3726fd1e6a2b19b3ca35623243524fd8e608fda9
[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 };
58
59 /* State of each fd in consumer */
60 enum lttng_consumer_stream_state {
61 LTTNG_CONSUMER_ACTIVE_STREAM,
62 LTTNG_CONSUMER_PAUSE_STREAM,
63 LTTNG_CONSUMER_DELETE_STREAM,
64 };
65
66 enum lttng_consumer_type {
67 LTTNG_CONSUMER_UNKNOWN = 0,
68 LTTNG_CONSUMER_KERNEL,
69 LTTNG_CONSUMER64_UST,
70 LTTNG_CONSUMER32_UST,
71 };
72
73 enum consumer_endpoint_status {
74 CONSUMER_ENDPOINT_ACTIVE,
75 CONSUMER_ENDPOINT_INACTIVE,
76 };
77
78 enum consumer_channel_output {
79 CONSUMER_CHANNEL_MMAP = 0,
80 CONSUMER_CHANNEL_SPLICE = 1,
81 };
82
83 enum consumer_channel_type {
84 CONSUMER_CHANNEL_TYPE_METADATA = 0,
85 CONSUMER_CHANNEL_TYPE_DATA = 1,
86 };
87
88 struct stream_list {
89 struct cds_list_head head;
90 unsigned int count;
91 };
92
93 /* Stub. */
94 struct consumer_metadata_cache;
95
96 struct lttng_consumer_channel {
97 /* HT node used for consumer_data.channel_ht */
98 struct lttng_ht_node_u64 node;
99 /* Indexed key. Incremented value in the consumer. */
100 uint64_t key;
101 /* Number of streams referencing this channel */
102 int refcount;
103 /* Tracing session id on the session daemon side. */
104 uint64_t session_id;
105 /* Channel trace file path name. */
106 char pathname[PATH_MAX];
107 /* Channel name. */
108 char name[LTTNG_SYMBOL_NAME_LEN];
109 /* UID and GID of the channel. */
110 uid_t uid;
111 gid_t gid;
112 /* Relayd id of the channel. -1 if it does not apply. */
113 int64_t relayd_id;
114 /*
115 * Number of streams NOT initialized yet. This is used in order to not
116 * delete this channel if streams are getting initialized.
117 */
118 unsigned int nb_init_stream_left;
119 /* Output type (mmap or splice). */
120 enum consumer_channel_output output;
121 /* Channel type for stream */
122 enum consumer_channel_type type;
123
124 /* For UST */
125 struct ustctl_consumer_channel *uchan;
126 unsigned char uuid[UUID_STR_LEN];
127 /*
128 * Temporary stream list used to store the streams once created and waiting
129 * to be sent to the session daemon by receiving the
130 * LTTNG_CONSUMER_GET_CHANNEL.
131 */
132 struct stream_list streams;
133 /*
134 * Set if the channel is metadata. We keep a reference to the stream
135 * because we have to flush data once pushed by the session daemon. For a
136 * regular channel, this is always set to NULL.
137 */
138 struct lttng_consumer_stream *metadata_stream;
139
140 /* for UST */
141 int wait_fd;
142 /* Node within channel thread ht */
143 struct lttng_ht_node_u64 wait_fd_node;
144
145 /* Metadata cache is metadata channel */
146 struct consumer_metadata_cache *metadata_cache;
147 /* For metadata periodical flush */
148 int switch_timer_enabled;
149 timer_t switch_timer;
150 int switch_timer_error;
151
152 /* On-disk circular buffer */
153 uint64_t tracefile_size;
154 uint64_t tracefile_count;
155 };
156
157 /*
158 * Internal representation of the streams, sessiond_key is used to identify
159 * uniquely a stream.
160 */
161 struct lttng_consumer_stream {
162 /* HT node used by the data_ht and metadata_ht */
163 struct lttng_ht_node_u64 node;
164 /* stream indexed per channel key node */
165 struct lttng_ht_node_u64 node_channel_id;
166 /* HT node used in consumer_data.stream_list_ht */
167 struct lttng_ht_node_u64 node_session_id;
168 /* Pointer to associated channel. */
169 struct lttng_consumer_channel *chan;
170
171 /* Key by which the stream is indexed for 'node'. */
172 uint64_t key;
173 /*
174 * File descriptor of the data output file. This can be either a file or a
175 * socket fd for relayd streaming.
176 */
177 int out_fd; /* output file to write the data */
178 /* Write position in the output file descriptor */
179 off_t out_fd_offset;
180 enum lttng_consumer_stream_state state;
181 int shm_fd_is_copy;
182 int data_read;
183 int hangup_flush_done;
184 enum lttng_event_output output;
185 /* Maximum subbuffer size. */
186 unsigned long max_sb_size;
187
188 /*
189 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
190 * used for the mmap base and offset.
191 */
192 void *mmap_base;
193 unsigned long mmap_len;
194
195 /* For UST */
196
197 int wait_fd;
198 /* UID/GID of the user owning the session to which stream belongs */
199 uid_t uid;
200 gid_t gid;
201 /* Network sequence number. Indicating on which relayd socket it goes. */
202 uint64_t net_seq_idx;
203 /* Identify if the stream is the metadata */
204 unsigned int metadata_flag;
205 /* Used when the stream is set for network streaming */
206 uint64_t relayd_stream_id;
207 /*
208 * When sending a stream packet to a relayd, this number is used to track
209 * the packet sent by the consumer and seen by the relayd. When sending the
210 * data header to the relayd, this number is sent and if the transmission
211 * was successful, it is incremented.
212 *
213 * Even if the full data is not fully transmitted it won't matter since
214 * only two possible error can happen after that where either the relayd
215 * died or a read error is detected on the stream making this value useless
216 * after that.
217 *
218 * This value SHOULD be read/updated atomically or with the lock acquired.
219 */
220 uint64_t next_net_seq_num;
221 /*
222 * Lock to use the stream FDs since they are used between threads.
223 *
224 * This is nested INSIDE the consumer_data lock.
225 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
226 */
227 pthread_mutex_t lock;
228 /* Tracing session id */
229 uint64_t session_id;
230 /*
231 * Indicates if the stream end point is still active or not (network
232 * streaming or local file system). The thread "owning" the stream is
233 * handling this status and can be notified of a state change through the
234 * consumer data appropriate pipe.
235 */
236 enum consumer_endpoint_status endpoint_status;
237 /* Stream name. Format is: <channel_name>_<cpu_number> */
238 char name[LTTNG_SYMBOL_NAME_LEN];
239 /* Internal state of libustctl. */
240 struct ustctl_consumer_stream *ustream;
241 struct cds_list_head send_node;
242 /* On-disk circular buffer */
243 uint64_t tracefile_size_current;
244 uint64_t tracefile_count_current;
245 };
246
247 /*
248 * Internal representation of a relayd socket pair.
249 */
250 struct consumer_relayd_sock_pair {
251 /* Network sequence number. */
252 int64_t net_seq_idx;
253 /* Number of stream associated with this relayd */
254 unsigned int refcount;
255
256 /*
257 * This flag indicates whether or not we should destroy this object. The
258 * destruction should ONLY occurs when this flag is set and the refcount is
259 * set to zero.
260 */
261 unsigned int destroy_flag;
262
263 /*
264 * Mutex protecting the control socket to avoid out of order packets
265 * between threads sending data to the relayd. Since metadata data is sent
266 * over that socket, at least two sendmsg() are needed (header + data)
267 * creating a race for packets to overlap between threads using it.
268 *
269 * This is nested INSIDE the consumer_data lock.
270 * This is nested INSIDE the stream lock.
271 */
272 pthread_mutex_t ctrl_sock_mutex;
273
274 /* Control socket. Command and metadata are passed over it */
275 struct lttcomm_relayd_sock control_sock;
276
277 /*
278 * We don't need a mutex at this point since we only splice or write single
279 * large chunk of data with a header appended at the begining. Moreover,
280 * this socket is for now only used in a single thread.
281 */
282 struct lttcomm_relayd_sock data_sock;
283 struct lttng_ht_node_u64 node;
284
285 /* Session id on both sides for the sockets. */
286 uint64_t relayd_session_id;
287 uint64_t sessiond_session_id;
288 };
289
290 /*
291 * UST consumer local data to the program. One or more instance per
292 * process.
293 */
294 struct lttng_consumer_local_data {
295 /*
296 * Function to call when data is available on a buffer.
297 * Returns the number of bytes read, or negative error value.
298 */
299 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
300 struct lttng_consumer_local_data *ctx);
301 /*
302 * function to call when we receive a new channel, it receives a
303 * newly allocated channel, depending on the return code of this
304 * function, the new channel will be handled by the application
305 * or the library.
306 *
307 * Returns:
308 * > 0 (success, FD is kept by application)
309 * == 0 (success, FD is left to library)
310 * < 0 (error)
311 */
312 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
313 /*
314 * function to call when we receive a new stream, it receives a
315 * newly allocated stream, depending on the return code of this
316 * function, the new stream will be handled by the application
317 * or the library.
318 *
319 * Returns:
320 * > 0 (success, FD is kept by application)
321 * == 0 (success, FD is left to library)
322 * < 0 (error)
323 */
324 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
325 /*
326 * function to call when a stream is getting updated by the session
327 * daemon, this function receives the sessiond key and the new
328 * state, depending on the return code of this function the
329 * update of state for the stream is handled by the application
330 * or the library.
331 *
332 * Returns:
333 * > 0 (success, FD is kept by application)
334 * == 0 (success, FD is left to library)
335 * < 0 (error)
336 */
337 int (*on_update_stream)(int sessiond_key, uint32_t state);
338 enum lttng_consumer_type type;
339 /* socket to communicate errors with sessiond */
340 int consumer_error_socket;
341 /* socket to ask metadata to sessiond */
342 int consumer_metadata_socket;
343 /* socket to exchange commands with sessiond */
344 char *consumer_command_sock_path;
345 /* communication with splice */
346 int consumer_thread_pipe[2];
347 int consumer_channel_pipe[2];
348 int consumer_splice_metadata_pipe[2];
349 /* Data stream poll thread pipe. To transfer data stream to the thread */
350 struct lttng_pipe *consumer_data_pipe;
351 /* to let the signal handler wake up the fd receiver thread */
352 int consumer_should_quit[2];
353 /* Metadata poll thread pipe. Transfer metadata stream to it */
354 struct lttng_pipe *consumer_metadata_pipe;
355 };
356
357 /*
358 * Library-level data. One instance per process.
359 */
360 struct lttng_consumer_global_data {
361 /*
362 * At this time, this lock is used to ensure coherence between the count
363 * and number of element in the hash table. It's also a protection for
364 * concurrent read/write between threads.
365 *
366 * This is nested OUTSIDE the stream lock.
367 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
368 */
369 pthread_mutex_t lock;
370
371 /*
372 * Number of streams in the data stream hash table declared outside.
373 * Protected by consumer_data.lock.
374 */
375 int stream_count;
376
377 /* Channel hash table protected by consumer_data.lock. */
378 struct lttng_ht *channel_ht;
379 /*
380 * Flag specifying if the local array of FDs needs update in the
381 * poll function. Protected by consumer_data.lock.
382 */
383 unsigned int need_update;
384 enum lttng_consumer_type type;
385
386 /*
387 * Relayd socket(s) hashtable indexed by network sequence number. Each
388 * stream has an index which associate the right relayd socket to use.
389 */
390 struct lttng_ht *relayd_ht;
391
392 /*
393 * This hash table contains all streams (metadata and data) indexed by
394 * session id. In other words, the ht is indexed by session id and each
395 * bucket contains the list of associated streams.
396 *
397 * This HT uses the "node_session_id" of the consumer stream.
398 */
399 struct lttng_ht *stream_list_ht;
400
401 /*
402 * This HT uses the "node_channel_id" of the consumer stream.
403 */
404 struct lttng_ht *stream_per_chan_id_ht;
405 };
406
407 /*
408 * Init consumer data structures.
409 */
410 void lttng_consumer_init(void);
411
412 /*
413 * Set the error socket for communication with a session daemon.
414 */
415 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
416 int sock);
417
418 /*
419 * Set the command socket path for communication with a session daemon.
420 */
421 void lttng_consumer_set_command_sock_path(
422 struct lttng_consumer_local_data *ctx, char *sock);
423
424 /*
425 * Send return code to session daemon.
426 *
427 * Returns the return code of sendmsg : the number of bytes transmitted or -1
428 * on error.
429 */
430 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd);
431
432 /*
433 * Called from signal handler to ensure a clean exit.
434 */
435 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx);
436
437 /*
438 * Cleanup the daemon's socket on exit.
439 */
440 void lttng_consumer_cleanup(void);
441
442 /*
443 * Flush pending writes to trace output disk file.
444 */
445 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
446 off_t orig_offset);
447
448 /*
449 * Poll on the should_quit pipe and the command socket return -1 on error and
450 * should exit, 0 if data is available on the command socket
451 */
452 int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
453
454 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
455 uint64_t stream_key,
456 enum lttng_consumer_stream_state state,
457 const char *channel_name,
458 uid_t uid,
459 gid_t gid,
460 int relayd_id,
461 uint64_t session_id,
462 int cpu,
463 int *alloc_ret,
464 enum consumer_channel_type type);
465 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
466 uint64_t session_id,
467 const char *pathname,
468 const char *name,
469 uid_t uid,
470 gid_t gid,
471 int relayd_id,
472 enum lttng_event_output output,
473 uint64_t tracefile_size,
474 uint64_t tracefile_count);
475 void consumer_del_stream(struct lttng_consumer_stream *stream,
476 struct lttng_ht *ht);
477 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
478 struct lttng_ht *ht);
479 int consumer_add_channel(struct lttng_consumer_channel *channel,
480 struct lttng_consumer_local_data *ctx);
481 void consumer_del_channel(struct lttng_consumer_channel *channel);
482
483 /* lttng-relayd consumer command */
484 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
485 int net_seq_idx);
486 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
487 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
488 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
489 size_t data_size);
490 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
491
492 struct lttng_consumer_local_data *lttng_consumer_create(
493 enum lttng_consumer_type type,
494 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
495 struct lttng_consumer_local_data *ctx),
496 int (*recv_channel)(struct lttng_consumer_channel *channel),
497 int (*recv_stream)(struct lttng_consumer_stream *stream),
498 int (*update_stream)(int sessiond_key, uint32_t state));
499 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
500 ssize_t lttng_consumer_on_read_subbuffer_mmap(
501 struct lttng_consumer_local_data *ctx,
502 struct lttng_consumer_stream *stream, unsigned long len,
503 unsigned long padding);
504 ssize_t lttng_consumer_on_read_subbuffer_splice(
505 struct lttng_consumer_local_data *ctx,
506 struct lttng_consumer_stream *stream, unsigned long len,
507 unsigned long padding);
508 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
509 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
510 unsigned long *pos);
511 void *consumer_thread_metadata_poll(void *data);
512 void *consumer_thread_data_poll(void *data);
513 void *consumer_thread_sessiond_poll(void *data);
514 void *consumer_thread_channel_poll(void *data);
515 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
516 int sock, struct pollfd *consumer_sockpoll);
517
518 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
519 struct lttng_consumer_local_data *ctx);
520 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
521 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
522 struct lttng_consumer_local_data *ctx, int sock,
523 struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
524 unsigned int sessiond_id);
525 void consumer_flag_relayd_for_destroy(
526 struct consumer_relayd_sock_pair *relayd);
527 int consumer_data_pending(uint64_t id);
528 int consumer_send_status_msg(int sock, int ret_code);
529 int consumer_send_status_channel(int sock,
530 struct lttng_consumer_channel *channel);
531 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
532 uint64_t key);
533
534 #endif /* LIB_CONSUMER_H */
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