2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
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.
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
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.
20 #ifndef LIB_CONSUMER_H
21 #define LIB_CONSUMER_H
26 #include <urcu/list.h>
28 #include <lttng/lttng.h>
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>
35 /* Commands for consumer */
36 enum lttng_consumer_command
{
37 LTTNG_CONSUMER_ADD_CHANNEL
,
38 LTTNG_CONSUMER_ADD_STREAM
,
39 /* pause, delete, active depending on fd state */
40 LTTNG_CONSUMER_UPDATE_STREAM
,
41 /* inform the consumer to quit when all fd has hang up */
43 LTTNG_CONSUMER_ADD_RELAYD_SOCKET
,
44 /* Inform the consumer to kill a specific relayd connection */
45 LTTNG_CONSUMER_DESTROY_RELAYD
,
46 /* Return to the sessiond if there is data pending for a session */
47 LTTNG_CONSUMER_DATA_PENDING
,
48 /* Consumer creates a channel and returns it to sessiond. */
49 LTTNG_CONSUMER_ASK_CHANNEL_CREATION
,
50 LTTNG_CONSUMER_GET_CHANNEL
,
51 LTTNG_CONSUMER_DESTROY_CHANNEL
,
52 LTTNG_CONSUMER_PUSH_METADATA
,
53 LTTNG_CONSUMER_CLOSE_METADATA
,
54 LTTNG_CONSUMER_SETUP_METADATA
,
55 LTTNG_CONSUMER_FLUSH_CHANNEL
,
58 /* State of each fd in consumer */
59 enum lttng_consumer_stream_state
{
60 LTTNG_CONSUMER_ACTIVE_STREAM
,
61 LTTNG_CONSUMER_PAUSE_STREAM
,
62 LTTNG_CONSUMER_DELETE_STREAM
,
65 enum lttng_consumer_type
{
66 LTTNG_CONSUMER_UNKNOWN
= 0,
67 LTTNG_CONSUMER_KERNEL
,
72 enum consumer_endpoint_status
{
73 CONSUMER_ENDPOINT_ACTIVE
,
74 CONSUMER_ENDPOINT_INACTIVE
,
77 enum consumer_channel_output
{
78 CONSUMER_CHANNEL_MMAP
= 0,
79 CONSUMER_CHANNEL_SPLICE
= 1,
82 enum consumer_channel_type
{
83 CONSUMER_CHANNEL_TYPE_METADATA
= 0,
84 CONSUMER_CHANNEL_TYPE_DATA
= 1,
88 struct cds_list_head head
;
93 struct consumer_metadata_cache
;
95 struct lttng_consumer_channel
{
96 /* HT node used for consumer_data.channel_ht */
97 struct lttng_ht_node_u64 node
;
98 /* Indexed key. Incremented value in the consumer. */
100 /* Number of streams referencing this channel */
102 /* Tracing session id on the session daemon side. */
104 /* Channel trace file path name. */
105 char pathname
[PATH_MAX
];
107 char name
[LTTNG_SYMBOL_NAME_LEN
];
108 /* UID and GID of the channel. */
111 /* Relayd id of the channel. -1 if it does not apply. */
114 * Number of streams NOT initialized yet. This is used in order to not
115 * delete this channel if streams are getting initialized.
117 unsigned int nb_init_stream_left
;
118 /* Output type (mmap or splice). */
119 enum consumer_channel_output output
;
120 /* Channel type for stream */
121 enum consumer_channel_type type
;
124 struct ustctl_consumer_channel
*uchan
;
125 unsigned char uuid
[UUID_STR_LEN
];
127 * Temporary stream list used to store the streams once created and waiting
128 * to be sent to the session daemon by receiving the
129 * LTTNG_CONSUMER_GET_CHANNEL.
131 struct stream_list streams
;
133 * Set if the channel is metadata. We keep a reference to the stream
134 * because we have to flush data once pushed by the session daemon. For a
135 * regular channel, this is always set to NULL.
137 struct lttng_consumer_stream
*metadata_stream
;
141 /* Node within channel thread ht */
142 struct lttng_ht_node_u64 wait_fd_node
;
144 /* Metadata cache is metadata channel */
145 struct consumer_metadata_cache
*metadata_cache
;
146 /* For metadata periodical flush */
147 int switch_timer_enabled
;
148 timer_t switch_timer
;
152 * Internal representation of the streams, sessiond_key is used to identify
155 struct lttng_consumer_stream
{
156 /* HT node used by the data_ht and metadata_ht */
157 struct lttng_ht_node_u64 node
;
158 /* stream indexed per channel key node */
159 struct lttng_ht_node_u64 node_channel_id
;
160 /* HT node used in consumer_data.stream_list_ht */
161 struct lttng_ht_node_u64 node_session_id
;
162 /* Pointer to associated channel. */
163 struct lttng_consumer_channel
*chan
;
165 /* Key by which the stream is indexed for 'node'. */
168 * File descriptor of the data output file. This can be either a file or a
169 * socket fd for relayd streaming.
171 int out_fd
; /* output file to write the data */
172 /* Write position in the output file descriptor */
174 enum lttng_consumer_stream_state state
;
177 int hangup_flush_done
;
178 enum lttng_event_output output
;
179 /* Maximum subbuffer size. */
180 unsigned long max_sb_size
;
183 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
184 * used for the mmap base and offset.
187 unsigned long mmap_len
;
192 /* UID/GID of the user owning the session to which stream belongs */
195 /* Network sequence number. Indicating on which relayd socket it goes. */
196 uint64_t net_seq_idx
;
197 /* Identify if the stream is the metadata */
198 unsigned int metadata_flag
;
199 /* Used when the stream is set for network streaming */
200 uint64_t relayd_stream_id
;
202 * When sending a stream packet to a relayd, this number is used to track
203 * the packet sent by the consumer and seen by the relayd. When sending the
204 * data header to the relayd, this number is sent and if the transmission
205 * was successful, it is incremented.
207 * Even if the full data is not fully transmitted it won't matter since
208 * only two possible error can happen after that where either the relayd
209 * died or a read error is detected on the stream making this value useless
212 * This value SHOULD be read/updated atomically or with the lock acquired.
214 uint64_t next_net_seq_num
;
216 * Lock to use the stream FDs since they are used between threads.
218 * This is nested INSIDE the consumer_data lock.
219 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
221 pthread_mutex_t lock
;
222 /* Tracing session id */
225 * Indicates if the stream end point is still active or not (network
226 * streaming or local file system). The thread "owning" the stream is
227 * handling this status and can be notified of a state change through the
228 * consumer data appropriate pipe.
230 enum consumer_endpoint_status endpoint_status
;
231 /* Stream name. Format is: <channel_name>_<cpu_number> */
232 char name
[LTTNG_SYMBOL_NAME_LEN
];
233 /* Internal state of libustctl. */
234 struct ustctl_consumer_stream
*ustream
;
235 struct cds_list_head send_node
;
239 * Internal representation of a relayd socket pair.
241 struct consumer_relayd_sock_pair
{
242 /* Network sequence number. */
244 /* Number of stream associated with this relayd */
245 unsigned int refcount
;
248 * This flag indicates whether or not we should destroy this object. The
249 * destruction should ONLY occurs when this flag is set and the refcount is
252 unsigned int destroy_flag
;
255 * Mutex protecting the control socket to avoid out of order packets
256 * between threads sending data to the relayd. Since metadata data is sent
257 * over that socket, at least two sendmsg() are needed (header + data)
258 * creating a race for packets to overlap between threads using it.
260 * This is nested INSIDE the consumer_data lock.
261 * This is nested INSIDE the stream lock.
263 pthread_mutex_t ctrl_sock_mutex
;
265 /* Control socket. Command and metadata are passed over it */
266 struct lttcomm_sock control_sock
;
269 * We don't need a mutex at this point since we only splice or write single
270 * large chunk of data with a header appended at the begining. Moreover,
271 * this socket is for now only used in a single thread.
273 struct lttcomm_sock data_sock
;
274 struct lttng_ht_node_u64 node
;
276 /* Session id on both sides for the sockets. */
277 uint64_t relayd_session_id
;
278 uint64_t sessiond_session_id
;
282 * UST consumer local data to the program. One or more instance per
285 struct lttng_consumer_local_data
{
287 * Function to call when data is available on a buffer.
288 * Returns the number of bytes read, or negative error value.
290 ssize_t (*on_buffer_ready
)(struct lttng_consumer_stream
*stream
,
291 struct lttng_consumer_local_data
*ctx
);
293 * function to call when we receive a new channel, it receives a
294 * newly allocated channel, depending on the return code of this
295 * function, the new channel will be handled by the application
299 * > 0 (success, FD is kept by application)
300 * == 0 (success, FD is left to library)
303 int (*on_recv_channel
)(struct lttng_consumer_channel
*channel
);
305 * function to call when we receive a new stream, it receives a
306 * newly allocated stream, depending on the return code of this
307 * function, the new stream will be handled by the application
311 * > 0 (success, FD is kept by application)
312 * == 0 (success, FD is left to library)
315 int (*on_recv_stream
)(struct lttng_consumer_stream
*stream
);
317 * function to call when a stream is getting updated by the session
318 * daemon, this function receives the sessiond key and the new
319 * state, depending on the return code of this function the
320 * update of state for the stream is handled by the application
324 * > 0 (success, FD is kept by application)
325 * == 0 (success, FD is left to library)
328 int (*on_update_stream
)(int sessiond_key
, uint32_t state
);
329 enum lttng_consumer_type type
;
330 /* socket to communicate errors with sessiond */
331 int consumer_error_socket
;
332 /* socket to ask metadata to sessiond */
333 int consumer_metadata_socket
;
334 /* socket to exchange commands with sessiond */
335 char *consumer_command_sock_path
;
336 /* communication with splice */
337 int consumer_thread_pipe
[2];
338 int consumer_channel_pipe
[2];
339 int consumer_splice_metadata_pipe
[2];
340 /* Data stream poll thread pipe. To transfer data stream to the thread */
341 int consumer_data_pipe
[2];
342 /* to let the signal handler wake up the fd receiver thread */
343 int consumer_should_quit
[2];
344 /* Metadata poll thread pipe. Transfer metadata stream to it */
345 int consumer_metadata_pipe
[2];
349 * Library-level data. One instance per process.
351 struct lttng_consumer_global_data
{
353 * At this time, this lock is used to ensure coherence between the count
354 * and number of element in the hash table. It's also a protection for
355 * concurrent read/write between threads.
357 * This is nested OUTSIDE the stream lock.
358 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
360 pthread_mutex_t lock
;
363 * Number of streams in the data stream hash table declared outside.
364 * Protected by consumer_data.lock.
368 /* Channel hash table protected by consumer_data.lock. */
369 struct lttng_ht
*channel_ht
;
371 * Flag specifying if the local array of FDs needs update in the
372 * poll function. Protected by consumer_data.lock.
374 unsigned int need_update
;
375 enum lttng_consumer_type type
;
378 * Relayd socket(s) hashtable indexed by network sequence number. Each
379 * stream has an index which associate the right relayd socket to use.
381 struct lttng_ht
*relayd_ht
;
384 * This hash table contains all streams (metadata and data) indexed by
385 * session id. In other words, the ht is indexed by session id and each
386 * bucket contains the list of associated streams.
388 * This HT uses the "node_session_id" of the consumer stream.
390 struct lttng_ht
*stream_list_ht
;
393 * This HT uses the "node_channel_id" of the consumer stream.
395 struct lttng_ht
*stream_per_chan_id_ht
;
399 * Init consumer data structures.
401 void lttng_consumer_init(void);
404 * Set the error socket for communication with a session daemon.
406 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data
*ctx
,
410 * Set the command socket path for communication with a session daemon.
412 void lttng_consumer_set_command_sock_path(
413 struct lttng_consumer_local_data
*ctx
, char *sock
);
416 * Send return code to session daemon.
418 * Returns the return code of sendmsg : the number of bytes transmitted or -1
421 int lttng_consumer_send_error(struct lttng_consumer_local_data
*ctx
, int cmd
);
424 * Called from signal handler to ensure a clean exit.
426 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
);
429 * Cleanup the daemon's socket on exit.
431 void lttng_consumer_cleanup(void);
434 * Flush pending writes to trace output disk file.
436 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream
*stream
,
440 * Poll on the should_quit pipe and the command socket return -1 on error and
441 * should exit, 0 if data is available on the command socket
443 int lttng_consumer_poll_socket(struct pollfd
*kconsumer_sockpoll
);
445 struct lttng_consumer_stream
*consumer_allocate_stream(uint64_t channel_key
,
447 enum lttng_consumer_stream_state state
,
448 const char *channel_name
,
455 enum consumer_channel_type type
);
456 struct lttng_consumer_channel
*consumer_allocate_channel(uint64_t key
,
458 const char *pathname
,
463 enum lttng_event_output output
);
464 void consumer_del_stream(struct lttng_consumer_stream
*stream
,
465 struct lttng_ht
*ht
);
466 void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
467 struct lttng_ht
*ht
);
468 int consumer_add_channel(struct lttng_consumer_channel
*channel
,
469 struct lttng_consumer_local_data
*ctx
);
470 void consumer_del_channel(struct lttng_consumer_channel
*channel
);
472 /* lttng-relayd consumer command */
473 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
475 struct consumer_relayd_sock_pair
*consumer_find_relayd(uint64_t key
);
476 struct lttng_consumer_channel
*consumer_find_channel(uint64_t key
);
477 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream
*stream
,
479 void consumer_steal_stream_key(int key
, struct lttng_ht
*ht
);
481 struct lttng_consumer_local_data
*lttng_consumer_create(
482 enum lttng_consumer_type type
,
483 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
484 struct lttng_consumer_local_data
*ctx
),
485 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
486 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
487 int (*update_stream
)(int sessiond_key
, uint32_t state
));
488 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
);
489 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
490 struct lttng_consumer_local_data
*ctx
,
491 struct lttng_consumer_stream
*stream
, unsigned long len
,
492 unsigned long padding
);
493 ssize_t
lttng_consumer_on_read_subbuffer_splice(
494 struct lttng_consumer_local_data
*ctx
,
495 struct lttng_consumer_stream
*stream
, unsigned long len
,
496 unsigned long padding
);
497 int lttng_consumer_take_snapshot(struct lttng_consumer_stream
*stream
);
498 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
500 void *consumer_thread_metadata_poll(void *data
);
501 void *consumer_thread_data_poll(void *data
);
502 void *consumer_thread_sessiond_poll(void *data
);
503 void *consumer_thread_channel_poll(void *data
);
504 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
505 int sock
, struct pollfd
*consumer_sockpoll
);
507 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
508 struct lttng_consumer_local_data
*ctx
);
509 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
);
510 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
511 struct lttng_consumer_local_data
*ctx
, int sock
,
512 struct pollfd
*consumer_sockpoll
, struct lttcomm_sock
*relayd_sock
,
513 unsigned int sessiond_id
);
514 void consumer_flag_relayd_for_destroy(
515 struct consumer_relayd_sock_pair
*relayd
);
516 int consumer_data_pending(uint64_t id
);
517 int consumer_send_status_msg(int sock
, int ret_code
);
518 int consumer_send_status_channel(int sock
,
519 struct lttng_consumer_channel
*channel
);
521 #endif /* LIB_CONSUMER_H */