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3bd1e081 MD |
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> | |
6df2e2c9 | 25 | #include <unistd.h> |
e4421fec | 26 | |
3bd1e081 | 27 | #include <lttng/lttng.h> |
10a8a223 | 28 | |
b9182dd9 DG |
29 | #include <common/hashtable/hashtable.h> |
30 | #include <common/compat/fcntl.h> | |
3bd1e081 MD |
31 | |
32 | /* | |
33 | * When the receiving thread dies, we need to have a way to make the polling | |
34 | * thread exit eventually. If all FDs hang up (normal case when the | |
32258573 DG |
35 | * lttng-sessiond stops), we can exit cleanly, but if there is a problem and |
36 | * for whatever reason some FDs remain open, the consumer should still exit | |
3bd1e081 MD |
37 | * eventually. |
38 | * | |
39 | * If the timeout is reached, it means that during this period no events | |
40 | * occurred on the FDs so we need to force an exit. This case should not happen | |
41 | * but it is a safety to ensure we won't block the consumer indefinitely. | |
42 | * | |
43 | * The value of 2 seconds is an arbitrary choice. | |
44 | */ | |
45 | #define LTTNG_CONSUMER_POLL_TIMEOUT 2000 | |
46 | ||
47 | /* Commands for consumer */ | |
48 | enum lttng_consumer_command { | |
49 | LTTNG_CONSUMER_ADD_CHANNEL, | |
50 | LTTNG_CONSUMER_ADD_STREAM, | |
51 | /* pause, delete, active depending on fd state */ | |
52 | LTTNG_CONSUMER_UPDATE_STREAM, | |
53 | /* inform the consumer to quit when all fd has hang up */ | |
54 | LTTNG_CONSUMER_STOP, | |
55 | }; | |
56 | ||
57 | /* State of each fd in consumer */ | |
58 | enum lttng_consumer_stream_state { | |
59 | LTTNG_CONSUMER_ACTIVE_STREAM, | |
60 | LTTNG_CONSUMER_PAUSE_STREAM, | |
61 | LTTNG_CONSUMER_DELETE_STREAM, | |
62 | }; | |
63 | ||
3bd1e081 MD |
64 | enum lttng_consumer_type { |
65 | LTTNG_CONSUMER_UNKNOWN = 0, | |
66 | LTTNG_CONSUMER_KERNEL, | |
7753dea8 MD |
67 | LTTNG_CONSUMER64_UST, |
68 | LTTNG_CONSUMER32_UST, | |
3bd1e081 MD |
69 | }; |
70 | ||
71 | struct lttng_consumer_channel { | |
e4421fec | 72 | struct lttng_ht_node_ulong node; |
3bd1e081 MD |
73 | int key; |
74 | uint64_t max_sb_size; /* the subbuffer size for this channel */ | |
75 | int refcount; /* Number of streams referencing this channel */ | |
76 | /* For UST */ | |
77 | int shm_fd; | |
78 | int wait_fd; | |
79 | void *mmap_base; | |
80 | size_t mmap_len; | |
13161846 | 81 | struct lttng_ust_shm_handle *handle; |
3bd1e081 | 82 | int nr_streams; |
b5c5fc29 | 83 | int wait_fd_is_copy; |
5af2f756 | 84 | int cpucount; |
3bd1e081 MD |
85 | }; |
86 | ||
87 | /* Forward declaration for UST. */ | |
13161846 | 88 | struct lttng_ust_lib_ring_buffer; |
3bd1e081 MD |
89 | |
90 | /* | |
91 | * Internal representation of the streams, sessiond_key is used to identify | |
92 | * uniquely a stream. | |
93 | */ | |
94 | struct lttng_consumer_stream { | |
e4421fec | 95 | struct lttng_ht_node_ulong node; |
3bd1e081 MD |
96 | struct lttng_consumer_channel *chan; /* associated channel */ |
97 | /* | |
98 | * key is the key used by the session daemon to refer to the | |
99 | * object in the consumer daemon. | |
100 | */ | |
101 | int key; | |
102 | int shm_fd; | |
103 | int wait_fd; | |
104 | int out_fd; /* output file to write the data */ | |
105 | off_t out_fd_offset; /* write position in the output file descriptor */ | |
106 | char path_name[PATH_MAX]; /* tracefile name */ | |
107 | enum lttng_consumer_stream_state state; | |
108 | size_t shm_len; | |
109 | void *mmap_base; | |
110 | size_t mmap_len; | |
111 | enum lttng_event_output output; /* splice or mmap */ | |
b5c5fc29 MD |
112 | int shm_fd_is_copy; |
113 | int wait_fd_is_copy; | |
3bd1e081 | 114 | /* For UST */ |
13161846 | 115 | struct lttng_ust_lib_ring_buffer *buf; |
3bd1e081 | 116 | int cpu; |
4078b776 | 117 | int data_read; |
d056b477 | 118 | int hangup_flush_done; |
6df2e2c9 MD |
119 | /* UID/GID of the user owning the session to which stream belongs */ |
120 | uid_t uid; | |
121 | gid_t gid; | |
3bd1e081 MD |
122 | }; |
123 | ||
124 | /* | |
125 | * UST consumer local data to the program. One or more instance per | |
126 | * process. | |
127 | */ | |
128 | struct lttng_consumer_local_data { | |
4078b776 MD |
129 | /* |
130 | * Function to call when data is available on a buffer. | |
131 | * Returns the number of bytes read, or negative error value. | |
132 | */ | |
133 | ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream, | |
d41f73b7 | 134 | struct lttng_consumer_local_data *ctx); |
3bd1e081 MD |
135 | /* |
136 | * function to call when we receive a new channel, it receives a | |
137 | * newly allocated channel, depending on the return code of this | |
138 | * function, the new channel will be handled by the application | |
139 | * or the library. | |
140 | * | |
141 | * Returns: | |
142 | * > 0 (success, FD is kept by application) | |
143 | * == 0 (success, FD is left to library) | |
144 | * < 0 (error) | |
145 | */ | |
146 | int (*on_recv_channel)(struct lttng_consumer_channel *channel); | |
147 | /* | |
148 | * function to call when we receive a new stream, it receives a | |
149 | * newly allocated stream, depending on the return code of this | |
150 | * function, the new stream will be handled by the application | |
151 | * or the library. | |
152 | * | |
153 | * Returns: | |
154 | * > 0 (success, FD is kept by application) | |
155 | * == 0 (success, FD is left to library) | |
156 | * < 0 (error) | |
157 | */ | |
158 | int (*on_recv_stream)(struct lttng_consumer_stream *stream); | |
159 | /* | |
160 | * function to call when a stream is getting updated by the session | |
161 | * daemon, this function receives the sessiond key and the new | |
162 | * state, depending on the return code of this function the | |
163 | * update of state for the stream is handled by the application | |
164 | * or the library. | |
165 | * | |
166 | * Returns: | |
167 | * > 0 (success, FD is kept by application) | |
168 | * == 0 (success, FD is left to library) | |
169 | * < 0 (error) | |
170 | */ | |
171 | int (*on_update_stream)(int sessiond_key, uint32_t state); | |
172 | /* socket to communicate errors with sessiond */ | |
173 | int consumer_error_socket; | |
174 | /* socket to exchange commands with sessiond */ | |
175 | char *consumer_command_sock_path; | |
176 | /* communication with splice */ | |
177 | int consumer_thread_pipe[2]; | |
178 | /* pipe to wake the poll thread when necessary */ | |
179 | int consumer_poll_pipe[2]; | |
180 | /* to let the signal handler wake up the fd receiver thread */ | |
181 | int consumer_should_quit[2]; | |
182 | }; | |
183 | ||
184 | /* | |
185 | * Library-level data. One instance per process. | |
186 | */ | |
187 | struct lttng_consumer_global_data { | |
e4421fec | 188 | |
3bd1e081 | 189 | /* |
e4421fec DG |
190 | * At this time, this lock is used to ensure coherence between the count |
191 | * and number of element in the hash table. It's also a protection for | |
6065ceec DG |
192 | * concurrent read/write between threads. |
193 | * | |
194 | * XXX: We need to see if this lock is still needed with the lockless RCU | |
195 | * hash tables. | |
3bd1e081 MD |
196 | */ |
197 | pthread_mutex_t lock; | |
e4421fec | 198 | |
3bd1e081 | 199 | /* |
e4421fec | 200 | * Number of streams in the hash table. Protected by consumer_data.lock. |
3bd1e081 MD |
201 | */ |
202 | int stream_count; | |
203 | /* | |
e4421fec | 204 | * Hash tables of streams and channels. Protected by consumer_data.lock. |
3bd1e081 | 205 | */ |
e4421fec DG |
206 | struct lttng_ht *stream_ht; |
207 | struct lttng_ht *channel_ht; | |
3bd1e081 MD |
208 | /* |
209 | * Flag specifying if the local array of FDs needs update in the | |
210 | * poll function. Protected by consumer_data.lock. | |
211 | */ | |
212 | unsigned int need_update; | |
213 | enum lttng_consumer_type type; | |
214 | }; | |
215 | ||
e4421fec DG |
216 | /* |
217 | * Init consumer data structures. | |
218 | */ | |
219 | extern void lttng_consumer_init(void); | |
220 | ||
3bd1e081 MD |
221 | /* |
222 | * Set the error socket for communication with a session daemon. | |
223 | */ | |
224 | extern void lttng_consumer_set_error_sock( | |
225 | struct lttng_consumer_local_data *ctx, int sock); | |
226 | ||
227 | /* | |
228 | * Set the command socket path for communication with a session daemon. | |
229 | */ | |
230 | extern void lttng_consumer_set_command_sock_path( | |
231 | struct lttng_consumer_local_data *ctx, char *sock); | |
232 | ||
233 | /* | |
234 | * Send return code to session daemon. | |
235 | * | |
236 | * Returns the return code of sendmsg : the number of bytes transmitted or -1 | |
237 | * on error. | |
238 | */ | |
239 | extern int lttng_consumer_send_error( | |
240 | struct lttng_consumer_local_data *ctx, int cmd); | |
241 | ||
242 | /* | |
243 | * Called from signal handler to ensure a clean exit. | |
244 | */ | |
245 | extern void lttng_consumer_should_exit( | |
246 | struct lttng_consumer_local_data *ctx); | |
247 | ||
248 | /* | |
249 | * Cleanup the daemon's socket on exit. | |
250 | */ | |
251 | extern void lttng_consumer_cleanup(void); | |
252 | ||
253 | /* | |
254 | * Flush pending writes to trace output disk file. | |
255 | */ | |
256 | extern void lttng_consumer_sync_trace_file( | |
257 | struct lttng_consumer_stream *stream, off_t orig_offset); | |
258 | ||
259 | /* | |
260 | * Poll on the should_quit pipe and the command socket return -1 on error and | |
261 | * should exit, 0 if data is available on the command socket | |
262 | */ | |
263 | extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll); | |
264 | ||
265 | extern int consumer_update_poll_array( | |
266 | struct lttng_consumer_local_data *ctx, struct pollfd **pollfd, | |
267 | struct lttng_consumer_stream **local_consumer_streams); | |
268 | ||
269 | extern struct lttng_consumer_stream *consumer_allocate_stream( | |
270 | int channel_key, int stream_key, | |
271 | int shm_fd, int wait_fd, | |
272 | enum lttng_consumer_stream_state state, | |
273 | uint64_t mmap_len, | |
274 | enum lttng_event_output output, | |
6df2e2c9 MD |
275 | const char *path_name, |
276 | uid_t uid, | |
277 | gid_t gid); | |
3bd1e081 MD |
278 | extern int consumer_add_stream(struct lttng_consumer_stream *stream); |
279 | extern void consumer_del_stream(struct lttng_consumer_stream *stream); | |
280 | extern void consumer_change_stream_state(int stream_key, | |
281 | enum lttng_consumer_stream_state state); | |
282 | extern void consumer_del_channel(struct lttng_consumer_channel *channel); | |
283 | extern struct lttng_consumer_channel *consumer_allocate_channel( | |
284 | int channel_key, | |
285 | int shm_fd, int wait_fd, | |
286 | uint64_t mmap_len, | |
287 | uint64_t max_sb_size); | |
288 | int consumer_add_channel(struct lttng_consumer_channel *channel); | |
289 | ||
290 | extern struct lttng_consumer_local_data *lttng_consumer_create( | |
291 | enum lttng_consumer_type type, | |
4078b776 | 292 | ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, |
d41f73b7 | 293 | struct lttng_consumer_local_data *ctx), |
3bd1e081 MD |
294 | int (*recv_channel)(struct lttng_consumer_channel *channel), |
295 | int (*recv_stream)(struct lttng_consumer_stream *stream), | |
296 | int (*update_stream)(int sessiond_key, uint32_t state)); | |
297 | extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx); | |
4078b776 | 298 | extern ssize_t lttng_consumer_on_read_subbuffer_mmap( |
3bd1e081 MD |
299 | struct lttng_consumer_local_data *ctx, |
300 | struct lttng_consumer_stream *stream, unsigned long len); | |
4078b776 | 301 | extern ssize_t lttng_consumer_on_read_subbuffer_splice( |
3bd1e081 MD |
302 | struct lttng_consumer_local_data *ctx, |
303 | struct lttng_consumer_stream *stream, unsigned long len); | |
304 | extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, | |
305 | struct lttng_consumer_stream *stream); | |
306 | extern int lttng_consumer_get_produced_snapshot( | |
307 | struct lttng_consumer_local_data *ctx, | |
308 | struct lttng_consumer_stream *stream, | |
309 | unsigned long *pos); | |
310 | extern void *lttng_consumer_thread_poll_fds(void *data); | |
311 | extern void *lttng_consumer_thread_receive_fds(void *data); | |
312 | extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, | |
313 | int sock, struct pollfd *consumer_sockpoll); | |
314 | ||
4078b776 | 315 | ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, |
d41f73b7 MD |
316 | struct lttng_consumer_local_data *ctx); |
317 | int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream); | |
318 | ||
3bd1e081 | 319 | #endif /* _LTTNG_CONSUMER_H */ |