64f958233cdc6ccb22ee671a5d5feb51fd6cae67
[lttng-tools.git] / src / bin / lttng-sessiond / rotation-thread.c
1 /*
2 * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <lttng/trigger/trigger.h>
21 #include <common/error.h>
22 #include <common/config/session-config.h>
23 #include <common/defaults.h>
24 #include <common/utils.h>
25 #include <common/futex.h>
26 #include <common/align.h>
27 #include <common/time.h>
28 #include <common/hashtable/utils.h>
29 #include <sys/eventfd.h>
30 #include <sys/stat.h>
31 #include <time.h>
32 #include <signal.h>
33 #include <inttypes.h>
34
35 #include <common/kernel-ctl/kernel-ctl.h>
36 #include <lttng/notification/channel-internal.h>
37 #include <lttng/rotate-internal.h>
38
39 #include "rotation-thread.h"
40 #include "lttng-sessiond.h"
41 #include "health-sessiond.h"
42 #include "rotate.h"
43 #include "cmd.h"
44 #include "session.h"
45 #include "timer.h"
46 #include "notification-thread-commands.h"
47
48 #include <urcu.h>
49 #include <urcu/list.h>
50
51 struct lttng_notification_channel *rotate_notification_channel = NULL;
52
53 struct rotation_thread {
54 struct lttng_poll_event events;
55 };
56
57 struct rotation_thread_job {
58 enum rotation_thread_job_type type;
59 struct ltt_session *session;
60 /* List member in struct rotation_thread_timer_queue. */
61 struct cds_list_head head;
62 };
63
64 /*
65 * The timer thread enqueues jobs and wakes up the rotation thread.
66 * When the rotation thread wakes up, it empties the queue.
67 */
68 struct rotation_thread_timer_queue {
69 struct lttng_pipe *event_pipe;
70 struct cds_list_head list;
71 pthread_mutex_t lock;
72 };
73
74 struct rotation_thread_handle {
75 struct rotation_thread_timer_queue *rotation_timer_queue;
76 /* Access to the notification thread cmd_queue */
77 struct notification_thread_handle *notification_thread_handle;
78 sem_t *notification_thread_ready;
79 };
80
81 static
82 const char *get_job_type_str(enum rotation_thread_job_type job_type)
83 {
84 switch (job_type) {
85 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
86 return "CHECK_PENDING_ROTATION";
87 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
88 return "SCHEDULED_ROTATION";
89 default:
90 abort();
91 }
92 }
93
94 struct rotation_thread_timer_queue *rotation_thread_timer_queue_create(void)
95 {
96 struct rotation_thread_timer_queue *queue = NULL;
97
98 queue = zmalloc(sizeof(*queue));
99 if (!queue) {
100 PERROR("Failed to allocate timer rotate queue");
101 goto end;
102 }
103
104 queue->event_pipe = lttng_pipe_open(FD_CLOEXEC | O_NONBLOCK);
105 CDS_INIT_LIST_HEAD(&queue->list);
106 pthread_mutex_init(&queue->lock, NULL);
107 end:
108 return queue;
109 }
110
111 void log_job_destruction(const struct rotation_thread_job *job)
112 {
113 enum lttng_error_level log_level;
114 const char *job_type_str = get_job_type_str(job->type);
115
116 switch (job->type) {
117 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
118 /*
119 * Not a problem, the scheduled rotation is racing with the teardown
120 * of the daemon. In this case, the rotation will not happen, which
121 * is not a problem (or at least, not important enough to delay
122 * the shutdown of the session daemon).
123 */
124 log_level = PRINT_DBG;
125 break;
126 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
127 /* This is not expected to happen; warn the user. */
128 log_level = PRINT_WARN;
129 break;
130 default:
131 abort();
132 }
133
134 LOG(log_level, "Rotation thread timer queue still contains job of type %s targeting session \"%s\" on destruction",
135 job_type_str, job->session->name);
136 }
137
138 void rotation_thread_timer_queue_destroy(
139 struct rotation_thread_timer_queue *queue)
140 {
141 struct rotation_thread_job *job, *tmp_job;
142
143 if (!queue) {
144 return;
145 }
146
147 lttng_pipe_destroy(queue->event_pipe);
148
149 pthread_mutex_lock(&queue->lock);
150 /* Empty wait queue. */
151 cds_list_for_each_entry_safe(job, tmp_job, &queue->list, head) {
152 log_job_destruction(job);
153 cds_list_del(&job->head);
154 free(job);
155 }
156 pthread_mutex_unlock(&queue->lock);
157 pthread_mutex_destroy(&queue->lock);
158 free(queue);
159 }
160
161 /*
162 * Destroy the thread data previously created by the init function.
163 */
164 void rotation_thread_handle_destroy(
165 struct rotation_thread_handle *handle)
166 {
167 free(handle);
168 }
169
170 struct rotation_thread_handle *rotation_thread_handle_create(
171 struct rotation_thread_timer_queue *rotation_timer_queue,
172 struct notification_thread_handle *notification_thread_handle,
173 sem_t *notification_thread_ready)
174 {
175 struct rotation_thread_handle *handle;
176
177 handle = zmalloc(sizeof(*handle));
178 if (!handle) {
179 goto end;
180 }
181
182 handle->rotation_timer_queue = rotation_timer_queue;
183 handle->notification_thread_handle = notification_thread_handle;
184 handle->notification_thread_ready = notification_thread_ready;
185
186 end:
187 return handle;
188 }
189
190 /*
191 * Called with the rotation_thread_timer_queue lock held.
192 * Return true if the same timer job already exists in the queue, false if not.
193 */
194 static
195 bool timer_job_exists(const struct rotation_thread_timer_queue *queue,
196 enum rotation_thread_job_type job_type,
197 struct ltt_session *session)
198 {
199 bool exists = false;
200 struct rotation_thread_job *job;
201
202 cds_list_for_each_entry(job, &queue->list, head) {
203 if (job->session == session && job->type == job_type) {
204 exists = true;
205 goto end;
206 }
207 }
208 end:
209 return exists;
210 }
211
212 void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
213 enum rotation_thread_job_type job_type,
214 struct ltt_session *session)
215 {
216 int ret;
217 const char * const dummy = "!";
218 struct rotation_thread_job *job = NULL;
219 const char *job_type_str = get_job_type_str(job_type);
220
221 pthread_mutex_lock(&queue->lock);
222 if (timer_job_exists(queue, job_type, session)) {
223 /*
224 * This timer job is already pending, we don't need to add
225 * it.
226 */
227 goto end;
228 }
229
230 job = zmalloc(sizeof(struct rotation_thread_job));
231 if (!job) {
232 PERROR("Failed to allocate rotation thread job of type \"%s\" for session \"%s\"",
233 job_type_str, session->name);
234 goto end;
235 }
236 /* No reason for this to fail as the caller must hold a reference. */
237 (void) session_get(session);
238
239 job->session = session;
240 job->type = job_type;
241 cds_list_add_tail(&job->head, &queue->list);
242
243 ret = lttng_write(lttng_pipe_get_writefd(queue->event_pipe), dummy,
244 1);
245 if (ret < 0) {
246 /*
247 * We do not want to block in the timer handler, the job has
248 * been enqueued in the list, the wakeup pipe is probably full,
249 * the job will be processed when the rotation_thread catches
250 * up.
251 */
252 if (errno == EAGAIN || errno == EWOULDBLOCK) {
253 /*
254 * Not an error, but would be surprising and indicate
255 * that the rotation thread can't keep up with the
256 * current load.
257 */
258 DBG("Wake-up pipe of rotation thread job queue is full");
259 goto end;
260 }
261 PERROR("Failed to wake-up the rotation thread after pushing a job of type \"%s\" for session \"%s\"",
262 job_type_str, session->name);
263 goto end;
264 }
265
266 end:
267 pthread_mutex_unlock(&queue->lock);
268 }
269
270 static
271 int init_poll_set(struct lttng_poll_event *poll_set,
272 struct rotation_thread_handle *handle)
273 {
274 int ret;
275
276 /*
277 * Create pollset with size 2:
278 * - quit pipe,
279 * - rotation thread timer queue pipe,
280 */
281 ret = sessiond_set_thread_pollset(poll_set, 2);
282 if (ret) {
283 goto error;
284 }
285 ret = lttng_poll_add(poll_set,
286 lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe),
287 LPOLLIN | LPOLLERR);
288 if (ret < 0) {
289 ERR("[rotation-thread] Failed to add rotate_pending fd to pollset");
290 goto error;
291 }
292
293 return ret;
294 error:
295 lttng_poll_clean(poll_set);
296 return ret;
297 }
298
299 static
300 void fini_thread_state(struct rotation_thread *state)
301 {
302 lttng_poll_clean(&state->events);
303 if (rotate_notification_channel) {
304 lttng_notification_channel_destroy(rotate_notification_channel);
305 }
306 }
307
308 static
309 int init_thread_state(struct rotation_thread_handle *handle,
310 struct rotation_thread *state)
311 {
312 int ret;
313
314 memset(state, 0, sizeof(*state));
315 lttng_poll_init(&state->events);
316
317 ret = init_poll_set(&state->events, handle);
318 if (ret) {
319 ERR("[rotation-thread] Failed to initialize rotation thread poll set");
320 goto end;
321 }
322
323 /*
324 * We wait until the notification thread is ready to create the
325 * notification channel and add it to the poll_set.
326 */
327 sem_wait(handle->notification_thread_ready);
328 rotate_notification_channel = lttng_notification_channel_create(
329 lttng_session_daemon_notification_endpoint);
330 if (!rotate_notification_channel) {
331 ERR("[rotation-thread] Could not create notification channel");
332 ret = -1;
333 goto end;
334 }
335 ret = lttng_poll_add(&state->events, rotate_notification_channel->socket,
336 LPOLLIN | LPOLLERR);
337 if (ret < 0) {
338 ERR("[rotation-thread] Failed to add notification fd to pollset");
339 goto end;
340 }
341
342 end:
343 return ret;
344 }
345
346 static
347 int check_session_rotation_pending_local_on_consumer(
348 const struct ltt_session *session,
349 struct consumer_socket *socket, bool *rotation_completed)
350 {
351 int ret;
352
353 pthread_mutex_lock(socket->lock);
354 DBG("[rotation-thread] Checking for locally pending rotation on the %s consumer for session %s",
355 lttng_consumer_type_str(socket->type),
356 session->name);
357 ret = consumer_check_rotation_pending_local(socket,
358 session->id,
359 session->current_archive_id - 1);
360 pthread_mutex_unlock(socket->lock);
361
362 if (ret == 0) {
363 /* Rotation was completed on this consumer. */
364 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" was completed on the %s consumer",
365 session->current_archive_id - 1,
366 session->name,
367 lttng_consumer_type_str(socket->type));
368 *rotation_completed = true;
369 } else if (ret == 1) {
370 /* Rotation pending on this consumer. */
371 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
372 session->current_archive_id - 1,
373 session->name,
374 lttng_consumer_type_str(socket->type));
375 *rotation_completed = false;
376 ret = 0;
377 } else {
378 /* Not a fatal error. */
379 ERR("[rotation-thread] Encountered an error when checking if local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
380 session->current_archive_id - 1,
381 session->name,
382 lttng_consumer_type_str(socket->type));
383 *rotation_completed = false;
384 }
385 return ret;
386 }
387
388 static
389 int check_session_rotation_pending_local(struct ltt_session *session)
390 {
391 int ret = 0;
392 struct consumer_socket *socket;
393 struct cds_lfht_iter iter;
394 bool rotation_completed = true;
395
396 /*
397 * Check for a local pending rotation on all consumers (32-bit
398 * user space, 64-bit user space, and kernel).
399 */
400 DBG("[rotation-thread] Checking for pending local rotation on session \"%s\", trace archive %" PRIu64,
401 session->name, session->current_archive_id - 1);
402
403 rcu_read_lock();
404 if (!session->ust_session) {
405 goto skip_ust;
406 }
407 cds_lfht_for_each_entry(session->ust_session->consumer->socks->ht,
408 &iter, socket, node.node) {
409 ret = check_session_rotation_pending_local_on_consumer(session,
410 socket, &rotation_completed);
411 if (ret || !rotation_completed) {
412 goto end;
413 }
414 }
415
416 skip_ust:
417 if (!session->kernel_session) {
418 goto skip_kernel;
419 }
420 cds_lfht_for_each_entry(session->kernel_session->consumer->socks->ht,
421 &iter, socket, node.node) {
422 ret = check_session_rotation_pending_local_on_consumer(session,
423 socket, &rotation_completed);
424 if (ret || !rotation_completed) {
425 goto end;
426 }
427 }
428 skip_kernel:
429 end:
430 rcu_read_unlock();
431
432 if (rotation_completed) {
433 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is complete on all consumers",
434 session->current_archive_id - 1,
435 session->name);
436 session->rotation_pending_local = false;
437 }
438 if (ret) {
439 ret = session_reset_rotation_state(session,
440 LTTNG_ROTATION_STATE_ERROR);
441 if (ret) {
442 ERR("Failed to reset rotation state of session \"%s\"",
443 session->name);
444 }
445 }
446 return 0;
447 }
448
449 static
450 int check_session_rotation_pending_relay(struct ltt_session *session)
451 {
452 int ret;
453 struct consumer_socket *socket;
454 struct cds_lfht_iter iter;
455 bool rotation_completed = true;
456 const struct consumer_output *output;
457
458 /*
459 * Check for a pending rotation on any consumer as we only use
460 * it as a "tunnel" to the relayd.
461 */
462
463 rcu_read_lock();
464 if (session->ust_session) {
465 cds_lfht_first(session->ust_session->consumer->socks->ht,
466 &iter);
467 output = session->ust_session->consumer;
468 } else {
469 cds_lfht_first(session->kernel_session->consumer->socks->ht,
470 &iter);
471 output = session->kernel_session->consumer;
472 }
473 assert(cds_lfht_iter_get_node(&iter));
474
475 socket = caa_container_of(cds_lfht_iter_get_node(&iter),
476 typeof(*socket), node.node);
477
478 pthread_mutex_lock(socket->lock);
479 DBG("[rotation-thread] Checking for pending relay rotation on session \"%s\", trace archive %" PRIu64 " through the %s consumer",
480 session->name, session->current_archive_id - 1,
481 lttng_consumer_type_str(socket->type));
482 ret = consumer_check_rotation_pending_relay(socket,
483 output,
484 session->id,
485 session->current_archive_id - 1);
486 pthread_mutex_unlock(socket->lock);
487
488 if (ret == 0) {
489 /* Rotation was completed on the relay. */
490 DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" was completed",
491 session->current_archive_id - 1,
492 session->name);
493 } else if (ret == 1) {
494 /* Rotation pending on relay. */
495 DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" is pending",
496 session->current_archive_id - 1,
497 session->name);
498 rotation_completed = false;
499 } else {
500 /* Not a fatal error. */
501 ERR("[rotation-thread] Encountered an error when checking if rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the relay",
502 session->current_archive_id - 1,
503 session->name);
504 ret = session_reset_rotation_state(session,
505 LTTNG_ROTATION_STATE_ERROR);
506 if (ret) {
507 ERR("Failed to reset rotation state of session \"%s\"",
508 session->name);
509 }
510 rotation_completed = false;
511 }
512
513 rcu_read_unlock();
514
515 if (rotation_completed) {
516 DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " of session \"%s\" is complete on the relay",
517 session->current_archive_id - 1,
518 session->name);
519 session->rotation_pending_relay = false;
520 }
521 return 0;
522 }
523
524 /*
525 * Check if the last rotation was completed, called with session lock held.
526 */
527 static
528 int check_session_rotation_pending(struct ltt_session *session,
529 struct notification_thread_handle *notification_thread_handle)
530 {
531 int ret;
532 struct lttng_trace_archive_location *location;
533 time_t now;
534
535 DBG("[rotation-thread] Checking for pending rotation on session \"%s\", trace archive %" PRIu64,
536 session->name, session->current_archive_id - 1);
537
538 if (session->rotation_pending_local) {
539 /* Updates session->rotation_pending_local as needed. */
540 ret = check_session_rotation_pending_local(session);
541 if (ret) {
542 goto end;
543 }
544
545 /*
546 * No need to check for a pending rotation on the relay
547 * since the rotation is not even completed locally yet.
548 */
549 if (session->rotation_pending_local) {
550 goto end;
551 }
552 }
553
554 if (session->rotation_pending_relay) {
555 /* Updates session->rotation_pending_relay as needed. */
556 ret = check_session_rotation_pending_relay(session);
557 if (ret) {
558 goto end;
559 }
560
561 if (session->rotation_pending_relay) {
562 goto end;
563 }
564 }
565
566 DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " completed for "
567 "session %s", session->current_archive_id - 1,
568 session->name);
569
570 /* Rename the completed trace archive's location. */
571 now = time(NULL);
572 if (now == (time_t) -1) {
573 ret = session_reset_rotation_state(session,
574 LTTNG_ROTATION_STATE_ERROR);
575 if (ret) {
576 ERR("Failed to reset rotation state of session \"%s\"",
577 session->name);
578 }
579 ret = LTTNG_ERR_UNK;
580 goto end;
581 }
582
583 ret = rename_completed_chunk(session, now);
584 if (ret < 0) {
585 ERR("Failed to rename completed rotation chunk");
586 goto end;
587 }
588 session->last_chunk_start_ts = session->current_chunk_start_ts;
589
590 /*
591 * Now we can clear the "ONGOING" state in the session. New
592 * rotations can start now.
593 */
594 session->rotation_state = LTTNG_ROTATION_STATE_COMPLETED;
595
596 /* Ownership of location is transferred. */
597 location = session_get_trace_archive_location(session);
598 ret = notification_thread_command_session_rotation_completed(
599 notification_thread_handle,
600 session->name,
601 session->uid,
602 session->gid,
603 session->current_archive_id,
604 location);
605 if (ret != LTTNG_OK) {
606 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
607 session->name);
608 }
609
610 if (!session->active) {
611 /*
612 * A stop command was issued during the rotation, it is
613 * up to the rotation completion check to perform the
614 * renaming of the last chunk that was produced.
615 */
616 ret = notification_thread_command_session_rotation_ongoing(
617 notification_thread_handle,
618 session->name,
619 session->uid,
620 session->gid,
621 session->current_archive_id);
622 if (ret != LTTNG_OK) {
623 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
624 session->name);
625 }
626
627 ret = rename_active_chunk(session);
628 if (ret < 0) {
629 ERR("[rotation-thread] Failed to rename active rotation chunk");
630 goto end;
631 }
632
633 /* Ownership of location is transferred. */
634 location = session_get_trace_archive_location(session);
635 ret = notification_thread_command_session_rotation_completed(
636 notification_thread_handle,
637 session->name,
638 session->uid,
639 session->gid,
640 session->current_archive_id,
641 location);
642 if (ret != LTTNG_OK) {
643 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
644 session->name);
645 }
646 }
647
648 ret = 0;
649 end:
650 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
651 DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " is still pending for session %s",
652 session->current_archive_id - 1, session->name);
653 ret = timer_session_rotation_pending_check_start(session,
654 DEFAULT_ROTATE_PENDING_TIMER);
655 if (ret) {
656 ERR("Re-enabling rotate pending timer");
657 ret = -1;
658 goto end;
659 }
660 }
661
662 return ret;
663 }
664
665 /* Call with the session and session_list locks held. */
666 static
667 int launch_session_rotation(struct ltt_session *session)
668 {
669 int ret;
670 struct lttng_rotate_session_return rotation_return;
671
672 DBG("[rotation-thread] Launching scheduled time-based rotation on session \"%s\"",
673 session->name);
674
675 ret = cmd_rotate_session(session, &rotation_return);
676 if (ret == LTTNG_OK) {
677 DBG("[rotation-thread] Scheduled time-based rotation successfully launched on session \"%s\"",
678 session->name);
679 } else {
680 /* Don't consider errors as fatal. */
681 DBG("[rotation-thread] Scheduled time-based rotation aborted for session %s: %s",
682 session->name, lttng_strerror(ret));
683 }
684 return 0;
685 }
686
687 static
688 int run_job(struct rotation_thread_job *job, struct ltt_session *session,
689 struct notification_thread_handle *notification_thread_handle)
690 {
691 int ret;
692
693 switch (job->type) {
694 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
695 ret = launch_session_rotation(session);
696 break;
697 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
698 ret = check_session_rotation_pending(session,
699 notification_thread_handle);
700 break;
701 default:
702 abort();
703 }
704 return ret;
705 }
706
707 static
708 int handle_job_queue(struct rotation_thread_handle *handle,
709 struct rotation_thread *state,
710 struct rotation_thread_timer_queue *queue)
711 {
712 int ret = 0;
713 int fd = lttng_pipe_get_readfd(queue->event_pipe);
714 char buf;
715
716 ret = lttng_read(fd, &buf, 1);
717 if (ret != 1) {
718 ERR("[rotation-thread] Failed to read from wakeup pipe (fd = %i)", fd);
719 ret = -1;
720 goto end;
721 }
722
723 for (;;) {
724 struct ltt_session *session;
725 struct rotation_thread_job *job;
726
727 /* Take the queue lock only to pop an element from the list. */
728 pthread_mutex_lock(&queue->lock);
729 if (cds_list_empty(&queue->list)) {
730 pthread_mutex_unlock(&queue->lock);
731 break;
732 }
733 job = cds_list_first_entry(&queue->list,
734 typeof(*job), head);
735 cds_list_del(&job->head);
736 pthread_mutex_unlock(&queue->lock);
737
738 session_lock_list();
739 session = job->session;
740 if (!session) {
741 DBG("[rotation-thread] Session \"%s\" not found",
742 session->name);
743 /*
744 * This is a non-fatal error, and we cannot report it to
745 * the user (timer), so just print the error and
746 * continue the processing.
747 *
748 * While the timer thread will purge pending signals for
749 * a session on the session's destruction, it is
750 * possible for a job targeting that session to have
751 * already been queued before it was destroyed.
752 */
753 session_unlock_list();
754 free(job);
755 session_put(session);
756 continue;
757 }
758
759 session_lock(session);
760 ret = run_job(job, session, handle->notification_thread_handle);
761 session_unlock(session);
762 session_put(session);
763 session_unlock_list();
764 free(job);
765 if (ret) {
766 goto end;
767 }
768 }
769
770 ret = 0;
771
772 end:
773 return ret;
774 }
775
776 static
777 int handle_condition(const struct lttng_condition *condition,
778 const struct lttng_evaluation *evaluation,
779 struct notification_thread_handle *notification_thread_handle)
780 {
781 int ret = 0;
782 const char *condition_session_name = NULL;
783 enum lttng_condition_type condition_type;
784 enum lttng_condition_status condition_status;
785 enum lttng_evaluation_status evaluation_status;
786 uint64_t consumed;
787 struct ltt_session *session;
788
789 condition_type = lttng_condition_get_type(condition);
790
791 if (condition_type != LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE) {
792 ret = -1;
793 ERR("[rotation-thread] Condition type and session usage type are not the same");
794 goto end;
795 }
796
797 /* Fetch info to test */
798 condition_status = lttng_condition_session_consumed_size_get_session_name(
799 condition, &condition_session_name);
800 if (condition_status != LTTNG_CONDITION_STATUS_OK) {
801 ERR("[rotation-thread] Session name could not be fetched");
802 ret = -1;
803 goto end;
804 }
805 evaluation_status = lttng_evaluation_session_consumed_size_get_consumed_size(evaluation,
806 &consumed);
807 if (evaluation_status != LTTNG_EVALUATION_STATUS_OK) {
808 ERR("[rotation-thread] Failed to get evaluation");
809 ret = -1;
810 goto end;
811 }
812
813 session_lock_list();
814 session = session_find_by_name(condition_session_name);
815 if (!session) {
816 ret = -1;
817 session_unlock_list();
818 ERR("[rotation-thread] Session \"%s\" not found",
819 condition_session_name);
820 goto end;
821 }
822 session_lock(session);
823 session_unlock_list();
824
825 ret = unsubscribe_session_consumed_size_rotation(session,
826 notification_thread_handle);
827 if (ret) {
828 goto end_unlock;
829 }
830
831 ret = cmd_rotate_session(session, NULL);
832 if (ret == -LTTNG_ERR_ROTATION_PENDING) {
833 DBG("Rotate already pending, subscribe to the next threshold value");
834 } else if (ret != LTTNG_OK) {
835 ERR("[rotation-thread] Failed to rotate on size notification with error: %s",
836 lttng_strerror(ret));
837 ret = -1;
838 goto end_unlock;
839 }
840 ret = subscribe_session_consumed_size_rotation(session,
841 consumed + session->rotate_size,
842 notification_thread_handle);
843 if (ret) {
844 ERR("[rotation-thread] Failed to subscribe to session consumed size condition");
845 goto end_unlock;
846 }
847 ret = 0;
848
849 end_unlock:
850 session_unlock(session);
851 session_put(session);
852 end:
853 return ret;
854 }
855
856 static
857 int handle_notification_channel(int fd,
858 struct rotation_thread_handle *handle,
859 struct rotation_thread *state)
860 {
861 int ret;
862 bool notification_pending;
863 struct lttng_notification *notification = NULL;
864 enum lttng_notification_channel_status status;
865 const struct lttng_evaluation *notification_evaluation;
866 const struct lttng_condition *notification_condition;
867
868 status = lttng_notification_channel_has_pending_notification(
869 rotate_notification_channel, &notification_pending);
870 if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
871 ERR("[rotation-thread ]Error occurred while checking for pending notification");
872 ret = -1;
873 goto end;
874 }
875
876 if (!notification_pending) {
877 ret = 0;
878 goto end;
879 }
880
881 /* Receive the next notification. */
882 status = lttng_notification_channel_get_next_notification(
883 rotate_notification_channel,
884 &notification);
885
886 switch (status) {
887 case LTTNG_NOTIFICATION_CHANNEL_STATUS_OK:
888 break;
889 case LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED:
890 /* Not an error, we will wait for the next one */
891 ret = 0;
892 goto end;;
893 case LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED:
894 ERR("Notification channel was closed");
895 ret = -1;
896 goto end;
897 default:
898 /* Unhandled conditions / errors. */
899 ERR("Unknown notification channel status");
900 ret = -1;
901 goto end;
902 }
903
904 notification_condition = lttng_notification_get_condition(notification);
905 notification_evaluation = lttng_notification_get_evaluation(notification);
906
907 ret = handle_condition(notification_condition, notification_evaluation,
908 handle->notification_thread_handle);
909
910 end:
911 lttng_notification_destroy(notification);
912 return ret;
913 }
914
915 void *thread_rotation(void *data)
916 {
917 int ret;
918 struct rotation_thread_handle *handle = data;
919 struct rotation_thread thread;
920
921 DBG("[rotation-thread] Started rotation thread");
922
923 if (!handle) {
924 ERR("[rotation-thread] Invalid thread context provided");
925 goto end;
926 }
927
928 rcu_register_thread();
929 rcu_thread_online();
930
931 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
932 health_code_update();
933
934 ret = init_thread_state(handle, &thread);
935 if (ret) {
936 goto error;
937 }
938
939 /* Ready to handle client connections. */
940 sessiond_notify_ready();
941
942 while (true) {
943 int fd_count, i;
944
945 health_poll_entry();
946 DBG("[rotation-thread] Entering poll wait");
947 ret = lttng_poll_wait(&thread.events, -1);
948 DBG("[rotation-thread] Poll wait returned (%i)", ret);
949 health_poll_exit();
950 if (ret < 0) {
951 /*
952 * Restart interrupted system call.
953 */
954 if (errno == EINTR) {
955 continue;
956 }
957 ERR("[rotation-thread] Error encountered during lttng_poll_wait (%i)", ret);
958 goto error;
959 }
960
961 fd_count = ret;
962 for (i = 0; i < fd_count; i++) {
963 int fd = LTTNG_POLL_GETFD(&thread.events, i);
964 uint32_t revents = LTTNG_POLL_GETEV(&thread.events, i);
965
966 DBG("[rotation-thread] Handling fd (%i) activity (%u)",
967 fd, revents);
968
969 if (revents & LPOLLERR) {
970 ERR("[rotation-thread] Polling returned an error on fd %i", fd);
971 goto error;
972 }
973
974 if (sessiond_check_thread_quit_pipe(fd, revents)) {
975 DBG("[rotation-thread] Quit pipe activity");
976 /* TODO flush the queue. */
977 goto exit;
978 } else if (fd == lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe)) {
979 ret = handle_job_queue(handle, &thread,
980 handle->rotation_timer_queue);
981 if (ret) {
982 ERR("[rotation-thread] Failed to handle rotation timer pipe event");
983 goto error;
984 }
985 } else if (fd == rotate_notification_channel->socket) {
986 ret = handle_notification_channel(fd, handle,
987 &thread);
988 if (ret) {
989 ERR("[rotation-thread] Error occurred while handling activity on notification channel socket");
990 goto error;
991 }
992 }
993 }
994 }
995 exit:
996 error:
997 DBG("[rotation-thread] Exit");
998 fini_thread_state(&thread);
999 health_unregister(health_sessiond);
1000 rcu_thread_offline();
1001 rcu_unregister_thread();
1002 end:
1003 return NULL;
1004 }
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