695 end:
3696 return ret;
3697 }
3698
3699 /*
3700 * Search for a relayd associated to the session id and return the reference.
3701 *
3702 * A rcu read side lock MUST be acquire before calling this function and locked
3703 * until the relayd object is no longer necessary.
3704 */
3705 static struct consumer_relayd_sock_pair *find_relayd_by_session_id(uint64_t id)
3706 {
3707 struct lttng_ht_iter iter;
3708 struct consumer_relayd_sock_pair *relayd = NULL;
3709
3710 /* Iterate over all relayd since they are indexed by net_seq_idx. */
3711 cds_lfht_for_each_entry(consumer_data.relayd_ht->ht, &iter.iter, relayd,
3712 node.node) {
3713 /*
3714 * Check by sessiond id which is unique here where the relayd session
3715 * id might not be when having multiple relayd.
3716 */
3717 if (relayd->sessiond_session_id == id) {
3718 /* Found the relayd. There can be only one per id. */
3719 goto found;
3720 }
3721 }
3722
3723 return NULL;
3724
3725 found:
3726 return relayd;
3727 }
3728
3729 /*
3730 * Check if for a given session id there is still data needed to be extract
3731 * from the buffers.
3732 *
3733 * Return 1 if data is pending or else 0 meaning ready to be read.
3734 */
3735 int consumer_data_pending(uint64_t id)
3736 {
3737 int ret;
3738 struct lttng_ht_iter iter;
3739 struct lttng_ht *ht;
3740 struct lttng_consumer_stream *stream;
3741 struct consumer_relayd_sock_pair *relayd = NULL;
3742 int (*data_pending)(struct lttng_consumer_stream *);
3743
3744 DBG("Consumer data pending command on session id %" PRIu64, id);
3745
3746 rcu_read_lock();
3747 pthread_mutex_lock(&consumer_data.lock);