2bcb0db24d88fed6419d21685023bf1dbe0ffccb
[lttng-tools.git] / src / common / consumer.h
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
5 *
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.
9 *
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
13 * more details.
14 *
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.
18 */
19
20 #ifndef LIB_CONSUMER_H
21 #define LIB_CONSUMER_H
22
23 #include <limits.h>
24 #include <poll.h>
25 #include <unistd.h>
26
27 #include <lttng/lttng.h>
28
29 #include <common/hashtable/hashtable.h>
30 #include <common/compat/fcntl.h>
31 #include <common/sessiond-comm/sessiond-comm.h>
32
33 /* Commands for consumer */
34 enum lttng_consumer_command {
35 LTTNG_CONSUMER_ADD_CHANNEL,
36 LTTNG_CONSUMER_ADD_STREAM,
37 /* pause, delete, active depending on fd state */
38 LTTNG_CONSUMER_UPDATE_STREAM,
39 /* inform the consumer to quit when all fd has hang up */
40 LTTNG_CONSUMER_STOP,
41 LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
42 /* Inform the consumer to kill a specific relayd connection */
43 LTTNG_CONSUMER_DESTROY_RELAYD,
44 /* Return to the sessiond if there is data pending for a session */
45 LTTNG_CONSUMER_DATA_PENDING,
46 };
47
48 /* State of each fd in consumer */
49 enum lttng_consumer_stream_state {
50 LTTNG_CONSUMER_ACTIVE_STREAM,
51 LTTNG_CONSUMER_PAUSE_STREAM,
52 LTTNG_CONSUMER_DELETE_STREAM,
53 };
54
55 enum lttng_consumer_type {
56 LTTNG_CONSUMER_UNKNOWN = 0,
57 LTTNG_CONSUMER_KERNEL,
58 LTTNG_CONSUMER64_UST,
59 LTTNG_CONSUMER32_UST,
60 };
61
62 enum consumer_endpoint_status {
63 CONSUMER_ENDPOINT_ACTIVE,
64 CONSUMER_ENDPOINT_INACTIVE,
65 };
66
67 struct lttng_consumer_channel {
68 struct lttng_ht_node_ulong node;
69 int key;
70 uint64_t max_sb_size; /* the subbuffer size for this channel */
71 int refcount; /* Number of streams referencing this channel */
72 /*
73 * The number of streams to receive initially. Used to guarantee that we do
74 * not destroy a channel before receiving all its associated streams.
75 */
76 unsigned int nb_init_streams;
77
78 /* For UST */
79 int shm_fd;
80 int wait_fd;
81 void *mmap_base;
82 size_t mmap_len;
83 struct lttng_ust_shm_handle *handle;
84 int wait_fd_is_copy;
85 int cpucount;
86 };
87
88 /* Forward declaration for UST. */
89 struct lttng_ust_lib_ring_buffer;
90
91 /*
92 * Internal representation of the streams, sessiond_key is used to identify
93 * uniquely a stream.
94 */
95 struct lttng_consumer_stream {
96 /* HT node used by the data_ht and metadata_ht */
97 struct lttng_ht_node_ulong node;
98 /* HT node used in consumer_data.stream_list_ht */
99 struct lttng_ht_node_ulong node_session_id;
100 struct lttng_consumer_channel *chan; /* associated channel */
101 /*
102 * key is the key used by the session daemon to refer to the
103 * object in the consumer daemon.
104 */
105 int key;
106 int shm_fd;
107 int wait_fd;
108 int out_fd; /* output file to write the data */
109 off_t out_fd_offset; /* write position in the output file descriptor */
110 char path_name[PATH_MAX]; /* tracefile name */
111 enum lttng_consumer_stream_state state;
112 size_t shm_len;
113 void *mmap_base;
114 size_t mmap_len;
115 enum lttng_event_output output; /* splice or mmap */
116 int shm_fd_is_copy;
117 int wait_fd_is_copy;
118 /* For UST */
119 struct lttng_ust_lib_ring_buffer *buf;
120 int cpu;
121 int data_read;
122 int hangup_flush_done;
123 /* UID/GID of the user owning the session to which stream belongs */
124 uid_t uid;
125 gid_t gid;
126 /* Network sequence number. Indicating on which relayd socket it goes. */
127 int net_seq_idx;
128 /* Identify if the stream is the metadata */
129 unsigned int metadata_flag;
130 /* Used when the stream is set for network streaming */
131 uint64_t relayd_stream_id;
132 /* Next sequence number to use for trace packet */
133 uint64_t next_net_seq_num;
134 /*
135 * Lock to use the stream FDs since they are used between threads. Using
136 * this lock with network streaming, when using the control mutex of a
137 * consumer_relayd_sock_pair, make sure to acquire this lock BEFORE locking
138 * it and releasing it AFTER the control mutex unlock.
139 */
140 pthread_mutex_t lock;
141 /* Tracing session id */
142 uint64_t session_id;
143 /*
144 * Indicates if the stream end point is still active or not (network
145 * streaming or local file system). The thread "owning" the stream is
146 * handling this status and can be notified of a state change through the
147 * consumer data appropriate pipe.
148 */
149 enum consumer_endpoint_status endpoint_status;
150 };
151
152 /*
153 * Internal representation of a relayd socket pair.
154 */
155 struct consumer_relayd_sock_pair {
156 /* Network sequence number. */
157 int net_seq_idx;
158 /* Number of stream associated with this relayd */
159 unsigned int refcount;
160
161 /*
162 * This flag indicates whether or not we should destroy this object. The
163 * destruction should ONLY occurs when this flag is set and the refcount is
164 * set to zero.
165 */
166 unsigned int destroy_flag;
167
168 /*
169 * Mutex protecting the control socket to avoid out of order packets
170 * between threads sending data to the relayd. Since metadata data is sent
171 * over that socket, at least two sendmsg() are needed (header + data)
172 * creating a race for packets to overlap between threads using it.
173 */
174 pthread_mutex_t ctrl_sock_mutex;
175
176 /* Control socket. Command and metadata are passed over it */
177 struct lttcomm_sock control_sock;
178
179 /*
180 * We don't need a mutex at this point since we only splice or write single
181 * large chunk of data with a header appended at the begining. Moreover,
182 * this socket is for now only used in a single thread.
183 */
184 struct lttcomm_sock data_sock;
185 struct lttng_ht_node_ulong node;
186 };
187
188 /*
189 * UST consumer local data to the program. One or more instance per
190 * process.
191 */
192 struct lttng_consumer_local_data {
193 /*
194 * Function to call when data is available on a buffer.
195 * Returns the number of bytes read, or negative error value.
196 */
197 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
198 struct lttng_consumer_local_data *ctx);
199 /*
200 * function to call when we receive a new channel, it receives a
201 * newly allocated channel, depending on the return code of this
202 * function, the new channel will be handled by the application
203 * or the library.
204 *
205 * Returns:
206 * > 0 (success, FD is kept by application)
207 * == 0 (success, FD is left to library)
208 * < 0 (error)
209 */
210 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
211 /*
212 * function to call when we receive a new stream, it receives a
213 * newly allocated stream, depending on the return code of this
214 * function, the new stream will be handled by the application
215 * or the library.
216 *
217 * Returns:
218 * > 0 (success, FD is kept by application)
219 * == 0 (success, FD is left to library)
220 * < 0 (error)
221 */
222 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
223 /*
224 * function to call when a stream is getting updated by the session
225 * daemon, this function receives the sessiond key and the new
226 * state, depending on the return code of this function the
227 * update of state for the stream is handled by the application
228 * or the library.
229 *
230 * Returns:
231 * > 0 (success, FD is kept by application)
232 * == 0 (success, FD is left to library)
233 * < 0 (error)
234 */
235 int (*on_update_stream)(int sessiond_key, uint32_t state);
236 /* socket to communicate errors with sessiond */
237 int consumer_error_socket;
238 /* socket to exchange commands with sessiond */
239 char *consumer_command_sock_path;
240 /* communication with splice */
241 int consumer_thread_pipe[2];
242 int consumer_splice_metadata_pipe[2];
243 /* Data stream poll thread pipe. To transfer data stream to the thread */
244 int consumer_data_pipe[2];
245 /* to let the signal handler wake up the fd receiver thread */
246 int consumer_should_quit[2];
247 /* Metadata poll thread pipe. Transfer metadata stream to it */
248 int consumer_metadata_pipe[2];
249 };
250
251 /*
252 * Library-level data. One instance per process.
253 */
254 struct lttng_consumer_global_data {
255 /*
256 * At this time, this lock is used to ensure coherence between the count
257 * and number of element in the hash table. It's also a protection for
258 * concurrent read/write between threads.
259 *
260 * XXX: We need to see if this lock is still needed with the lockless RCU
261 * hash tables.
262 */
263 pthread_mutex_t lock;
264
265 /*
266 * Number of streams in the data stream hash table declared outside.
267 * Protected by consumer_data.lock.
268 */
269 int stream_count;
270
271 /* Channel hash table protected by consumer_data.lock. */
272 struct lttng_ht *channel_ht;
273 /*
274 * Flag specifying if the local array of FDs needs update in the
275 * poll function. Protected by consumer_data.lock.
276 */
277 unsigned int need_update;
278 enum lttng_consumer_type type;
279
280 /*
281 * Relayd socket(s) hashtable indexed by network sequence number. Each
282 * stream has an index which associate the right relayd socket to use.
283 */
284 struct lttng_ht *relayd_ht;
285
286 /*
287 * This hash table contains all streams (metadata and data) indexed by
288 * session id. In other words, the ht is indexed by session id and each
289 * bucket contains the list of associated streams.
290 *
291 * This HT uses the "node_session_id" of the consumer stream.
292 */
293 struct lttng_ht *stream_list_ht;
294 };
295
296 /* Defined in consumer.c and coupled with explanations */
297 extern struct lttng_ht *metadata_ht;
298 extern struct lttng_ht *data_ht;
299
300 /*
301 * Init consumer data structures.
302 */
303 extern void lttng_consumer_init(void);
304
305 /*
306 * Set the error socket for communication with a session daemon.
307 */
308 extern void lttng_consumer_set_error_sock(
309 struct lttng_consumer_local_data *ctx, int sock);
310
311 /*
312 * Set the command socket path for communication with a session daemon.
313 */
314 extern void lttng_consumer_set_command_sock_path(
315 struct lttng_consumer_local_data *ctx, char *sock);
316
317 /*
318 * Send return code to session daemon.
319 *
320 * Returns the return code of sendmsg : the number of bytes transmitted or -1
321 * on error.
322 */
323 extern int lttng_consumer_send_error(
324 struct lttng_consumer_local_data *ctx, int cmd);
325
326 /*
327 * Called from signal handler to ensure a clean exit.
328 */
329 extern void lttng_consumer_should_exit(
330 struct lttng_consumer_local_data *ctx);
331
332 /*
333 * Cleanup the daemon's socket on exit.
334 */
335 extern void lttng_consumer_cleanup(void);
336
337 /*
338 * Flush pending writes to trace output disk file.
339 */
340 extern void lttng_consumer_sync_trace_file(
341 struct lttng_consumer_stream *stream, off_t orig_offset);
342
343 /*
344 * Poll on the should_quit pipe and the command socket return -1 on error and
345 * should exit, 0 if data is available on the command socket
346 */
347 extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
348
349 extern struct lttng_consumer_stream *consumer_allocate_stream(
350 int channel_key, int stream_key,
351 int shm_fd, int wait_fd,
352 enum lttng_consumer_stream_state state,
353 uint64_t mmap_len,
354 enum lttng_event_output output,
355 const char *path_name,
356 uid_t uid,
357 gid_t gid,
358 int net_index,
359 int metadata_flag,
360 uint64_t session_id,
361 int *alloc_ret);
362 extern void consumer_del_stream(struct lttng_consumer_stream *stream,
363 struct lttng_ht *ht);
364 extern void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
365 struct lttng_ht *ht);
366 extern void consumer_del_channel(struct lttng_consumer_channel *channel);
367 extern struct lttng_consumer_channel *consumer_allocate_channel(
368 int channel_key,
369 int shm_fd, int wait_fd,
370 uint64_t mmap_len,
371 uint64_t max_sb_size,
372 unsigned int nb_init_streams);
373 int consumer_add_channel(struct lttng_consumer_channel *channel);
374
375 /* lttng-relayd consumer command */
376 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
377 int net_seq_idx);
378 struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
379 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
380 size_t data_size);
381 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
382
383 extern struct lttng_consumer_local_data *lttng_consumer_create(
384 enum lttng_consumer_type type,
385 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
386 struct lttng_consumer_local_data *ctx),
387 int (*recv_channel)(struct lttng_consumer_channel *channel),
388 int (*recv_stream)(struct lttng_consumer_stream *stream),
389 int (*update_stream)(int sessiond_key, uint32_t state));
390 extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
391 extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
392 struct lttng_consumer_local_data *ctx,
393 struct lttng_consumer_stream *stream, unsigned long len,
394 unsigned long padding);
395 extern ssize_t lttng_consumer_on_read_subbuffer_splice(
396 struct lttng_consumer_local_data *ctx,
397 struct lttng_consumer_stream *stream, unsigned long len,
398 unsigned long padding);
399 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
400 struct lttng_consumer_stream *stream);
401 extern int lttng_consumer_get_produced_snapshot(
402 struct lttng_consumer_local_data *ctx,
403 struct lttng_consumer_stream *stream,
404 unsigned long *pos);
405 extern void *consumer_thread_metadata_poll(void *data);
406 extern void *consumer_thread_data_poll(void *data);
407 extern void *consumer_thread_sessiond_poll(void *data);
408 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
409 int sock, struct pollfd *consumer_sockpoll);
410
411 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
412 struct lttng_consumer_local_data *ctx);
413 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
414 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
415 struct lttng_consumer_local_data *ctx, int sock,
416 struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
417 void consumer_flag_relayd_for_destroy(
418 struct consumer_relayd_sock_pair *relayd);
419 int consumer_data_pending(uint64_t id);
420
421 #endif /* LIB_CONSUMER_H */
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