Live timer set up
[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 + 12
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 /* LTTng 2.3 padding limit */
296 unsigned int live_timer_interval; /* usec */
297
298 char padding[LTTNG_CHANNEL_ATTR_PADDING1];
299 };
300
301 /*
302 * Channel information structure. For both kernel and user-space.
303 *
304 * The structures should be initialized to zero before use.
305 */
306 #define LTTNG_CHANNEL_PADDING1 16
307 struct lttng_channel {
308 char name[LTTNG_SYMBOL_NAME_LEN];
309 uint32_t enabled;
310 struct lttng_channel_attr attr;
311
312 char padding[LTTNG_CHANNEL_PADDING1];
313 };
314
315 #define LTTNG_CALIBRATE_PADDING1 16
316 struct lttng_calibrate {
317 enum lttng_calibrate_type type;
318
319 char padding[LTTNG_CALIBRATE_PADDING1];
320 };
321
322 /*
323 * Basic session information.
324 *
325 * This is an 'output data' meaning that it only comes *from* the session
326 * daemon *to* the lttng client. It's basically a 'human' representation of
327 * tracing entities (here a session).
328 *
329 * The structures should be initialized to zero before use.
330 */
331 #define LTTNG_SESSION_PADDING1 12
332 struct lttng_session {
333 char name[NAME_MAX];
334 /* The path where traces are written */
335 char path[PATH_MAX];
336 uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
337 uint32_t snapshot_mode;
338 unsigned int live_timer_interval; /* usec */
339
340 char padding[LTTNG_SESSION_PADDING1];
341 };
342
343 /*
344 * Handle used as a context for commands.
345 *
346 * The structures should be initialized to zero before use.
347 */
348 #define LTTNG_HANDLE_PADDING1 16
349 struct lttng_handle {
350 char session_name[NAME_MAX];
351 struct lttng_domain domain;
352
353 char padding[LTTNG_HANDLE_PADDING1];
354 };
355
356 /*
357 * Public LTTng control API
358 *
359 * For functions having an lttng domain type as parameter, if a bad value is
360 * given, NO default is applied and an error is returned.
361 *
362 * On success, all functions of the API return 0 or the size of the allocated
363 * array (in bytes).
364 *
365 * On error, a negative value is returned being a specific lttng-tools error
366 * code which can be humanly interpreted with lttng_strerror(err).
367 *
368 * Exceptions to this are noted below.
369 */
370
371 /*
372 * Create a handle used as a context for every request made to the library.
373 *
374 * This handle contains the session name and lttng domain on which the command
375 * will be executed.
376 * The returned pointer will be NULL in case of malloc() error.
377 */
378 extern struct lttng_handle *lttng_create_handle(const char *session_name,
379 struct lttng_domain *domain);
380
381 /*
382 * Destroy an handle.
383 *
384 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
385 * unusable.
386 */
387 extern void lttng_destroy_handle(struct lttng_handle *handle);
388
389 /*
390 * Create a tracing session using a name and an optional URL.
391 *
392 * If _url_ is NULL, no consumer is created for the session. The name can't be
393 * NULL here.
394 */
395 extern int lttng_create_session(const char *name, const char *url);
396
397 /*
398 * Create a tracing session that will exclusively be used for snapshot meaning
399 * the session will be in no output mode and every channel enabled for that
400 * session will be set in overwrite mode and in mmap output since splice is not
401 * supported.
402 *
403 * If an url is given, it will be used to create a default snapshot output
404 * using it as a destination. If NULL, no output will be defined and an
405 * add-output call will be needed.
406 *
407 * Name can't be NULL.
408 */
409 extern int lttng_create_session_snapshot(const char *name,
410 const char *snapshot_url);
411
412 /*
413 * Create a session exclusively used for live reading.
414 *
415 * In this mode, the switch-timer parameter is forced for each UST channel, a
416 * live-switch-timer is enabled for kernel channels, manually setting
417 * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
418 * indexes are sent and metadata is checked for each packet.
419 *
420 * Returns LTTNG_OK on success or a negative error code.
421 */
422 extern int lttng_create_session_live(const char *name, const char *url,
423 unsigned int timer_interval);
424
425 /*
426 * Destroy a tracing session.
427 *
428 * The session will not be usable anymore, tracing will be stopped for all
429 * registered traces, and the tracing buffers will be flushed.
430 *
431 * The name can't be NULL here.
432 */
433 extern int lttng_destroy_session(const char *name);
434
435 /*
436 * List all the tracing sessions.
437 *
438 * Return the size (number of entries) of the "lttng_session" array. Caller
439 * must free(3).
440 */
441 extern int lttng_list_sessions(struct lttng_session **sessions);
442
443 /*
444 * List the registered domain(s) of a session.
445 *
446 * Return the size (number of entries) of the "lttng_domain" array. Caller
447 * must free(3).
448 */
449 extern int lttng_list_domains(const char *session_name,
450 struct lttng_domain **domains);
451
452 /*
453 * List the channel(s) of a session.
454 *
455 * Return the size (number of entries) of the "lttng_channel" array. Caller
456 * must free(3).
457 */
458 extern int lttng_list_channels(struct lttng_handle *handle,
459 struct lttng_channel **channels);
460
461 /*
462 * List the event(s) of a session channel.
463 *
464 * Return the size (number of entries) of the "lttng_event" array.
465 * Caller must free(3).
466 */
467 extern int lttng_list_events(struct lttng_handle *handle,
468 const char *channel_name, struct lttng_event **events);
469
470 /*
471 * List the available tracepoints of a specific lttng domain.
472 *
473 * Return the size (number of entries) of the "lttng_event" array.
474 * Caller must free(3).
475 */
476 extern int lttng_list_tracepoints(struct lttng_handle *handle,
477 struct lttng_event **events);
478
479 /*
480 * List the available tracepoints fields of a specific lttng domain.
481 *
482 * Return the size (number of entries) of the "lttng_event_field" array.
483 * Caller must free(3).
484 */
485 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
486 struct lttng_event_field **fields);
487
488 /*
489 * Check if a session daemon is alive.
490 *
491 * Return 1 if alive or 0 if not. On error returns a negative value.
492 */
493 extern int lttng_session_daemon_alive(void);
494
495 /*
496 * Set the tracing group for the *current* flow of execution.
497 *
498 * On success, returns 0 else a negative value on error being a lttng error
499 * code found in lttng-error.h
500 */
501 extern int lttng_set_tracing_group(const char *name);
502
503 /*
504 * Return a human-readable error message for an lttng-tools error code.
505 *
506 * Parameter MUST be a negative value or else you'll get a generic message.
507 */
508 extern const char *lttng_strerror(int code);
509
510 /*
511 * This call registers an "outside consumer" for a session and an lttng domain.
512 * No consumer will be spawned and all fds/commands will go through the socket
513 * path given (socket_path).
514 *
515 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
516 * command socket. The error socket is not supported yet for roaming consumers.
517 */
518 extern int lttng_register_consumer(struct lttng_handle *handle,
519 const char *socket_path);
520
521 /*
522 * Start tracing for *all* registered traces (kernel and user-space).
523 */
524 extern int lttng_start_tracing(const char *session_name);
525
526 /*
527 * Stop tracing for *all* registered traces (kernel and user-space).
528 *
529 * This call will wait for data availability for each domain of the session so
530 * this can take an abritrary amount of time. However, when returning you have
531 * the guarantee that the data is ready to be read and analyse. Use the
532 * _no_wait call below to avoid this behavior.
533 *
534 * The session_name can't be NULL.
535 */
536 extern int lttng_stop_tracing(const char *session_name);
537
538 /*
539 * Behave exactly like lttng_stop_tracing but does not wait for data
540 * availability.
541 */
542 extern int lttng_stop_tracing_no_wait(const char *session_name);
543
544 /*
545 * Add context to event(s) for a specific channel (or for all).
546 *
547 * If channel_name is NULL, a lookup of the event's channel is done. If both
548 * are NULL, the context is applied to all events of all channels.
549 *
550 * Note that whatever event_name value is, a context can not be added to an
551 * event, so we just ignore it for now.
552 */
553 extern int lttng_add_context(struct lttng_handle *handle,
554 struct lttng_event_context *ctx, const char *event_name,
555 const char *channel_name);
556
557 /*
558 * Create or enable an event (or events) for a channel.
559 *
560 * If the event you are trying to enable does not exist, it will be created,
561 * else it is enabled.
562 * If channel_name is NULL, the default channel is used (channel0).
563 *
564 * The handle and ev params can not be NULL.
565 */
566 extern int lttng_enable_event(struct lttng_handle *handle,
567 struct lttng_event *ev, const char *channel_name);
568
569 /*
570 * Create or enable an event with a specific filter.
571 *
572 * If the event you are trying to enable does not exist, it will be created,
573 * else it is enabled.
574 * If ev is NULL, all events are enabled with that filter.
575 * If channel_name is NULL, the default channel is used (channel0) and created
576 * if not found.
577 * If filter_expression is NULL, an event without associated filter is
578 * created.
579 */
580 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
581 struct lttng_event *event, const char *channel_name,
582 const char *filter_expression);
583
584 /*
585 * Create or enable a channel.
586 *
587 * The chan and handle params can not be NULL.
588 */
589 extern int lttng_enable_channel(struct lttng_handle *handle,
590 struct lttng_channel *chan);
591
592 /*
593 * Disable event(s) of a channel and domain.
594 *
595 * If name is NULL, all events are disabled.
596 * If channel_name is NULL, the default channel is used (channel0).
597 */
598 extern int lttng_disable_event(struct lttng_handle *handle,
599 const char *name, const char *channel_name);
600
601 /*
602 * Disable channel.
603 *
604 */
605 extern int lttng_disable_channel(struct lttng_handle *handle,
606 const char *name);
607
608 /*
609 * Calibrate LTTng overhead.
610 *
611 * The chan and handle params can not be NULL.
612 */
613 extern int lttng_calibrate(struct lttng_handle *handle,
614 struct lttng_calibrate *calibrate);
615
616 /*
617 * Set the default channel attributes for a specific domain and an allocated
618 * lttng_channel_attr pointer.
619 *
620 * If one or both arguments are NULL, nothing happens.
621 */
622 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
623 struct lttng_channel_attr *attr);
624
625 /*
626 * Set URL for a consumer for a session and domain.
627 *
628 * Both data and control URL must be defined. If both URLs are the same, only
629 * the control URL is used even for network streaming.
630 *
631 * Default port are 5342 and 5343 respectively for control and data which uses
632 * the TCP protocol.
633 */
634 extern int lttng_set_consumer_url(struct lttng_handle *handle,
635 const char *control_url, const char *data_url);
636
637 /*
638 * Enable the consumer for a session and domain.
639 */
640 extern LTTNG_DEPRECATED("This call is now obsolete.")
641 int lttng_enable_consumer(struct lttng_handle *handle);
642
643 /*
644 * Disable consumer for a session and domain.
645 */
646 extern LTTNG_DEPRECATED("This call is now obsolete.")
647 int lttng_disable_consumer(struct lttng_handle *handle);
648
649 /*
650 * Check session daemon health for a specific component.
651 *
652 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
653 * the control library was not able to connect to the session daemon health
654 * socket.
655 *
656 * Any other positive value is an lttcomm error which can be translate with
657 * lttng_strerror().
658 *
659 * Please see lttng-health-check(3) man page for more information.
660 */
661 extern int lttng_health_check(enum lttng_health_component c);
662
663 /*
664 * For a given session name, this call checks if the data is ready to be read
665 * or is still being extracted by the consumer(s) (pending) hence not ready to
666 * be used by any readers.
667 *
668 * Return 0 if there is _no_ data pending in the buffers thus having a
669 * guarantee that the data can be read safely. Else, return 1 if there is still
670 * traced data is pending. On error, a negative value is returned and readable
671 * by lttng_strerror().
672 */
673 extern int lttng_data_pending(const char *session_name);
674
675 #ifdef __cplusplus
676 }
677 #endif
678
679 #endif /* LTTNG_H */
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