Merge duplicate code in consumer for add relayd
[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 /*
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
38 * eventually.
39 *
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.
43 *
44 * The value of 2 seconds is an arbitrary choice.
45 */
46 #define LTTNG_CONSUMER_POLL_TIMEOUT 2000
47
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 */
55 LTTNG_CONSUMER_STOP,
56 LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
57 /* Inform the consumer to kill a specific relayd connection */
58 LTTNG_CONSUMER_DESTROY_RELAYD,
59 };
60
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,
66 };
67
68 enum lttng_consumer_type {
69 LTTNG_CONSUMER_UNKNOWN = 0,
70 LTTNG_CONSUMER_KERNEL,
71 LTTNG_CONSUMER64_UST,
72 LTTNG_CONSUMER32_UST,
73 };
74
75 struct lttng_consumer_channel {
76 struct lttng_ht_node_ulong node;
77 int key;
78 uint64_t max_sb_size; /* the subbuffer size for this channel */
79 int refcount; /* Number of streams referencing this channel */
80 /* For UST */
81 int shm_fd;
82 int wait_fd;
83 void *mmap_base;
84 size_t mmap_len;
85 struct lttng_ust_shm_handle *handle;
86 int nr_streams;
87 int wait_fd_is_copy;
88 int cpucount;
89 };
90
91 /* Forward declaration for UST. */
92 struct lttng_ust_lib_ring_buffer;
93
94 /*
95 * Internal representation of the streams, sessiond_key is used to identify
96 * uniquely a stream.
97 */
98 struct lttng_consumer_stream {
99 struct lttng_ht_node_ulong node;
100 struct lttng_ht_node_ulong waitfd_node;
101 struct lttng_consumer_channel *chan; /* associated channel */
102 /*
103 * key is the key used by the session daemon to refer to the
104 * object in the consumer daemon.
105 */
106 int key;
107 int shm_fd;
108 int wait_fd;
109 int out_fd; /* output file to write the data */
110 off_t out_fd_offset; /* write position in the output file descriptor */
111 char path_name[PATH_MAX]; /* tracefile name */
112 enum lttng_consumer_stream_state state;
113 size_t shm_len;
114 void *mmap_base;
115 size_t mmap_len;
116 enum lttng_event_output output; /* splice or mmap */
117 int shm_fd_is_copy;
118 int wait_fd_is_copy;
119 /* For UST */
120 struct lttng_ust_lib_ring_buffer *buf;
121 int cpu;
122 int data_read;
123 int hangup_flush_done;
124 /* UID/GID of the user owning the session to which stream belongs */
125 uid_t uid;
126 gid_t gid;
127 /* Network sequence number. Indicating on which relayd socket it goes. */
128 int net_seq_idx;
129 /* Identify if the stream is the metadata */
130 unsigned int metadata_flag;
131 /* Used when the stream is set for network streaming */
132 uint64_t relayd_stream_id;
133 /* Next sequence number to use for trace packet */
134 uint64_t next_net_seq_num;
135 };
136
137 /*
138 * Internal representation of a relayd socket pair.
139 */
140 struct consumer_relayd_sock_pair {
141 /* Network sequence number. */
142 int net_seq_idx;
143 /* Number of stream associated with this relayd */
144 unsigned int refcount;
145
146 /*
147 * This flag indicates whether or not we should destroy this object. The
148 * destruction should ONLY occurs when this flag is set and the refcount is
149 * set to zero.
150 */
151 unsigned int destroy_flag;
152
153 /*
154 * Mutex protecting the control socket to avoid out of order packets
155 * between threads sending data to the relayd. Since metadata data is sent
156 * over that socket, at least two sendmsg() are needed (header + data)
157 * creating a race for packets to overlap between threads using it.
158 */
159 pthread_mutex_t ctrl_sock_mutex;
160
161 /* Control socket. Command and metadata are passed over it */
162 struct lttcomm_sock control_sock;
163
164 /*
165 * We don't need a mutex at this point since we only splice or write single
166 * large chunk of data with a header appended at the begining. Moreover,
167 * this socket is for now only used in a single thread.
168 */
169 struct lttcomm_sock data_sock;
170 struct lttng_ht_node_ulong node;
171 };
172
173 /*
174 * UST consumer local data to the program. One or more instance per
175 * process.
176 */
177 struct lttng_consumer_local_data {
178 /*
179 * Function to call when data is available on a buffer.
180 * Returns the number of bytes read, or negative error value.
181 */
182 ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
183 struct lttng_consumer_local_data *ctx);
184 /*
185 * function to call when we receive a new channel, it receives a
186 * newly allocated channel, depending on the return code of this
187 * function, the new channel will be handled by the application
188 * or the library.
189 *
190 * Returns:
191 * > 0 (success, FD is kept by application)
192 * == 0 (success, FD is left to library)
193 * < 0 (error)
194 */
195 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
196 /*
197 * function to call when we receive a new stream, it receives a
198 * newly allocated stream, depending on the return code of this
199 * function, the new stream will be handled by the application
200 * or the library.
201 *
202 * Returns:
203 * > 0 (success, FD is kept by application)
204 * == 0 (success, FD is left to library)
205 * < 0 (error)
206 */
207 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
208 /*
209 * function to call when a stream is getting updated by the session
210 * daemon, this function receives the sessiond key and the new
211 * state, depending on the return code of this function the
212 * update of state for the stream is handled by the application
213 * or the library.
214 *
215 * Returns:
216 * > 0 (success, FD is kept by application)
217 * == 0 (success, FD is left to library)
218 * < 0 (error)
219 */
220 int (*on_update_stream)(int sessiond_key, uint32_t state);
221 /* socket to communicate errors with sessiond */
222 int consumer_error_socket;
223 /* socket to exchange commands with sessiond */
224 char *consumer_command_sock_path;
225 /* communication with splice */
226 int consumer_thread_pipe[2];
227 /* pipe to wake the poll thread when necessary */
228 int consumer_poll_pipe[2];
229 /* to let the signal handler wake up the fd receiver thread */
230 int consumer_should_quit[2];
231 };
232
233 /*
234 * Library-level data. One instance per process.
235 */
236 struct lttng_consumer_global_data {
237 /*
238 * At this time, this lock is used to ensure coherence between the count
239 * and number of element in the hash table. It's also a protection for
240 * concurrent read/write between threads.
241 *
242 * XXX: We need to see if this lock is still needed with the lockless RCU
243 * hash tables.
244 */
245 pthread_mutex_t lock;
246
247 /*
248 * Number of streams in the hash table. Protected by consumer_data.lock.
249 */
250 int stream_count;
251 /*
252 * Hash tables of streams and channels. Protected by consumer_data.lock.
253 */
254 struct lttng_ht *stream_ht;
255 struct lttng_ht *channel_ht;
256 /*
257 * Flag specifying if the local array of FDs needs update in the
258 * poll function. Protected by consumer_data.lock.
259 */
260 unsigned int need_update;
261 enum lttng_consumer_type type;
262
263 /*
264 * Relayd socket(s) hashtable indexed by network sequence number. Each
265 * stream has an index which associate the right relayd socket to use.
266 */
267 struct lttng_ht *relayd_ht;
268 };
269
270 /*
271 * Init consumer data structures.
272 */
273 extern void lttng_consumer_init(void);
274
275 /*
276 * Set the error socket for communication with a session daemon.
277 */
278 extern void lttng_consumer_set_error_sock(
279 struct lttng_consumer_local_data *ctx, int sock);
280
281 /*
282 * Set the command socket path for communication with a session daemon.
283 */
284 extern void lttng_consumer_set_command_sock_path(
285 struct lttng_consumer_local_data *ctx, char *sock);
286
287 /*
288 * Send return code to session daemon.
289 *
290 * Returns the return code of sendmsg : the number of bytes transmitted or -1
291 * on error.
292 */
293 extern int lttng_consumer_send_error(
294 struct lttng_consumer_local_data *ctx, int cmd);
295
296 /*
297 * Called from signal handler to ensure a clean exit.
298 */
299 extern void lttng_consumer_should_exit(
300 struct lttng_consumer_local_data *ctx);
301
302 /*
303 * Cleanup the daemon's socket on exit.
304 */
305 extern void lttng_consumer_cleanup(void);
306
307 /*
308 * Flush pending writes to trace output disk file.
309 */
310 extern void lttng_consumer_sync_trace_file(
311 struct lttng_consumer_stream *stream, off_t orig_offset);
312
313 /*
314 * Poll on the should_quit pipe and the command socket return -1 on error and
315 * should exit, 0 if data is available on the command socket
316 */
317 extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
318
319 extern int consumer_update_poll_array(
320 struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
321 struct lttng_consumer_stream **local_consumer_streams,
322 struct lttng_ht *metadata_ht);
323
324 extern struct lttng_consumer_stream *consumer_allocate_stream(
325 int channel_key, int stream_key,
326 int shm_fd, int wait_fd,
327 enum lttng_consumer_stream_state state,
328 uint64_t mmap_len,
329 enum lttng_event_output output,
330 const char *path_name,
331 uid_t uid,
332 gid_t gid,
333 int net_index,
334 int metadata_flag);
335 extern int consumer_add_stream(struct lttng_consumer_stream *stream);
336 extern void consumer_del_stream(struct lttng_consumer_stream *stream);
337 extern void consumer_change_stream_state(int stream_key,
338 enum lttng_consumer_stream_state state);
339 extern void consumer_del_channel(struct lttng_consumer_channel *channel);
340 extern struct lttng_consumer_channel *consumer_allocate_channel(
341 int channel_key,
342 int shm_fd, int wait_fd,
343 uint64_t mmap_len,
344 uint64_t max_sb_size);
345 int consumer_add_channel(struct lttng_consumer_channel *channel);
346
347 /* lttng-relayd consumer command */
348 int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd);
349 struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
350 int net_seq_idx);
351 struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
352 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
353 size_t data_size);
354 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
355
356 extern struct lttng_consumer_local_data *lttng_consumer_create(
357 enum lttng_consumer_type type,
358 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
359 struct lttng_consumer_local_data *ctx),
360 int (*recv_channel)(struct lttng_consumer_channel *channel),
361 int (*recv_stream)(struct lttng_consumer_stream *stream),
362 int (*update_stream)(int sessiond_key, uint32_t state));
363 extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
364 extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
365 struct lttng_consumer_local_data *ctx,
366 struct lttng_consumer_stream *stream, unsigned long len);
367 extern ssize_t lttng_consumer_on_read_subbuffer_splice(
368 struct lttng_consumer_local_data *ctx,
369 struct lttng_consumer_stream *stream, unsigned long len);
370 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
371 struct lttng_consumer_stream *stream);
372 extern int lttng_consumer_get_produced_snapshot(
373 struct lttng_consumer_local_data *ctx,
374 struct lttng_consumer_stream *stream,
375 unsigned long *pos);
376 extern void *lttng_consumer_thread_poll_fds(void *data);
377 extern void *lttng_consumer_thread_receive_fds(void *data);
378 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
379 int sock, struct pollfd *consumer_sockpoll);
380
381 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
382 struct lttng_consumer_local_data *ctx);
383 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
384 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
385 struct lttng_consumer_local_data *ctx, int sock,
386 struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
387
388 #endif /* LIB_CONSUMER_H */
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