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