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
,
57 /* State of each fd in consumer */
58 enum lttng_consumer_stream_state
{
59 LTTNG_CONSUMER_ACTIVE_STREAM
,
60 LTTNG_CONSUMER_PAUSE_STREAM
,
61 LTTNG_CONSUMER_DELETE_STREAM
,
64 enum lttng_consumer_type
{
65 LTTNG_CONSUMER_UNKNOWN
= 0,
66 LTTNG_CONSUMER_KERNEL
,
71 enum consumer_endpoint_status
{
72 CONSUMER_ENDPOINT_ACTIVE
,
73 CONSUMER_ENDPOINT_INACTIVE
,
76 enum consumer_channel_output
{
77 CONSUMER_CHANNEL_MMAP
= 0,
78 CONSUMER_CHANNEL_SPLICE
= 1,
81 enum consumer_channel_type
{
82 CONSUMER_CHANNEL_TYPE_METADATA
= 0,
83 CONSUMER_CHANNEL_TYPE_DATA
= 1,
87 struct cds_list_head head
;
91 struct lttng_consumer_channel
{
92 /* HT node used for consumer_data.channel_ht */
93 struct lttng_ht_node_u64 node
;
94 /* Indexed key. Incremented value in the consumer. */
96 /* Number of streams referencing this channel */
98 /* Tracing session id on the session daemon side. */
100 /* Channel trace file path name. */
101 char pathname
[PATH_MAX
];
103 char name
[LTTNG_SYMBOL_NAME_LEN
];
104 /* UID and GID of the channel. */
107 /* Relayd id of the channel. -1 if it does not apply. */
110 * Number of streams NOT initialized yet. This is used in order to not
111 * delete this channel if streams are getting initialized.
113 unsigned int nb_init_stream_left
;
114 /* Output type (mmap or splice). */
115 enum consumer_channel_output output
;
116 /* Channel type for stream */
117 enum consumer_channel_type type
;
120 struct ustctl_consumer_channel
*uchan
;
121 unsigned char uuid
[UUID_STR_LEN
];
123 * Temporary stream list used to store the streams once created and waiting
124 * to be sent to the session daemon by receiving the
125 * LTTNG_CONSUMER_GET_CHANNEL.
127 struct stream_list streams
;
129 * Set if the channel is metadata. We keep a reference to the stream
130 * because we have to flush data once pushed by the session daemon. For a
131 * regular channel, this is always set to NULL.
133 struct lttng_consumer_stream
*metadata_stream
;
135 * Metadata written so far. Helps keeping track of
136 * contiguousness and order.
138 uint64_t contig_metadata_written
;
142 * Internal representation of the streams, sessiond_key is used to identify
145 struct lttng_consumer_stream
{
146 /* HT node used by the data_ht and metadata_ht */
147 struct lttng_ht_node_u64 node
;
148 /* HT node used in consumer_data.stream_list_ht */
149 struct lttng_ht_node_u64 node_session_id
;
150 /* Pointer to associated channel. */
151 struct lttng_consumer_channel
*chan
;
153 /* Key by which the stream is indexed for 'node'. */
156 * File descriptor of the data output file. This can be either a file or a
157 * socket fd for relayd streaming.
159 int out_fd
; /* output file to write the data */
160 /* Write position in the output file descriptor */
162 enum lttng_consumer_stream_state state
;
165 int hangup_flush_done
;
166 enum lttng_event_output output
;
167 /* Maximum subbuffer size. */
168 unsigned long max_sb_size
;
171 * Still used by the kernel for MMAP output. For UST, the ustctl getter is
172 * used for the mmap base and offset.
175 unsigned long mmap_len
;
180 /* UID/GID of the user owning the session to which stream belongs */
183 /* Network sequence number. Indicating on which relayd socket it goes. */
184 uint64_t net_seq_idx
;
185 /* Identify if the stream is the metadata */
186 unsigned int metadata_flag
;
187 /* Used when the stream is set for network streaming */
188 uint64_t relayd_stream_id
;
190 * When sending a stream packet to a relayd, this number is used to track
191 * the packet sent by the consumer and seen by the relayd. When sending the
192 * data header to the relayd, this number is sent and if the transmission
193 * was successful, it is incremented.
195 * Even if the full data is not fully transmitted it won't matter since
196 * only two possible error can happen after that where either the relayd
197 * died or a read error is detected on the stream making this value useless
200 * This value SHOULD be read/updated atomically or with the lock acquired.
202 uint64_t next_net_seq_num
;
204 * Lock to use the stream FDs since they are used between threads.
206 * This is nested INSIDE the consumer_data lock.
207 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
209 pthread_mutex_t lock
;
210 /* Tracing session id */
213 * Indicates if the stream end point is still active or not (network
214 * streaming or local file system). The thread "owning" the stream is
215 * handling this status and can be notified of a state change through the
216 * consumer data appropriate pipe.
218 enum consumer_endpoint_status endpoint_status
;
219 /* Stream name. Format is: <channel_name>_<cpu_number> */
220 char name
[LTTNG_SYMBOL_NAME_LEN
];
221 /* Internal state of libustctl. */
222 struct ustctl_consumer_stream
*ustream
;
223 struct cds_list_head send_node
;
227 * Internal representation of a relayd socket pair.
229 struct consumer_relayd_sock_pair
{
230 /* Network sequence number. */
232 /* Number of stream associated with this relayd */
233 unsigned int refcount
;
236 * This flag indicates whether or not we should destroy this object. The
237 * destruction should ONLY occurs when this flag is set and the refcount is
240 unsigned int destroy_flag
;
243 * Mutex protecting the control socket to avoid out of order packets
244 * between threads sending data to the relayd. Since metadata data is sent
245 * over that socket, at least two sendmsg() are needed (header + data)
246 * creating a race for packets to overlap between threads using it.
248 * This is nested INSIDE the consumer_data lock.
249 * This is nested INSIDE the stream lock.
251 pthread_mutex_t ctrl_sock_mutex
;
253 /* Control socket. Command and metadata are passed over it */
254 struct lttcomm_sock control_sock
;
257 * We don't need a mutex at this point since we only splice or write single
258 * large chunk of data with a header appended at the begining. Moreover,
259 * this socket is for now only used in a single thread.
261 struct lttcomm_sock data_sock
;
262 struct lttng_ht_node_u64 node
;
264 /* Session id on both sides for the sockets. */
265 uint64_t relayd_session_id
;
266 uint64_t sessiond_session_id
;
270 * UST consumer local data to the program. One or more instance per
273 struct lttng_consumer_local_data
{
275 * Function to call when data is available on a buffer.
276 * Returns the number of bytes read, or negative error value.
278 ssize_t (*on_buffer_ready
)(struct lttng_consumer_stream
*stream
,
279 struct lttng_consumer_local_data
*ctx
);
281 * function to call when we receive a new channel, it receives a
282 * newly allocated channel, depending on the return code of this
283 * function, the new channel will be handled by the application
287 * > 0 (success, FD is kept by application)
288 * == 0 (success, FD is left to library)
291 int (*on_recv_channel
)(struct lttng_consumer_channel
*channel
);
293 * function to call when we receive a new stream, it receives a
294 * newly allocated stream, depending on the return code of this
295 * function, the new stream 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_stream
)(struct lttng_consumer_stream
*stream
);
305 * function to call when a stream is getting updated by the session
306 * daemon, this function receives the sessiond key and the new
307 * state, depending on the return code of this function the
308 * update of state for the stream is handled by the application
312 * > 0 (success, FD is kept by application)
313 * == 0 (success, FD is left to library)
316 int (*on_update_stream
)(int sessiond_key
, uint32_t state
);
317 /* socket to communicate errors with sessiond */
318 int consumer_error_socket
;
319 /* socket to exchange commands with sessiond */
320 char *consumer_command_sock_path
;
321 /* communication with splice */
322 int consumer_thread_pipe
[2];
323 int consumer_splice_metadata_pipe
[2];
324 /* Data stream poll thread pipe. To transfer data stream to the thread */
325 int consumer_data_pipe
[2];
326 /* to let the signal handler wake up the fd receiver thread */
327 int consumer_should_quit
[2];
328 /* Metadata poll thread pipe. Transfer metadata stream to it */
329 int consumer_metadata_pipe
[2];
333 * Library-level data. One instance per process.
335 struct lttng_consumer_global_data
{
337 * At this time, this lock is used to ensure coherence between the count
338 * and number of element in the hash table. It's also a protection for
339 * concurrent read/write between threads.
341 * This is nested OUTSIDE the stream lock.
342 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
344 pthread_mutex_t lock
;
347 * Number of streams in the data stream hash table declared outside.
348 * Protected by consumer_data.lock.
352 /* Channel hash table protected by consumer_data.lock. */
353 struct lttng_ht
*channel_ht
;
355 * Flag specifying if the local array of FDs needs update in the
356 * poll function. Protected by consumer_data.lock.
358 unsigned int need_update
;
359 enum lttng_consumer_type type
;
362 * Relayd socket(s) hashtable indexed by network sequence number. Each
363 * stream has an index which associate the right relayd socket to use.
365 struct lttng_ht
*relayd_ht
;
368 * This hash table contains all streams (metadata and data) indexed by
369 * session id. In other words, the ht is indexed by session id and each
370 * bucket contains the list of associated streams.
372 * This HT uses the "node_session_id" of the consumer stream.
374 struct lttng_ht
*stream_list_ht
;
378 * Init consumer data structures.
380 void lttng_consumer_init(void);
383 * Set the error socket for communication with a session daemon.
385 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data
*ctx
,
389 * Set the command socket path for communication with a session daemon.
391 void lttng_consumer_set_command_sock_path(
392 struct lttng_consumer_local_data
*ctx
, char *sock
);
395 * Send return code to session daemon.
397 * Returns the return code of sendmsg : the number of bytes transmitted or -1
400 int lttng_consumer_send_error(struct lttng_consumer_local_data
*ctx
, int cmd
);
403 * Called from signal handler to ensure a clean exit.
405 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
);
408 * Cleanup the daemon's socket on exit.
410 void lttng_consumer_cleanup(void);
413 * Flush pending writes to trace output disk file.
415 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream
*stream
,
419 * Poll on the should_quit pipe and the command socket return -1 on error and
420 * should exit, 0 if data is available on the command socket
422 int lttng_consumer_poll_socket(struct pollfd
*kconsumer_sockpoll
);
424 struct lttng_consumer_stream
*consumer_allocate_stream(uint64_t channel_key
,
426 enum lttng_consumer_stream_state state
,
427 const char *channel_name
,
434 enum consumer_channel_type type
);
435 struct lttng_consumer_channel
*consumer_allocate_channel(uint64_t key
,
437 const char *pathname
,
442 enum lttng_event_output output
);
443 void consumer_del_stream(struct lttng_consumer_stream
*stream
,
444 struct lttng_ht
*ht
);
445 void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
446 struct lttng_ht
*ht
);
447 int consumer_add_channel(struct lttng_consumer_channel
*channel
);
448 void consumer_del_channel(struct lttng_consumer_channel
*channel
);
450 /* lttng-relayd consumer command */
451 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
453 struct consumer_relayd_sock_pair
*consumer_find_relayd(uint64_t key
);
454 struct lttng_consumer_channel
*consumer_find_channel(uint64_t key
);
455 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream
*stream
,
457 void consumer_steal_stream_key(int key
, struct lttng_ht
*ht
);
459 struct lttng_consumer_local_data
*lttng_consumer_create(
460 enum lttng_consumer_type type
,
461 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
462 struct lttng_consumer_local_data
*ctx
),
463 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
464 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
465 int (*update_stream
)(int sessiond_key
, uint32_t state
));
466 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
);
467 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
468 struct lttng_consumer_local_data
*ctx
,
469 struct lttng_consumer_stream
*stream
, unsigned long len
,
470 unsigned long padding
);
471 ssize_t
lttng_consumer_on_read_subbuffer_splice(
472 struct lttng_consumer_local_data
*ctx
,
473 struct lttng_consumer_stream
*stream
, unsigned long len
,
474 unsigned long padding
);
475 int lttng_consumer_take_snapshot(struct lttng_consumer_stream
*stream
);
476 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
478 void *consumer_thread_metadata_poll(void *data
);
479 void *consumer_thread_data_poll(void *data
);
480 void *consumer_thread_sessiond_poll(void *data
);
481 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
482 int sock
, struct pollfd
*consumer_sockpoll
);
484 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
485 struct lttng_consumer_local_data
*ctx
);
486 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
);
487 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
488 struct lttng_consumer_local_data
*ctx
, int sock
,
489 struct pollfd
*consumer_sockpoll
, struct lttcomm_sock
*relayd_sock
,
490 unsigned int sessiond_id
);
491 void consumer_flag_relayd_for_destroy(
492 struct consumer_relayd_sock_pair
*relayd
);
493 int consumer_data_pending(uint64_t id
);
494 int consumer_send_status_msg(int sock
, int ret_code
);
495 int consumer_send_status_channel(int sock
,
496 struct lttng_consumer_channel
*channel
);
498 #endif /* LIB_CONSUMER_H */