listing and activation of loglevel by number
[lttng-tools.git] / include / lttng / lttng-consumer.h
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
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
8 * of the License.
9 *
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.
14 *
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.
18 */
19
20 #ifndef _LTTNG_CONSUMER_H
21 #define _LTTNG_CONSUMER_H
22
23 #include <limits.h>
24 #include <poll.h>
25 #include <urcu/list.h>
26 #include <lttng/lttng.h>
27
28 /*
29 * When the receiving thread dies, we need to have a way to make the polling
30 * thread exit eventually. If all FDs hang up (normal case when the
31 * lttng-sessiond stops), we can exit cleanly, but if there is a problem and
32 * for whatever reason some FDs remain open, the consumer should still exit
33 * eventually.
34 *
35 * If the timeout is reached, it means that during this period no events
36 * occurred on the FDs so we need to force an exit. This case should not happen
37 * but it is a safety to ensure we won't block the consumer indefinitely.
38 *
39 * The value of 2 seconds is an arbitrary choice.
40 */
41 #define LTTNG_CONSUMER_POLL_TIMEOUT 2000
42
43 /* Commands for consumer */
44 enum lttng_consumer_command {
45 LTTNG_CONSUMER_ADD_CHANNEL,
46 LTTNG_CONSUMER_ADD_STREAM,
47 /* pause, delete, active depending on fd state */
48 LTTNG_CONSUMER_UPDATE_STREAM,
49 /* inform the consumer to quit when all fd has hang up */
50 LTTNG_CONSUMER_STOP,
51 };
52
53 /* State of each fd in consumer */
54 enum lttng_consumer_stream_state {
55 LTTNG_CONSUMER_ACTIVE_STREAM,
56 LTTNG_CONSUMER_PAUSE_STREAM,
57 LTTNG_CONSUMER_DELETE_STREAM,
58 };
59
60 struct lttng_consumer_channel_list {
61 struct cds_list_head head;
62 };
63
64 struct lttng_consumer_stream_list {
65 struct cds_list_head head;
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 cds_list_head list;
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 shm_fd_is_copy;
88 int wait_fd_is_copy;
89 int cpucount;
90 };
91
92 /* Forward declaration for UST. */
93 struct lttng_ust_lib_ring_buffer;
94
95 /*
96 * Internal representation of the streams, sessiond_key is used to identify
97 * uniquely a stream.
98 */
99 struct lttng_consumer_stream {
100 struct cds_list_head list;
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 hangup_flush_done;
123 };
124
125 /*
126 * UST consumer local data to the program. One or more instance per
127 * process.
128 */
129 struct lttng_consumer_local_data {
130 /* function to call when data is available on a buffer */
131 int (*on_buffer_ready)(struct lttng_consumer_stream *stream,
132 struct lttng_consumer_local_data *ctx);
133 /*
134 * function to call when we receive a new channel, it receives a
135 * newly allocated channel, depending on the return code of this
136 * function, the new channel will be handled by the application
137 * or the library.
138 *
139 * Returns:
140 * > 0 (success, FD is kept by application)
141 * == 0 (success, FD is left to library)
142 * < 0 (error)
143 */
144 int (*on_recv_channel)(struct lttng_consumer_channel *channel);
145 /*
146 * function to call when we receive a new stream, it receives a
147 * newly allocated stream, depending on the return code of this
148 * function, the new stream will be handled by the application
149 * or the library.
150 *
151 * Returns:
152 * > 0 (success, FD is kept by application)
153 * == 0 (success, FD is left to library)
154 * < 0 (error)
155 */
156 int (*on_recv_stream)(struct lttng_consumer_stream *stream);
157 /*
158 * function to call when a stream is getting updated by the session
159 * daemon, this function receives the sessiond key and the new
160 * state, depending on the return code of this function the
161 * update of state for the stream is handled by the application
162 * or the library.
163 *
164 * Returns:
165 * > 0 (success, FD is kept by application)
166 * == 0 (success, FD is left to library)
167 * < 0 (error)
168 */
169 int (*on_update_stream)(int sessiond_key, uint32_t state);
170 /* socket to communicate errors with sessiond */
171 int consumer_error_socket;
172 /* socket to exchange commands with sessiond */
173 char *consumer_command_sock_path;
174 /* communication with splice */
175 int consumer_thread_pipe[2];
176 /* pipe to wake the poll thread when necessary */
177 int consumer_poll_pipe[2];
178 /* to let the signal handler wake up the fd receiver thread */
179 int consumer_should_quit[2];
180 };
181
182 /*
183 * Library-level data. One instance per process.
184 */
185 struct lttng_consumer_global_data {
186 /*
187 * consumer_data.lock protects consumer_data.fd_list,
188 * consumer_data.stream_count, and consumer_data.need_update. It
189 * ensures the count matches the number of items in the fd_list.
190 * It ensures the list updates *always* trigger an fd_array
191 * update (therefore need to make list update vs
192 * consumer_data.need_update flag update atomic, and also flag
193 * read, fd array and flag clear atomic).
194 */
195 pthread_mutex_t lock;
196 /*
197 * Number of streams in the list below. Protected by
198 * consumer_data.lock.
199 */
200 int stream_count;
201 /*
202 * Lists of streams and channels. Protected by consumer_data.lock.
203 */
204 struct lttng_consumer_stream_list stream_list;
205 struct lttng_consumer_channel_list channel_list;
206 /*
207 * Flag specifying if the local array of FDs needs update in the
208 * poll function. Protected by consumer_data.lock.
209 */
210 unsigned int need_update;
211 enum lttng_consumer_type type;
212 };
213
214 /*
215 * Set the error socket for communication with a session daemon.
216 */
217 extern void lttng_consumer_set_error_sock(
218 struct lttng_consumer_local_data *ctx, int sock);
219
220 /*
221 * Set the command socket path for communication with a session daemon.
222 */
223 extern void lttng_consumer_set_command_sock_path(
224 struct lttng_consumer_local_data *ctx, char *sock);
225
226 /*
227 * Send return code to session daemon.
228 *
229 * Returns the return code of sendmsg : the number of bytes transmitted or -1
230 * on error.
231 */
232 extern int lttng_consumer_send_error(
233 struct lttng_consumer_local_data *ctx, int cmd);
234
235 /*
236 * Called from signal handler to ensure a clean exit.
237 */
238 extern void lttng_consumer_should_exit(
239 struct lttng_consumer_local_data *ctx);
240
241 /*
242 * Cleanup the daemon's socket on exit.
243 */
244 extern void lttng_consumer_cleanup(void);
245
246 /*
247 * Flush pending writes to trace output disk file.
248 */
249 extern void lttng_consumer_sync_trace_file(
250 struct lttng_consumer_stream *stream, off_t orig_offset);
251
252 /*
253 * Poll on the should_quit pipe and the command socket return -1 on error and
254 * should exit, 0 if data is available on the command socket
255 */
256 extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
257
258 extern int consumer_update_poll_array(
259 struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
260 struct lttng_consumer_stream **local_consumer_streams);
261
262 extern struct lttng_consumer_stream *consumer_allocate_stream(
263 int channel_key, int stream_key,
264 int shm_fd, int wait_fd,
265 enum lttng_consumer_stream_state state,
266 uint64_t mmap_len,
267 enum lttng_event_output output,
268 const char *path_name);
269 extern int consumer_add_stream(struct lttng_consumer_stream *stream);
270 extern void consumer_del_stream(struct lttng_consumer_stream *stream);
271 extern void consumer_change_stream_state(int stream_key,
272 enum lttng_consumer_stream_state state);
273 extern void consumer_del_channel(struct lttng_consumer_channel *channel);
274 extern struct lttng_consumer_channel *consumer_allocate_channel(
275 int channel_key,
276 int shm_fd, int wait_fd,
277 uint64_t mmap_len,
278 uint64_t max_sb_size);
279 int consumer_add_channel(struct lttng_consumer_channel *channel);
280
281 extern struct lttng_consumer_local_data *lttng_consumer_create(
282 enum lttng_consumer_type type,
283 int (*buffer_ready)(struct lttng_consumer_stream *stream,
284 struct lttng_consumer_local_data *ctx),
285 int (*recv_channel)(struct lttng_consumer_channel *channel),
286 int (*recv_stream)(struct lttng_consumer_stream *stream),
287 int (*update_stream)(int sessiond_key, uint32_t state));
288 extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
289 extern int lttng_consumer_on_read_subbuffer_mmap(
290 struct lttng_consumer_local_data *ctx,
291 struct lttng_consumer_stream *stream, unsigned long len);
292 extern int lttng_consumer_on_read_subbuffer_splice(
293 struct lttng_consumer_local_data *ctx,
294 struct lttng_consumer_stream *stream, unsigned long len);
295 extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
296 struct lttng_consumer_stream *stream);
297 extern int lttng_consumer_get_produced_snapshot(
298 struct lttng_consumer_local_data *ctx,
299 struct lttng_consumer_stream *stream,
300 unsigned long *pos);
301 extern void *lttng_consumer_thread_poll_fds(void *data);
302 extern void *lttng_consumer_thread_receive_fds(void *data);
303 extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
304 int sock, struct pollfd *consumer_sockpoll);
305
306 int lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
307 struct lttng_consumer_local_data *ctx);
308 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
309
310 #endif /* _LTTNG_CONSUMER_H */
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