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