Add create session snapshot API in lttng-sessiond
[lttng-tools.git] / include / lttng / lttng.h
1 /*
2 * lttng.h
3 *
4 * Linux Trace Toolkit Control Library Header File
5 *
6 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
7 *
8 * This library is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU Lesser General Public License, version 2.1 only,
10 * as published by the Free Software Foundation.
11 *
12 * This library is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
15 * for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #ifndef LTTNG_H
23 #define LTTNG_H
24
25 #include <limits.h>
26 #include <stdint.h>
27 #include <sys/types.h>
28
29 /* Error codes that can be returned by API calls */
30 #include <lttng/lttng-error.h>
31
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35
36 /*
37 * Event symbol length. Copied from LTTng kernel ABI.
38 */
39 #define LTTNG_SYMBOL_NAME_LEN 256
40
41 /*
42 * Every lttng_event_* structure both apply to kernel event and user-space
43 * event.
44 */
45
46 /*
47 * Domain types: the different possible tracers.
48 */
49 enum lttng_domain_type {
50 LTTNG_DOMAIN_KERNEL = 1,
51 LTTNG_DOMAIN_UST = 2,
52
53 /*
54 * For now, the domains below are not implemented. However, we keep them
55 * here in order to retain their enum values for future development. Note
56 * that it is on the roadmap to implement them.
57 *
58 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
59 LTTNG_DOMAIN_UST_PID = 4,
60 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
61 */
62 };
63
64 /*
65 * Instrumentation type of tracing event.
66 */
67 enum lttng_event_type {
68 LTTNG_EVENT_ALL = -1,
69 LTTNG_EVENT_TRACEPOINT = 0,
70 LTTNG_EVENT_PROBE = 1,
71 LTTNG_EVENT_FUNCTION = 2,
72 LTTNG_EVENT_FUNCTION_ENTRY = 3,
73 LTTNG_EVENT_NOOP = 4,
74 LTTNG_EVENT_SYSCALL = 5,
75 };
76
77 /*
78 * Loglevel information.
79 */
80 enum lttng_loglevel_type {
81 LTTNG_EVENT_LOGLEVEL_ALL = 0,
82 LTTNG_EVENT_LOGLEVEL_RANGE = 1,
83 LTTNG_EVENT_LOGLEVEL_SINGLE = 2,
84 };
85
86 /*
87 * Available loglevels.
88 */
89 enum lttng_loglevel {
90 LTTNG_LOGLEVEL_EMERG = 0,
91 LTTNG_LOGLEVEL_ALERT = 1,
92 LTTNG_LOGLEVEL_CRIT = 2,
93 LTTNG_LOGLEVEL_ERR = 3,
94 LTTNG_LOGLEVEL_WARNING = 4,
95 LTTNG_LOGLEVEL_NOTICE = 5,
96 LTTNG_LOGLEVEL_INFO = 6,
97 LTTNG_LOGLEVEL_DEBUG_SYSTEM = 7,
98 LTTNG_LOGLEVEL_DEBUG_PROGRAM = 8,
99 LTTNG_LOGLEVEL_DEBUG_PROCESS = 9,
100 LTTNG_LOGLEVEL_DEBUG_MODULE = 10,
101 LTTNG_LOGLEVEL_DEBUG_UNIT = 11,
102 LTTNG_LOGLEVEL_DEBUG_FUNCTION = 12,
103 LTTNG_LOGLEVEL_DEBUG_LINE = 13,
104 LTTNG_LOGLEVEL_DEBUG = 14,
105 };
106
107 /*
108 * LTTng consumer mode
109 */
110 enum lttng_event_output {
111 LTTNG_EVENT_SPLICE = 0,
112 LTTNG_EVENT_MMAP = 1,
113 };
114
115 /* Event context possible type */
116 enum lttng_event_context_type {
117 LTTNG_EVENT_CONTEXT_PID = 0,
118 LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1,
119 LTTNG_EVENT_CONTEXT_PROCNAME = 2,
120 LTTNG_EVENT_CONTEXT_PRIO = 3,
121 LTTNG_EVENT_CONTEXT_NICE = 4,
122 LTTNG_EVENT_CONTEXT_VPID = 5,
123 LTTNG_EVENT_CONTEXT_TID = 6,
124 LTTNG_EVENT_CONTEXT_VTID = 7,
125 LTTNG_EVENT_CONTEXT_PPID = 8,
126 LTTNG_EVENT_CONTEXT_VPPID = 9,
127 LTTNG_EVENT_CONTEXT_PTHREAD_ID = 10,
128 LTTNG_EVENT_CONTEXT_HOSTNAME = 11,
129 LTTNG_EVENT_CONTEXT_IP = 12,
130 };
131
132 enum lttng_calibrate_type {
133 LTTNG_CALIBRATE_FUNCTION = 0,
134 };
135
136 /* Health component for the health check function. */
137 enum lttng_health_component {
138 LTTNG_HEALTH_CMD,
139 LTTNG_HEALTH_APP_MANAGE,
140 LTTNG_HEALTH_APP_REG,
141 LTTNG_HEALTH_KERNEL,
142 LTTNG_HEALTH_CONSUMER,
143 LTTNG_HEALTH_HT_CLEANUP,
144 LTTNG_HEALTH_APP_MANAGE_NOTIFY,
145 LTTNG_HEALTH_APP_REG_DISPATCH,
146 LTTNG_HEALTH_ALL,
147 };
148
149 /* Buffer type for a specific domain. */
150 enum lttng_buffer_type {
151 LTTNG_BUFFER_PER_PID, /* Only supported by UST being the default. */
152 LTTNG_BUFFER_PER_UID, /* Only supported by UST. */
153 LTTNG_BUFFER_GLOBAL, /* Only supported by the Kernel. */
154 };
155
156 /*
157 * The structures should be initialized to zero before use.
158 */
159 #define LTTNG_DOMAIN_PADDING1 12
160 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
161 struct lttng_domain {
162 enum lttng_domain_type type;
163 enum lttng_buffer_type buf_type;
164 char padding[LTTNG_DOMAIN_PADDING1];
165
166 union {
167 pid_t pid;
168 char exec_name[NAME_MAX];
169 char padding[LTTNG_DOMAIN_PADDING2];
170 } attr;
171 };
172
173 /*
174 * Perf counter attributes
175 *
176 * The structures should be initialized to zero before use.
177 */
178 #define LTTNG_PERF_EVENT_PADDING1 16
179 struct lttng_event_perf_counter_ctx {
180 uint32_t type;
181 uint64_t config;
182 char name[LTTNG_SYMBOL_NAME_LEN];
183
184 char padding[LTTNG_PERF_EVENT_PADDING1];
185 };
186
187 /*
188 * Event/channel context
189 *
190 * The structures should be initialized to zero before use.
191 */
192 #define LTTNG_EVENT_CONTEXT_PADDING1 16
193 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
194 struct lttng_event_context {
195 enum lttng_event_context_type ctx;
196 char padding[LTTNG_EVENT_CONTEXT_PADDING1];
197
198 union {
199 struct lttng_event_perf_counter_ctx perf_counter;
200 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
201 } u;
202 };
203
204 /*
205 * Event probe.
206 *
207 * Either addr is used or symbol_name and offset.
208 *
209 * The structures should be initialized to zero before use.
210 */
211 #define LTTNG_EVENT_PROBE_PADDING1 16
212 struct lttng_event_probe_attr {
213 uint64_t addr;
214
215 uint64_t offset;
216 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
217
218 char padding[LTTNG_EVENT_PROBE_PADDING1];
219 };
220
221 /*
222 * Function tracer
223 *
224 * The structures should be initialized to zero before use.
225 */
226 #define LTTNG_EVENT_FUNCTION_PADDING1 16
227 struct lttng_event_function_attr {
228 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
229
230 char padding[LTTNG_EVENT_FUNCTION_PADDING1];
231 };
232
233 /*
234 * Generic lttng event
235 *
236 * The structures should be initialized to zero before use.
237 */
238 #define LTTNG_EVENT_PADDING1 15
239 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
240 struct lttng_event {
241 enum lttng_event_type type;
242 char name[LTTNG_SYMBOL_NAME_LEN];
243
244 enum lttng_loglevel_type loglevel_type;
245 int loglevel;
246
247 int32_t enabled; /* Does not apply: -1 */
248 pid_t pid;
249 unsigned char filter; /* filter enabled ? */
250
251 char padding[LTTNG_EVENT_PADDING1];
252
253 /* Per event type configuration */
254 union {
255 struct lttng_event_probe_attr probe;
256 struct lttng_event_function_attr ftrace;
257
258 char padding[LTTNG_EVENT_PADDING2];
259 } attr;
260 };
261
262 enum lttng_event_field_type {
263 LTTNG_EVENT_FIELD_OTHER = 0,
264 LTTNG_EVENT_FIELD_INTEGER = 1,
265 LTTNG_EVENT_FIELD_ENUM = 2,
266 LTTNG_EVENT_FIELD_FLOAT = 3,
267 LTTNG_EVENT_FIELD_STRING = 4,
268 };
269
270 #define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32
271 struct lttng_event_field {
272 char field_name[LTTNG_SYMBOL_NAME_LEN];
273 enum lttng_event_field_type type;
274 char padding[LTTNG_EVENT_FIELD_PADDING];
275 struct lttng_event event;
276 int nowrite;
277 };
278
279 /*
280 * Tracer channel attributes. For both kernel and user-space.
281 *
282 * The structures should be initialized to zero before use.
283 */
284 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 16
285 struct lttng_channel_attr {
286 int overwrite; /* 1: overwrite, 0: discard */
287 uint64_t subbuf_size; /* bytes */
288 uint64_t num_subbuf; /* power of 2 */
289 unsigned int switch_timer_interval; /* usec */
290 unsigned int read_timer_interval; /* usec */
291 enum lttng_event_output output; /* splice, mmap */
292 /* LTTng 2.1 padding limit */
293 uint64_t tracefile_size; /* bytes */
294 uint64_t tracefile_count; /* number of tracefiles */
295
296 char padding[LTTNG_CHANNEL_ATTR_PADDING1];
297 };
298
299 /*
300 * Channel information structure. For both kernel and user-space.
301 *
302 * The structures should be initialized to zero before use.
303 */
304 #define LTTNG_CHANNEL_PADDING1 16
305 struct lttng_channel {
306 char name[LTTNG_SYMBOL_NAME_LEN];
307 uint32_t enabled;
308 struct lttng_channel_attr attr;
309
310 char padding[LTTNG_CHANNEL_PADDING1];
311 };
312
313 #define LTTNG_CALIBRATE_PADDING1 16
314 struct lttng_calibrate {
315 enum lttng_calibrate_type type;
316
317 char padding[LTTNG_CALIBRATE_PADDING1];
318 };
319
320 /*
321 * Basic session information.
322 *
323 * This is an 'output data' meaning that it only comes *from* the session
324 * daemon *to* the lttng client. It's basically a 'human' representation of
325 * tracing entities (here a session).
326 *
327 * The structures should be initialized to zero before use.
328 */
329 #define LTTNG_SESSION_PADDING1 16
330 struct lttng_session {
331 char name[NAME_MAX];
332 /* The path where traces are written */
333 char path[PATH_MAX];
334 uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
335
336 char padding[LTTNG_SESSION_PADDING1];
337 };
338
339 /*
340 * Handle used as a context for commands.
341 *
342 * The structures should be initialized to zero before use.
343 */
344 #define LTTNG_HANDLE_PADDING1 16
345 struct lttng_handle {
346 char session_name[NAME_MAX];
347 struct lttng_domain domain;
348
349 char padding[LTTNG_HANDLE_PADDING1];
350 };
351
352 /*
353 * Public LTTng control API
354 *
355 * For functions having an lttng domain type as parameter, if a bad value is
356 * given, NO default is applied and an error is returned.
357 *
358 * On success, all functions of the API return 0 or the size of the allocated
359 * array (in bytes).
360 *
361 * On error, a negative value is returned being a specific lttng-tools error
362 * code which can be humanly interpreted with lttng_strerror(err).
363 *
364 * Exceptions to this are noted below.
365 */
366
367 /*
368 * Create a handle used as a context for every request made to the library.
369 *
370 * This handle contains the session name and lttng domain on which the command
371 * will be executed.
372 * The returned pointer will be NULL in case of malloc() error.
373 */
374 extern struct lttng_handle *lttng_create_handle(const char *session_name,
375 struct lttng_domain *domain);
376
377 /*
378 * Destroy an handle.
379 *
380 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
381 * unusable.
382 */
383 extern void lttng_destroy_handle(struct lttng_handle *handle);
384
385 /*
386 * Create a tracing session using a name and an optional URL.
387 *
388 * If _url_ is NULL, no consumer is created for the session. The name can't be
389 * NULL here.
390 */
391 extern int lttng_create_session(const char *name, const char *url);
392
393 /*
394 * Create a tracing session that will exclusively be used for snapshot meaning
395 * the session will be in no output mode and every channel enabled for that
396 * session will be set in overwrite mode and in mmap output since splice is not
397 * supported.
398 *
399 * If an url is given, it will be used to create a default snapshot output
400 * using it as a destination. If NULL, no output will be defined and an
401 * add-output call will be needed.
402 *
403 * Name can't be NULL.
404 */
405 extern int lttng_create_session_snapshot(const char *name,
406 const char *snapshot_url);
407
408 /*
409 * Destroy a tracing session.
410 *
411 * The session will not be usable anymore, tracing will be stopped for all
412 * registered traces, and the tracing buffers will be flushed.
413 *
414 * The name can't be NULL here.
415 */
416 extern int lttng_destroy_session(const char *name);
417
418 /*
419 * List all the tracing sessions.
420 *
421 * Return the size (number of entries) of the "lttng_session" array. Caller
422 * must free(3).
423 */
424 extern int lttng_list_sessions(struct lttng_session **sessions);
425
426 /*
427 * List the registered domain(s) of a session.
428 *
429 * Return the size (number of entries) of the "lttng_domain" array. Caller
430 * must free(3).
431 */
432 extern int lttng_list_domains(const char *session_name,
433 struct lttng_domain **domains);
434
435 /*
436 * List the channel(s) of a session.
437 *
438 * Return the size (number of entries) of the "lttng_channel" array. Caller
439 * must free(3).
440 */
441 extern int lttng_list_channels(struct lttng_handle *handle,
442 struct lttng_channel **channels);
443
444 /*
445 * List the event(s) of a session channel.
446 *
447 * Return the size (number of entries) of the "lttng_event" array.
448 * Caller must free(3).
449 */
450 extern int lttng_list_events(struct lttng_handle *handle,
451 const char *channel_name, struct lttng_event **events);
452
453 /*
454 * List the available tracepoints of a specific lttng domain.
455 *
456 * Return the size (number of entries) of the "lttng_event" array.
457 * Caller must free(3).
458 */
459 extern int lttng_list_tracepoints(struct lttng_handle *handle,
460 struct lttng_event **events);
461
462 /*
463 * List the available tracepoints fields of a specific lttng domain.
464 *
465 * Return the size (number of entries) of the "lttng_event_field" array.
466 * Caller must free(3).
467 */
468 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
469 struct lttng_event_field **fields);
470
471 /*
472 * Check if a session daemon is alive.
473 *
474 * Return 1 if alive or 0 if not. On error returns a negative value.
475 */
476 extern int lttng_session_daemon_alive(void);
477
478 /*
479 * Set the tracing group for the *current* flow of execution.
480 *
481 * On success, returns 0 else a negative value on error being a lttng error
482 * code found in lttng-error.h
483 */
484 extern int lttng_set_tracing_group(const char *name);
485
486 /*
487 * Return a human-readable error message for an lttng-tools error code.
488 *
489 * Parameter MUST be a negative value or else you'll get a generic message.
490 */
491 extern const char *lttng_strerror(int code);
492
493 /*
494 * This call registers an "outside consumer" for a session and an lttng domain.
495 * No consumer will be spawned and all fds/commands will go through the socket
496 * path given (socket_path).
497 *
498 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
499 * command socket. The error socket is not supported yet for roaming consumers.
500 */
501 extern int lttng_register_consumer(struct lttng_handle *handle,
502 const char *socket_path);
503
504 /*
505 * Start tracing for *all* registered traces (kernel and user-space).
506 */
507 extern int lttng_start_tracing(const char *session_name);
508
509 /*
510 * Stop tracing for *all* registered traces (kernel and user-space).
511 *
512 * This call will wait for data availability for each domain of the session so
513 * this can take an abritrary amount of time. However, when returning you have
514 * the guarantee that the data is ready to be read and analyse. Use the
515 * _no_wait call below to avoid this behavior.
516 *
517 * The session_name can't be NULL.
518 */
519 extern int lttng_stop_tracing(const char *session_name);
520
521 /*
522 * Behave exactly like lttng_stop_tracing but does not wait for data
523 * availability.
524 */
525 extern int lttng_stop_tracing_no_wait(const char *session_name);
526
527 /*
528 * Add context to event(s) for a specific channel (or for all).
529 *
530 * If channel_name is NULL, a lookup of the event's channel is done. If both
531 * are NULL, the context is applied to all events of all channels.
532 *
533 * Note that whatever event_name value is, a context can not be added to an
534 * event, so we just ignore it for now.
535 */
536 extern int lttng_add_context(struct lttng_handle *handle,
537 struct lttng_event_context *ctx, const char *event_name,
538 const char *channel_name);
539
540 /*
541 * Create or enable an event (or events) for a channel.
542 *
543 * If the event you are trying to enable does not exist, it will be created,
544 * else it is enabled.
545 * If channel_name is NULL, the default channel is used (channel0).
546 *
547 * The handle and ev params can not be NULL.
548 */
549 extern int lttng_enable_event(struct lttng_handle *handle,
550 struct lttng_event *ev, const char *channel_name);
551
552 /*
553 * Create or enable an event with a specific filter.
554 *
555 * If the event you are trying to enable does not exist, it will be created,
556 * else it is enabled.
557 * If ev is NULL, all events are enabled with that filter.
558 * If channel_name is NULL, the default channel is used (channel0) and created
559 * if not found.
560 * If filter_expression is NULL, an event without associated filter is
561 * created.
562 */
563 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
564 struct lttng_event *event, const char *channel_name,
565 const char *filter_expression);
566
567 /*
568 * Create or enable a channel.
569 *
570 * The chan and handle params can not be NULL.
571 */
572 extern int lttng_enable_channel(struct lttng_handle *handle,
573 struct lttng_channel *chan);
574
575 /*
576 * Disable event(s) of a channel and domain.
577 *
578 * If name is NULL, all events are disabled.
579 * If channel_name is NULL, the default channel is used (channel0).
580 */
581 extern int lttng_disable_event(struct lttng_handle *handle,
582 const char *name, const char *channel_name);
583
584 /*
585 * Disable channel.
586 *
587 */
588 extern int lttng_disable_channel(struct lttng_handle *handle,
589 const char *name);
590
591 /*
592 * Calibrate LTTng overhead.
593 *
594 * The chan and handle params can not be NULL.
595 */
596 extern int lttng_calibrate(struct lttng_handle *handle,
597 struct lttng_calibrate *calibrate);
598
599 /*
600 * Set the default channel attributes for a specific domain and an allocated
601 * lttng_channel_attr pointer.
602 *
603 * If one or both arguments are NULL, nothing happens.
604 */
605 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
606 struct lttng_channel_attr *attr);
607
608 /*
609 * Set URL for a consumer for a session and domain.
610 *
611 * Both data and control URL must be defined. If both URLs are the same, only
612 * the control URL is used even for network streaming.
613 *
614 * Default port are 5342 and 5343 respectively for control and data which uses
615 * the TCP protocol.
616 */
617 extern int lttng_set_consumer_url(struct lttng_handle *handle,
618 const char *control_url, const char *data_url);
619
620 /*
621 * Enable the consumer for a session and domain.
622 */
623 extern LTTNG_DEPRECATED("This call is now obsolete.")
624 int lttng_enable_consumer(struct lttng_handle *handle);
625
626 /*
627 * Disable consumer for a session and domain.
628 */
629 extern LTTNG_DEPRECATED("This call is now obsolete.")
630 int lttng_disable_consumer(struct lttng_handle *handle);
631
632 /*
633 * Check session daemon health for a specific component.
634 *
635 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
636 * the control library was not able to connect to the session daemon health
637 * socket.
638 *
639 * Any other positive value is an lttcomm error which can be translate with
640 * lttng_strerror().
641 *
642 * Please see lttng-health-check(3) man page for more information.
643 */
644 extern int lttng_health_check(enum lttng_health_component c);
645
646 /*
647 * For a given session name, this call checks if the data is ready to be read
648 * or is still being extracted by the consumer(s) (pending) hence not ready to
649 * be used by any readers.
650 *
651 * Return 0 if there is _no_ data pending in the buffers thus having a
652 * guarantee that the data can be read safely. Else, return 1 if there is still
653 * traced data is pending. On error, a negative value is returned and readable
654 * by lttng_strerror().
655 */
656 extern int lttng_data_pending(const char *session_name);
657
658 #ifdef __cplusplus
659 }
660 #endif
661
662 #endif /* LTTNG_H */
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