2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 #ifndef _LTTNG_CONSUMER_H
21 #define _LTTNG_CONSUMER_H
27 #include <lttng/lttng.h>
31 * When the receiving thread dies, we need to have a way to make the polling
32 * thread exit eventually. If all FDs hang up (normal case when the
33 * lttng-sessiond stops), we can exit cleanly, but if there is a problem and
34 * for whatever reason some FDs remain open, the consumer should still exit
37 * If the timeout is reached, it means that during this period no events
38 * occurred on the FDs so we need to force an exit. This case should not happen
39 * but it is a safety to ensure we won't block the consumer indefinitely.
41 * The value of 2 seconds is an arbitrary choice.
43 #define LTTNG_CONSUMER_POLL_TIMEOUT 2000
45 /* Commands for consumer */
46 enum lttng_consumer_command
{
47 LTTNG_CONSUMER_ADD_CHANNEL
,
48 LTTNG_CONSUMER_ADD_STREAM
,
49 /* pause, delete, active depending on fd state */
50 LTTNG_CONSUMER_UPDATE_STREAM
,
51 /* inform the consumer to quit when all fd has hang up */
55 /* State of each fd in consumer */
56 enum lttng_consumer_stream_state
{
57 LTTNG_CONSUMER_ACTIVE_STREAM
,
58 LTTNG_CONSUMER_PAUSE_STREAM
,
59 LTTNG_CONSUMER_DELETE_STREAM
,
62 enum lttng_consumer_type
{
63 LTTNG_CONSUMER_UNKNOWN
= 0,
64 LTTNG_CONSUMER_KERNEL
,
69 struct lttng_consumer_channel
{
70 struct lttng_ht_node_ulong node
;
72 uint64_t max_sb_size
; /* the subbuffer size for this channel */
73 int refcount
; /* Number of streams referencing this channel */
79 struct lttng_ust_shm_handle
*handle
;
85 /* Forward declaration for UST. */
86 struct lttng_ust_lib_ring_buffer
;
89 * Internal representation of the streams, sessiond_key is used to identify
92 struct lttng_consumer_stream
{
93 struct lttng_ht_node_ulong node
;
94 struct lttng_consumer_channel
*chan
; /* associated channel */
96 * key is the key used by the session daemon to refer to the
97 * object in the consumer daemon.
102 int out_fd
; /* output file to write the data */
103 off_t out_fd_offset
; /* write position in the output file descriptor */
104 char path_name
[PATH_MAX
]; /* tracefile name */
105 enum lttng_consumer_stream_state state
;
109 enum lttng_event_output output
; /* splice or mmap */
113 struct lttng_ust_lib_ring_buffer
*buf
;
115 int hangup_flush_done
;
116 /* UID/GID of the user owning the session to which stream belongs */
122 * UST consumer local data to the program. One or more instance per
125 struct lttng_consumer_local_data
{
126 /* function to call when data is available on a buffer */
127 int (*on_buffer_ready
)(struct lttng_consumer_stream
*stream
,
128 struct lttng_consumer_local_data
*ctx
);
130 * function to call when we receive a new channel, it receives a
131 * newly allocated channel, depending on the return code of this
132 * function, the new channel will be handled by the application
136 * > 0 (success, FD is kept by application)
137 * == 0 (success, FD is left to library)
140 int (*on_recv_channel
)(struct lttng_consumer_channel
*channel
);
142 * function to call when we receive a new stream, it receives a
143 * newly allocated stream, depending on the return code of this
144 * function, the new stream will be handled by the application
148 * > 0 (success, FD is kept by application)
149 * == 0 (success, FD is left to library)
152 int (*on_recv_stream
)(struct lttng_consumer_stream
*stream
);
154 * function to call when a stream is getting updated by the session
155 * daemon, this function receives the sessiond key and the new
156 * state, depending on the return code of this function the
157 * update of state for the stream is handled by the application
161 * > 0 (success, FD is kept by application)
162 * == 0 (success, FD is left to library)
165 int (*on_update_stream
)(int sessiond_key
, uint32_t state
);
166 /* socket to communicate errors with sessiond */
167 int consumer_error_socket
;
168 /* socket to exchange commands with sessiond */
169 char *consumer_command_sock_path
;
170 /* communication with splice */
171 int consumer_thread_pipe
[2];
172 /* pipe to wake the poll thread when necessary */
173 int consumer_poll_pipe
[2];
174 /* to let the signal handler wake up the fd receiver thread */
175 int consumer_should_quit
[2];
179 * Library-level data. One instance per process.
181 struct lttng_consumer_global_data
{
184 * At this time, this lock is used to ensure coherence between the count
185 * and number of element in the hash table. It's also a protection for
186 * concurrent read/write between threads.
188 * XXX: We need to see if this lock is still needed with the lockless RCU
191 pthread_mutex_t lock
;
194 * Number of streams in the hash table. Protected by consumer_data.lock.
198 * Hash tables of streams and channels. Protected by consumer_data.lock.
200 struct lttng_ht
*stream_ht
;
201 struct lttng_ht
*channel_ht
;
203 * Flag specifying if the local array of FDs needs update in the
204 * poll function. Protected by consumer_data.lock.
206 unsigned int need_update
;
207 enum lttng_consumer_type type
;
211 * Init consumer data structures.
213 extern void lttng_consumer_init(void);
216 * Set the error socket for communication with a session daemon.
218 extern void lttng_consumer_set_error_sock(
219 struct lttng_consumer_local_data
*ctx
, int sock
);
222 * Set the command socket path for communication with a session daemon.
224 extern void lttng_consumer_set_command_sock_path(
225 struct lttng_consumer_local_data
*ctx
, char *sock
);
228 * Send return code to session daemon.
230 * Returns the return code of sendmsg : the number of bytes transmitted or -1
233 extern int lttng_consumer_send_error(
234 struct lttng_consumer_local_data
*ctx
, int cmd
);
237 * Called from signal handler to ensure a clean exit.
239 extern void lttng_consumer_should_exit(
240 struct lttng_consumer_local_data
*ctx
);
243 * Cleanup the daemon's socket on exit.
245 extern void lttng_consumer_cleanup(void);
248 * Flush pending writes to trace output disk file.
250 extern void lttng_consumer_sync_trace_file(
251 struct lttng_consumer_stream
*stream
, off_t orig_offset
);
254 * Poll on the should_quit pipe and the command socket return -1 on error and
255 * should exit, 0 if data is available on the command socket
257 extern int lttng_consumer_poll_socket(struct pollfd
*kconsumer_sockpoll
);
259 extern int consumer_update_poll_array(
260 struct lttng_consumer_local_data
*ctx
, struct pollfd
**pollfd
,
261 struct lttng_consumer_stream
**local_consumer_streams
);
263 extern struct lttng_consumer_stream
*consumer_allocate_stream(
264 int channel_key
, int stream_key
,
265 int shm_fd
, int wait_fd
,
266 enum lttng_consumer_stream_state state
,
268 enum lttng_event_output output
,
269 const char *path_name
,
272 extern int consumer_add_stream(struct lttng_consumer_stream
*stream
);
273 extern void consumer_del_stream(struct lttng_consumer_stream
*stream
);
274 extern void consumer_change_stream_state(int stream_key
,
275 enum lttng_consumer_stream_state state
);
276 extern void consumer_del_channel(struct lttng_consumer_channel
*channel
);
277 extern struct lttng_consumer_channel
*consumer_allocate_channel(
279 int shm_fd
, int wait_fd
,
281 uint64_t max_sb_size
);
282 int consumer_add_channel(struct lttng_consumer_channel
*channel
);
284 extern struct lttng_consumer_local_data
*lttng_consumer_create(
285 enum lttng_consumer_type type
,
286 int (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
287 struct lttng_consumer_local_data
*ctx
),
288 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
289 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
290 int (*update_stream
)(int sessiond_key
, uint32_t state
));
291 extern void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
);
292 extern int lttng_consumer_on_read_subbuffer_mmap(
293 struct lttng_consumer_local_data
*ctx
,
294 struct lttng_consumer_stream
*stream
, unsigned long len
);
295 extern int lttng_consumer_on_read_subbuffer_splice(
296 struct lttng_consumer_local_data
*ctx
,
297 struct lttng_consumer_stream
*stream
, unsigned long len
);
298 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
299 struct lttng_consumer_stream
*stream
);
300 extern int lttng_consumer_get_produced_snapshot(
301 struct lttng_consumer_local_data
*ctx
,
302 struct lttng_consumer_stream
*stream
,
304 extern void *lttng_consumer_thread_poll_fds(void *data
);
305 extern void *lttng_consumer_thread_receive_fds(void *data
);
306 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
307 int sock
, struct pollfd
*consumer_sockpoll
);
309 int lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
310 struct lttng_consumer_local_data
*ctx
);
311 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
);
313 #endif /* _LTTNG_CONSUMER_H */