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
27 #include <lttng/lttng.h>
29 #include <common/hashtable/hashtable.h>
30 #include <common/compat/fcntl.h>
31 #include <common/sessiond-comm/sessiond-comm.h>
34 * When the receiving thread dies, we need to have a way to make the polling
35 * thread exit eventually. If all FDs hang up (normal case when the
36 * lttng-sessiond stops), we can exit cleanly, but if there is a problem and
37 * for whatever reason some FDs remain open, the consumer should still exit
40 * If the timeout is reached, it means that during this period no events
41 * occurred on the FDs so we need to force an exit. This case should not happen
42 * but it is a safety to ensure we won't block the consumer indefinitely.
44 * The value of 2 seconds is an arbitrary choice.
46 #define LTTNG_CONSUMER_POLL_TIMEOUT 2000
48 /* Commands for consumer */
49 enum lttng_consumer_command
{
50 LTTNG_CONSUMER_ADD_CHANNEL
,
51 LTTNG_CONSUMER_ADD_STREAM
,
52 /* pause, delete, active depending on fd state */
53 LTTNG_CONSUMER_UPDATE_STREAM
,
54 /* inform the consumer to quit when all fd has hang up */
56 LTTNG_CONSUMER_ADD_RELAYD_SOCKET
,
57 /* Inform the consumer to kill a specific relayd connection */
58 LTTNG_CONSUMER_DESTROY_RELAYD
,
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
,
68 enum lttng_consumer_type
{
69 LTTNG_CONSUMER_UNKNOWN
= 0,
70 LTTNG_CONSUMER_KERNEL
,
75 struct lttng_consumer_channel
{
76 struct lttng_ht_node_ulong node
;
78 uint64_t max_sb_size
; /* the subbuffer size for this channel */
79 int refcount
; /* Number of streams referencing this channel */
81 * The number of streams to receive initially. Used to guarantee that we do
82 * not destroy a channel before receiving all its associated streams.
84 unsigned int nb_init_streams
;
91 struct lttng_ust_shm_handle
*handle
;
96 /* Forward declaration for UST. */
97 struct lttng_ust_lib_ring_buffer
;
100 * Internal representation of the streams, sessiond_key is used to identify
103 struct lttng_consumer_stream
{
104 struct lttng_ht_node_ulong node
;
105 struct lttng_ht_node_ulong waitfd_node
;
106 struct lttng_consumer_channel
*chan
; /* associated channel */
108 * key is the key used by the session daemon to refer to the
109 * object in the consumer daemon.
114 int out_fd
; /* output file to write the data */
115 off_t out_fd_offset
; /* write position in the output file descriptor */
116 char path_name
[PATH_MAX
]; /* tracefile name */
117 enum lttng_consumer_stream_state state
;
121 enum lttng_event_output output
; /* splice or mmap */
125 struct lttng_ust_lib_ring_buffer
*buf
;
128 int hangup_flush_done
;
129 /* UID/GID of the user owning the session to which stream belongs */
132 /* Network sequence number. Indicating on which relayd socket it goes. */
134 /* Identify if the stream is the metadata */
135 unsigned int metadata_flag
;
136 /* Used when the stream is set for network streaming */
137 uint64_t relayd_stream_id
;
138 /* Next sequence number to use for trace packet */
139 uint64_t next_net_seq_num
;
143 * Internal representation of a relayd socket pair.
145 struct consumer_relayd_sock_pair
{
146 /* Network sequence number. */
148 /* Number of stream associated with this relayd */
149 unsigned int refcount
;
152 * This flag indicates whether or not we should destroy this object. The
153 * destruction should ONLY occurs when this flag is set and the refcount is
156 unsigned int destroy_flag
;
159 * Mutex protecting the control socket to avoid out of order packets
160 * between threads sending data to the relayd. Since metadata data is sent
161 * over that socket, at least two sendmsg() are needed (header + data)
162 * creating a race for packets to overlap between threads using it.
164 pthread_mutex_t ctrl_sock_mutex
;
166 /* Control socket. Command and metadata are passed over it */
167 struct lttcomm_sock control_sock
;
170 * We don't need a mutex at this point since we only splice or write single
171 * large chunk of data with a header appended at the begining. Moreover,
172 * this socket is for now only used in a single thread.
174 struct lttcomm_sock data_sock
;
175 struct lttng_ht_node_ulong node
;
179 * UST consumer local data to the program. One or more instance per
182 struct lttng_consumer_local_data
{
184 * Function to call when data is available on a buffer.
185 * Returns the number of bytes read, or negative error value.
187 ssize_t (*on_buffer_ready
)(struct lttng_consumer_stream
*stream
,
188 struct lttng_consumer_local_data
*ctx
);
190 * function to call when we receive a new channel, it receives a
191 * newly allocated channel, depending on the return code of this
192 * function, the new channel will be handled by the application
196 * > 0 (success, FD is kept by application)
197 * == 0 (success, FD is left to library)
200 int (*on_recv_channel
)(struct lttng_consumer_channel
*channel
);
202 * function to call when we receive a new stream, it receives a
203 * newly allocated stream, depending on the return code of this
204 * function, the new stream will be handled by the application
208 * > 0 (success, FD is kept by application)
209 * == 0 (success, FD is left to library)
212 int (*on_recv_stream
)(struct lttng_consumer_stream
*stream
);
214 * function to call when a stream is getting updated by the session
215 * daemon, this function receives the sessiond key and the new
216 * state, depending on the return code of this function the
217 * update of state for the stream is handled by the application
221 * > 0 (success, FD is kept by application)
222 * == 0 (success, FD is left to library)
225 int (*on_update_stream
)(int sessiond_key
, uint32_t state
);
226 /* socket to communicate errors with sessiond */
227 int consumer_error_socket
;
228 /* socket to exchange commands with sessiond */
229 char *consumer_command_sock_path
;
230 /* communication with splice */
231 int consumer_thread_pipe
[2];
232 int consumer_splice_metadata_pipe
[2];
233 /* pipe to wake the poll thread when necessary */
234 int consumer_poll_pipe
[2];
235 /* to let the signal handler wake up the fd receiver thread */
236 int consumer_should_quit
[2];
237 /* Metadata poll thread pipe. Transfer metadata stream to it */
238 int consumer_metadata_pipe
[2];
242 * Library-level data. One instance per process.
244 struct lttng_consumer_global_data
{
246 * At this time, this lock is used to ensure coherence between the count
247 * and number of element in the hash table. It's also a protection for
248 * concurrent read/write between threads.
250 * XXX: We need to see if this lock is still needed with the lockless RCU
253 pthread_mutex_t lock
;
256 * Number of streams in the hash table. Protected by consumer_data.lock.
260 * Hash tables of streams and channels. Protected by consumer_data.lock.
262 struct lttng_ht
*stream_ht
;
263 struct lttng_ht
*channel_ht
;
265 * Flag specifying if the local array of FDs needs update in the
266 * poll function. Protected by consumer_data.lock.
268 unsigned int need_update
;
269 enum lttng_consumer_type type
;
272 * Relayd socket(s) hashtable indexed by network sequence number. Each
273 * stream has an index which associate the right relayd socket to use.
275 struct lttng_ht
*relayd_ht
;
278 /* Defined in consumer.c and coupled with explanations */
279 extern struct lttng_ht
*metadata_ht
;
280 extern struct lttng_ht
*data_ht
;
283 * Init consumer data structures.
285 extern void lttng_consumer_init(void);
288 * Set the error socket for communication with a session daemon.
290 extern void lttng_consumer_set_error_sock(
291 struct lttng_consumer_local_data
*ctx
, int sock
);
294 * Set the command socket path for communication with a session daemon.
296 extern void lttng_consumer_set_command_sock_path(
297 struct lttng_consumer_local_data
*ctx
, char *sock
);
300 * Send return code to session daemon.
302 * Returns the return code of sendmsg : the number of bytes transmitted or -1
305 extern int lttng_consumer_send_error(
306 struct lttng_consumer_local_data
*ctx
, int cmd
);
309 * Called from signal handler to ensure a clean exit.
311 extern void lttng_consumer_should_exit(
312 struct lttng_consumer_local_data
*ctx
);
315 * Cleanup the daemon's socket on exit.
317 extern void lttng_consumer_cleanup(void);
320 * Flush pending writes to trace output disk file.
322 extern void lttng_consumer_sync_trace_file(
323 struct lttng_consumer_stream
*stream
, off_t orig_offset
);
326 * Poll on the should_quit pipe and the command socket return -1 on error and
327 * should exit, 0 if data is available on the command socket
329 extern int lttng_consumer_poll_socket(struct pollfd
*kconsumer_sockpoll
);
331 extern struct lttng_consumer_stream
*consumer_allocate_stream(
332 int channel_key
, int stream_key
,
333 int shm_fd
, int wait_fd
,
334 enum lttng_consumer_stream_state state
,
336 enum lttng_event_output output
,
337 const char *path_name
,
343 extern void consumer_del_stream(struct lttng_consumer_stream
*stream
,
344 struct lttng_ht
*ht
);
345 extern void consumer_del_metadata_stream(struct lttng_consumer_stream
*stream
,
346 struct lttng_ht
*ht
);
347 extern void consumer_change_stream_state(int stream_key
,
348 enum lttng_consumer_stream_state state
);
349 extern void consumer_del_channel(struct lttng_consumer_channel
*channel
);
350 extern struct lttng_consumer_channel
*consumer_allocate_channel(
352 int shm_fd
, int wait_fd
,
354 uint64_t max_sb_size
,
355 unsigned int nb_init_streams
);
356 int consumer_add_channel(struct lttng_consumer_channel
*channel
);
358 /* lttng-relayd consumer command */
359 struct consumer_relayd_sock_pair
*consumer_allocate_relayd_sock_pair(
361 struct consumer_relayd_sock_pair
*consumer_find_relayd(int key
);
362 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream
*stream
,
364 void consumer_steal_stream_key(int key
, struct lttng_ht
*ht
);
366 extern struct lttng_consumer_local_data
*lttng_consumer_create(
367 enum lttng_consumer_type type
,
368 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
369 struct lttng_consumer_local_data
*ctx
),
370 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
371 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
372 int (*update_stream
)(int sessiond_key
, uint32_t state
));
373 extern void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
);
374 extern ssize_t
lttng_consumer_on_read_subbuffer_mmap(
375 struct lttng_consumer_local_data
*ctx
,
376 struct lttng_consumer_stream
*stream
, unsigned long len
,
377 unsigned long padding
);
378 extern ssize_t
lttng_consumer_on_read_subbuffer_splice(
379 struct lttng_consumer_local_data
*ctx
,
380 struct lttng_consumer_stream
*stream
, unsigned long len
,
381 unsigned long padding
);
382 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
383 struct lttng_consumer_stream
*stream
);
384 extern int lttng_consumer_get_produced_snapshot(
385 struct lttng_consumer_local_data
*ctx
,
386 struct lttng_consumer_stream
*stream
,
388 extern void *consumer_thread_metadata_poll(void *data
);
389 extern void *consumer_thread_data_poll(void *data
);
390 extern void *consumer_thread_sessiond_poll(void *data
);
391 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
392 int sock
, struct pollfd
*consumer_sockpoll
);
394 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
395 struct lttng_consumer_local_data
*ctx
);
396 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
);
397 int consumer_add_relayd_socket(int net_seq_idx
, int sock_type
,
398 struct lttng_consumer_local_data
*ctx
, int sock
,
399 struct pollfd
*consumer_sockpoll
, struct lttcomm_sock
*relayd_sock
);
400 void consumer_flag_relayd_for_destroy(
401 struct consumer_relayd_sock_pair
*relayd
);
403 #endif /* LIB_CONSUMER_H */