Fix: update next_net_seq_num after sending header
[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 /*
133 * When sending a stream packet to a relayd, this number is used to track
134 * the packet sent by the consumer and seen by the relayd. When sending the
135 * data header to the relayd, this number is sent and if the transmission
136 * was successful, it is incremented.
137 *
138 * Even if the full data is not fully transmitted it won't matter since
139 * only two possible error can happen after that where either the relayd
140 * died or a read error is detected on the stream making this value useless
141 * after that.
142 *
143 * This value SHOULD be read/updated atomically or with the lock acquired.
144 */
145 uint64_t next_net_seq_num;
146 /*
147 * Lock to use the stream FDs since they are used between threads.
148 *
149 * This is nested INSIDE the consumer_data lock.
150 * This is nested OUTSIDE consumer_relayd_sock_pair lock.
151 */
152 pthread_mutex_t lock;
153 /* Tracing session id */
154 uint64_t session_id;
155 /*
156 * Indicates if the stream end point is still active or not (network
157 * streaming or local file system). The thread "owning" the stream is
158 * handling this status and can be notified of a state change through the
159 * consumer data appropriate pipe.
160 */
161 enum consumer_endpoint_status endpoint_status;
162 };
163
164 /*
165 * Internal representation of a relayd socket pair.
166 */
167 struct consumer_relayd_sock_pair {
168 /* Network sequence number. */
169 int net_seq_idx;
170 /* Number of stream associated with this relayd */
171 unsigned int refcount;
172
173 /*
174 * This flag indicates whether or not we should destroy this object. The
175 * destruction should ONLY occurs when this flag is set and the refcount is
176 * set to zero.
177 */
178 unsigned int destroy_flag;
179
180 /*
181 * Mutex protecting the control socket to avoid out of order packets
182 * between threads sending data to the relayd. Since metadata data is sent
183 * over that socket, at least two sendmsg() are needed (header + data)
184 * creating a race for packets to overlap between threads using it.
185 *
186 * This is nested INSIDE the consumer_data lock.
187 * This is nested INSIDE the stream lock.
188 */
189 pthread_mutex_t ctrl_sock_mutex;
190
191 /* Control socket. Command and metadata are passed over it */
192 struct lttcomm_sock control_sock;
193
194 /*
195 * We don't need a mutex at this point since we only splice or write single
196 * large chunk of data with a header appended at the begining. Moreover,
197 * this socket is for now only used in a single thread.
198 */
199 struct lttcomm_sock data_sock;
200 struct lttng_ht_node_ulong node;
201
202 /* Session id on both sides for the sockets. */
203 uint64_t relayd_session_id;
204 uint64_t sessiond_session_id;
205 };
206
207 /*
208 * UST consumer local data to the program. One or more instance per
209 * process.
210 */
211 struct lttng_consumer_local_data {
212 /*
213 * Function to call when data is available on a buffer.
214 * Returns the number of bytes read, or negative error value.
215 */
216 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
217 struct lttng_consumer_local_data *ctx);
218 /*
219 * function to call when we receive a new channel, it receives a
220 * newly allocated channel, depending on the return code of this
221 * function, the new channel will be handled by the application
222 * or the library.
223 *
224 * Returns:
225 * > 0 (success, FD is kept by application)
226 * == 0 (success, FD is left to library)
227 * < 0 (error)
228 */
229 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
230 /*
231 * function to call when we receive a new stream, it receives a
232 * newly allocated stream, depending on the return code of this
233 * function, the new stream will be handled by the application
234 * or the library.
235 *
236 * Returns:
237 * > 0 (success, FD is kept by application)
238 * == 0 (success, FD is left to library)
239 * < 0 (error)
240 */
241 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
242 /*
243 * function to call when a stream is getting updated by the session
244 * daemon, this function receives the sessiond key and the new
245 * state, depending on the return code of this function the
246 * update of state for the stream is handled by the application
247 * or the library.
248 *
249 * Returns:
250 * > 0 (success, FD is kept by application)
251 * == 0 (success, FD is left to library)
252 * < 0 (error)
253 */
254 int (*on_update_stream)(int sessiond_key, uint32_t state);
255 /* socket to communicate errors with sessiond */
256 int consumer_error_socket;
257 /* socket to exchange commands with sessiond */
258 char *consumer_command_sock_path;
259 /* communication with splice */
260 int consumer_thread_pipe[2];
261 int consumer_splice_metadata_pipe[2];
262 /* Data stream poll thread pipe. To transfer data stream to the thread */
263 int consumer_data_pipe[2];
264 /* to let the signal handler wake up the fd receiver thread */
265 int consumer_should_quit[2];
266 /* Metadata poll thread pipe. Transfer metadata stream to it */
267 int consumer_metadata_pipe[2];
268 };
269
270 /*
271 * Library-level data. One instance per process.
272 */
273 struct lttng_consumer_global_data {
274 /*
275 * At this time, this lock is used to ensure coherence between the count
276 * and number of element in the hash table. It's also a protection for
277 * concurrent read/write between threads.
278 *
279 * This is nested OUTSIDE the stream lock.
280 * This is nested OUTSIDE the consumer_relayd_sock_pair lock.
281 */
282 pthread_mutex_t lock;
283
284 /*
285 * Number of streams in the data stream hash table declared outside.
286 * Protected by consumer_data.lock.
287 */
288 int stream_count;
289
290 /* Channel hash table protected by consumer_data.lock. */
291 struct lttng_ht *channel_ht;
292 /*
293 * Flag specifying if the local array of FDs needs update in the
294 * poll function. Protected by consumer_data.lock.
295 */
296 unsigned int need_update;
297 enum lttng_consumer_type type;
298
299 /*
300 * Relayd socket(s) hashtable indexed by network sequence number. Each
301 * stream has an index which associate the right relayd socket to use.
302 */
303 struct lttng_ht *relayd_ht;
304
305 /*
306 * This hash table contains all streams (metadata and data) indexed by
307 * session id. In other words, the ht is indexed by session id and each
308 * bucket contains the list of associated streams.
309 *
310 * This HT uses the "node_session_id" of the consumer stream.
311 */
312 struct lttng_ht *stream_list_ht;
313 };
314
315 /*
316 * Init consumer data structures.
317 */
318 extern void lttng_consumer_init(void);
319
320 /*
321 * Set the error socket for communication with a session daemon.
322 */
323 extern void lttng_consumer_set_error_sock(
324 struct lttng_consumer_local_data *ctx, int sock);
325
326 /*
327 * Set the command socket path for communication with a session daemon.
328 */
329 extern void lttng_consumer_set_command_sock_path(
330 struct lttng_consumer_local_data *ctx, char *sock);
331
332 /*
333 * Send return code to session daemon.
334 *
335 * Returns the return code of sendmsg : the number of bytes transmitted or -1
336 * on error.
337 */
338 extern int lttng_consumer_send_error(
339 struct lttng_consumer_local_data *ctx, int cmd);
340
341 /*
342 * Called from signal handler to ensure a clean exit.
343 */
344 extern void lttng_consumer_should_exit(
345 struct lttng_consumer_local_data *ctx);
346
347 /*
348 * Cleanup the daemon's socket on exit.
349 */
350 extern void lttng_consumer_cleanup(void);
351
352 /*
353 * Flush pending writes to trace output disk file.
354 */
355 extern void lttng_consumer_sync_trace_file(
356 struct lttng_consumer_stream *stream, off_t orig_offset);
357
358 /*
359 * Poll on the should_quit pipe and the command socket return -1 on error and
360 * should exit, 0 if data is available on the command socket
361 */
362 extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
363
364 extern struct lttng_consumer_stream *consumer_allocate_stream(
365 int channel_key, int stream_key,
366 int shm_fd, int wait_fd,
367 enum lttng_consumer_stream_state state,
368 uint64_t mmap_len,
369 enum lttng_event_output output,
370 const char *path_name,
371 uid_t uid,
372 gid_t gid,
373 int net_index,
374 int metadata_flag,
375 uint64_t session_id,
376 int *alloc_ret);
377 extern void consumer_del_stream(struct lttng_consumer_stream *stream,
378 struct lttng_ht *ht);
379 extern void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
380 struct lttng_ht *ht);
381 extern void consumer_del_channel(struct lttng_consumer_channel *channel);
382 extern struct lttng_consumer_channel *consumer_allocate_channel(
383 int channel_key,
384 int shm_fd, int wait_fd,
385 uint64_t mmap_len,
386 uint64_t max_sb_size,
387 unsigned int nb_init_streams);
388 int consumer_add_channel(struct lttng_consumer_channel *channel);
389
390 /* lttng-relayd consumer command */
391 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
392 int net_seq_idx);
393 struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
394 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
395 size_t data_size);
396 void consumer_steal_stream_key(int key, struct lttng_ht *ht);
397
398 extern struct lttng_consumer_local_data *lttng_consumer_create(
399 enum lttng_consumer_type type,
400 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
401 struct lttng_consumer_local_data *ctx),
402 int (*recv_channel)(struct lttng_consumer_channel *channel),
403 int (*recv_stream)(struct lttng_consumer_stream *stream),
404 int (*update_stream)(int sessiond_key, uint32_t state));
405 extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
406 extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
407 struct lttng_consumer_local_data *ctx,
408 struct lttng_consumer_stream *stream, unsigned long len,
409 unsigned long padding);
410 extern ssize_t lttng_consumer_on_read_subbuffer_splice(
411 struct lttng_consumer_local_data *ctx,
412 struct lttng_consumer_stream *stream, unsigned long len,
413 unsigned long padding);
414 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
415 struct lttng_consumer_stream *stream);
416 extern int lttng_consumer_get_produced_snapshot(
417 struct lttng_consumer_local_data *ctx,
418 struct lttng_consumer_stream *stream,
419 unsigned long *pos);
420 extern void *consumer_thread_metadata_poll(void *data);
421 extern void *consumer_thread_data_poll(void *data);
422 extern void *consumer_thread_sessiond_poll(void *data);
423 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
424 int sock, struct pollfd *consumer_sockpoll);
425
426 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
427 struct lttng_consumer_local_data *ctx);
428 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
429 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
430 struct lttng_consumer_local_data *ctx, int sock,
431 struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock,
432 unsigned int sessiond_id);
433 void consumer_flag_relayd_for_destroy(
434 struct consumer_relayd_sock_pair *relayd);
435 int consumer_data_pending(uint64_t id);
436 int consumer_send_status_msg(int sock, int ret_code);
437
438 #endif /* LIB_CONSUMER_H */
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