2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <common/common.h>
27 #include <common/index/index.h>
28 #include <common/kernel-consumer/kernel-consumer.h>
29 #include <common/relayd/relayd.h>
30 #include <common/ust-consumer/ust-consumer.h>
32 #include "consumer-stream.h"
35 * RCU call to free stream. MUST only be used with call_rcu().
37 static void free_stream_rcu(struct rcu_head
*head
)
39 struct lttng_ht_node_u64
*node
=
40 caa_container_of(head
, struct lttng_ht_node_u64
, head
);
41 struct lttng_consumer_stream
*stream
=
42 caa_container_of(node
, struct lttng_consumer_stream
, node
);
44 pthread_mutex_destroy(&stream
->lock
);
49 * Close stream on the relayd side. This call can destroy a relayd if the
52 * A RCU read side lock MUST be acquired if the relayd object was looked up in
53 * a hash table before calling this.
55 void consumer_stream_relayd_close(struct lttng_consumer_stream
*stream
,
56 struct consumer_relayd_sock_pair
*relayd
)
63 if (stream
->sent_to_relayd
) {
64 uatomic_dec(&relayd
->refcount
);
65 assert(uatomic_read(&relayd
->refcount
) >= 0);
68 /* Closing streams requires to lock the control socket. */
69 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
70 ret
= relayd_send_close_stream(&relayd
->control_sock
,
71 stream
->relayd_stream_id
,
72 stream
->next_net_seq_num
- 1);
73 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
75 DBG("Unable to close stream on the relayd. Continuing");
77 * Continue here. There is nothing we can do for the relayd.
78 * Chances are that the relayd has closed the socket so we just
79 * continue cleaning up.
83 /* Both conditions are met, we destroy the relayd. */
84 if (uatomic_read(&relayd
->refcount
) == 0 &&
85 uatomic_read(&relayd
->destroy_flag
)) {
86 consumer_destroy_relayd(relayd
);
88 stream
->net_seq_idx
= (uint64_t) -1ULL;
89 stream
->sent_to_relayd
= 0;
93 * Close stream's file descriptors and, if needed, close stream also on the
96 * The consumer data lock MUST be acquired.
97 * The stream lock MUST be acquired.
99 void consumer_stream_close(struct lttng_consumer_stream
*stream
)
102 struct consumer_relayd_sock_pair
*relayd
;
106 switch (consumer_data
.type
) {
107 case LTTNG_CONSUMER_KERNEL
:
108 if (stream
->mmap_base
!= NULL
) {
109 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
115 if (stream
->wait_fd
>= 0) {
116 ret
= close(stream
->wait_fd
);
120 stream
->wait_fd
= -1;
123 case LTTNG_CONSUMER32_UST
:
124 case LTTNG_CONSUMER64_UST
:
127 * Special case for the metadata since the wait fd is an internal pipe
128 * polled in the metadata thread.
130 if (stream
->metadata_flag
&& stream
->chan
->monitor
) {
131 int rpipe
= stream
->ust_metadata_poll_pipe
[0];
134 * This will stop the channel timer if one and close the write side
135 * of the metadata poll pipe.
137 lttng_ustconsumer_close_metadata(stream
->chan
);
141 PERROR("closing metadata pipe read side");
143 stream
->ust_metadata_poll_pipe
[0] = -1;
149 ERR("Unknown consumer_data type");
153 /* Close output fd. Could be a socket or local file at this point. */
154 if (stream
->out_fd
>= 0) {
155 ret
= close(stream
->out_fd
);
162 if (stream
->index_fd
>= 0) {
163 ret
= close(stream
->index_fd
);
165 PERROR("close stream index_fd");
167 stream
->index_fd
= -1;
170 /* Check and cleanup relayd if needed. */
172 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
173 if (relayd
!= NULL
) {
174 consumer_stream_relayd_close(stream
, relayd
);
180 * Delete the stream from all possible hash tables.
182 * The consumer data lock MUST be acquired.
183 * The stream lock MUST be acquired.
185 void consumer_stream_delete(struct lttng_consumer_stream
*stream
,
189 struct lttng_ht_iter iter
;
192 /* Should NEVER be called not in monitor mode. */
193 assert(stream
->chan
->monitor
);
198 iter
.iter
.node
= &stream
->node
.node
;
199 ret
= lttng_ht_del(ht
, &iter
);
203 /* Delete from stream per channel ID hash table. */
204 iter
.iter
.node
= &stream
->node_channel_id
.node
;
206 * The returned value is of no importance. Even if the node is NOT in the
207 * hash table, we continue since we may have been called by a code path
208 * that did not add the stream to a (all) hash table. Same goes for the
209 * next call ht del call.
211 (void) lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
213 /* Delete from the global stream list. */
214 iter
.iter
.node
= &stream
->node_session_id
.node
;
215 /* See the previous ht del on why we ignore the returned value. */
216 (void) lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
220 if (!stream
->metadata_flag
) {
221 /* Decrement the stream count of the global consumer data. */
222 assert(consumer_data
.stream_count
> 0);
223 consumer_data
.stream_count
--;
228 * Free the given stream within a RCU call.
230 void consumer_stream_free(struct lttng_consumer_stream
*stream
)
234 call_rcu(&stream
->node
.head
, free_stream_rcu
);
238 * Destroy the stream's buffers of the tracer.
240 void consumer_stream_destroy_buffers(struct lttng_consumer_stream
*stream
)
244 switch (consumer_data
.type
) {
245 case LTTNG_CONSUMER_KERNEL
:
247 case LTTNG_CONSUMER32_UST
:
248 case LTTNG_CONSUMER64_UST
:
249 lttng_ustconsumer_del_stream(stream
);
252 ERR("Unknown consumer_data type");
258 * Destroy and close a already created stream.
260 static void destroy_close_stream(struct lttng_consumer_stream
*stream
)
264 DBG("Consumer stream destroy monitored key: %" PRIu64
, stream
->key
);
266 /* Destroy tracer buffers of the stream. */
267 consumer_stream_destroy_buffers(stream
);
268 /* Close down everything including the relayd if one. */
269 consumer_stream_close(stream
);
273 * Decrement the stream's channel refcount and if down to 0, return the channel
274 * pointer so it can be destroyed by the caller or NULL if not.
276 static struct lttng_consumer_channel
*unref_channel(
277 struct lttng_consumer_stream
*stream
)
279 struct lttng_consumer_channel
*free_chan
= NULL
;
282 assert(stream
->chan
);
284 /* Update refcount of channel and see if we need to destroy it. */
285 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
286 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
287 free_chan
= stream
->chan
;
294 * Destroy a stream completely. This will delete, close and free the stream.
295 * Once return, the stream is NO longer usable. Its channel may get destroyed
296 * if conditions are met for a monitored stream.
298 * This MUST be called WITHOUT the consumer data and stream lock acquired if
299 * the stream is in _monitor_ mode else it does not matter.
301 void consumer_stream_destroy(struct lttng_consumer_stream
*stream
,
306 /* Stream is in monitor mode. */
307 if (stream
->monitor
) {
308 struct lttng_consumer_channel
*free_chan
= NULL
;
311 * This means that the stream was successfully removed from the streams
312 * list of the channel and sent to the right thread managing this
313 * stream thus being globally visible.
315 if (stream
->globally_visible
) {
316 pthread_mutex_lock(&consumer_data
.lock
);
317 pthread_mutex_lock(&stream
->chan
->lock
);
318 pthread_mutex_lock(&stream
->lock
);
319 /* Remove every reference of the stream in the consumer. */
320 consumer_stream_delete(stream
, ht
);
322 destroy_close_stream(stream
);
324 /* Update channel's refcount of the stream. */
325 free_chan
= unref_channel(stream
);
327 /* Indicates that the consumer data state MUST be updated after this. */
328 consumer_data
.need_update
= 1;
330 pthread_mutex_unlock(&stream
->lock
);
331 pthread_mutex_unlock(&stream
->chan
->lock
);
332 pthread_mutex_unlock(&consumer_data
.lock
);
335 * If the stream is not visible globally, this needs to be done
336 * outside of the consumer data lock section.
338 free_chan
= unref_channel(stream
);
342 consumer_del_channel(free_chan
);
345 destroy_close_stream(stream
);
348 /* Free stream within a RCU call. */
349 consumer_stream_free(stream
);
353 * Write index of a specific stream either on the relayd or local disk.
355 * Return 0 on success or else a negative value.
357 int consumer_stream_write_index(struct lttng_consumer_stream
*stream
,
358 struct ctf_packet_index
*index
)
361 struct consumer_relayd_sock_pair
*relayd
;
367 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
369 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
370 ret
= relayd_send_index(&relayd
->control_sock
, index
,
371 stream
->relayd_stream_id
, stream
->next_net_seq_num
- 1);
372 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
376 size_ret
= index_write(stream
->index_fd
, index
,
377 sizeof(struct ctf_packet_index
));
378 if (size_ret
< sizeof(struct ctf_packet_index
)) {
394 * Actually do the metadata sync using the given metadata stream.
396 * Return 0 on success else a negative value. ENODATA can be returned also
397 * indicating that there is no metadata available for that stream.
399 static int do_sync_metadata(struct lttng_consumer_stream
*metadata
,
400 struct lttng_consumer_local_data
*ctx
)
405 assert(metadata
->metadata_flag
);
409 * In UST, since we have to write the metadata from the cache packet
410 * by packet, we might need to start this procedure multiple times
411 * until all the metadata from the cache has been extracted.
416 * - Lock the metadata stream
417 * - Check if metadata stream node was deleted before locking.
418 * - if yes, release and return success
419 * - Check if new metadata is ready (flush + snapshot pos)
420 * - If nothing : release and return.
421 * - Lock the metadata_rdv_lock
422 * - Unlock the metadata stream
423 * - cond_wait on metadata_rdv to wait the wakeup from the
425 * - Unlock the metadata_rdv_lock
427 pthread_mutex_lock(&metadata
->lock
);
430 * There is a possibility that we were able to acquire a reference on the
431 * stream from the RCU hash table but between then and now, the node might
432 * have been deleted just before the lock is acquired. Thus, after locking,
433 * we make sure the metadata node has not been deleted which means that the
434 * buffers are closed.
436 * In that case, there is no need to sync the metadata hence returning a
437 * success return code.
439 ret
= cds_lfht_is_node_deleted(&metadata
->node
.node
);
442 goto end_unlock_mutex
;
446 case LTTNG_CONSUMER_KERNEL
:
448 * Empty the metadata cache and flush the current stream.
450 ret
= lttng_kconsumer_sync_metadata(metadata
);
452 case LTTNG_CONSUMER32_UST
:
453 case LTTNG_CONSUMER64_UST
:
455 * Ask the sessiond if we have new metadata waiting and update the
456 * consumer metadata cache.
458 ret
= lttng_ustconsumer_sync_metadata(ctx
, metadata
);
466 * Error or no new metadata, we exit here.
468 if (ret
<= 0 || ret
== ENODATA
) {
469 goto end_unlock_mutex
;
473 * At this point, new metadata have been flushed, so we wait on the
474 * rendez-vous point for the metadata thread to wake us up when it
475 * finishes consuming the metadata and continue execution.
478 pthread_mutex_lock(&metadata
->metadata_rdv_lock
);
481 * Release metadata stream lock so the metadata thread can process it.
483 pthread_mutex_unlock(&metadata
->lock
);
486 * Wait on the rendez-vous point. Once woken up, it means the metadata was
487 * consumed and thus synchronization is achieved.
489 pthread_cond_wait(&metadata
->metadata_rdv
, &metadata
->metadata_rdv_lock
);
490 pthread_mutex_unlock(&metadata
->metadata_rdv_lock
);
491 } while (ret
== EAGAIN
);
497 pthread_mutex_unlock(&metadata
->lock
);
502 * Synchronize the metadata using a given session ID. A successful acquisition
503 * of a metadata stream will trigger a request to the session daemon and a
504 * snapshot so the metadata thread can consume it.
506 * This function call is a rendez-vous point between the metadata thread and
509 * Return 0 on success or else a negative value.
511 int consumer_stream_sync_metadata(struct lttng_consumer_local_data
*ctx
,
515 struct lttng_consumer_stream
*stream
= NULL
;
516 struct lttng_ht_iter iter
;
521 /* Ease our life a bit. */
522 ht
= consumer_data
.stream_list_ht
;
526 /* Search the metadata associated with the session id of the given stream. */
528 cds_lfht_for_each_entry_duplicate(ht
->ht
,
529 ht
->hash_fct(&session_id
, lttng_ht_seed
), ht
->match_fct
,
530 &session_id
, &iter
.iter
, stream
, node_session_id
.node
) {
531 if (!stream
->metadata_flag
) {
535 ret
= do_sync_metadata(stream
, ctx
);
542 * Force return code to 0 (success) since ret might be ENODATA for instance
543 * which is not an error but rather that we should come back.