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1239a312 | 1 | /* |
ab5be9fa MJ |
2 | * Copyright (C) 2014 David Goulet <dgoulet@efficios.com> |
3 | * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
1239a312 | 4 | * |
ab5be9fa | 5 | * SPDX-License-Identifier: LGPL-2.1-only |
1239a312 | 6 | * |
1239a312 DG |
7 | */ |
8 | ||
9 | #ifndef LTTNG_SESSION_H | |
10 | #define LTTNG_SESSION_H | |
11 | ||
12 | #ifdef __cplusplus | |
13 | extern "C" { | |
14 | #endif | |
15 | ||
4bd69c5f | 16 | #include <lttng/lttng-export.h> |
55c9e7ca | 17 | |
048f01ef PP |
18 | /*! |
19 | @addtogroup api_session | |
20 | @{ | |
21 | */ | |
22 | ||
23 | #include <lttng/constant.h> | |
24 | ||
55c9e7ca | 25 | struct lttng_handle; |
b178f53e | 26 | struct lttng_session_descriptor; |
3e3665b8 | 27 | struct lttng_destruction_handle; |
b178f53e | 28 | |
28f23191 | 29 | #define LTTNG_SESSION_PADDING1 8 |
048f01ef PP |
30 | |
31 | /*! | |
32 | @brief | |
33 | Recording session summary. | |
34 | ||
35 | The purpose of such a structure is to provide information about a | |
36 | \lt_obj_session itself, but not about its \lt_obj_domains | |
37 | and \lt_obj_channels (use lttng_list_domains() and lttng_list_channels() | |
38 | for this). | |
39 | ||
40 | lttng_list_sessions() sets a pointer to an array of all the available | |
41 | recording session summaries. | |
42 | */ | |
1239a312 | 43 | struct lttng_session { |
048f01ef | 44 | /// Name. |
36d2e35d | 45 | char name[LTTNG_NAME_MAX]; |
048f01ef PP |
46 | |
47 | /*! | |
48 | @brief | |
49 | <em>Human-readable</em> representation of the output (local | |
50 | or remote). | |
51 | */ | |
1239a312 | 52 | char path[PATH_MAX]; |
048f01ef PP |
53 | |
54 | /*! | |
55 | @brief | |
56 | 1 if this recording session is active (started), or 0 | |
57 | otherwise. | |
58 | ||
59 | @sa lttng_start_tracing() -- | |
60 | Starts a recording session. | |
61 | @sa lttng_stop_tracing() -- | |
62 | Stops a recording session. | |
63 | */ | |
28f23191 | 64 | uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ |
048f01ef PP |
65 | |
66 | /*! | |
67 | @brief | |
68 | 1 if this recording session was created in | |
69 | \ref api-session-snapshot-mode "snapshot mode", | |
70 | or 0 otherwise. | |
71 | ||
72 | @note | |
73 | If this member is 1, then the | |
74 | lttng_session::live_timer_interval member is 0. | |
75 | */ | |
1239a312 | 76 | uint32_t snapshot_mode; |
048f01ef PP |
77 | |
78 | /*! | |
79 | @brief | |
80 | Period (µs) of the \ref api-channel-live-timer "live timers" | |
81 | of the channels of this recording session, or 0 if this | |
82 | recording session wasn't created in | |
83 | \ref api-session-live-mode "live mode". | |
84 | ||
85 | @note | |
86 | If this member is \em not 0, then the | |
87 | lttng_session::snapshot_mode member is 0. | |
88 | */ | |
28f23191 | 89 | unsigned int live_timer_interval; /* usec */ |
1239a312 | 90 | |
e9af56b3 JG |
91 | /* |
92 | * End of public attributes. | |
93 | * The remaining fields are used to deal with ABI management concerns. | |
94 | */ | |
95 | ||
96 | /* | |
97 | * 32-bit architectures are already naturally aligned on 4 bytes after | |
98 | * 'live_timer_interval'. However, the offset does not result in a | |
99 | * natural alignment on 64-bit architectures. Adding 4 bytes of | |
100 | * padding here results in an aligned offset after 'alignement_padding' | |
101 | * for both bitnesses. | |
102 | * | |
103 | * This was added since not all compilers appear to align unions in the | |
104 | * same way. Some (e.g. MSVC) do not seem to impose an alignement | |
105 | * constraint while others (e.g. gcc, clang, icc) seem to align it to | |
106 | * ensure 'ptr' is naturally aligned. | |
107 | */ | |
108 | char alignment_padding[4]; | |
b178f53e | 109 | union { |
e9af56b3 JG |
110 | /* |
111 | * Ensure the 'extended' union has the same size for both | |
112 | * 32-bit and 64-bit builds. | |
113 | */ | |
b178f53e JG |
114 | char padding[LTTNG_SESSION_PADDING1]; |
115 | void *ptr; | |
116 | } extended; | |
1239a312 DG |
117 | }; |
118 | ||
048f01ef PP |
119 | /*! |
120 | @brief | |
121 | Creates a recording session from the recording session descriptor | |
122 | \lt_p{session_descriptor}. | |
123 | ||
124 | See \ref api_session_descr to learn how to create a recording session | |
125 | descriptor. | |
126 | ||
127 | On success, if the name property of \lt_p{session_descriptor} isn't set, | |
128 | this function sets it to the automatically generated name of the | |
129 | recording session. Get the recording session name with | |
130 | lttng_session_descriptor_get_session_name(). | |
131 | ||
132 | @param[in] session_descriptor | |
133 | Descriptor from which to create a recording session. | |
134 | ||
135 | @returns | |
136 | #LTTNG_OK on success, or a \em negative enumerator otherwise. | |
137 | ||
138 | @lt_pre_conn | |
139 | @lt_pre_not_null{session_descriptor} | |
140 | @pre | |
141 | If the name property of \lt_p{session_descriptor} is set, then no | |
142 | available recording session has this name. | |
143 | ||
144 | @sa \ref api_session_descr. | |
145 | @sa \lt_man{lttng-create,1} | |
146 | */ | |
28f23191 JG |
147 | LTTNG_EXPORT extern enum lttng_error_code |
148 | lttng_create_session_ext(struct lttng_session_descriptor *session_descriptor); | |
b178f53e | 149 | |
048f01ef PP |
150 | /*! |
151 | @brief | |
152 | Creates a recording session named \lt_p{session_name} in | |
153 | \ref api-session-local-mode "local" | |
154 | or \ref api-session-net-mode "network streaming" mode, optionally | |
155 | setting its output URL to \lt_p{output_url}. | |
1239a312 | 156 | |
048f01ef PP |
157 | @deprecated |
158 | Use lttng_create_session_ext() with a dedicated | |
159 | local or network streaming | |
160 | \ref api_session_descr "recording session descriptor". | |
1239a312 | 161 | |
048f01ef PP |
162 | @param[in] session_name |
163 | Name of the new recording session. | |
164 | @param[in] output_url | |
165 | @parblock | |
166 | \ref api-session-url "Output URL" of the recording session to | |
167 | create. | |
1239a312 | 168 | |
048f01ef PP |
169 | If it's a \ref api-session-one-port-url "single-port output URL", |
170 | then the trace data port is \lt_def_net_data_port. | |
1239a312 | 171 | |
048f01ef PP |
172 | If \c NULL, LTTng doesn't write any trace data for this recording |
173 | session. | |
174 | @endparblock | |
175 | ||
176 | @returns | |
177 | 0 on success, or a \em negative #lttng_error_code enumerator | |
178 | otherwise. | |
179 | ||
180 | @lt_pre_conn | |
181 | @lt_pre_not_null{session_name} | |
182 | @lt_pre_sess_name_not_auto{session_name} | |
183 | @pre | |
184 | No available recording session is named \lt_p{session_name}. | |
185 | @pre | |
186 | <strong>If not \c NULL</strong>, \lt_p{output_url} is a valid | |
187 | \ref api-session-url "output URL". | |
188 | ||
189 | @sa lttng_create_session_snapshot() -- | |
190 | Creates a recording session in snapshot mode. | |
191 | @sa lttng_create_session_live() -- | |
192 | Creates a recording session in live mode. | |
193 | @sa \lt_man{lttng-create,1} | |
194 | */ | |
195 | LTTNG_EXPORT extern int lttng_create_session(const char *session_name, const char *output_url); | |
196 | ||
197 | /*! | |
198 | @brief | |
199 | Creates a recording session named \lt_p{session_name} in | |
200 | \ref api-session-snapshot-mode "snapshot" mode, optionally setting | |
201 | the URL of its initial snapshot output to \lt_p{output_url}. | |
202 | ||
203 | @deprecated | |
204 | Use lttng_create_session_ext() with a dedicated snapshot | |
205 | \ref api_session_descr "recording session descriptor". | |
206 | ||
207 | @param[in] session_name | |
208 | Name of the new recording session. | |
209 | @param[in] output_url | |
210 | @parblock | |
211 | \ref api-session-url "URL" of an initial snapshot output | |
212 | which LTTng adds to this recording session. | |
213 | ||
214 | If it's a \ref api-session-one-port-url "single-port output URL", | |
215 | then the trace data port is \lt_def_net_data_port. | |
216 | ||
217 | This initial snapshot output is named <code>snapshot-0</code>. | |
218 | ||
219 | If \c NULL, then the created recording session has no initial | |
220 | snapshot output: you need to either add one with | |
221 | lttng_snapshot_add_output() or provide one when you take a snapshot | |
222 | with lttng_snapshot_record(). | |
223 | @endparblock | |
224 | ||
225 | @returns | |
226 | 0 on success, or a \em negative #lttng_error_code enumerator | |
227 | otherwise. | |
228 | ||
229 | @lt_pre_conn | |
230 | @lt_pre_not_null{session_name} | |
231 | @lt_pre_sess_name_not_auto{session_name} | |
232 | @pre | |
233 | No available recording session is named \lt_p{session_name}. | |
234 | @pre | |
235 | <strong>If not \c NULL</strong>, \lt_p{output_url} is a valid | |
236 | \ref api-session-url "output URL". | |
237 | ||
238 | @sa lttng_create_session() -- | |
239 | Creates a recording session in local or network streaming mode. | |
240 | @sa lttng_create_session_live() -- | |
241 | Creates a recording session in live mode. | |
242 | @sa \lt_man{lttng-create,1} | |
243 | */ | |
244 | LTTNG_EXPORT extern int lttng_create_session_snapshot(const char *session_name, | |
245 | const char *output_url); | |
246 | ||
247 | /*! | |
248 | @brief | |
249 | Creates a recording session named \lt_p{session_name} in | |
250 | \ref api-session-live-mode "live" mode, optionally setting its | |
251 | URL to \lt_p{output_url}. | |
252 | ||
253 | @deprecated | |
254 | Use lttng_create_session_ext() with a dedicated live | |
255 | \ref api_session_descr "recording session descriptor". | |
256 | ||
257 | @param[in] session_name | |
258 | Name of the new recording session. | |
259 | @param[in] output_url | |
260 | @parblock | |
261 | \ref api-session-url "Output URL" of the recording session to | |
262 | create: \ref api-session-one-port-url "single-port" or | |
263 | \ref api-session-two-port-url "two-port". | |
264 | ||
265 | If it's a \ref api-session-one-port-url "single-port output URL", | |
266 | then the trace data port is \lt_def_net_data_port. | |
267 | ||
268 | If \c NULL, this function uses \lt_def_net_url. | |
269 | @endparblock | |
270 | @param[in] live_timer_period | |
271 | Period (µs) of the \ref api-channel-live-timer "live timers" of all | |
272 | the channels of the created recording session. | |
273 | ||
274 | @returns | |
275 | 0 on success, or a \em negative #lttng_error_code enumerator | |
276 | otherwise. | |
277 | ||
278 | @lt_pre_conn | |
279 | @lt_pre_not_null{session_name} | |
280 | @lt_pre_sess_name_not_auto{session_name} | |
281 | @pre | |
282 | No available recording session is named \lt_p{session_name}. | |
283 | @pre | |
284 | <strong>If not \c NULL</strong>, \lt_p{output_url} is a valid | |
285 | \ref api-session-one-port-url "single-port output URL" or | |
286 | \ref api-session-two-port-url "two-port output URL". | |
287 | @pre | |
288 | \lt_p{live_timer_period} ≥ 1 | |
289 | ||
290 | @sa lttng_create_session() -- | |
291 | Creates a recording session in local or network streaming mode. | |
292 | @sa lttng_create_session_snapshot() -- | |
293 | Creates a recording session in snapshot mode. | |
294 | @sa \lt_man{lttng-create,1} | |
295 | */ | |
296 | LTTNG_EXPORT extern int lttng_create_session_live(const char *session_name, | |
297 | const char *output_url, | |
298 | unsigned int live_timer_period); | |
299 | ||
300 | /*! | |
301 | @brief | |
302 | Destroys the recording session named \lt_p{session_name}, blocking | |
303 | until the operation completes. | |
304 | ||
305 | @deprecated | |
306 | Use lttng_destroy_session_ext(). | |
307 | ||
308 | "Destroying" a recording session means freeing the resources which the | |
309 | LTTng daemons and tracers acquired for it, also making sure to flush all | |
310 | the recorded trace data to either the local file system or the connected | |
311 | LTTng relay daemon (see \lt_man{lttng-relayd,8}), depending on the | |
312 | \ref api-session-modes "recording session mode". | |
313 | ||
314 | This function stops any recording activity within the recording session | |
315 | named \lt_p{session_name}. | |
316 | ||
317 | This function implicitly calls lttng_stop_tracing(), blocking until the | |
318 | trace data of the recording session becomes valid. Use | |
319 | lttng_destroy_session_no_wait() to avoid a blocking call. | |
320 | ||
321 | @param[in] session_name | |
322 | Name of the recording session to destroy. | |
323 | ||
324 | @returns | |
325 | 0 on success, or a \em negative #lttng_error_code enumerator | |
326 | otherwise. | |
327 | ||
328 | @lt_pre_conn | |
329 | @lt_pre_not_null{session_name} | |
330 | @lt_pre_sess_exists{session_name} | |
331 | ||
332 | @sa lttng_destroy_session_no_wait() -- | |
333 | Initiates the destruction operation of a recording session, | |
334 | returning immediately. | |
335 | @sa \lt_man{lttng-destroy,1} | |
336 | */ | |
337 | LTTNG_EXPORT extern int lttng_destroy_session(const char *session_name); | |
338 | ||
339 | /*! | |
340 | @brief | |
341 | Initiates the destruction operation of the recording session named | |
342 | \lt_p{session_name}. | |
343 | ||
344 | @deprecated | |
345 | Use lttng_destroy_session_ext(). | |
346 | ||
347 | "Destroying" a recording session means freeing the resources which the | |
348 | LTTng daemons and tracers acquired for it, also making sure to flush all | |
349 | the recorded trace data to either the local file system or the connected | |
350 | LTTng relay daemon (see \lt_man{lttng-relayd,8}), depending on the | |
351 | \ref api-session-modes "recording session mode". | |
352 | ||
353 | Unlike lttng_destroy_session(), this function does \em not block until | |
354 | the destruction operation is complete: it returns immediately. This | |
355 | means the trace(s) of the recording session might not be valid when | |
356 | this function returns, and there's no way to know when it/they become | |
357 | valid. | |
358 | ||
359 | @param[in] session_name | |
360 | Name of the recording session to destroy. | |
361 | ||
362 | @returns | |
363 | 0 on success, or a \em negative #lttng_error_code enumerator | |
364 | otherwise. | |
365 | ||
366 | @lt_pre_conn | |
367 | @lt_pre_not_null{session_name} | |
368 | @lt_pre_sess_exists{session_name} | |
369 | @pre | |
370 | No destruction operation is in progress for the recording session | |
371 | named \lt_p{session_name}. | |
372 | ||
373 | @sa lttng_destroy_session() -- | |
374 | Destroys a recording session, blocking until the operation | |
375 | completes. | |
376 | @sa \lt_man{lttng-destroy,1} | |
377 | */ | |
378 | LTTNG_EXPORT extern int lttng_destroy_session_no_wait(const char *session_name); | |
379 | ||
380 | /*! | |
381 | @brief | |
382 | Initiates a destruction operation of the recording session | |
383 | named \lt_p{session_name}. | |
384 | ||
385 | "Destroying" a recording session means freeing the resources which the | |
386 | LTTng daemons and tracers acquired for it, also making sure to flush all | |
387 | the recorded trace data to either the local file system or the connected | |
388 | LTTng relay daemon (see \lt_man{lttng-relayd,8}), depending on the | |
389 | \ref api-session-modes "recording session mode". | |
390 | ||
391 | This function doesn't block until the destruction operation completes: | |
392 | it only initiates the operation. | |
393 | Use \lt_p{*handle} to wait for the operation to complete. | |
394 | ||
395 | @param[in] session_name | |
396 | Name of the recording session to destroy. | |
397 | @param[out] handle | |
398 | @parblock | |
399 | <strong>On success</strong>, this function sets \lt_p{*handle} to | |
400 | a handle which identifies this recording session destruction | |
401 | operation. | |
402 | ||
403 | May be \c NULL. | |
404 | ||
405 | Wait for the completion of this destruction operation with | |
406 | lttng_destruction_handle_wait_for_completion(). | |
407 | ||
408 | Destroy \lt_p{*handle} with lttng_destruction_handle_destroy(). | |
409 | @endparblock | |
410 | ||
411 | @returns | |
412 | #LTTNG_OK on success, or a \em negative enumerator otherwise. | |
413 | ||
414 | @lt_pre_conn | |
415 | @lt_pre_not_null{session_name} | |
416 | @lt_pre_sess_exists{session_name} | |
417 | @pre | |
418 | No destruction operation is in progress for the recording session | |
419 | named \lt_p{session_name}. | |
420 | ||
421 | @sa \lt_man{lttng-destroy,1} | |
422 | */ | |
28f23191 JG |
423 | LTTNG_EXPORT extern enum lttng_error_code |
424 | lttng_destroy_session_ext(const char *session_name, struct lttng_destruction_handle **handle); | |
3e3665b8 | 425 | |
048f01ef PP |
426 | /*! |
427 | @brief | |
428 | Sets \lt_p{*sessions} to the summaries of all the available | |
429 | recording sessions. | |
e20ee7c2 | 430 | |
048f01ef PP |
431 | @param[out] sessions |
432 | @parblock | |
433 | <strong>On success</strong>, this function sets \lt_p{*sessions} to | |
434 | the summaries of the available recording sessions. | |
435 | ||
436 | Free \lt_p{*sessions} with <code>free()</code>. | |
437 | @endparblock | |
438 | ||
439 | @returns | |
440 | The number of items in \lt_p{*sessions} on success, or a \em | |
441 | negative #lttng_error_code enumerator otherwise. | |
442 | ||
443 | @lt_pre_conn | |
444 | @lt_pre_not_null{sessions} | |
445 | ||
446 | @sa \lt_man{lttng-list,1} | |
447 | */ | |
4bd69c5f | 448 | LTTNG_EXPORT extern int lttng_list_sessions(struct lttng_session **sessions); |
1239a312 | 449 | |
048f01ef PP |
450 | /*! |
451 | @brief | |
452 | Sets \lt_p{*creation_timestamp} to the timestamp of the creation of | |
453 | the recording session summarized by \lt_p{session}. | |
454 | ||
455 | @param[in] session | |
456 | Summary of the recording session of which to get the creation | |
457 | timestamp, as obtained with lttng_list_sessions(). | |
458 | @param[out] creation_timestamp | |
459 | <strong>On success</strong>, this function sets | |
460 | \lt_p{*creation_timestamp} to the Unix timestamp of the creation of | |
461 | \lt_p{session}. | |
462 | ||
463 | @returns | |
464 | #LTTNG_OK on success, or a \em negative enumerator otherwise. | |
465 | ||
466 | @lt_pre_conn | |
467 | @lt_pre_not_null{session} | |
468 | @pre | |
469 | The recording session summarized by \lt_p{session} is accessible | |
470 | within the connected session daemon. | |
471 | @lt_pre_not_null{creation_timestamp} | |
472 | */ | |
28f23191 | 473 | LTTNG_EXPORT extern enum lttng_error_code |
048f01ef | 474 | lttng_session_get_creation_time(const struct lttng_session *session, uint64_t *creation_timestamp); |
b178f53e | 475 | |
048f01ef PP |
476 | /*! |
477 | @brief | |
478 | Sets the path of the directory containing the shared memory files | |
479 | holding the channel ring buffers of the recording session named | |
480 | \lt_p{session_name} on the local file sytem to \lt_p{shm_dir}. | |
481 | ||
482 | Specifying a location on an | |
483 | <a href="https://en.wikipedia.org/wiki/Non-volatile_random-access_memory">NVRAM</a> | |
484 | file system makes it possible to recover the latest recorded trace data | |
485 | when the system reboots after a crash with the \lt_man{lttng-crash,1} | |
486 | utility. | |
487 | ||
488 | @param[in] session_name | |
489 | Name of the recording session of which to set the shared memory | |
490 | file directory path. | |
491 | @param[in] shm_dir | |
492 | Path of the directory containing the shared memory files of the | |
493 | recording session named \lt_p{session_name}. | |
494 | ||
495 | @returns | |
496 | 0 on success, or a \em negative #lttng_error_code enumerator | |
497 | otherwise. | |
498 | ||
499 | @lt_pre_conn | |
500 | @lt_pre_not_null{session_name} | |
501 | @lt_pre_sess_exists{session_name} | |
502 | @lt_pre_sess_never_active{session_name} | |
503 | @lt_pre_not_null{shm_dir} | |
504 | @pre | |
505 | \lt_p{shm_dir} is a writable directory. | |
506 | */ | |
507 | LTTNG_EXPORT extern int lttng_set_session_shm_path(const char *session_name, const char *shm_dir); | |
508 | ||
509 | /// @} | |
d7ba1388 | 510 | |
1239a312 DG |
511 | #ifdef __cplusplus |
512 | } | |
513 | #endif | |
514 | ||
515 | #endif /* LTTNG_SESSION_H */ |