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
,
54 /* State of each fd in consumer */
55 enum lttng_consumer_stream_state
{
56 LTTNG_CONSUMER_ACTIVE_STREAM
,
57 LTTNG_CONSUMER_PAUSE_STREAM
,
58 LTTNG_CONSUMER_DELETE_STREAM
,
61 enum lttng_consumer_type
{
62 LTTNG_CONSUMER_UNKNOWN
= 0,
63 LTTNG_CONSUMER_KERNEL
,
68 enum consumer_endpoint_status
{
69 CONSUMER_ENDPOINT_ACTIVE
,
70 CONSUMER_ENDPOINT_INACTIVE
,
73 enum consumer_channel_output
{
74 CONSUMER_CHANNEL_MMAP
= 0,
75 CONSUMER_CHANNEL_SPLICE
= 1,
78 enum consumer_channel_type
{
79 CONSUMER_CHANNEL_TYPE_METADATA
= 0,
80 CONSUMER_CHANNEL_TYPE_DATA
= 1,
84 struct cds_list_head head
;
88 struct lttng_consumer_channel
{
89 /* HT node used for consumer_data.channel_ht */
90 struct lttng_ht_node_ulong node
;
91 /* Indexed key. Incremented value in the consumer. */
93 /* Number of streams referencing this channel */
95 /* Tracing session id on the session daemon side. */
97 /* Channel trace file path name. */
98 char pathname
[PATH_MAX
];
100 char name
[LTTNG_SYMBOL_NAME_LEN
];
101 /* UID and GID of the channel. */
104 /* Relayd id of the channel. -1 if it does not apply. */
107 * Number of streams NOT initialized yet. This is used in order to not
108 * delete this channel if streams are getting initialized.
110 unsigned int nb_init_stream_left
;
111 /* Output type (mmap or splice). */
112 enum consumer_channel_output output
;
113 /* Channel type for stream */
114 enum consumer_channel_type type
;
117 struct ustctl_consumer_channel
*uchan
;
118 unsigned char uuid
[UUID_STR_LEN
];
120 * Temporary stream list used to store the streams once created and waiting
121 * to be sent to the session daemon by receiving the
122 * LTTNG_CONSUMER_GET_CHANNEL.
124 struct stream_list streams
;
128 * Internal representation of the streams, sessiond_key is used to identify
131 struct lttng_consumer_stream
{
132 /* HT node used by the data_ht and metadata_ht */
133 struct lttng_ht_node_ulong node
;
134 /* HT node used in consumer_data.stream_list_ht */
135 struct lttng_ht_node_ulong node_session_id
;
136 /* Pointer to associated channel. */
137 struct lttng_consumer_channel
*chan
;
139 /* Key by which the stream is indexed for 'node'. */
142 * File descriptor of the data output file. This can be either a file or a
143 * socket fd for relayd streaming.
145 int out_fd
; /* output file to write the data */
146 /* Write position in the output file descriptor */
148 enum lttng_consumer_stream_state state
;
151 int hangup_flush_done
;
152 enum lttng_event_output output
;
153 /* Maximum subbuffer size. */
154 unsigned long max_sb_size
;
157 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
158 * used for the mmap base and offset.
161 unsigned long mmap_len
;
166 /* UID/GID of the user owning the session to which stream belongs */
169 /* Network sequence number. Indicating on which relayd socket it goes. */
171 /* Identify if the stream is the metadata */
172 unsigned int metadata_flag
;
173 /* Used when the stream is set for network streaming */
174 uint64_t relayd_stream_id
;
176 * When sending a stream packet to a relayd, this number is used to track
177 * the packet sent by the consumer and seen by the relayd. When sending the
178 * data header to the relayd, this number is sent and if the transmission
179 * was successful, it is incremented.
181 * Even if the full data is not fully transmitted it won't matter since
182 * only two possible error can happen after that where either the relayd
183 * died or a read error is detected on the stream making this value useless
186 * This value SHOULD be read/updated atomically or with the lock acquired.
188 uint64_t next_net_seq_num
;
190 * Lock to use the stream FDs since they are used between threads.
192 * This is nested INSIDE the consumer_data lock.
193 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
195 pthread_mutex_t lock
;
196 /* Tracing session id */
199 * Indicates if the stream end point is still active or not (network
200 * streaming or local file system). The thread "owning" the stream is
201 * handling this status and can be notified of a state change through the
202 * consumer data appropriate pipe.
204 enum consumer_endpoint_status endpoint_status
;
205 /* Stream name. Format is: <channel_name>_<cpu_number> */
206 char name
[LTTNG_SYMBOL_NAME_LEN
];
207 /* Internal state of libustctl. */
208 struct ustctl_consumer_stream
*ustream
;
209 struct cds_list_head send_node
;
213 * Internal representation of a relayd socket pair.
215 struct consumer_relayd_sock_pair
{
216 /* Network sequence number. */
218 /* Number of stream associated with this relayd */
219 unsigned int refcount
;
222 * This flag indicates whether or not we should destroy this object. The
223 * destruction should ONLY occurs when this flag is set and the refcount is
226 unsigned int destroy_flag
;
229 * Mutex protecting the control socket to avoid out of order packets
230 * between threads sending data to the relayd. Since metadata data is sent
231 * over that socket, at least two sendmsg() are needed (header + data)
232 * creating a race for packets to overlap between threads using it.
234 * This is nested INSIDE the consumer_data lock.
235 * This is nested INSIDE the stream lock.
237 pthread_mutex_t ctrl_sock_mutex
;
239 /* Control socket. Command and metadata are passed over it */
240 struct lttcomm_sock control_sock
;
243 * We don't need a mutex at this point since we only splice or write single
244 * large chunk of data with a header appended at the begining. Moreover,
245 * this socket is for now only used in a single thread.
247 struct lttcomm_sock data_sock
;
248 struct lttng_ht_node_ulong node
;
250 /* Session id on both sides for the sockets. */
251 uint64_t relayd_session_id
;
252 uint64_t sessiond_session_id
;
256 * UST consumer local data to the program. One or more instance per
259 struct lttng_consumer_local_data
{
261 * Function to call when data is available on a buffer.
262 * Returns the number of bytes read, or negative error value.
264 ssize_t (*on_buffer_ready
)(struct lttng_consumer_stream
*stream
,
265 struct lttng_consumer_local_data
*ctx
);
267 * function to call when we receive a new channel, it receives a
268 * newly allocated channel, depending on the return code of this
269 * function, the new channel will be handled by the application
273 * > 0 (success, FD is kept by application)
274 * == 0 (success, FD is left to library)
277 int (*on_recv_channel
)(struct lttng_consumer_channel
*channel
);
279 * function to call when we receive a new stream, it receives a
280 * newly allocated stream, depending on the return code of this
281 * function, the new stream will be handled by the application
285 * > 0 (success, FD is kept by application)
286 * == 0 (success, FD is left to library)
289 int (*on_recv_stream
)(struct lttng_consumer_stream
*stream
);
291 * function to call when a stream is getting updated by the session
292 * daemon, this function receives the sessiond key and the new
293 * state, depending on the return code of this function the
294 * update of state for the stream is handled by the application
298 * > 0 (success, FD is kept by application)
299 * == 0 (success, FD is left to library)
302 int (*on_update_stream
)(int sessiond_key
, uint32_t state
);
303 /* socket to communicate errors with sessiond */
304 int consumer_error_socket
;
305 /* socket to exchange commands with sessiond */
306 char *consumer_command_sock_path
;
307 /* communication with splice */
308 int consumer_thread_pipe
[2];
309 int consumer_splice_metadata_pipe
[2];
310 /* Data stream poll thread pipe. To transfer data stream to the thread */
311 int consumer_data_pipe
[2];
312 /* to let the signal handler wake up the fd receiver thread */
313 int consumer_should_quit
[2];
314 /* Metadata poll thread pipe. Transfer metadata stream to it */
315 int consumer_metadata_pipe
[2];
319 * Library-level data. One instance per process.
321 struct lttng_consumer_global_data
{
323 * At this time, this lock is used to ensure coherence between the count
324 * and number of element in the hash table. It's also a protection for
325 * concurrent read/write between threads.
327 * This is nested OUTSIDE the stream lock.
328 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
330 pthread_mutex_t lock
;
333 * Number of streams in the data stream hash table declared outside.
334 * Protected by consumer_data.lock.
338 /* Channel hash table protected by consumer_data.lock. */
339 struct lttng_ht
*channel_ht
;
341 * Flag specifying if the local array of FDs needs update in the
342 * poll function. Protected by consumer_data.lock.
344 unsigned int need_update
;
345 enum lttng_consumer_type type
;
348 * Relayd socket(s) hashtable indexed by network sequence number. Each
349 * stream has an index which associate the right relayd socket to use.
351 struct lttng_ht
*relayd_ht
;
354 * This hash table contains all streams (metadata and data) indexed by
355 * session id. In other words, the ht is indexed by session id and each
356 * bucket contains the list of associated streams.
358 * This HT uses the "node_session_id" of the consumer stream.
360 struct lttng_ht
*stream_list_ht
;
364 * Init consumer data structures.
366 void lttng_consumer_init(void);
369 * Set the error socket for communication with a session daemon.
371 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data
*ctx
,
375 * Set the command socket path for communication with a session daemon.
377 void lttng_consumer_set_command_sock_path(
378 struct lttng_consumer_local_data
*ctx
, char *sock
);
381 * Send return code to session daemon.
383 * Returns the return code of sendmsg : the number of bytes transmitted or -1
386 int lttng_consumer_send_error(struct lttng_consumer_local_data
*ctx
, int cmd
);
389 * Called from signal handler to ensure a clean exit.
391 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
);
394 * Cleanup the daemon's socket on exit.
396 void lttng_consumer_cleanup(void);
399 * Flush pending writes to trace output disk file.
401 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream
*stream
,
405 * Poll on the should_quit pipe and the command socket return -1 on error and
406 * should exit, 0 if data is available on the command socket
408 int lttng_consumer_poll_socket(struct pollfd
*kconsumer_sockpoll
);
410 struct lttng_consumer_stream
*consumer_allocate_stream(int channel_key
,
412 enum lttng_consumer_stream_state state
,
413 const char *channel_name
,
420 enum consumer_channel_type type
);
421 struct lttng_consumer_channel
*consumer_allocate_channel(unsigned long key
,
423 const char *pathname
,
428 enum lttng_event_output output
);
429 void consumer_del_stream(struct lttng_consumer_stream
*stream
,
430 struct lttng_ht
*ht
);
431 void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
432 struct lttng_ht
*ht
);
433 int consumer_add_channel(struct lttng_consumer_channel
*channel
);
434 void consumer_del_channel(struct lttng_consumer_channel
*channel
);
436 /* lttng-relayd consumer command */
437 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
439 struct consumer_relayd_sock_pair
*consumer_find_relayd(int key
);
440 struct lttng_consumer_channel
*consumer_find_channel(unsigned long key
);
441 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream
*stream
,
443 void consumer_steal_stream_key(int key
, struct lttng_ht
*ht
);
445 struct lttng_consumer_local_data
*lttng_consumer_create(
446 enum lttng_consumer_type type
,
447 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
448 struct lttng_consumer_local_data
*ctx
),
449 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
450 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
451 int (*update_stream
)(int sessiond_key
, uint32_t state
));
452 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
);
453 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
454 struct lttng_consumer_local_data
*ctx
,
455 struct lttng_consumer_stream
*stream
, unsigned long len
,
456 unsigned long padding
);
457 ssize_t
lttng_consumer_on_read_subbuffer_splice(
458 struct lttng_consumer_local_data
*ctx
,
459 struct lttng_consumer_stream
*stream
, unsigned long len
,
460 unsigned long padding
);
461 int lttng_consumer_take_snapshot(struct lttng_consumer_stream
*stream
);
462 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
464 void *consumer_thread_metadata_poll(void *data
);
465 void *consumer_thread_data_poll(void *data
);
466 void *consumer_thread_sessiond_poll(void *data
);
467 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
468 int sock
, struct pollfd
*consumer_sockpoll
);
470 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
471 struct lttng_consumer_local_data
*ctx
);
472 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
);
473 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
474 struct lttng_consumer_local_data
*ctx
, int sock
,
475 struct pollfd
*consumer_sockpoll
, struct lttcomm_sock
*relayd_sock
,
476 unsigned int sessiond_id
);
477 void consumer_flag_relayd_for_destroy(
478 struct consumer_relayd_sock_pair
*relayd
);
479 int consumer_data_pending(uint64_t id
);
480 int consumer_send_status_msg(int sock
, int ret_code
);
481 int consumer_send_status_channel(int sock
,
482 struct lttng_consumer_channel
*channel
);
484 #endif /* LIB_CONSUMER_H */