91f6b5ca15a6ddbdcbc8f28e641f824e34a4c64d
[lttng-tools.git] / src / common / consumer.h
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #ifndef LIB_CONSUMER_H
21 #define LIB_CONSUMER_H
22
23 #include <limits.h>
24 #include <poll.h>
25 #include <unistd.h>
26 #include <urcu/list.h>
27
28 #include <lttng/lttng.h>
29
30 #include <common/hashtable/hashtable.h>
31 #include <common/compat/fcntl.h>
32 #include <common/compat/uuid.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <common/pipe.h>
35
36 /* Commands for consumer */
37 enum lttng_consumer_command {
38 LTTNG_CONSUMER_ADD_CHANNEL,
39 LTTNG_CONSUMER_ADD_STREAM,
40 /* pause, delete, active depending on fd state */
41 LTTNG_CONSUMER_UPDATE_STREAM,
42 /* inform the consumer to quit when all fd has hang up */
43 LTTNG_CONSUMER_STOP,
44 LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
45 /* Inform the consumer to kill a specific relayd connection */
46 LTTNG_CONSUMER_DESTROY_RELAYD,
47 /* Return to the sessiond if there is data pending for a session */
48 LTTNG_CONSUMER_DATA_PENDING,
49 /* Consumer creates a channel and returns it to sessiond. */
50 LTTNG_CONSUMER_ASK_CHANNEL_CREATION,
51 LTTNG_CONSUMER_GET_CHANNEL,
52 LTTNG_CONSUMER_DESTROY_CHANNEL,
53 LTTNG_CONSUMER_PUSH_METADATA,
54 LTTNG_CONSUMER_CLOSE_METADATA,
55 LTTNG_CONSUMER_SETUP_METADATA,
56 LTTNG_CONSUMER_FLUSH_CHANNEL,
57 LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
58 LTTNG_CONSUMER_SNAPSHOT_METADATA,
59 };
60
61 /* State of each fd in consumer */
62 enum lttng_consumer_stream_state {
63 LTTNG_CONSUMER_ACTIVE_STREAM,
64 LTTNG_CONSUMER_PAUSE_STREAM,
65 LTTNG_CONSUMER_DELETE_STREAM,
66 };
67
68 enum lttng_consumer_type {
69 LTTNG_CONSUMER_UNKNOWN = 0,
70 LTTNG_CONSUMER_KERNEL,
71 LTTNG_CONSUMER64_UST,
72 LTTNG_CONSUMER32_UST,
73 };
74
75 enum consumer_endpoint_status {
76 CONSUMER_ENDPOINT_ACTIVE,
77 CONSUMER_ENDPOINT_INACTIVE,
78 };
79
80 enum consumer_channel_output {
81 CONSUMER_CHANNEL_MMAP = 0,
82 CONSUMER_CHANNEL_SPLICE = 1,
83 };
84
85 enum consumer_channel_type {
86 CONSUMER_CHANNEL_TYPE_METADATA = 0,
87 CONSUMER_CHANNEL_TYPE_DATA = 1,
88 };
89
90 extern struct lttng_consumer_global_data consumer_data;
91
92 struct stream_list {
93 struct cds_list_head head;
94 unsigned int count;
95 };
96
97 /* Stub. */
98 struct consumer_metadata_cache;
99
100 struct lttng_consumer_channel {
101 /* HT node used for consumer_data.channel_ht */
102 struct lttng_ht_node_u64 node;
103 /* Indexed key. Incremented value in the consumer. */
104 uint64_t key;
105 /* Number of streams referencing this channel */
106 int refcount;
107 /* Tracing session id on the session daemon side. */
108 uint64_t session_id;
109 /*
110 * Session id when requesting metadata to the session daemon for
111 * a session with per-PID buffers.
112 */
113 uint64_t session_id_per_pid;
114 /* Channel trace file path name. */
115 char pathname[PATH_MAX];
116 /* Channel name. */
117 char name[LTTNG_SYMBOL_NAME_LEN];
118 /* UID and GID of the session owning this channel. */
119 uid_t uid;
120 gid_t gid;
121 /* Relayd id of the channel. -1ULL if it does not apply. */
122 uint64_t relayd_id;
123 /*
124 * Number of streams NOT initialized yet. This is used in order to not
125 * delete this channel if streams are getting initialized.
126 */
127 unsigned int nb_init_stream_left;
128 /* Output type (mmap or splice). */
129 enum consumer_channel_output output;
130 /* Channel type for stream */
131 enum consumer_channel_type type;
132
133 /* For UST */
134 uid_t ust_app_uid; /* Application UID. */
135 struct ustctl_consumer_channel *uchan;
136 unsigned char uuid[UUID_STR_LEN];
137 /*
138 * Temporary stream list used to store the streams once created and waiting
139 * to be sent to the session daemon by receiving the
140 * LTTNG_CONSUMER_GET_CHANNEL.
141 */
142 struct stream_list streams;
143
144 /*
145 * Set if the channel is metadata. We keep a reference to the stream
146 * because we have to flush data once pushed by the session daemon. For a
147 * regular channel, this is always set to NULL.
148 */
149 struct lttng_consumer_stream *metadata_stream;
150
151 /* for UST */
152 int wait_fd;
153 /* Node within channel thread ht */
154 struct lttng_ht_node_u64 wait_fd_node;
155
156 /* Metadata cache is metadata channel */
157 struct consumer_metadata_cache *metadata_cache;
158 /* For metadata periodical flush */
159 int switch_timer_enabled;
160 timer_t switch_timer;
161 int switch_timer_error;
162
163 /* On-disk circular buffer */
164 uint64_t tracefile_size;
165 uint64_t tracefile_count;
166 /*
167 * Monitor or not the streams of this channel meaning this indicates if the
168 * streams should be sent to the data/metadata thread or added to the no
169 * monitor list of the channel.
170 */
171 unsigned int monitor;
172
173 /*
174 * Channel lock.
175 *
176 * This lock protects against concurrent update of channel.
177 *
178 * This is nested INSIDE the consumer data lock.
179 * This is nested OUTSIDE the channel timer lock.
180 * This is nested OUTSIDE the metadata cache lock.
181 * This is nested OUTSIDE stream lock.
182 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
183 */
184 pthread_mutex_t lock;
185
186 /*
187 * Channel teardown lock.
188 *
189 * This lock protect against teardown of channel. It is _never_
190 * taken by the timer handler.
191 *
192 * This is nested INSIDE the consumer data lock.
193 * This is nested INSIDE the channel lock.
194 * This is nested OUTSIDE the metadata cache lock.
195 * This is nested OUTSIDE stream lock.
196 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
197 */
198 pthread_mutex_t timer_lock;
199 };
200
201 /*
202 * Internal representation of the streams, sessiond_key is used to identify
203 * uniquely a stream.
204 */
205 struct lttng_consumer_stream {
206 /* HT node used by the data_ht and metadata_ht */
207 struct lttng_ht_node_u64 node;
208 /* stream indexed per channel key node */
209 struct lttng_ht_node_u64 node_channel_id;
210 /* HT node used in consumer_data.stream_list_ht */
211 struct lttng_ht_node_u64 node_session_id;
212 /* Pointer to associated channel. */
213 struct lttng_consumer_channel *chan;
214
215 /* Key by which the stream is indexed for 'node'. */
216 uint64_t key;
217 /*
218 * File descriptor of the data output file. This can be either a file or a
219 * socket fd for relayd streaming.
220 */
221 int out_fd; /* output file to write the data */
222 /* Write position in the output file descriptor */
223 off_t out_fd_offset;
224 /* Amount of bytes written to the output */
225 uint64_t output_written;
226 enum lttng_consumer_stream_state state;
227 int shm_fd_is_copy;
228 int data_read;
229 int hangup_flush_done;
230 enum lttng_event_output output;
231 /* Maximum subbuffer size. */
232 unsigned long max_sb_size;
233
234 /*
235 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
236 * used for the mmap base and offset.
237 */
238 void *mmap_base;
239 unsigned long mmap_len;
240
241 /* For UST */
242
243 int wait_fd;
244 /* UID/GID of the user owning the session to which stream belongs */
245 uid_t uid;
246 gid_t gid;
247 /* Network sequence number. Indicating on which relayd socket it goes. */
248 uint64_t net_seq_idx;
249 /*
250 * Indicate if this stream was successfully sent to a relayd. This is set
251 * after the refcount of the relayd is incremented and is checked when the
252 * stream is closed before decrementing the refcount in order to avoid an
253 * unbalanced state.
254 */
255 unsigned int sent_to_relayd;
256
257 /* Identify if the stream is the metadata */
258 unsigned int metadata_flag;
259 /* Used when the stream is set for network streaming */
260 uint64_t relayd_stream_id;
261 /*
262 * When sending a stream packet to a relayd, this number is used to track
263 * the packet sent by the consumer and seen by the relayd. When sending the
264 * data header to the relayd, this number is sent and if the transmission
265 * was successful, it is incremented.
266 *
267 * Even if the full data is not fully transmitted it won't matter since
268 * only two possible error can happen after that where either the relayd
269 * died or a read error is detected on the stream making this value useless
270 * after that.
271 *
272 * This value SHOULD be read/updated atomically or with the lock acquired.
273 */
274 uint64_t next_net_seq_num;
275 /*
276 * Lock to use the stream FDs since they are used between threads.
277 *
278 * This is nested INSIDE the consumer_data lock.
279 * This is nested INSIDE the metadata cache lock.
280 * This is nested INSIDE the channel lock.
281 * This is nested INSIDE the channel timer lock.
282 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
283 */
284 pthread_mutex_t lock;
285 /* Tracing session id */
286 uint64_t session_id;
287 /*
288 * Indicates if the stream end point is still active or not (network
289 * streaming or local file system). The thread "owning" the stream is
290 * handling this status and can be notified of a state change through the
291 * consumer data appropriate pipe.
292 */
293 enum consumer_endpoint_status endpoint_status;
294 /* Stream name. Format is: <channel_name>_<cpu_number> */
295 char name[LTTNG_SYMBOL_NAME_LEN];
296 /* Internal state of libustctl. */
297 struct ustctl_consumer_stream *ustream;
298 struct cds_list_head send_node;
299 /* On-disk circular buffer */
300 uint64_t tracefile_size_current;
301 uint64_t tracefile_count_current;
302 /*
303 * Monitor or not the streams of this channel meaning this indicates if the
304 * streams should be sent to the data/metadata thread or added to the no
305 * monitor list of the channel.
306 */
307 unsigned int monitor;
308 /*
309 * Indicate if the stream is globally visible meaning that it has been
310 * added to the multiple hash tables. If *not* set, NO lock should be
311 * acquired in the destroy path.
312 */
313 unsigned int globally_visible;
314 /*
315 * Pipe to wake up the metadata poll thread when the UST metadata
316 * cache is updated.
317 */
318 int ust_metadata_poll_pipe[2];
319 /*
320 * How much metadata was read from the metadata cache and sent
321 * to the channel.
322 */
323 uint64_t ust_metadata_pushed;
324 };
325
326 /*
327 * Internal representation of a relayd socket pair.
328 */
329 struct consumer_relayd_sock_pair {
330 /* Network sequence number. */
331 uint64_t net_seq_idx;
332 /* Number of stream associated with this relayd */
333 unsigned int refcount;
334
335 /*
336 * This flag indicates whether or not we should destroy this object. The
337 * destruction should ONLY occurs when this flag is set and the refcount is
338 * set to zero.
339 */
340 unsigned int destroy_flag;
341
342 /*
343 * Mutex protecting the control socket to avoid out of order packets
344 * between threads sending data to the relayd. Since metadata data is sent
345 * over that socket, at least two sendmsg() are needed (header + data)
346 * creating a race for packets to overlap between threads using it.
347 *
348 * This is nested INSIDE the consumer_data lock.
349 * This is nested INSIDE the stream lock.
350 */
351 pthread_mutex_t ctrl_sock_mutex;
352
353 /* Control socket. Command and metadata are passed over it */
354 struct lttcomm_relayd_sock control_sock;
355
356 /*
357 * We don't need a mutex at this point since we only splice or write single
358 * large chunk of data with a header appended at the begining. Moreover,
359 * this socket is for now only used in a single thread.
360 */
361 struct lttcomm_relayd_sock data_sock;
362 struct lttng_ht_node_u64 node;
363
364 /* Session id on both sides for the sockets. */
365 uint64_t relayd_session_id;
366 uint64_t sessiond_session_id;
367 };
368
369 /*
370 * UST consumer local data to the program. One or more instance per
371 * process.
372 */
373 struct lttng_consumer_local_data {
374 /*
375 * Function to call when data is available on a buffer.
376 * Returns the number of bytes read, or negative error value.
377 */
378 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
379 struct lttng_consumer_local_data *ctx);
380 /*
381 * function to call when we receive a new channel, it receives a
382 * newly allocated channel, depending on the return code of this
383 * function, the new channel will be handled by the application
384 * or the library.
385 *
386 * Returns:
387 * > 0 (success, FD is kept by application)
388 * == 0 (success, FD is left to library)
389 * < 0 (error)
390 */
391 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
392 /*
393 * function to call when we receive a new stream, it receives a
394 * newly allocated stream, depending on the return code of this
395 * function, the new stream will be handled by the application
396 * or the library.
397 *
398 * Returns:
399 * > 0 (success, FD is kept by application)
400 * == 0 (success, FD is left to library)
401 * < 0 (error)
402 */
403 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
404 /*
405 * function to call when a stream is getting updated by the session
406 * daemon, this function receives the sessiond key and the new
407 * state, depending on the return code of this function the
408 * update of state for the stream is handled by the application
409 * or the library.
410 *
411 * Returns:
412 * > 0 (success, FD is kept by application)
413 * == 0 (success, FD is left to library)
414 * < 0 (error)
415 */
416 int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
417 enum lttng_consumer_type type;
418 /* socket to communicate errors with sessiond */
419 int consumer_error_socket;
420 /* socket to ask metadata to sessiond. */
421 int consumer_metadata_socket;
422 /*
423 * Protect consumer_metadata_socket.
424 *
425 * This is nested OUTSIDE the metadata cache lock.
426 */
427 pthread_mutex_t metadata_socket_lock;
428 /* socket to exchange commands with sessiond */
429 char *consumer_command_sock_path;
430 /* communication with splice */
431 int consumer_thread_pipe[2];
432 int consumer_channel_pipe[2];
433 int consumer_splice_metadata_pipe[2];
434 /* Data stream poll thread pipe. To transfer data stream to the thread */
435 struct lttng_pipe *consumer_data_pipe;
436 /* to let the signal handler wake up the fd receiver thread */
437 int consumer_should_quit[2];
438 /* Metadata poll thread pipe. Transfer metadata stream to it */
439 struct lttng_pipe *consumer_metadata_pipe;
440 };
441
442 /*
443 * Library-level data. One instance per process.
444 */
445 struct lttng_consumer_global_data {
446 /*
447 * At this time, this lock is used to ensure coherence between the count
448 * and number of element in the hash table. It's also a protection for
449 * concurrent read/write between threads.
450 *
451 * This is nested OUTSIDE the stream lock.
452 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
453 */
454 pthread_mutex_t lock;
455
456 /*
457 * Number of streams in the data stream hash table declared outside.
458 * Protected by consumer_data.lock.
459 */
460 int stream_count;
461
462 /* Channel hash table protected by consumer_data.lock. */
463 struct lttng_ht *channel_ht;
464 /*
465 * Flag specifying if the local array of FDs needs update in the
466 * poll function. Protected by consumer_data.lock.
467 */
468 unsigned int need_update;
469 enum lttng_consumer_type type;
470
471 /*
472 * Relayd socket(s) hashtable indexed by network sequence number. Each
473 * stream has an index which associate the right relayd socket to use.
474 */
475 struct lttng_ht *relayd_ht;
476
477 /*
478 * This hash table contains all streams (metadata and data) indexed by
479 * session id. In other words, the ht is indexed by session id and each
480 * bucket contains the list of associated streams.
481 *
482 * This HT uses the "node_session_id" of the consumer stream.
483 */
484 struct lttng_ht *stream_list_ht;
485
486 /*
487 * This HT uses the "node_channel_id" of the consumer stream.
488 */
489 struct lttng_ht *stream_per_chan_id_ht;
490 };
491
492 /*
493 * Init consumer data structures.
494 */
495 void lttng_consumer_init(void);
496
497 /*
498 * Set the error socket for communication with a session daemon.
499 */
500 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
501 int sock);
502
503 /*
504 * Set the command socket path for communication with a session daemon.
505 */
506 void lttng_consumer_set_command_sock_path(
507 struct lttng_consumer_local_data *ctx, char *sock);
508
509 /*
510 * Send return code to session daemon.
511 *
512 * Returns the return code of sendmsg : the number of bytes transmitted or -1
513 * on error.
514 */
515 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
516
517 /*
518 * Called from signal handler to ensure a clean exit.
519 */
520 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
521
522 /*
523 * Cleanup the daemon's socket on exit.
524 */
525 void lttng_consumer_cleanup(void);
526
527 /*
528 * Flush pending writes to trace output disk file.
529 */
530 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
531 off_t orig_offset);
532
533 /*
534 * Poll on the should_quit pipe and the command socket return -1 on error and
535 * should exit, 0 if data is available on the command socket
536 */
537 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
538
539 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
540 uint64_t stream_key,
541 enum lttng_consumer_stream_state state,
542 const char *channel_name,
543 uid_t uid,
544 gid_t gid,
545 uint64_t relayd_id,
546 uint64_t session_id,
547 int cpu,
548 int *alloc_ret,
549 enum consumer_channel_type type,
550 unsigned int monitor);
551 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
552 uint64_t session_id,
553 const char *pathname,
554 const char *name,
555 uid_t uid,
556 gid_t gid,
557 uint64_t relayd_id,
558 enum lttng_event_output output,
559 uint64_t tracefile_size,
560 uint64_t tracefile_count,
561 uint64_t session_id_per_pid,
562 unsigned int monitor);
563 void consumer_del_stream(struct lttng_consumer_stream *stream,
564 struct lttng_ht *ht);
565 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
566 struct lttng_ht *ht);
567 int consumer_add_channel(struct lttng_consumer_channel *channel,
568 struct lttng_consumer_local_data *ctx);
569 void consumer_del_channel(struct lttng_consumer_channel *channel);
570
571 /* lttng-relayd consumer command */
572 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
573 uint64_t net_seq_idx);
574 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
575 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
576 void close_relayd_stream(struct lttng_consumer_stream *stream);
577 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
578 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
579 size_t data_size);
580 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
581
582 struct lttng_consumer_local_data *lttng_consumer_create(
583 enum lttng_consumer_type type,
584 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
585 struct lttng_consumer_local_data *ctx),
586 int (*recv_channel)(struct lttng_consumer_channel *channel),
587 int (*recv_stream)(struct lttng_consumer_stream *stream),
588 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
589 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
590 ssize_t lttng_consumer_on_read_subbuffer_mmap(
591 struct lttng_consumer_local_data *ctx,
592 struct lttng_consumer_stream *stream, unsigned long len,
593 unsigned long padding);
594 ssize_t lttng_consumer_on_read_subbuffer_splice(
595 struct lttng_consumer_local_data *ctx,
596 struct lttng_consumer_stream *stream, unsigned long len,
597 unsigned long padding);
598 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
599 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
600 unsigned long *pos);
601 void *consumer_thread_metadata_poll(void *data);
602 void *consumer_thread_data_poll(void *data);
603 void *consumer_thread_sessiond_poll(void *data);
604 void *consumer_thread_channel_poll(void *data);
605 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
606 int sock, struct pollfd *consumer_sockpoll);
607
608 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
609 struct lttng_consumer_local_data *ctx);
610 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
611 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
612 struct lttng_consumer_local_data *ctx, int sock,
613 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
614 uint64_t sessiond_id);
615 void consumer_flag_relayd_for_destroy(
616 struct consumer_relayd_sock_pair *relayd);
617 int consumer_data_pending(uint64_t id);
618 int consumer_send_status_msg(int sock, int ret_code);
619 int consumer_send_status_channel(int sock,
620 struct lttng_consumer_channel *channel);
621 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
622 uint64_t key);
623 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
624 unsigned long consumer_get_consumed_maxsize(unsigned long consumed_pos,
625 unsigned long produced_pos, uint64_t max_stream_size);
626 int consumer_add_data_stream(struct lttng_consumer_stream *stream);
627 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream);
628 int consumer_add_metadata_stream(struct lttng_consumer_stream *stream);
629 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream);
630
631 #endif /* LIB_CONSUMER_H */
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