4ffffd84ff237bedddbf1bbc27c325c32136b521
[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 12
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 uint32_t snapshot_mode;
336
337 char padding[LTTNG_SESSION_PADDING1];
338 };
339
340 /*
341 * Handle used as a context for commands.
342 *
343 * The structures should be initialized to zero before use.
344 */
345 #define LTTNG_HANDLE_PADDING1 16
346 struct lttng_handle {
347 char session_name[NAME_MAX];
348 struct lttng_domain domain;
349
350 char padding[LTTNG_HANDLE_PADDING1];
351 };
352
353 /*
354 * Public LTTng control API
355 *
356 * For functions having an lttng domain type as parameter, if a bad value is
357 * given, NO default is applied and an error is returned.
358 *
359 * On success, all functions of the API return 0 or the size of the allocated
360 * array (in bytes).
361 *
362 * On error, a negative value is returned being a specific lttng-tools error
363 * code which can be humanly interpreted with lttng_strerror(err).
364 *
365 * Exceptions to this are noted below.
366 */
367
368 /*
369 * Create a handle used as a context for every request made to the library.
370 *
371 * This handle contains the session name and lttng domain on which the command
372 * will be executed.
373 * The returned pointer will be NULL in case of malloc() error.
374 */
375 extern struct lttng_handle *lttng_create_handle(const char *session_name,
376 struct lttng_domain *domain);
377
378 /*
379 * Destroy an handle.
380 *
381 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
382 * unusable.
383 */
384 extern void lttng_destroy_handle(struct lttng_handle *handle);
385
386 /*
387 * Create a tracing session using a name and an optional URL.
388 *
389 * If _url_ is NULL, no consumer is created for the session. The name can't be
390 * NULL here.
391 */
392 extern int lttng_create_session(const char *name, const char *url);
393
394 /*
395 * Create a tracing session that will exclusively be used for snapshot meaning
396 * the session will be in no output mode and every channel enabled for that
397 * session will be set in overwrite mode and in mmap output since splice is not
398 * supported.
399 *
400 * If an url is given, it will be used to create a default snapshot output
401 * using it as a destination. If NULL, no output will be defined and an
402 * add-output call will be needed.
403 *
404 * Name can't be NULL.
405 */
406 extern int lttng_create_session_snapshot(const char *name,
407 const char *snapshot_url);
408
409 /*
410 * Destroy a tracing session.
411 *
412 * The session will not be usable anymore, tracing will be stopped for all
413 * registered traces, and the tracing buffers will be flushed.
414 *
415 * The name can't be NULL here.
416 */
417 extern int lttng_destroy_session(const char *name);
418
419 /*
420 * List all the tracing sessions.
421 *
422 * Return the size (number of entries) of the "lttng_session" array. Caller
423 * must free(3).
424 */
425 extern int lttng_list_sessions(struct lttng_session **sessions);
426
427 /*
428 * List the registered domain(s) of a session.
429 *
430 * Return the size (number of entries) of the "lttng_domain" array. Caller
431 * must free(3).
432 */
433 extern int lttng_list_domains(const char *session_name,
434 struct lttng_domain **domains);
435
436 /*
437 * List the channel(s) of a session.
438 *
439 * Return the size (number of entries) of the "lttng_channel" array. Caller
440 * must free(3).
441 */
442 extern int lttng_list_channels(struct lttng_handle *handle,
443 struct lttng_channel **channels);
444
445 /*
446 * List the event(s) of a session channel.
447 *
448 * Return the size (number of entries) of the "lttng_event" array.
449 * Caller must free(3).
450 */
451 extern int lttng_list_events(struct lttng_handle *handle,
452 const char *channel_name, struct lttng_event **events);
453
454 /*
455 * List the available tracepoints of a specific lttng domain.
456 *
457 * Return the size (number of entries) of the "lttng_event" array.
458 * Caller must free(3).
459 */
460 extern int lttng_list_tracepoints(struct lttng_handle *handle,
461 struct lttng_event **events);
462
463 /*
464 * List the available tracepoints fields of a specific lttng domain.
465 *
466 * Return the size (number of entries) of the "lttng_event_field" array.
467 * Caller must free(3).
468 */
469 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
470 struct lttng_event_field **fields);
471
472 /*
473 * Check if a session daemon is alive.
474 *
475 * Return 1 if alive or 0 if not. On error returns a negative value.
476 */
477 extern int lttng_session_daemon_alive(void);
478
479 /*
480 * Set the tracing group for the *current* flow of execution.
481 *
482 * On success, returns 0 else a negative value on error being a lttng error
483 * code found in lttng-error.h
484 */
485 extern int lttng_set_tracing_group(const char *name);
486
487 /*
488 * Return a human-readable error message for an lttng-tools error code.
489 *
490 * Parameter MUST be a negative value or else you'll get a generic message.
491 */
492 extern const char *lttng_strerror(int code);
493
494 /*
495 * This call registers an "outside consumer" for a session and an lttng domain.
496 * No consumer will be spawned and all fds/commands will go through the socket
497 * path given (socket_path).
498 *
499 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
500 * command socket. The error socket is not supported yet for roaming consumers.
501 */
502 extern int lttng_register_consumer(struct lttng_handle *handle,
503 const char *socket_path);
504
505 /*
506 * Start tracing for *all* registered traces (kernel and user-space).
507 */
508 extern int lttng_start_tracing(const char *session_name);
509
510 /*
511 * Stop tracing for *all* registered traces (kernel and user-space).
512 *
513 * This call will wait for data availability for each domain of the session so
514 * this can take an abritrary amount of time. However, when returning you have
515 * the guarantee that the data is ready to be read and analyse. Use the
516 * _no_wait call below to avoid this behavior.
517 *
518 * The session_name can't be NULL.
519 */
520 extern int lttng_stop_tracing(const char *session_name);
521
522 /*
523 * Behave exactly like lttng_stop_tracing but does not wait for data
524 * availability.
525 */
526 extern int lttng_stop_tracing_no_wait(const char *session_name);
527
528 /*
529 * Add context to event(s) for a specific channel (or for all).
530 *
531 * If channel_name is NULL, a lookup of the event's channel is done. If both
532 * are NULL, the context is applied to all events of all channels.
533 *
534 * Note that whatever event_name value is, a context can not be added to an
535 * event, so we just ignore it for now.
536 */
537 extern int lttng_add_context(struct lttng_handle *handle,
538 struct lttng_event_context *ctx, const char *event_name,
539 const char *channel_name);
540
541 /*
542 * Create or enable an event (or events) for a channel.
543 *
544 * If the event you are trying to enable does not exist, it will be created,
545 * else it is enabled.
546 * If channel_name is NULL, the default channel is used (channel0).
547 *
548 * The handle and ev params can not be NULL.
549 */
550 extern int lttng_enable_event(struct lttng_handle *handle,
551 struct lttng_event *ev, const char *channel_name);
552
553 /*
554 * Create or enable an event with a specific filter.
555 *
556 * If the event you are trying to enable does not exist, it will be created,
557 * else it is enabled.
558 * If ev is NULL, all events are enabled with that filter.
559 * If channel_name is NULL, the default channel is used (channel0) and created
560 * if not found.
561 * If filter_expression is NULL, an event without associated filter is
562 * created.
563 */
564 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
565 struct lttng_event *event, const char *channel_name,
566 const char *filter_expression);
567
568 /*
569 * Create or enable a channel.
570 *
571 * The chan and handle params can not be NULL.
572 */
573 extern int lttng_enable_channel(struct lttng_handle *handle,
574 struct lttng_channel *chan);
575
576 /*
577 * Disable event(s) of a channel and domain.
578 *
579 * If name is NULL, all events are disabled.
580 * If channel_name is NULL, the default channel is used (channel0).
581 */
582 extern int lttng_disable_event(struct lttng_handle *handle,
583 const char *name, const char *channel_name);
584
585 /*
586 * Disable channel.
587 *
588 */
589 extern int lttng_disable_channel(struct lttng_handle *handle,
590 const char *name);
591
592 /*
593 * Calibrate LTTng overhead.
594 *
595 * The chan and handle params can not be NULL.
596 */
597 extern int lttng_calibrate(struct lttng_handle *handle,
598 struct lttng_calibrate *calibrate);
599
600 /*
601 * Set the default channel attributes for a specific domain and an allocated
602 * lttng_channel_attr pointer.
603 *
604 * If one or both arguments are NULL, nothing happens.
605 */
606 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
607 struct lttng_channel_attr *attr);
608
609 /*
610 * Set URL for a consumer for a session and domain.
611 *
612 * Both data and control URL must be defined. If both URLs are the same, only
613 * the control URL is used even for network streaming.
614 *
615 * Default port are 5342 and 5343 respectively for control and data which uses
616 * the TCP protocol.
617 */
618 extern int lttng_set_consumer_url(struct lttng_handle *handle,
619 const char *control_url, const char *data_url);
620
621 /*
622 * Enable the consumer for a session and domain.
623 */
624 extern LTTNG_DEPRECATED("This call is now obsolete.")
625 int lttng_enable_consumer(struct lttng_handle *handle);
626
627 /*
628 * Disable consumer for a session and domain.
629 */
630 extern LTTNG_DEPRECATED("This call is now obsolete.")
631 int lttng_disable_consumer(struct lttng_handle *handle);
632
633 /*
634 * Check session daemon health for a specific component.
635 *
636 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
637 * the control library was not able to connect to the session daemon health
638 * socket.
639 *
640 * Any other positive value is an lttcomm error which can be translate with
641 * lttng_strerror().
642 *
643 * Please see lttng-health-check(3) man page for more information.
644 */
645 extern int lttng_health_check(enum lttng_health_component c);
646
647 /*
648 * For a given session name, this call checks if the data is ready to be read
649 * or is still being extracted by the consumer(s) (pending) hence not ready to
650 * be used by any readers.
651 *
652 * Return 0 if there is _no_ data pending in the buffers thus having a
653 * guarantee that the data can be read safely. Else, return 1 if there is still
654 * traced data is pending. On error, a negative value is returned and readable
655 * by lttng_strerror().
656 */
657 extern int lttng_data_pending(const char *session_name);
658
659 #ifdef __cplusplus
660 }
661 #endif
662
663 #endif /* LTTNG_H */
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