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 ERR("Unknown consumer_data type");
131 /* Close output fd. Could be a socket or local file at this point. */
132 if (stream
->out_fd
>= 0) {
133 ret
= close(stream
->out_fd
);
140 if (stream
->index_fd
>= 0) {
141 ret
= close(stream
->index_fd
);
143 PERROR("close stream index_fd");
145 stream
->index_fd
= -1;
148 /* Check and cleanup relayd if needed. */
150 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
151 if (relayd
!= NULL
) {
152 consumer_stream_relayd_close(stream
, relayd
);
158 * Delete the stream from all possible hash tables.
160 * The consumer data lock MUST be acquired.
161 * The stream lock MUST be acquired.
163 void consumer_stream_delete(struct lttng_consumer_stream
*stream
,
167 struct lttng_ht_iter iter
;
170 /* Should NEVER be called not in monitor mode. */
171 assert(stream
->chan
->monitor
);
176 iter
.iter
.node
= &stream
->node
.node
;
177 ret
= lttng_ht_del(ht
, &iter
);
181 /* Delete from stream per channel ID hash table. */
182 iter
.iter
.node
= &stream
->node_channel_id
.node
;
184 * The returned value is of no importance. Even if the node is NOT in the
185 * hash table, we continue since we may have been called by a code path
186 * that did not add the stream to a (all) hash table. Same goes for the
187 * next call ht del call.
189 (void) lttng_ht_del(consumer_data
.stream_per_chan_id_ht
, &iter
);
191 /* Delete from the global stream list. */
192 iter
.iter
.node
= &stream
->node_session_id
.node
;
193 /* See the previous ht del on why we ignore the returned value. */
194 (void) lttng_ht_del(consumer_data
.stream_list_ht
, &iter
);
198 /* Decrement the stream count of the global consumer data. */
199 assert(consumer_data
.stream_count
> 0);
200 consumer_data
.stream_count
--;
204 * Free the given stream within a RCU call.
206 void consumer_stream_free(struct lttng_consumer_stream
*stream
)
210 call_rcu(&stream
->node
.head
, free_stream_rcu
);
214 * Destroy the stream's buffers of the tracer.
216 void consumer_stream_destroy_buffers(struct lttng_consumer_stream
*stream
)
220 switch (consumer_data
.type
) {
221 case LTTNG_CONSUMER_KERNEL
:
223 case LTTNG_CONSUMER32_UST
:
224 case LTTNG_CONSUMER64_UST
:
225 lttng_ustconsumer_del_stream(stream
);
228 ERR("Unknown consumer_data type");
234 * Destroy and close a already created stream.
236 static void destroy_close_stream(struct lttng_consumer_stream
*stream
)
240 DBG("Consumer stream destroy monitored key: %" PRIu64
, stream
->key
);
242 /* Destroy tracer buffers of the stream. */
243 consumer_stream_destroy_buffers(stream
);
244 /* Close down everything including the relayd if one. */
245 consumer_stream_close(stream
);
249 * Decrement the stream's channel refcount and if down to 0, return the channel
250 * pointer so it can be destroyed by the caller or NULL if not.
252 static struct lttng_consumer_channel
*unref_channel(
253 struct lttng_consumer_stream
*stream
)
255 struct lttng_consumer_channel
*free_chan
= NULL
;
258 assert(stream
->chan
);
260 /* Update refcount of channel and see if we need to destroy it. */
261 if (!uatomic_sub_return(&stream
->chan
->refcount
, 1)
262 && !uatomic_read(&stream
->chan
->nb_init_stream_left
)) {
263 free_chan
= stream
->chan
;
270 * Destroy a stream completely. This will delete, close and free the stream.
271 * Once return, the stream is NO longer usable. Its channel may get destroyed
272 * if conditions are met for a monitored stream.
274 * This MUST be called WITHOUT the consumer data and stream lock acquired if
275 * the stream is in _monitor_ mode else it does not matter.
277 void consumer_stream_destroy(struct lttng_consumer_stream
*stream
,
282 /* Stream is in monitor mode. */
283 if (stream
->monitor
) {
284 struct lttng_consumer_channel
*free_chan
= NULL
;
287 * This means that the stream was successfully removed from the streams
288 * list of the channel and sent to the right thread managing this
289 * stream thus being globally visible.
291 if (stream
->globally_visible
) {
292 pthread_mutex_lock(&consumer_data
.lock
);
293 pthread_mutex_lock(&stream
->chan
->lock
);
294 pthread_mutex_lock(&stream
->lock
);
295 /* Remove every reference of the stream in the consumer. */
296 consumer_stream_delete(stream
, ht
);
298 destroy_close_stream(stream
);
300 /* Update channel's refcount of the stream. */
301 free_chan
= unref_channel(stream
);
303 /* Indicates that the consumer data state MUST be updated after this. */
304 consumer_data
.need_update
= 1;
306 pthread_mutex_unlock(&stream
->lock
);
307 pthread_mutex_unlock(&stream
->chan
->lock
);
308 pthread_mutex_unlock(&consumer_data
.lock
);
311 * If the stream is not visible globally, this needs to be done
312 * outside of the consumer data lock section.
314 free_chan
= unref_channel(stream
);
318 consumer_del_channel(free_chan
);
321 destroy_close_stream(stream
);
324 /* Free stream within a RCU call. */
325 consumer_stream_free(stream
);
329 * Write index of a specific stream either on the relayd or local disk.
331 * Return 0 on success or else a negative value.
333 int consumer_stream_write_index(struct lttng_consumer_stream
*stream
,
334 struct ctf_packet_index
*index
)
337 struct consumer_relayd_sock_pair
*relayd
;
343 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
345 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
346 ret
= relayd_send_index(&relayd
->control_sock
, index
,
347 stream
->relayd_stream_id
, stream
->next_net_seq_num
- 1);
348 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
352 size_ret
= index_write(stream
->index_fd
, index
,
353 sizeof(struct ctf_packet_index
));
354 if (size_ret
< sizeof(struct ctf_packet_index
)) {
370 * Synchronize the metadata using a given session ID. A successful acquisition
371 * of a metadata stream will trigger a request to the session daemon and a
372 * snapshot so the metadata thread can consume it.
374 * This function call is a rendez-vous point between the metadata thread and
377 * Return 0 on success or else a negative value.
379 int consumer_stream_sync_metadata(struct lttng_consumer_local_data
*ctx
,
383 struct lttng_consumer_stream
*metadata
= NULL
, *stream
= NULL
;
384 struct lttng_ht_iter iter
;
389 /* Ease our life a bit. */
390 ht
= consumer_data
.stream_list_ht
;
394 /* Search the metadata associated with the session id of the given stream. */
396 cds_lfht_for_each_entry_duplicate(ht
->ht
,
397 ht
->hash_fct(&session_id
, lttng_ht_seed
), ht
->match_fct
,
398 &session_id
, &iter
.iter
, stream
, node_session_id
.node
) {
399 if (stream
->metadata_flag
) {
410 * In UST, since we have to write the metadata from the cache packet
411 * by packet, we might need to start this procedure multiple times
412 * until all the metadata from the cache has been extracted.
417 * - Lock the metadata stream
418 * - Check if metadata stream node was deleted before locking.
419 * - if yes, release and return success
420 * - Check if new metadata is ready (flush + snapshot pos)
421 * - If nothing : release and return.
422 * - Lock the metadata_rdv_lock
423 * - Unlock the metadata stream
424 * - cond_wait on metadata_rdv to wait the wakeup from the
426 * - Unlock the metadata_rdv_lock
428 pthread_mutex_lock(&metadata
->lock
);
431 * There is a possibility that we were able to acquire a reference on the
432 * stream from the RCU hash table but between then and now, the node might
433 * have been deleted just before the lock is acquired. Thus, after locking,
434 * we make sure the metadata node has not been deleted which means that the
435 * buffers are closed.
437 * In that case, there is no need to sync the metadata hence returning a
438 * success return code.
440 ret
= cds_lfht_is_node_deleted(&metadata
->node
.node
);
443 goto end_unlock_mutex
;
447 case LTTNG_CONSUMER_KERNEL
:
449 * Empty the metadata cache and flush the current stream.
451 ret
= lttng_kconsumer_sync_metadata(metadata
);
453 case LTTNG_CONSUMER32_UST
:
454 case LTTNG_CONSUMER64_UST
:
456 * Ask the sessiond if we have new metadata waiting and update the
457 * consumer metadata cache.
459 ret
= lttng_ustconsumer_sync_metadata(ctx
, metadata
);
467 * Error or no new metadata, we exit here.
469 if (ret
<= 0 || ret
== ENODATA
) {
470 goto end_unlock_mutex
;
474 * At this point, new metadata have been flushed, so we wait on the
475 * rendez-vous point for the metadata thread to wake us up when it
476 * finishes consuming the metadata and continue execution.
479 pthread_mutex_lock(&metadata
->metadata_rdv_lock
);
482 * Release metadata stream lock so the metadata thread can process it.
484 pthread_mutex_unlock(&metadata
->lock
);
487 * Wait on the rendez-vous point. Once woken up, it means the metadata was
488 * consumed and thus synchronization is achieved.
490 pthread_cond_wait(&metadata
->metadata_rdv
, &metadata
->metadata_rdv_lock
);
491 pthread_mutex_unlock(&metadata
->metadata_rdv_lock
);
492 } while (ret
== EAGAIN
);
498 pthread_mutex_unlock(&metadata
->lock
);