Fix: relayd refcount updates for stream
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
CommitLineData
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1/*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
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5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
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8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
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14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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17 */
18
19#define _GNU_SOURCE
20#include <assert.h>
f02e1e8a 21#include <lttng/ust-ctl.h>
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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>
dbb5dfe6 28#include <sys/stat.h>
3bd1e081 29#include <sys/types.h>
77c7c900 30#include <inttypes.h>
3bd1e081 31#include <unistd.h>
ffe60014 32#include <urcu/list.h>
331744e3 33#include <signal.h>
0857097f 34
990570ed 35#include <common/common.h>
10a8a223 36#include <common/sessiond-comm/sessiond-comm.h>
00e2e675 37#include <common/relayd/relayd.h>
dbb5dfe6 38#include <common/compat/fcntl.h>
331744e3 39#include <common/consumer-metadata-cache.h>
10a50311 40#include <common/consumer-stream.h>
331744e3 41#include <common/consumer-timer.h>
fe4477ee 42#include <common/utils.h>
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43
44#include "ust-consumer.h"
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45
46extern struct lttng_consumer_global_data consumer_data;
47extern int consumer_poll_timeout;
48extern volatile int consumer_quit;
49
50/*
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51 * Free channel object and all streams associated with it. This MUST be used
52 * only and only if the channel has _NEVER_ been added to the global channel
53 * hash table.
3bd1e081 54 */
ffe60014 55static void destroy_channel(struct lttng_consumer_channel *channel)
3bd1e081 56{
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57 struct lttng_consumer_stream *stream, *stmp;
58
59 assert(channel);
60
61 DBG("UST consumer cleaning stream list");
62
63 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
64 send_node) {
65 cds_list_del(&stream->send_node);
66 ustctl_destroy_stream(stream->ustream);
67 free(stream);
68 }
69
70 /*
71 * If a channel is available meaning that was created before the streams
72 * were, delete it.
73 */
74 if (channel->uchan) {
75 lttng_ustconsumer_del_channel(channel);
76 }
77 free(channel);
78}
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79
80/*
ffe60014 81 * Add channel to internal consumer state.
3bd1e081 82 *
ffe60014 83 * Returns 0 on success or else a negative value.
3bd1e081 84 */
ffe60014
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85static int add_channel(struct lttng_consumer_channel *channel,
86 struct lttng_consumer_local_data *ctx)
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87{
88 int ret = 0;
89
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90 assert(channel);
91 assert(ctx);
92
93 if (ctx->on_recv_channel != NULL) {
94 ret = ctx->on_recv_channel(channel);
95 if (ret == 0) {
d8ef542d 96 ret = consumer_add_channel(channel, ctx);
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97 } else if (ret < 0) {
98 /* Most likely an ENOMEM. */
99 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
100 goto error;
101 }
102 } else {
d8ef542d 103 ret = consumer_add_channel(channel, ctx);
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104 }
105
d88aee68 106 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
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107
108error:
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109 return ret;
110}
111
112/*
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113 * Allocate and return a consumer channel object.
114 */
115static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
116 const char *pathname, const char *name, uid_t uid, gid_t gid,
da009f2c 117 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
2bba9e53 118 uint64_t tracefile_size, uint64_t tracefile_count,
1950109e 119 uint64_t session_id_per_pid, unsigned int monitor)
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120{
121 assert(pathname);
122 assert(name);
123
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124 return consumer_allocate_channel(key, session_id, pathname, name, uid,
125 gid, relayd_id, output, tracefile_size,
126 tracefile_count, session_id_per_pid, monitor);
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127}
128
129/*
130 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
131 * error value if applicable is set in it else it is kept untouched.
3bd1e081 132 *
ffe60014 133 * Return NULL on error else the newly allocated stream object.
3bd1e081 134 */
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135static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
136 struct lttng_consumer_channel *channel,
137 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
138{
139 int alloc_ret;
140 struct lttng_consumer_stream *stream = NULL;
141
142 assert(channel);
143 assert(ctx);
144
145 stream = consumer_allocate_stream(channel->key,
146 key,
147 LTTNG_CONSUMER_ACTIVE_STREAM,
148 channel->name,
149 channel->uid,
150 channel->gid,
151 channel->relayd_id,
152 channel->session_id,
153 cpu,
154 &alloc_ret,
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155 channel->type,
156 channel->monitor);
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157 if (stream == NULL) {
158 switch (alloc_ret) {
159 case -ENOENT:
160 /*
161 * We could not find the channel. Can happen if cpu hotplug
162 * happens while tearing down.
163 */
164 DBG3("Could not find channel");
165 break;
166 case -ENOMEM:
167 case -EINVAL:
168 default:
169 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
170 break;
171 }
172 goto error;
173 }
174
175 stream->chan = channel;
176
177error:
178 if (_alloc_ret) {
179 *_alloc_ret = alloc_ret;
180 }
181 return stream;
182}
183
184/*
185 * Send the given stream pointer to the corresponding thread.
186 *
187 * Returns 0 on success else a negative value.
188 */
189static int send_stream_to_thread(struct lttng_consumer_stream *stream,
190 struct lttng_consumer_local_data *ctx)
191{
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192 int ret;
193 struct lttng_pipe *stream_pipe;
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194
195 /* Get the right pipe where the stream will be sent. */
196 if (stream->metadata_flag) {
dae10966 197 stream_pipe = ctx->consumer_metadata_pipe;
ffe60014 198 } else {
dae10966 199 stream_pipe = ctx->consumer_data_pipe;
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200 }
201
dae10966 202 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
ffe60014 203 if (ret < 0) {
dae10966
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204 ERR("Consumer write %s stream to pipe %d",
205 stream->metadata_flag ? "metadata" : "data",
206 lttng_pipe_get_writefd(stream_pipe));
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207 }
208
209 return ret;
210}
211
d88aee68
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212/*
213 * Create streams for the given channel using liblttng-ust-ctl.
214 *
215 * Return 0 on success else a negative value.
216 */
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217static int create_ust_streams(struct lttng_consumer_channel *channel,
218 struct lttng_consumer_local_data *ctx)
219{
220 int ret, cpu = 0;
221 struct ustctl_consumer_stream *ustream;
222 struct lttng_consumer_stream *stream;
223
224 assert(channel);
225 assert(ctx);
226
227 /*
228 * While a stream is available from ustctl. When NULL is returned, we've
229 * reached the end of the possible stream for the channel.
230 */
231 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
232 int wait_fd;
233
749d339a 234 wait_fd = ustctl_stream_get_wait_fd(ustream);
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235
236 /* Allocate consumer stream object. */
237 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
238 if (!stream) {
239 goto error_alloc;
240 }
241 stream->ustream = ustream;
242 /*
243 * Store it so we can save multiple function calls afterwards since
244 * this value is used heavily in the stream threads. This is UST
245 * specific so this is why it's done after allocation.
246 */
247 stream->wait_fd = wait_fd;
248
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249 /*
250 * Increment channel refcount since the channel reference has now been
251 * assigned in the allocation process above.
252 */
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253 if (stream->chan->monitor) {
254 uatomic_inc(&stream->chan->refcount);
255 }
b31398bb 256
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257 /*
258 * Order is important this is why a list is used. On error, the caller
259 * should clean this list.
260 */
261 cds_list_add_tail(&stream->send_node, &channel->streams.head);
262
263 ret = ustctl_get_max_subbuf_size(stream->ustream,
264 &stream->max_sb_size);
265 if (ret < 0) {
266 ERR("ustctl_get_max_subbuf_size failed for stream %s",
267 stream->name);
268 goto error;
269 }
270
271 /* Do actions once stream has been received. */
272 if (ctx->on_recv_stream) {
273 ret = ctx->on_recv_stream(stream);
274 if (ret < 0) {
275 goto error;
276 }
277 }
278
d88aee68 279 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
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280 stream->name, stream->key, stream->relayd_stream_id);
281
282 /* Set next CPU stream. */
283 channel->streams.count = ++cpu;
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284
285 /* Keep stream reference when creating metadata. */
286 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
287 channel->metadata_stream = stream;
288 }
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289 }
290
291 return 0;
292
293error:
294error_alloc:
295 return ret;
296}
297
298/*
299 * Create an UST channel with the given attributes and send it to the session
300 * daemon using the ust ctl API.
301 *
302 * Return 0 on success or else a negative value.
303 */
304static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
305 struct ustctl_consumer_channel **chanp)
306{
307 int ret;
308 struct ustctl_consumer_channel *channel;
309
310 assert(attr);
311 assert(chanp);
312
313 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
314 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
315 "switch_timer_interval: %u, read_timer_interval: %u, "
316 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
317 attr->num_subbuf, attr->switch_timer_interval,
318 attr->read_timer_interval, attr->output, attr->type);
319
320 channel = ustctl_create_channel(attr);
321 if (!channel) {
322 ret = -1;
323 goto error_create;
324 }
325
326 *chanp = channel;
327
328 return 0;
329
330error_create:
331 return ret;
332}
333
d88aee68
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334/*
335 * Send a single given stream to the session daemon using the sock.
336 *
337 * Return 0 on success else a negative value.
338 */
ffe60014
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339static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
340{
341 int ret;
342
343 assert(stream);
344 assert(sock >= 0);
345
d88aee68 346 DBG2("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
ffe60014
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347
348 /* Send stream to session daemon. */
349 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
350 if (ret < 0) {
351 goto error;
352 }
353
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354error:
355 return ret;
356}
357
358/*
359 * Send channel to sessiond.
360 *
d88aee68 361 * Return 0 on success or else a negative value.
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362 */
363static int send_sessiond_channel(int sock,
364 struct lttng_consumer_channel *channel,
365 struct lttng_consumer_local_data *ctx, int *relayd_error)
366{
f2a444f1 367 int ret, ret_code = LTTNG_OK;
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368 struct lttng_consumer_stream *stream;
369
370 assert(channel);
371 assert(ctx);
372 assert(sock >= 0);
373
374 DBG("UST consumer sending channel %s to sessiond", channel->name);
375
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376 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
377 /* Try to send the stream to the relayd if one is available. */
d01178b6 378 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
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379 if (ret < 0) {
380 /*
381 * Flag that the relayd was the problem here probably due to a
382 * communicaton error on the socket.
383 */
384 if (relayd_error) {
385 *relayd_error = 1;
386 }
f2a444f1 387 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
ffe60014 388 }
f2a444f1 389 }
ffe60014 390
f2a444f1
DG
391 /* Inform sessiond that we are about to send channel and streams. */
392 ret = consumer_send_status_msg(sock, ret_code);
393 if (ret < 0 || ret_code != LTTNG_OK) {
394 /*
395 * Either the session daemon is not responding or the relayd died so we
396 * stop now.
397 */
398 goto error;
399 }
400
401 /* Send channel to sessiond. */
402 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
403 if (ret < 0) {
404 goto error;
405 }
406
407 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
408 if (ret < 0) {
409 goto error;
410 }
411
412 /* The channel was sent successfully to the sessiond at this point. */
413 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
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414 /* Send stream to session daemon. */
415 ret = send_sessiond_stream(sock, stream);
416 if (ret < 0) {
417 goto error;
418 }
419 }
420
421 /* Tell sessiond there is no more stream. */
422 ret = ustctl_send_stream_to_sessiond(sock, NULL);
423 if (ret < 0) {
424 goto error;
425 }
426
427 DBG("UST consumer NULL stream sent to sessiond");
428
429 return 0;
430
431error:
f2a444f1
DG
432 if (ret_code != LTTNG_OK) {
433 ret = -1;
434 }
ffe60014
DG
435 return ret;
436}
437
438/*
439 * Creates a channel and streams and add the channel it to the channel internal
440 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
441 * received.
442 *
443 * Return 0 on success or else, a negative value is returned and the channel
444 * MUST be destroyed by consumer_del_channel().
445 */
446static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
447 struct lttng_consumer_channel *channel,
448 struct ustctl_consumer_channel_attr *attr)
3bd1e081
MD
449{
450 int ret;
451
ffe60014
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452 assert(ctx);
453 assert(channel);
454 assert(attr);
455
456 /*
457 * This value is still used by the kernel consumer since for the kernel,
458 * the stream ownership is not IN the consumer so we need to have the
459 * number of left stream that needs to be initialized so we can know when
460 * to delete the channel (see consumer.c).
461 *
462 * As for the user space tracer now, the consumer creates and sends the
463 * stream to the session daemon which only sends them to the application
464 * once every stream of a channel is received making this value useless
465 * because we they will be added to the poll thread before the application
466 * receives them. This ensures that a stream can not hang up during
467 * initilization of a channel.
468 */
469 channel->nb_init_stream_left = 0;
470
471 /* The reply msg status is handled in the following call. */
472 ret = create_ust_channel(attr, &channel->uchan);
473 if (ret < 0) {
10a50311 474 goto end;
3bd1e081
MD
475 }
476
d8ef542d
MD
477 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
478
10a50311
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479 /*
480 * For the snapshots (no monitor), we create the metadata streams
481 * on demand, not during the channel creation.
482 */
483 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
484 ret = 0;
485 goto end;
486 }
487
ffe60014
DG
488 /* Open all streams for this channel. */
489 ret = create_ust_streams(channel, ctx);
490 if (ret < 0) {
10a50311 491 goto end;
ffe60014
DG
492 }
493
10a50311 494end:
3bd1e081
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495 return ret;
496}
497
d88aee68
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498/*
499 * Send all stream of a channel to the right thread handling it.
500 *
501 * On error, return a negative value else 0 on success.
502 */
503static int send_streams_to_thread(struct lttng_consumer_channel *channel,
504 struct lttng_consumer_local_data *ctx)
505{
506 int ret = 0;
507 struct lttng_consumer_stream *stream, *stmp;
508
509 assert(channel);
510 assert(ctx);
511
512 /* Send streams to the corresponding thread. */
513 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
514 send_node) {
515 /* Sending the stream to the thread. */
516 ret = send_stream_to_thread(stream, ctx);
517 if (ret < 0) {
518 /*
519 * If we are unable to send the stream to the thread, there is
520 * a big problem so just stop everything.
521 */
522 goto error;
523 }
524
525 /* Remove node from the channel stream list. */
526 cds_list_del(&stream->send_node);
4891ece8
DG
527
528 /*
529 * From this point on, the stream's ownership has been moved away from
530 * the channel and becomes globally visible.
531 */
532 stream->globally_visible = 1;
d88aee68
DG
533 }
534
535error:
536 return ret;
537}
538
539/*
540 * Write metadata to the given channel using ustctl to convert the string to
541 * the ringbuffer.
331744e3
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542 * Called only from consumer_metadata_cache_write.
543 * The metadata cache lock MUST be acquired to write in the cache.
d88aee68
DG
544 *
545 * Return 0 on success else a negative value.
546 */
331744e3 547int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel *metadata,
d88aee68
DG
548 const char *metadata_str, uint64_t target_offset, uint64_t len)
549{
550 int ret;
551
552 assert(metadata);
553 assert(metadata_str);
554
555 DBG("UST consumer writing metadata to channel %s", metadata->name);
556
73811ecc
DG
557 if (!metadata->metadata_stream) {
558 ret = 0;
559 goto error;
560 }
561
331744e3
JD
562 assert(target_offset <= metadata->metadata_cache->max_offset);
563 ret = ustctl_write_metadata_to_channel(metadata->uchan,
564 metadata_str + target_offset, len);
d88aee68 565 if (ret < 0) {
8fd623e0 566 ERR("ustctl write metadata fail with ret %d, len %" PRIu64, ret, len);
d88aee68
DG
567 goto error;
568 }
d88aee68
DG
569
570 ustctl_flush_buffer(metadata->metadata_stream->ustream, 1);
571
572error:
573 return ret;
574}
575
7972aab2
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576/*
577 * Flush channel's streams using the given key to retrieve the channel.
578 *
579 * Return 0 on success else an LTTng error code.
580 */
581static int flush_channel(uint64_t chan_key)
582{
583 int ret = 0;
584 struct lttng_consumer_channel *channel;
585 struct lttng_consumer_stream *stream;
586 struct lttng_ht *ht;
587 struct lttng_ht_iter iter;
588
8fd623e0 589 DBG("UST consumer flush channel key %" PRIu64, chan_key);
7972aab2 590
a500c257 591 rcu_read_lock();
7972aab2
DG
592 channel = consumer_find_channel(chan_key);
593 if (!channel) {
8fd623e0 594 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
7972aab2
DG
595 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
596 goto error;
597 }
598
599 ht = consumer_data.stream_per_chan_id_ht;
600
601 /* For each stream of the channel id, flush it. */
7972aab2
DG
602 cds_lfht_for_each_entry_duplicate(ht->ht,
603 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
604 &channel->key, &iter.iter, stream, node_channel_id.node) {
605 ustctl_flush_buffer(stream->ustream, 1);
606 }
7972aab2 607error:
a500c257 608 rcu_read_unlock();
7972aab2
DG
609 return ret;
610}
611
d88aee68
DG
612/*
613 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
a500c257 614 * RCU read side lock MUST be acquired before calling this function.
d88aee68
DG
615 *
616 * Return 0 on success else an LTTng error code.
617 */
618static int close_metadata(uint64_t chan_key)
619{
ea88ca2a 620 int ret = 0;
d88aee68
DG
621 struct lttng_consumer_channel *channel;
622
8fd623e0 623 DBG("UST consumer close metadata key %" PRIu64, chan_key);
d88aee68
DG
624
625 channel = consumer_find_channel(chan_key);
626 if (!channel) {
84cc9aa0
DG
627 /*
628 * This is possible if the metadata thread has issue a delete because
629 * the endpoint point of the stream hung up. There is no way the
630 * session daemon can know about it thus use a DBG instead of an actual
631 * error.
632 */
633 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
d88aee68
DG
634 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
635 goto error;
636 }
637
ea88ca2a 638 pthread_mutex_lock(&consumer_data.lock);
73811ecc
DG
639
640 if (cds_lfht_is_node_deleted(&channel->node.node)) {
641 goto error_unlock;
642 }
643
644 if (channel->switch_timer_enabled == 1) {
645 DBG("Deleting timer on metadata channel");
646 consumer_timer_switch_stop(channel);
647 }
648
649 if (channel->metadata_stream) {
ea88ca2a
MD
650 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
651 if (ret < 0) {
652 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
653 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
654 goto error_unlock;
655 }
331744e3 656 }
d88aee68 657
ea88ca2a
MD
658error_unlock:
659 pthread_mutex_unlock(&consumer_data.lock);
d88aee68
DG
660error:
661 return ret;
662}
663
664/*
665 * RCU read side lock MUST be acquired before calling this function.
666 *
667 * Return 0 on success else an LTTng error code.
668 */
669static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
670{
671 int ret;
672 struct lttng_consumer_channel *metadata;
673
8fd623e0 674 DBG("UST consumer setup metadata key %" PRIu64, key);
d88aee68
DG
675
676 metadata = consumer_find_channel(key);
677 if (!metadata) {
678 ERR("UST consumer push metadata %" PRIu64 " not found", key);
679 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
10a50311
JD
680 goto end;
681 }
682
683 /*
684 * In no monitor mode, the metadata channel has no stream(s) so skip the
685 * ownership transfer to the metadata thread.
686 */
687 if (!metadata->monitor) {
688 DBG("Metadata channel in no monitor");
689 ret = 0;
690 goto end;
d88aee68
DG
691 }
692
693 /*
694 * Send metadata stream to relayd if one available. Availability is
695 * known if the stream is still in the list of the channel.
696 */
697 if (cds_list_empty(&metadata->streams.head)) {
698 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
699 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
f5a0c9cf 700 goto error_no_stream;
d88aee68
DG
701 }
702
703 /* Send metadata stream to relayd if needed. */
d01178b6
DG
704 ret = consumer_send_relayd_stream(metadata->metadata_stream,
705 metadata->pathname);
d88aee68
DG
706 if (ret < 0) {
707 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
708 goto error;
709 }
710
711 ret = send_streams_to_thread(metadata, ctx);
712 if (ret < 0) {
713 /*
714 * If we are unable to send the stream to the thread, there is
715 * a big problem so just stop everything.
716 */
717 ret = LTTCOMM_CONSUMERD_FATAL;
718 goto error;
719 }
720 /* List MUST be empty after or else it could be reused. */
721 assert(cds_list_empty(&metadata->streams.head));
722
10a50311
JD
723 ret = 0;
724 goto end;
d88aee68
DG
725
726error:
f2a444f1
DG
727 /*
728 * Delete metadata channel on error. At this point, the metadata stream can
729 * NOT be monitored by the metadata thread thus having the guarantee that
730 * the stream is still in the local stream list of the channel. This call
731 * will make sure to clean that list.
732 */
f5a0c9cf
DG
733 cds_list_del(&metadata->metadata_stream->send_node);
734 consumer_stream_destroy(metadata->metadata_stream, NULL);
735error_no_stream:
10a50311
JD
736end:
737 return ret;
738}
739
740/*
741 * Snapshot the whole metadata.
742 *
743 * Returns 0 on success, < 0 on error
744 */
745static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
746 struct lttng_consumer_local_data *ctx)
747{
748 int ret = 0;
749 ssize_t write_len;
750 uint64_t total_len = 0;
751 struct lttng_consumer_channel *metadata_channel;
752 struct lttng_consumer_stream *metadata_stream;
753
754 assert(path);
755 assert(ctx);
756
757 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
758 key, path);
759
760 rcu_read_lock();
761
762 metadata_channel = consumer_find_channel(key);
763 if (!metadata_channel) {
764 ERR("UST snapshot metadata channel not found for key %lu", key);
765 ret = -1;
766 goto error;
767 }
768 assert(!metadata_channel->monitor);
769
770 /*
771 * Ask the sessiond if we have new metadata waiting and update the
772 * consumer metadata cache.
773 */
774 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel);
775 if (ret < 0) {
776 goto error;
777 }
778
779 /*
780 * The metadata stream is NOT created in no monitor mode when the channel
781 * is created on a sessiond ask channel command.
782 */
783 ret = create_ust_streams(metadata_channel, ctx);
784 if (ret < 0) {
785 goto error;
786 }
787
788 metadata_stream = metadata_channel->metadata_stream;
789 assert(metadata_stream);
790
791 if (relayd_id != (uint64_t) -1ULL) {
792 metadata_stream->net_seq_idx = relayd_id;
793 ret = consumer_send_relayd_stream(metadata_stream, path);
794 if (ret < 0) {
795 goto error_stream;
796 }
797 } else {
798 ret = utils_create_stream_file(path, metadata_stream->name,
799 metadata_stream->chan->tracefile_size,
800 metadata_stream->tracefile_count_current,
801 metadata_stream->uid, metadata_stream->gid);
802 if (ret < 0) {
803 goto error_stream;
804 }
805 metadata_stream->out_fd = ret;
806 metadata_stream->tracefile_size_current = 0;
807 }
808
809 pthread_mutex_lock(&metadata_channel->metadata_cache->lock);
810 while (total_len < metadata_channel->metadata_cache->total_bytes_written) {
811 /*
812 * Write at most one packet of metadata into the channel
813 * to avoid blocking here.
814 */
815 write_len = ustctl_write_one_packet_to_channel(metadata_channel->uchan,
816 metadata_channel->metadata_cache->data,
817 metadata_channel->metadata_cache->total_bytes_written);
818 if (write_len < 0) {
819 ERR("UST consumer snapshot writing metadata packet");
820 ret = -1;
821 goto error_unlock;
822 }
823 total_len += write_len;
824
825 DBG("Written %" PRIu64 " bytes to metadata (left: %" PRIu64 ")",
826 write_len,
827 metadata_channel->metadata_cache->total_bytes_written - write_len);
828 ustctl_flush_buffer(metadata_stream->ustream, 1);
829 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
830 if (ret < 0) {
831 goto error_unlock;
832 }
833 }
834
835error_unlock:
836 pthread_mutex_unlock(&metadata_channel->metadata_cache->lock);
837
838error_stream:
839 /*
840 * Clean up the stream completly because the next snapshot will use a new
841 * metadata stream.
842 */
843 cds_list_del(&metadata_stream->send_node);
844 consumer_stream_destroy(metadata_stream, NULL);
845 metadata_channel->metadata_stream = NULL;
846
847error:
848 rcu_read_unlock();
849 return ret;
850}
851
852/*
853 * Take a snapshot of all the stream of a channel.
854 *
855 * Returns 0 on success, < 0 on error
856 */
857static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
858 struct lttng_consumer_local_data *ctx)
859{
860 int ret;
861 unsigned use_relayd = 0;
862 unsigned long consumed_pos, produced_pos;
863 struct lttng_consumer_channel *channel;
864 struct lttng_consumer_stream *stream;
865
866 assert(path);
867 assert(ctx);
868
869 rcu_read_lock();
870
871 if (relayd_id != (uint64_t) -1ULL) {
872 use_relayd = 1;
873 }
874
875 channel = consumer_find_channel(key);
876 if (!channel) {
877 ERR("UST snapshot channel not found for key %lu", key);
878 ret = -1;
879 goto error;
880 }
881 assert(!channel->monitor);
882 DBG("UST consumer snapshot channel %lu", key);
883
884 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
885 /* Lock stream because we are about to change its state. */
886 pthread_mutex_lock(&stream->lock);
887 stream->net_seq_idx = relayd_id;
888
889 if (use_relayd) {
890 ret = consumer_send_relayd_stream(stream, path);
891 if (ret < 0) {
892 goto error_unlock;
893 }
894 } else {
895 ret = utils_create_stream_file(path, stream->name,
896 stream->chan->tracefile_size,
897 stream->tracefile_count_current,
898 stream->uid, stream->gid);
899 if (ret < 0) {
900 goto error_unlock;
901 }
902 stream->out_fd = ret;
903 stream->tracefile_size_current = 0;
904
905 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
906 stream->name, stream->key);
907 }
908
909 ustctl_flush_buffer(stream->ustream, 1);
910
911 ret = lttng_ustconsumer_take_snapshot(stream);
912 if (ret < 0) {
913 ERR("Taking UST snapshot");
914 goto error_unlock;
915 }
916
917 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
918 if (ret < 0) {
919 ERR("Produced UST snapshot position");
920 goto error_unlock;
921 }
922
923 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
924 if (ret < 0) {
925 ERR("Consumerd UST snapshot position");
926 goto error_unlock;
927 }
928
929 while (consumed_pos < produced_pos) {
930 ssize_t read_len;
931 unsigned long len, padded_len;
932
933 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
934
935 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
936 if (ret < 0) {
937 if (ret != -EAGAIN) {
938 PERROR("ustctl_get_subbuf snapshot");
939 goto error_close_stream;
940 }
941 DBG("UST consumer get subbuf failed. Skipping it.");
942 consumed_pos += stream->max_sb_size;
943 continue;
944 }
945
946 ret = ustctl_get_subbuf_size(stream->ustream, &len);
947 if (ret < 0) {
948 ERR("Snapshot ustctl_get_subbuf_size");
949 goto error_put_subbuf;
950 }
951
952 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
953 if (ret < 0) {
954 ERR("Snapshot ustctl_get_padded_subbuf_size");
955 goto error_put_subbuf;
956 }
957
958 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
959 padded_len - len);
960 if (use_relayd) {
961 if (read_len != len) {
962 ret = -1;
963 goto error_put_subbuf;
964 }
965 } else {
966 if (read_len != padded_len) {
967 ret = -1;
968 goto error_put_subbuf;
969 }
970 }
971
972 ret = ustctl_put_subbuf(stream->ustream);
973 if (ret < 0) {
974 ERR("Snapshot ustctl_put_subbuf");
975 goto error_close_stream;
976 }
977 consumed_pos += stream->max_sb_size;
978 }
979
980 /* Simply close the stream so we can use it on the next snapshot. */
981 consumer_stream_close(stream);
982 pthread_mutex_unlock(&stream->lock);
983 }
984
985 rcu_read_unlock();
986 return 0;
987
988error_put_subbuf:
989 if (ustctl_put_subbuf(stream->ustream) < 0) {
990 ERR("Snapshot ustctl_put_subbuf");
991 }
992error_close_stream:
993 consumer_stream_close(stream);
994error_unlock:
995 pthread_mutex_unlock(&stream->lock);
996error:
997 rcu_read_unlock();
d88aee68
DG
998 return ret;
999}
1000
331744e3
JD
1001/*
1002 * Receive the metadata updates from the sessiond.
1003 */
1004int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1005 uint64_t len, struct lttng_consumer_channel *channel)
1006{
1007 int ret, ret_code = LTTNG_OK;
1008 char *metadata_str;
1009
8fd623e0 1010 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
331744e3
JD
1011
1012 metadata_str = zmalloc(len * sizeof(char));
1013 if (!metadata_str) {
1014 PERROR("zmalloc metadata string");
1015 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1016 goto end;
1017 }
1018
1019 /* Receive metadata string. */
1020 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1021 if (ret < 0) {
1022 /* Session daemon is dead so return gracefully. */
1023 ret_code = ret;
1024 goto end_free;
1025 }
1026
73811ecc
DG
1027 /*
1028 * XXX: The consumer data lock is acquired before calling metadata cache
1029 * write which calls push metadata that MUST be protected by the consumer
1030 * lock in order to be able to check the validity of the metadata stream of
1031 * the channel.
1032 *
1033 * Note that this will be subject to change to better fine grained locking
1034 * and ultimately try to get rid of this global consumer data lock.
1035 */
1036 pthread_mutex_lock(&consumer_data.lock);
1037
331744e3
JD
1038 pthread_mutex_lock(&channel->metadata_cache->lock);
1039 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
1040 if (ret < 0) {
1041 /* Unable to handle metadata. Notify session daemon. */
1042 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
a32bd775
DG
1043 /*
1044 * Skip metadata flush on write error since the offset and len might
1045 * not have been updated which could create an infinite loop below when
1046 * waiting for the metadata cache to be flushed.
1047 */
1048 pthread_mutex_unlock(&channel->metadata_cache->lock);
1049 pthread_mutex_unlock(&consumer_data.lock);
1050 goto end_free;
331744e3
JD
1051 }
1052 pthread_mutex_unlock(&channel->metadata_cache->lock);
73811ecc 1053 pthread_mutex_unlock(&consumer_data.lock);
331744e3
JD
1054
1055 while (consumer_metadata_cache_flushed(channel, offset + len)) {
1056 DBG("Waiting for metadata to be flushed");
1057 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1058 }
1059
1060end_free:
1061 free(metadata_str);
1062end:
1063 return ret_code;
1064}
1065
4cbc1a04
DG
1066/*
1067 * Receive command from session daemon and process it.
1068 *
1069 * Return 1 on success else a negative value or 0.
1070 */
3bd1e081
MD
1071int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1072 int sock, struct pollfd *consumer_sockpoll)
1073{
1074 ssize_t ret;
f50f23d9 1075 enum lttng_error_code ret_code = LTTNG_OK;
3bd1e081 1076 struct lttcomm_consumer_msg msg;
ffe60014 1077 struct lttng_consumer_channel *channel = NULL;
3bd1e081
MD
1078
1079 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1080 if (ret != sizeof(msg)) {
173af62f
DG
1081 DBG("Consumer received unexpected message size %zd (expects %zu)",
1082 ret, sizeof(msg));
3be74084
DG
1083 /*
1084 * The ret value might 0 meaning an orderly shutdown but this is ok
1085 * since the caller handles this.
1086 */
489f70e9 1087 if (ret > 0) {
c6857fcf 1088 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
489f70e9
MD
1089 ret = -1;
1090 }
3bd1e081
MD
1091 return ret;
1092 }
1093 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
f50f23d9
DG
1094 /*
1095 * Notify the session daemon that the command is completed.
1096 *
1097 * On transport layer error, the function call will print an error
1098 * message so handling the returned code is a bit useless since we
1099 * return an error code anyway.
1100 */
1101 (void) consumer_send_status_msg(sock, ret_code);
3bd1e081
MD
1102 return -ENOENT;
1103 }
1104
3f8e211f 1105 /* relayd needs RCU read-side lock */
b0b335c8
MD
1106 rcu_read_lock();
1107
3bd1e081 1108 switch (msg.cmd_type) {
00e2e675
DG
1109 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1110 {
f50f23d9 1111 /* Session daemon status message are handled in the following call. */
7735ef9e
DG
1112 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1113 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
46e6455f 1114 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
00e2e675
DG
1115 goto end_nosignal;
1116 }
173af62f
DG
1117 case LTTNG_CONSUMER_DESTROY_RELAYD:
1118 {
a6ba4fe1 1119 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
173af62f
DG
1120 struct consumer_relayd_sock_pair *relayd;
1121
a6ba4fe1 1122 DBG("UST consumer destroying relayd %" PRIu64, index);
173af62f
DG
1123
1124 /* Get relayd reference if exists. */
a6ba4fe1 1125 relayd = consumer_find_relayd(index);
173af62f 1126 if (relayd == NULL) {
3448e266 1127 DBG("Unable to find relayd %" PRIu64, index);
f50f23d9 1128 ret_code = LTTNG_ERR_NO_CONSUMER;
173af62f
DG
1129 }
1130
a6ba4fe1
DG
1131 /*
1132 * Each relayd socket pair has a refcount of stream attached to it
1133 * which tells if the relayd is still active or not depending on the
1134 * refcount value.
1135 *
1136 * This will set the destroy flag of the relayd object and destroy it
1137 * if the refcount reaches zero when called.
1138 *
1139 * The destroy can happen either here or when a stream fd hangs up.
1140 */
f50f23d9
DG
1141 if (relayd) {
1142 consumer_flag_relayd_for_destroy(relayd);
1143 }
1144
d88aee68 1145 goto end_msg_sessiond;
173af62f 1146 }
3bd1e081
MD
1147 case LTTNG_CONSUMER_UPDATE_STREAM:
1148 {
3f8e211f 1149 rcu_read_unlock();
7ad0a0cb 1150 return -ENOSYS;
3bd1e081 1151 }
6d805429 1152 case LTTNG_CONSUMER_DATA_PENDING:
53632229 1153 {
3be74084 1154 int ret, is_data_pending;
6d805429 1155 uint64_t id = msg.u.data_pending.session_id;
ca22feea 1156
6d805429 1157 DBG("UST consumer data pending command for id %" PRIu64, id);
ca22feea 1158
3be74084 1159 is_data_pending = consumer_data_pending(id);
ca22feea
DG
1160
1161 /* Send back returned value to session daemon */
3be74084
DG
1162 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1163 sizeof(is_data_pending));
ca22feea 1164 if (ret < 0) {
3be74084 1165 DBG("Error when sending the data pending ret code: %d", ret);
489f70e9 1166 goto error_fatal;
ca22feea 1167 }
f50f23d9
DG
1168
1169 /*
1170 * No need to send back a status message since the data pending
1171 * returned value is the response.
1172 */
ca22feea 1173 break;
53632229 1174 }
ffe60014
DG
1175 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1176 {
1177 int ret;
1178 struct ustctl_consumer_channel_attr attr;
1179
1180 /* Create a plain object and reserve a channel key. */
1181 channel = allocate_channel(msg.u.ask_channel.session_id,
1182 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1183 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1184 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1624d5b7
JD
1185 (enum lttng_event_output) msg.u.ask_channel.output,
1186 msg.u.ask_channel.tracefile_size,
2bba9e53 1187 msg.u.ask_channel.tracefile_count,
1950109e 1188 msg.u.ask_channel.session_id_per_pid,
2bba9e53 1189 msg.u.ask_channel.monitor);
ffe60014
DG
1190 if (!channel) {
1191 goto end_channel_error;
1192 }
1193
1194 /* Build channel attributes from received message. */
1195 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1196 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1197 attr.overwrite = msg.u.ask_channel.overwrite;
1198 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1199 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
7972aab2 1200 attr.chan_id = msg.u.ask_channel.chan_id;
10a50311 1201 attr.output = msg.u.ask_channel.output;
ffe60014
DG
1202 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1203
ffe60014
DG
1204 /* Translate and save channel type. */
1205 switch (msg.u.ask_channel.type) {
1206 case LTTNG_UST_CHAN_PER_CPU:
1207 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1208 attr.type = LTTNG_UST_CHAN_PER_CPU;
8633d6e3
MD
1209 /*
1210 * Set refcount to 1 for owner. Below, we will
1211 * pass ownership to the
1212 * consumer_thread_channel_poll() thread.
1213 */
1214 channel->refcount = 1;
ffe60014
DG
1215 break;
1216 case LTTNG_UST_CHAN_METADATA:
1217 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1218 attr.type = LTTNG_UST_CHAN_METADATA;
1219 break;
1220 default:
1221 assert(0);
1222 goto error_fatal;
1223 };
1224
1225 ret = ask_channel(ctx, sock, channel, &attr);
1226 if (ret < 0) {
1227 goto end_channel_error;
1228 }
1229
fc643247
MD
1230 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1231 ret = consumer_metadata_cache_allocate(channel);
1232 if (ret < 0) {
1233 ERR("Allocating metadata cache");
1234 goto end_channel_error;
1235 }
1236 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1237 attr.switch_timer_interval = 0;
1238 }
1239
ffe60014
DG
1240 /*
1241 * Add the channel to the internal state AFTER all streams were created
1242 * and successfully sent to session daemon. This way, all streams must
1243 * be ready before this channel is visible to the threads.
fc643247
MD
1244 * If add_channel succeeds, ownership of the channel is
1245 * passed to consumer_thread_channel_poll().
ffe60014
DG
1246 */
1247 ret = add_channel(channel, ctx);
1248 if (ret < 0) {
ea88ca2a
MD
1249 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1250 if (channel->switch_timer_enabled == 1) {
1251 consumer_timer_switch_stop(channel);
1252 }
1253 consumer_metadata_cache_destroy(channel);
1254 }
ffe60014
DG
1255 goto end_channel_error;
1256 }
1257
1258 /*
1259 * Channel and streams are now created. Inform the session daemon that
1260 * everything went well and should wait to receive the channel and
1261 * streams with ustctl API.
1262 */
1263 ret = consumer_send_status_channel(sock, channel);
1264 if (ret < 0) {
1265 /*
489f70e9 1266 * There is probably a problem on the socket.
ffe60014 1267 */
489f70e9 1268 goto error_fatal;
ffe60014
DG
1269 }
1270
1271 break;
1272 }
1273 case LTTNG_CONSUMER_GET_CHANNEL:
1274 {
1275 int ret, relayd_err = 0;
d88aee68 1276 uint64_t key = msg.u.get_channel.key;
ffe60014 1277 struct lttng_consumer_channel *channel;
ffe60014
DG
1278
1279 channel = consumer_find_channel(key);
1280 if (!channel) {
8fd623e0 1281 ERR("UST consumer get channel key %" PRIu64 " not found", key);
ffe60014
DG
1282 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1283 goto end_msg_sessiond;
1284 }
1285
ffe60014
DG
1286 /* Send everything to sessiond. */
1287 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1288 if (ret < 0) {
1289 if (relayd_err) {
1290 /*
1291 * We were unable to send to the relayd the stream so avoid
1292 * sending back a fatal error to the thread since this is OK
f2a444f1
DG
1293 * and the consumer can continue its work. The above call
1294 * has sent the error status message to the sessiond.
ffe60014 1295 */
f2a444f1 1296 goto end_nosignal;
ffe60014
DG
1297 }
1298 /*
1299 * The communicaton was broken hence there is a bad state between
1300 * the consumer and sessiond so stop everything.
1301 */
1302 goto error_fatal;
1303 }
1304
10a50311
JD
1305 /*
1306 * In no monitor mode, the streams ownership is kept inside the channel
1307 * so don't send them to the data thread.
1308 */
1309 if (!channel->monitor) {
1310 goto end_msg_sessiond;
1311 }
1312
d88aee68
DG
1313 ret = send_streams_to_thread(channel, ctx);
1314 if (ret < 0) {
1315 /*
1316 * If we are unable to send the stream to the thread, there is
1317 * a big problem so just stop everything.
1318 */
1319 goto error_fatal;
ffe60014 1320 }
ffe60014
DG
1321 /* List MUST be empty after or else it could be reused. */
1322 assert(cds_list_empty(&channel->streams.head));
d88aee68
DG
1323 goto end_msg_sessiond;
1324 }
1325 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1326 {
1327 uint64_t key = msg.u.destroy_channel.key;
d88aee68 1328
a0cbdd2e
MD
1329 /*
1330 * Only called if streams have not been sent to stream
1331 * manager thread. However, channel has been sent to
1332 * channel manager thread.
1333 */
1334 notify_thread_del_channel(ctx, key);
d88aee68 1335 goto end_msg_sessiond;
ffe60014 1336 }
d88aee68
DG
1337 case LTTNG_CONSUMER_CLOSE_METADATA:
1338 {
1339 int ret;
1340
1341 ret = close_metadata(msg.u.close_metadata.key);
1342 if (ret != 0) {
1343 ret_code = ret;
1344 }
1345
1346 goto end_msg_sessiond;
1347 }
7972aab2
DG
1348 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1349 {
1350 int ret;
1351
1352 ret = flush_channel(msg.u.flush_channel.key);
1353 if (ret != 0) {
1354 ret_code = ret;
1355 }
1356
1357 goto end_msg_sessiond;
1358 }
d88aee68 1359 case LTTNG_CONSUMER_PUSH_METADATA:
ffe60014
DG
1360 {
1361 int ret;
d88aee68 1362 uint64_t len = msg.u.push_metadata.len;
d88aee68 1363 uint64_t key = msg.u.push_metadata.key;
331744e3 1364 uint64_t offset = msg.u.push_metadata.target_offset;
ffe60014
DG
1365 struct lttng_consumer_channel *channel;
1366
8fd623e0
DG
1367 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1368 len);
ffe60014
DG
1369
1370 channel = consumer_find_channel(key);
1371 if (!channel) {
8fd623e0 1372 ERR("UST consumer push metadata %" PRIu64 " not found", key);
ffe60014 1373 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
4a2eb0ca 1374 goto end_msg_sessiond;
d88aee68
DG
1375 }
1376
1377 /* Tell session daemon we are ready to receive the metadata. */
ffe60014
DG
1378 ret = consumer_send_status_msg(sock, LTTNG_OK);
1379 if (ret < 0) {
1380 /* Somehow, the session daemon is not responding anymore. */
d88aee68
DG
1381 goto error_fatal;
1382 }
1383
1384 /* Wait for more data. */
1385 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
489f70e9 1386 goto error_fatal;
d88aee68
DG
1387 }
1388
331744e3
JD
1389 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1390 len, channel);
d88aee68 1391 if (ret < 0) {
331744e3 1392 /* error receiving from sessiond */
489f70e9 1393 goto error_fatal;
331744e3
JD
1394 } else {
1395 ret_code = ret;
d88aee68
DG
1396 goto end_msg_sessiond;
1397 }
d88aee68
DG
1398 }
1399 case LTTNG_CONSUMER_SETUP_METADATA:
1400 {
1401 int ret;
1402
1403 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1404 if (ret) {
1405 ret_code = ret;
1406 }
1407 goto end_msg_sessiond;
ffe60014 1408 }
6dc3064a
DG
1409 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1410 {
10a50311
JD
1411 if (msg.u.snapshot_channel.metadata) {
1412 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1413 msg.u.snapshot_channel.pathname,
1414 msg.u.snapshot_channel.relayd_id,
1415 ctx);
1416 if (ret < 0) {
1417 ERR("Snapshot metadata failed");
1418 ret_code = LTTNG_ERR_UST_META_FAIL;
1419 }
1420 } else {
1421 ret = snapshot_channel(msg.u.snapshot_channel.key,
1422 msg.u.snapshot_channel.pathname,
1423 msg.u.snapshot_channel.relayd_id,
1424 ctx);
1425 if (ret < 0) {
1426 ERR("Snapshot channel failed");
1427 ret_code = LTTNG_ERR_UST_CHAN_FAIL;
1428 }
1429 }
1430
6dc3064a
DG
1431 ret = consumer_send_status_msg(sock, ret_code);
1432 if (ret < 0) {
1433 /* Somehow, the session daemon is not responding anymore. */
1434 goto end_nosignal;
1435 }
1436 break;
1437 }
3bd1e081
MD
1438 default:
1439 break;
1440 }
3f8e211f 1441
3bd1e081 1442end_nosignal:
b0b335c8 1443 rcu_read_unlock();
4cbc1a04
DG
1444
1445 /*
1446 * Return 1 to indicate success since the 0 value can be a socket
1447 * shutdown during the recv() or send() call.
1448 */
1449 return 1;
ffe60014
DG
1450
1451end_msg_sessiond:
1452 /*
1453 * The returned value here is not useful since either way we'll return 1 to
1454 * the caller because the session daemon socket management is done
1455 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1456 */
489f70e9
MD
1457 ret = consumer_send_status_msg(sock, ret_code);
1458 if (ret < 0) {
1459 goto error_fatal;
1460 }
ffe60014
DG
1461 rcu_read_unlock();
1462 return 1;
1463end_channel_error:
1464 if (channel) {
1465 /*
1466 * Free channel here since no one has a reference to it. We don't
1467 * free after that because a stream can store this pointer.
1468 */
1469 destroy_channel(channel);
1470 }
1471 /* We have to send a status channel message indicating an error. */
1472 ret = consumer_send_status_channel(sock, NULL);
1473 if (ret < 0) {
1474 /* Stop everything if session daemon can not be notified. */
1475 goto error_fatal;
1476 }
1477 rcu_read_unlock();
1478 return 1;
1479error_fatal:
1480 rcu_read_unlock();
1481 /* This will issue a consumer stop. */
1482 return -1;
3bd1e081
MD
1483}
1484
ffe60014
DG
1485/*
1486 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1487 * compiled out, we isolate it in this library.
1488 */
1489int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1490 unsigned long *off)
3bd1e081 1491{
ffe60014
DG
1492 assert(stream);
1493 assert(stream->ustream);
b5c5fc29 1494
ffe60014 1495 return ustctl_get_mmap_read_offset(stream->ustream, off);
3bd1e081
MD
1496}
1497
ffe60014
DG
1498/*
1499 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1500 * compiled out, we isolate it in this library.
1501 */
1502void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
d056b477 1503{
ffe60014
DG
1504 assert(stream);
1505 assert(stream->ustream);
1506
1507 return ustctl_get_mmap_base(stream->ustream);
d056b477
MD
1508}
1509
ffe60014
DG
1510/*
1511 * Take a snapshot for a specific fd
1512 *
1513 * Returns 0 on success, < 0 on error
1514 */
1515int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
3bd1e081 1516{
ffe60014
DG
1517 assert(stream);
1518 assert(stream->ustream);
1519
1520 return ustctl_snapshot(stream->ustream);
3bd1e081
MD
1521}
1522
ffe60014
DG
1523/*
1524 * Get the produced position
1525 *
1526 * Returns 0 on success, < 0 on error
1527 */
1528int lttng_ustconsumer_get_produced_snapshot(
1529 struct lttng_consumer_stream *stream, unsigned long *pos)
3bd1e081 1530{
ffe60014
DG
1531 assert(stream);
1532 assert(stream->ustream);
1533 assert(pos);
7a57cf92 1534
ffe60014
DG
1535 return ustctl_snapshot_get_produced(stream->ustream, pos);
1536}
7a57cf92 1537
10a50311
JD
1538/*
1539 * Get the consumed position
1540 *
1541 * Returns 0 on success, < 0 on error
1542 */
1543int lttng_ustconsumer_get_consumed_snapshot(
1544 struct lttng_consumer_stream *stream, unsigned long *pos)
1545{
1546 assert(stream);
1547 assert(stream->ustream);
1548 assert(pos);
1549
1550 return ustctl_snapshot_get_consumed(stream->ustream, pos);
1551}
1552
ffe60014
DG
1553/*
1554 * Called when the stream signal the consumer that it has hang up.
1555 */
1556void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1557{
1558 assert(stream);
1559 assert(stream->ustream);
2c1dd183 1560
ffe60014
DG
1561 ustctl_flush_buffer(stream->ustream, 0);
1562 stream->hangup_flush_done = 1;
1563}
ee77a7b0 1564
ffe60014
DG
1565void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1566{
1567 assert(chan);
1568 assert(chan->uchan);
e316aad5 1569
ea88ca2a
MD
1570 if (chan->switch_timer_enabled == 1) {
1571 consumer_timer_switch_stop(chan);
1572 }
1573 consumer_metadata_cache_destroy(chan);
ffe60014 1574 ustctl_destroy_channel(chan->uchan);
3bd1e081
MD
1575}
1576
1577void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1578{
ffe60014
DG
1579 assert(stream);
1580 assert(stream->ustream);
d41f73b7 1581
ea88ca2a
MD
1582 if (stream->chan->switch_timer_enabled == 1) {
1583 consumer_timer_switch_stop(stream->chan);
1584 }
ffe60014
DG
1585 ustctl_destroy_stream(stream->ustream);
1586}
d41f73b7
MD
1587
1588int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1589 struct lttng_consumer_local_data *ctx)
1590{
1d4dfdef 1591 unsigned long len, subbuf_size, padding;
d41f73b7
MD
1592 int err;
1593 long ret = 0;
d41f73b7 1594 char dummy;
ffe60014
DG
1595 struct ustctl_consumer_stream *ustream;
1596
1597 assert(stream);
1598 assert(stream->ustream);
1599 assert(ctx);
d41f73b7 1600
ffe60014
DG
1601 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1602 stream->name);
1603
1604 /* Ease our life for what's next. */
1605 ustream = stream->ustream;
d41f73b7
MD
1606
1607 /* We can consume the 1 byte written into the wait_fd by UST */
effcf122 1608 if (!stream->hangup_flush_done) {
c617c0c6
MD
1609 ssize_t readlen;
1610
effcf122
MD
1611 do {
1612 readlen = read(stream->wait_fd, &dummy, 1);
87dc6a9c 1613 } while (readlen == -1 && errno == EINTR);
effcf122
MD
1614 if (readlen == -1) {
1615 ret = readlen;
1616 goto end;
1617 }
d41f73b7
MD
1618 }
1619
d41f73b7 1620 /* Get the next subbuffer */
ffe60014 1621 err = ustctl_get_next_subbuf(ustream);
d41f73b7 1622 if (err != 0) {
1d4dfdef 1623 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
d41f73b7
MD
1624 /*
1625 * This is a debug message even for single-threaded consumer,
1626 * because poll() have more relaxed criterions than get subbuf,
1627 * so get_subbuf may fail for short race windows where poll()
1628 * would issue wakeups.
1629 */
1630 DBG("Reserving sub buffer failed (everything is normal, "
ffe60014 1631 "it is due to concurrency) [ret: %d]", err);
d41f73b7
MD
1632 goto end;
1633 }
ffe60014 1634 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1d4dfdef 1635 /* Get the full padded subbuffer size */
ffe60014 1636 err = ustctl_get_padded_subbuf_size(ustream, &len);
effcf122 1637 assert(err == 0);
1d4dfdef
DG
1638
1639 /* Get subbuffer data size (without padding) */
ffe60014 1640 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1d4dfdef
DG
1641 assert(err == 0);
1642
1643 /* Make sure we don't get a subbuffer size bigger than the padded */
1644 assert(len >= subbuf_size);
1645
1646 padding = len - subbuf_size;
d41f73b7 1647 /* write the subbuffer to the tracefile */
1d4dfdef 1648 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
91dfef6e
DG
1649 /*
1650 * The mmap operation should write subbuf_size amount of data when network
1651 * streaming or the full padding (len) size when we are _not_ streaming.
1652 */
d88aee68
DG
1653 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1654 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
d41f73b7 1655 /*
91dfef6e 1656 * Display the error but continue processing to try to release the
c5c45efa
DG
1657 * subbuffer. This is a DBG statement since any unexpected kill or
1658 * signal, the application gets unregistered, relayd gets closed or
1659 * anything that affects the buffer lifetime will trigger this error.
1660 * So, for the sake of the user, don't print this error since it can
1661 * happen and it is OK with the code flow.
d41f73b7 1662 */
c5c45efa 1663 DBG("Error writing to tracefile "
8fd623e0 1664 "(ret: %ld != len: %lu != subbuf_size: %lu)",
91dfef6e 1665 ret, len, subbuf_size);
d41f73b7 1666 }
ffe60014 1667 err = ustctl_put_next_subbuf(ustream);
effcf122 1668 assert(err == 0);
331744e3 1669
d41f73b7
MD
1670end:
1671 return ret;
1672}
1673
ffe60014
DG
1674/*
1675 * Called when a stream is created.
fe4477ee
JD
1676 *
1677 * Return 0 on success or else a negative value.
ffe60014 1678 */
d41f73b7
MD
1679int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
1680{
fe4477ee
JD
1681 int ret;
1682
10a50311
JD
1683 assert(stream);
1684
fe4477ee 1685 /* Don't create anything if this is set for streaming. */
10a50311 1686 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
fe4477ee
JD
1687 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
1688 stream->chan->tracefile_size, stream->tracefile_count_current,
1689 stream->uid, stream->gid);
1690 if (ret < 0) {
1691 goto error;
1692 }
1693 stream->out_fd = ret;
1694 stream->tracefile_size_current = 0;
1695 }
1696 ret = 0;
1697
1698error:
1699 return ret;
d41f73b7 1700}
ca22feea
DG
1701
1702/*
1703 * Check if data is still being extracted from the buffers for a specific
4e9a4686
DG
1704 * stream. Consumer data lock MUST be acquired before calling this function
1705 * and the stream lock.
ca22feea 1706 *
6d805429 1707 * Return 1 if the traced data are still getting read else 0 meaning that the
ca22feea
DG
1708 * data is available for trace viewer reading.
1709 */
6d805429 1710int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
ca22feea
DG
1711{
1712 int ret;
1713
1714 assert(stream);
ffe60014 1715 assert(stream->ustream);
ca22feea 1716
6d805429 1717 DBG("UST consumer checking data pending");
c8f59ee5 1718
ffe60014 1719 ret = ustctl_get_next_subbuf(stream->ustream);
ca22feea
DG
1720 if (ret == 0) {
1721 /* There is still data so let's put back this subbuffer. */
ffe60014 1722 ret = ustctl_put_subbuf(stream->ustream);
ca22feea 1723 assert(ret == 0);
6d805429 1724 ret = 1; /* Data is pending */
4e9a4686 1725 goto end;
ca22feea
DG
1726 }
1727
6d805429
DG
1728 /* Data is NOT pending so ready to be read. */
1729 ret = 0;
ca22feea 1730
6efae65e
DG
1731end:
1732 return ret;
ca22feea 1733}
d88aee68
DG
1734
1735/*
1736 * Close every metadata stream wait fd of the metadata hash table. This
1737 * function MUST be used very carefully so not to run into a race between the
1738 * metadata thread handling streams and this function closing their wait fd.
1739 *
1740 * For UST, this is used when the session daemon hangs up. Its the metadata
1741 * producer so calling this is safe because we are assured that no state change
1742 * can occur in the metadata thread for the streams in the hash table.
1743 */
1744void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
1745{
1746 int ret;
1747 struct lttng_ht_iter iter;
1748 struct lttng_consumer_stream *stream;
1749
1750 assert(metadata_ht);
1751 assert(metadata_ht->ht);
1752
1753 DBG("UST consumer closing all metadata streams");
1754
1755 rcu_read_lock();
1756 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
1757 node.node) {
1758 int fd = stream->wait_fd;
1759
1760 /*
1761 * Whatever happens here we have to continue to try to close every
1762 * streams. Let's report at least the error on failure.
1763 */
1764 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1765 if (ret) {
1766 ERR("Unable to close metadata stream fd %d ret %d", fd, ret);
1767 }
1768 DBG("Metadata wait fd %d closed", fd);
1769 }
1770 rcu_read_unlock();
1771}
d8ef542d
MD
1772
1773void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
1774{
1775 int ret;
1776
1777 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1778 if (ret < 0) {
1779 ERR("Unable to close wakeup fd");
1780 }
1781}
331744e3
JD
1782
1783int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
1784 struct lttng_consumer_channel *channel)
1785{
1786 struct lttcomm_metadata_request_msg request;
1787 struct lttcomm_consumer_msg msg;
1788 enum lttng_error_code ret_code = LTTNG_OK;
1789 uint64_t len, key, offset;
1790 int ret;
1791
1792 assert(channel);
1793 assert(channel->metadata_cache);
1794
1795 /* send the metadata request to sessiond */
1796 switch (consumer_data.type) {
1797 case LTTNG_CONSUMER64_UST:
1798 request.bits_per_long = 64;
1799 break;
1800 case LTTNG_CONSUMER32_UST:
1801 request.bits_per_long = 32;
1802 break;
1803 default:
1804 request.bits_per_long = 0;
1805 break;
1806 }
1807
1808 request.session_id = channel->session_id;
1950109e 1809 request.session_id_per_pid = channel->session_id_per_pid;
331744e3
JD
1810 request.uid = channel->uid;
1811 request.key = channel->key;
1950109e
JD
1812 DBG("Sending metadata request to sessiond, session id %" PRIu64
1813 ", per-pid %" PRIu64,
1814 channel->session_id,
1815 channel->session_id_per_pid);
331744e3
JD
1816
1817 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
1818 sizeof(request));
1819 if (ret < 0) {
1820 ERR("Asking metadata to sessiond");
1821 goto end;
1822 }
1823
1824 /* Receive the metadata from sessiond */
1825 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
1826 sizeof(msg));
1827 if (ret != sizeof(msg)) {
8fd623e0 1828 DBG("Consumer received unexpected message size %d (expects %zu)",
331744e3
JD
1829 ret, sizeof(msg));
1830 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1831 /*
1832 * The ret value might 0 meaning an orderly shutdown but this is ok
1833 * since the caller handles this.
1834 */
1835 goto end;
1836 }
1837
1838 if (msg.cmd_type == LTTNG_ERR_UND) {
1839 /* No registry found */
1840 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
1841 ret_code);
1842 ret = 0;
1843 goto end;
1844 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
1845 ERR("Unexpected cmd_type received %d", msg.cmd_type);
1846 ret = -1;
1847 goto end;
1848 }
1849
1850 len = msg.u.push_metadata.len;
1851 key = msg.u.push_metadata.key;
1852 offset = msg.u.push_metadata.target_offset;
1853
1854 assert(key == channel->key);
1855 if (len == 0) {
1856 DBG("No new metadata to receive for key %" PRIu64, key);
1857 }
1858
1859 /* Tell session daemon we are ready to receive the metadata. */
1860 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
1861 LTTNG_OK);
1862 if (ret < 0 || len == 0) {
1863 /*
1864 * Somehow, the session daemon is not responding anymore or there is
1865 * nothing to receive.
1866 */
1867 goto end;
1868 }
1869
1870 ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
1871 key, offset, len, channel);
f2a444f1
DG
1872 if (ret_code >= 0) {
1873 /*
1874 * Only send the status msg if the sessiond is alive meaning a positive
1875 * ret code.
1876 */
1877 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
1878 }
331744e3
JD
1879 ret = 0;
1880
1881end:
1882 return ret;
1883}
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