Introduce pipe for UST metadata cache and stream
[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 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 struct ustctl_consumer_channel *uchan;
135 unsigned char uuid[UUID_STR_LEN];
136 /*
137 * Temporary stream list used to store the streams once created and waiting
138 * to be sent to the session daemon by receiving the
139 * LTTNG_CONSUMER_GET_CHANNEL.
140 */
141 struct stream_list streams;
142
143 /*
144 * Set if the channel is metadata. We keep a reference to the stream
145 * because we have to flush data once pushed by the session daemon. For a
146 * regular channel, this is always set to NULL.
147 */
148 struct lttng_consumer_stream *metadata_stream;
149
150 /* for UST */
151 int wait_fd;
152 /* Node within channel thread ht */
153 struct lttng_ht_node_u64 wait_fd_node;
154
155 /* Metadata cache is metadata channel */
156 struct consumer_metadata_cache *metadata_cache;
157 /* For metadata periodical flush */
158 int switch_timer_enabled;
159 timer_t switch_timer;
160 int switch_timer_error;
161
162 /* On-disk circular buffer */
163 uint64_t tracefile_size;
164 uint64_t tracefile_count;
165 /*
166 * Monitor or not the streams of this channel meaning this indicates if the
167 * streams should be sent to the data/metadata thread or added to the no
168 * monitor list of the channel.
169 */
170 unsigned int monitor;
171
172 /*
173 * Channel lock.
174 *
175 * This is nested INSIDE the consumer data lock.
176 * This is nested OUTSIDE the metadata cache lock.
177 * This is nested OUTSIDE stream lock.
178 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
179 */
180 pthread_mutex_t lock;
181 };
182
183 /*
184 * Internal representation of the streams, sessiond_key is used to identify
185 * uniquely a stream.
186 */
187 struct lttng_consumer_stream {
188 /* HT node used by the data_ht and metadata_ht */
189 struct lttng_ht_node_u64 node;
190 /* stream indexed per channel key node */
191 struct lttng_ht_node_u64 node_channel_id;
192 /* HT node used in consumer_data.stream_list_ht */
193 struct lttng_ht_node_u64 node_session_id;
194 /* Pointer to associated channel. */
195 struct lttng_consumer_channel *chan;
196
197 /* Key by which the stream is indexed for 'node'. */
198 uint64_t key;
199 /*
200 * File descriptor of the data output file. This can be either a file or a
201 * socket fd for relayd streaming.
202 */
203 int out_fd; /* output file to write the data */
204 /* Write position in the output file descriptor */
205 off_t out_fd_offset;
206 enum lttng_consumer_stream_state state;
207 int shm_fd_is_copy;
208 int data_read;
209 int hangup_flush_done;
210 enum lttng_event_output output;
211 /* Maximum subbuffer size. */
212 unsigned long max_sb_size;
213
214 /*
215 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
216 * used for the mmap base and offset.
217 */
218 void *mmap_base;
219 unsigned long mmap_len;
220
221 /* For UST */
222
223 int wait_fd;
224 /* UID/GID of the user owning the session to which stream belongs */
225 uid_t uid;
226 gid_t gid;
227 /* Network sequence number. Indicating on which relayd socket it goes. */
228 uint64_t net_seq_idx;
229 /*
230 * Indicate if this stream was successfully sent to a relayd. This is set
231 * after the refcount of the relayd is incremented and is checked when the
232 * stream is closed before decrementing the refcount in order to avoid an
233 * unbalanced state.
234 */
235 unsigned int sent_to_relayd;
236
237 /* Identify if the stream is the metadata */
238 unsigned int metadata_flag;
239 /* Used when the stream is set for network streaming */
240 uint64_t relayd_stream_id;
241 /*
242 * When sending a stream packet to a relayd, this number is used to track
243 * the packet sent by the consumer and seen by the relayd. When sending the
244 * data header to the relayd, this number is sent and if the transmission
245 * was successful, it is incremented.
246 *
247 * Even if the full data is not fully transmitted it won't matter since
248 * only two possible error can happen after that where either the relayd
249 * died or a read error is detected on the stream making this value useless
250 * after that.
251 *
252 * This value SHOULD be read/updated atomically or with the lock acquired.
253 */
254 uint64_t next_net_seq_num;
255 /*
256 * Lock to use the stream FDs since they are used between threads.
257 *
258 * This is nested INSIDE the consumer_data lock.
259 * This is nested INSIDE the metadata cache lock.
260 * This is nested INSIDE the channel lock.
261 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
262 */
263 pthread_mutex_t lock;
264 /* Tracing session id */
265 uint64_t session_id;
266 /*
267 * Indicates if the stream end point is still active or not (network
268 * streaming or local file system). The thread "owning" the stream is
269 * handling this status and can be notified of a state change through the
270 * consumer data appropriate pipe.
271 */
272 enum consumer_endpoint_status endpoint_status;
273 /* Stream name. Format is: <channel_name>_<cpu_number> */
274 char name[LTTNG_SYMBOL_NAME_LEN];
275 /* Internal state of libustctl. */
276 struct ustctl_consumer_stream *ustream;
277 struct cds_list_head send_node;
278 /* On-disk circular buffer */
279 uint64_t tracefile_size_current;
280 uint64_t tracefile_count_current;
281 /*
282 * Monitor or not the streams of this channel meaning this indicates if the
283 * streams should be sent to the data/metadata thread or added to the no
284 * monitor list of the channel.
285 */
286 unsigned int monitor;
287 /*
288 * Indicate if the stream is globally visible meaning that it has been
289 * added to the multiple hash tables. If *not* set, NO lock should be
290 * acquired in the destroy path.
291 */
292 unsigned int globally_visible;
293 /*
294 * Pipe to wake up the metadata poll thread when the UST metadata
295 * cache is updated.
296 */
297 int ust_metadata_poll_pipe[2];
298 /*
299 * How much metadata was read from the metadata cache and sent
300 * to the channel.
301 */
302 uint64_t ust_metadata_pushed;
303 };
304
305 /*
306 * Internal representation of a relayd socket pair.
307 */
308 struct consumer_relayd_sock_pair {
309 /* Network sequence number. */
310 uint64_t net_seq_idx;
311 /* Number of stream associated with this relayd */
312 unsigned int refcount;
313
314 /*
315 * This flag indicates whether or not we should destroy this object. The
316 * destruction should ONLY occurs when this flag is set and the refcount is
317 * set to zero.
318 */
319 unsigned int destroy_flag;
320
321 /*
322 * Mutex protecting the control socket to avoid out of order packets
323 * between threads sending data to the relayd. Since metadata data is sent
324 * over that socket, at least two sendmsg() are needed (header + data)
325 * creating a race for packets to overlap between threads using it.
326 *
327 * This is nested INSIDE the consumer_data lock.
328 * This is nested INSIDE the stream lock.
329 */
330 pthread_mutex_t ctrl_sock_mutex;
331
332 /* Control socket. Command and metadata are passed over it */
333 struct lttcomm_relayd_sock control_sock;
334
335 /*
336 * We don't need a mutex at this point since we only splice or write single
337 * large chunk of data with a header appended at the begining. Moreover,
338 * this socket is for now only used in a single thread.
339 */
340 struct lttcomm_relayd_sock data_sock;
341 struct lttng_ht_node_u64 node;
342
343 /* Session id on both sides for the sockets. */
344 uint64_t relayd_session_id;
345 uint64_t sessiond_session_id;
346 };
347
348 /*
349 * UST consumer local data to the program. One or more instance per
350 * process.
351 */
352 struct lttng_consumer_local_data {
353 /*
354 * Function to call when data is available on a buffer.
355 * Returns the number of bytes read, or negative error value.
356 */
357 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
358 struct lttng_consumer_local_data *ctx);
359 /*
360 * function to call when we receive a new channel, it receives a
361 * newly allocated channel, depending on the return code of this
362 * function, the new channel will be handled by the application
363 * or the library.
364 *
365 * Returns:
366 * > 0 (success, FD is kept by application)
367 * == 0 (success, FD is left to library)
368 * < 0 (error)
369 */
370 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
371 /*
372 * function to call when we receive a new stream, it receives a
373 * newly allocated stream, depending on the return code of this
374 * function, the new stream will be handled by the application
375 * or the library.
376 *
377 * Returns:
378 * > 0 (success, FD is kept by application)
379 * == 0 (success, FD is left to library)
380 * < 0 (error)
381 */
382 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
383 /*
384 * function to call when a stream is getting updated by the session
385 * daemon, this function receives the sessiond key and the new
386 * state, depending on the return code of this function the
387 * update of state for the stream is handled by the application
388 * or the library.
389 *
390 * Returns:
391 * > 0 (success, FD is kept by application)
392 * == 0 (success, FD is left to library)
393 * < 0 (error)
394 */
395 int (*on_update_stream)(uint64_t sessiond_key, uint32_t state);
396 enum lttng_consumer_type type;
397 /* socket to communicate errors with sessiond */
398 int consumer_error_socket;
399 /* socket to ask metadata to sessiond */
400 int consumer_metadata_socket;
401 /* socket to exchange commands with sessiond */
402 char *consumer_command_sock_path;
403 /* communication with splice */
404 int consumer_thread_pipe[2];
405 int consumer_channel_pipe[2];
406 int consumer_splice_metadata_pipe[2];
407 /* Data stream poll thread pipe. To transfer data stream to the thread */
408 struct lttng_pipe *consumer_data_pipe;
409 /* to let the signal handler wake up the fd receiver thread */
410 int consumer_should_quit[2];
411 /* Metadata poll thread pipe. Transfer metadata stream to it */
412 struct lttng_pipe *consumer_metadata_pipe;
413 };
414
415 /*
416 * Library-level data. One instance per process.
417 */
418 struct lttng_consumer_global_data {
419 /*
420 * At this time, this lock is used to ensure coherence between the count
421 * and number of element in the hash table. It's also a protection for
422 * concurrent read/write between threads.
423 *
424 * This is nested OUTSIDE the stream lock.
425 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
426 */
427 pthread_mutex_t lock;
428
429 /*
430 * Number of streams in the data stream hash table declared outside.
431 * Protected by consumer_data.lock.
432 */
433 int stream_count;
434
435 /* Channel hash table protected by consumer_data.lock. */
436 struct lttng_ht *channel_ht;
437 /*
438 * Flag specifying if the local array of FDs needs update in the
439 * poll function. Protected by consumer_data.lock.
440 */
441 unsigned int need_update;
442 enum lttng_consumer_type type;
443
444 /*
445 * Relayd socket(s) hashtable indexed by network sequence number. Each
446 * stream has an index which associate the right relayd socket to use.
447 */
448 struct lttng_ht *relayd_ht;
449
450 /*
451 * This hash table contains all streams (metadata and data) indexed by
452 * session id. In other words, the ht is indexed by session id and each
453 * bucket contains the list of associated streams.
454 *
455 * This HT uses the "node_session_id" of the consumer stream.
456 */
457 struct lttng_ht *stream_list_ht;
458
459 /*
460 * This HT uses the "node_channel_id" of the consumer stream.
461 */
462 struct lttng_ht *stream_per_chan_id_ht;
463 };
464
465 /*
466 * Init consumer data structures.
467 */
468 void lttng_consumer_init(void);
469
470 /*
471 * Set the error socket for communication with a session daemon.
472 */
473 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
474 int sock);
475
476 /*
477 * Set the command socket path for communication with a session daemon.
478 */
479 void lttng_consumer_set_command_sock_path(
480 struct lttng_consumer_local_data *ctx, char *sock);
481
482 /*
483 * Send return code to session daemon.
484 *
485 * Returns the return code of sendmsg : the number of bytes transmitted or -1
486 * on error.
487 */
488 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
489
490 /*
491 * Called from signal handler to ensure a clean exit.
492 */
493 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
494
495 /*
496 * Cleanup the daemon's socket on exit.
497 */
498 void lttng_consumer_cleanup(void);
499
500 /*
501 * Flush pending writes to trace output disk file.
502 */
503 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
504 off_t orig_offset);
505
506 /*
507 * Poll on the should_quit pipe and the command socket return -1 on error and
508 * should exit, 0 if data is available on the command socket
509 */
510 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
511
512 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
513 uint64_t stream_key,
514 enum lttng_consumer_stream_state state,
515 const char *channel_name,
516 uid_t uid,
517 gid_t gid,
518 uint64_t relayd_id,
519 uint64_t session_id,
520 int cpu,
521 int *alloc_ret,
522 enum consumer_channel_type type,
523 unsigned int monitor);
524 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
525 uint64_t session_id,
526 const char *pathname,
527 const char *name,
528 uid_t uid,
529 gid_t gid,
530 uint64_t relayd_id,
531 enum lttng_event_output output,
532 uint64_t tracefile_size,
533 uint64_t tracefile_count,
534 uint64_t session_id_per_pid,
535 unsigned int monitor);
536 void consumer_del_stream(struct lttng_consumer_stream *stream,
537 struct lttng_ht *ht);
538 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
539 struct lttng_ht *ht);
540 int consumer_add_channel(struct lttng_consumer_channel *channel,
541 struct lttng_consumer_local_data *ctx);
542 void consumer_del_channel(struct lttng_consumer_channel *channel);
543
544 /* lttng-relayd consumer command */
545 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
546 uint64_t net_seq_idx);
547 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
548 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
549 void close_relayd_stream(struct lttng_consumer_stream *stream);
550 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
551 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
552 size_t data_size);
553 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
554
555 struct lttng_consumer_local_data *lttng_consumer_create(
556 enum lttng_consumer_type type,
557 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
558 struct lttng_consumer_local_data *ctx),
559 int (*recv_channel)(struct lttng_consumer_channel *channel),
560 int (*recv_stream)(struct lttng_consumer_stream *stream),
561 int (*update_stream)(uint64_t sessiond_key, uint32_t state));
562 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
563 ssize_t lttng_consumer_on_read_subbuffer_mmap(
564 struct lttng_consumer_local_data *ctx,
565 struct lttng_consumer_stream *stream, unsigned long len,
566 unsigned long padding);
567 ssize_t lttng_consumer_on_read_subbuffer_splice(
568 struct lttng_consumer_local_data *ctx,
569 struct lttng_consumer_stream *stream, unsigned long len,
570 unsigned long padding);
571 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
572 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
573 unsigned long *pos);
574 void *consumer_thread_metadata_poll(void *data);
575 void *consumer_thread_data_poll(void *data);
576 void *consumer_thread_sessiond_poll(void *data);
577 void *consumer_thread_channel_poll(void *data);
578 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
579 int sock, struct pollfd *consumer_sockpoll);
580
581 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
582 struct lttng_consumer_local_data *ctx);
583 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
584 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
585 struct lttng_consumer_local_data *ctx, int sock,
586 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
587 uint64_t sessiond_id);
588 void consumer_flag_relayd_for_destroy(
589 struct consumer_relayd_sock_pair *relayd);
590 int consumer_data_pending(uint64_t id);
591 int consumer_send_status_msg(int sock, int ret_code);
592 int consumer_send_status_channel(int sock,
593 struct lttng_consumer_channel *channel);
594 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
595 uint64_t key);
596 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
597 unsigned long consumer_get_consumed_maxsize(unsigned long consumed_pos,
598 unsigned long produced_pos, uint64_t max_stream_size);
599
600 #endif /* LIB_CONSUMER_H */
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