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