e21b479777b0760d028876218cd12e63decb992f
[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 };
130
131 enum lttng_calibrate_type {
132 LTTNG_CALIBRATE_FUNCTION = 0,
133 };
134
135 /* Health component for the health check function. */
136 enum lttng_health_component {
137 LTTNG_HEALTH_CMD,
138 LTTNG_HEALTH_APP_MANAGE,
139 LTTNG_HEALTH_APP_REG,
140 LTTNG_HEALTH_KERNEL,
141 LTTNG_HEALTH_CONSUMER,
142 LTTNG_HEALTH_ALL,
143 };
144
145 /*
146 * The structures should be initialized to zero before use.
147 */
148 #define LTTNG_DOMAIN_PADDING1 16
149 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
150 struct lttng_domain {
151 enum lttng_domain_type type;
152 char padding[LTTNG_DOMAIN_PADDING1];
153
154 union {
155 pid_t pid;
156 char exec_name[NAME_MAX];
157 char padding[LTTNG_DOMAIN_PADDING2];
158 } attr;
159 };
160
161 /*
162 * Perf counter attributes
163 *
164 * The structures should be initialized to zero before use.
165 */
166 #define LTTNG_PERF_EVENT_PADDING1 16
167 struct lttng_event_perf_counter_ctx {
168 uint32_t type;
169 uint64_t config;
170 char name[LTTNG_SYMBOL_NAME_LEN];
171
172 char padding[LTTNG_PERF_EVENT_PADDING1];
173 };
174
175 /*
176 * Event/channel context
177 *
178 * The structures should be initialized to zero before use.
179 */
180 #define LTTNG_EVENT_CONTEXT_PADDING1 16
181 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
182 struct lttng_event_context {
183 enum lttng_event_context_type ctx;
184 char padding[LTTNG_EVENT_CONTEXT_PADDING1];
185
186 union {
187 struct lttng_event_perf_counter_ctx perf_counter;
188 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
189 } u;
190 };
191
192 /*
193 * Event probe.
194 *
195 * Either addr is used or symbol_name and offset.
196 *
197 * The structures should be initialized to zero before use.
198 */
199 #define LTTNG_EVENT_PROBE_PADDING1 16
200 struct lttng_event_probe_attr {
201 uint64_t addr;
202
203 uint64_t offset;
204 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
205
206 char padding[LTTNG_EVENT_PROBE_PADDING1];
207 };
208
209 /*
210 * Function tracer
211 *
212 * The structures should be initialized to zero before use.
213 */
214 #define LTTNG_EVENT_FUNCTION_PADDING1 16
215 struct lttng_event_function_attr {
216 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
217
218 char padding[LTTNG_EVENT_FUNCTION_PADDING1];
219 };
220
221 /*
222 * Generic lttng event
223 *
224 * The structures should be initialized to zero before use.
225 */
226 #define LTTNG_EVENT_PADDING1 15
227 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
228 struct lttng_event {
229 enum lttng_event_type type;
230 char name[LTTNG_SYMBOL_NAME_LEN];
231
232 enum lttng_loglevel_type loglevel_type;
233 int loglevel;
234
235 int32_t enabled; /* Does not apply: -1 */
236 pid_t pid;
237 unsigned char filter; /* filter enabled ? */
238
239 char padding[LTTNG_EVENT_PADDING1];
240
241 /* Per event type configuration */
242 union {
243 struct lttng_event_probe_attr probe;
244 struct lttng_event_function_attr ftrace;
245
246 char padding[LTTNG_EVENT_PADDING2];
247 } attr;
248 };
249
250 enum lttng_event_field_type {
251 LTTNG_EVENT_FIELD_OTHER = 0,
252 LTTNG_EVENT_FIELD_INTEGER = 1,
253 LTTNG_EVENT_FIELD_ENUM = 2,
254 LTTNG_EVENT_FIELD_FLOAT = 3,
255 LTTNG_EVENT_FIELD_STRING = 4,
256 };
257
258 #define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32
259 struct lttng_event_field {
260 char field_name[LTTNG_SYMBOL_NAME_LEN];
261 enum lttng_event_field_type type;
262 char padding[LTTNG_EVENT_FIELD_PADDING];
263 struct lttng_event event;
264 int nowrite;
265 };
266
267 /*
268 * Tracer channel attributes. For both kernel and user-space.
269 *
270 * The structures should be initialized to zero before use.
271 */
272 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32
273 struct lttng_channel_attr {
274 int overwrite; /* 1: overwrite, 0: discard */
275 uint64_t subbuf_size; /* bytes */
276 uint64_t num_subbuf; /* power of 2 */
277 unsigned int switch_timer_interval; /* usec */
278 unsigned int read_timer_interval; /* usec */
279 enum lttng_event_output output; /* splice, mmap */
280
281 char padding[LTTNG_CHANNEL_ATTR_PADDING1];
282 };
283
284 /*
285 * Channel information structure. For both kernel and user-space.
286 *
287 * The structures should be initialized to zero before use.
288 */
289 #define LTTNG_CHANNEL_PADDING1 16
290 struct lttng_channel {
291 char name[LTTNG_SYMBOL_NAME_LEN];
292 uint32_t enabled;
293 struct lttng_channel_attr attr;
294
295 char padding[LTTNG_CHANNEL_PADDING1];
296 };
297
298 #define LTTNG_CALIBRATE_PADDING1 16
299 struct lttng_calibrate {
300 enum lttng_calibrate_type type;
301
302 char padding[LTTNG_CALIBRATE_PADDING1];
303 };
304
305 /*
306 * Basic session information.
307 *
308 * This is an 'output data' meaning that it only comes *from* the session
309 * daemon *to* the lttng client. It's basically a 'human' representation of
310 * tracing entities (here a session).
311 *
312 * The structures should be initialized to zero before use.
313 */
314 #define LTTNG_SESSION_PADDING1 16
315 struct lttng_session {
316 char name[NAME_MAX];
317 /* The path where traces are written */
318 char path[PATH_MAX];
319 uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
320
321 char padding[LTTNG_SESSION_PADDING1];
322 };
323
324 /*
325 * Handle used as a context for commands.
326 *
327 * The structures should be initialized to zero before use.
328 */
329 #define LTTNG_HANDLE_PADDING1 16
330 struct lttng_handle {
331 char session_name[NAME_MAX];
332 struct lttng_domain domain;
333
334 char padding[LTTNG_HANDLE_PADDING1];
335 };
336
337 /*
338 * Public LTTng control API
339 *
340 * For functions having an lttng domain type as parameter, if a bad value is
341 * given, NO default is applied and an error is returned.
342 *
343 * On success, all functions of the API return 0 or the size of the allocated
344 * array (in bytes).
345 *
346 * On error, a negative value is returned being a specific lttng-tools error
347 * code which can be humanly interpreted with lttng_strerror(err).
348 *
349 * Exceptions to this are noted below.
350 */
351
352 /*
353 * Create a handle used as a context for every request made to the library.
354 *
355 * This handle contains the session name and lttng domain on which the command
356 * will be executed.
357 * The returned pointer will be NULL in case of malloc() error.
358 */
359 extern struct lttng_handle *lttng_create_handle(const char *session_name,
360 struct lttng_domain *domain);
361
362 /*
363 * Destroy an handle.
364 *
365 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
366 * unusable.
367 */
368 extern void lttng_destroy_handle(struct lttng_handle *handle);
369
370 /*
371 * Create a tracing session using a name and an optional URL.
372 *
373 * If _url_ is NULL, no consumer is created for the session. The name can't be
374 * NULL here.
375 */
376 extern int lttng_create_session(const char *name, const char *url);
377
378 /*
379 * Destroy a tracing session.
380 *
381 * The session will not be usable anymore, tracing will be stopped for all
382 * registered traces, and the tracing buffers will be flushed.
383 *
384 * The name can't be NULL here.
385 */
386 extern int lttng_destroy_session(const char *name);
387
388 /*
389 * List all the tracing sessions.
390 *
391 * Return the size (number of entries) of the "lttng_session" array. Caller
392 * must free(3).
393 */
394 extern int lttng_list_sessions(struct lttng_session **sessions);
395
396 /*
397 * List the registered domain(s) of a session.
398 *
399 * Return the size (number of entries) of the "lttng_domain" array. Caller
400 * must free(3).
401 */
402 extern int lttng_list_domains(const char *session_name,
403 struct lttng_domain **domains);
404
405 /*
406 * List the channel(s) of a session.
407 *
408 * Return the size (number of entries) of the "lttng_channel" array. Caller
409 * must free(3).
410 */
411 extern int lttng_list_channels(struct lttng_handle *handle,
412 struct lttng_channel **channels);
413
414 /*
415 * List the event(s) of a session channel.
416 *
417 * Return the size (number of entries) of the "lttng_event" array.
418 * Caller must free(3).
419 */
420 extern int lttng_list_events(struct lttng_handle *handle,
421 const char *channel_name, struct lttng_event **events);
422
423 /*
424 * List the available tracepoints of a specific lttng domain.
425 *
426 * Return the size (number of entries) of the "lttng_event" array.
427 * Caller must free(3).
428 */
429 extern int lttng_list_tracepoints(struct lttng_handle *handle,
430 struct lttng_event **events);
431
432 /*
433 * List the available tracepoints fields of a specific lttng domain.
434 *
435 * Return the size (number of entries) of the "lttng_event_field" array.
436 * Caller must free(3).
437 */
438 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
439 struct lttng_event_field **fields);
440
441 /*
442 * Check if a session daemon is alive.
443 *
444 * Return 1 if alive or 0 if not. On error returns a negative value.
445 */
446 extern int lttng_session_daemon_alive(void);
447
448 /*
449 * Set the tracing group for the *current* flow of execution.
450 *
451 * On success, returns 0 else a negative value on error being a lttng error
452 * code found in lttng-error.h
453 */
454 extern int lttng_set_tracing_group(const char *name);
455
456 /*
457 * Return a human-readable error message for an lttng-tools error code.
458 *
459 * Parameter MUST be a negative value or else you'll get a generic message.
460 */
461 extern const char *lttng_strerror(int code);
462
463 /*
464 * This call registers an "outside consumer" for a session and an lttng domain.
465 * No consumer will be spawned and all fds/commands will go through the socket
466 * path given (socket_path).
467 *
468 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
469 * command socket. The error socket is not supported yet for roaming consumers.
470 */
471 extern int lttng_register_consumer(struct lttng_handle *handle,
472 const char *socket_path);
473
474 /*
475 * Start tracing for *all* registered traces (kernel and user-space).
476 */
477 extern int lttng_start_tracing(const char *session_name);
478
479 /*
480 * Stop tracing for *all* registered traces (kernel and user-space).
481 *
482 * This call will wait for data availability for each domain of the session so
483 * this can take an abritrary amount of time. However, when returning you have
484 * the guarantee that the data is ready to be read and analyse. Use the
485 * _no_wait call below to avoid this behavior.
486 *
487 * The session_name can't be NULL.
488 */
489 extern int lttng_stop_tracing(const char *session_name);
490
491 /*
492 * Behave exactly like lttng_stop_tracing but does not wait for data
493 * availability.
494 */
495 extern int lttng_stop_tracing_no_wait(const char *session_name);
496
497 /*
498 * Add context to event(s) for a specific channel (or for all).
499 *
500 * If channel_name is NULL, a lookup of the event's channel is done. If both
501 * are NULL, the context is applied to all events of all channels.
502 *
503 * Note that whatever event_name value is, a context can not be added to an
504 * event, so we just ignore it for now.
505 */
506 extern int lttng_add_context(struct lttng_handle *handle,
507 struct lttng_event_context *ctx, const char *event_name,
508 const char *channel_name);
509
510 /*
511 * Create or enable an event (or events) for a channel.
512 *
513 * If the event you are trying to enable does not exist, it will be created,
514 * else it is enabled.
515 * If channel_name is NULL, the default channel is used (channel0).
516 *
517 * The handle and ev params can not be NULL.
518 */
519 extern int lttng_enable_event(struct lttng_handle *handle,
520 struct lttng_event *ev, const char *channel_name);
521
522 /*
523 * Create or enable an event with a specific filter.
524 *
525 * If the event you are trying to enable does not exist, it will be created,
526 * else it is enabled.
527 * If ev is NULL, all events are enabled with that filter.
528 * If channel_name is NULL, the default channel is used (channel0) and created
529 * if not found.
530 * If filter_expression is NULL, an event without associated filter is
531 * created.
532 */
533 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
534 struct lttng_event *event, const char *channel_name,
535 const char *filter_expression);
536
537 /*
538 * Create or enable a channel.
539 *
540 * The chan and handle params can not be NULL.
541 */
542 extern int lttng_enable_channel(struct lttng_handle *handle,
543 struct lttng_channel *chan);
544
545 /*
546 * Disable event(s) of a channel and domain.
547 *
548 * If name is NULL, all events are disabled.
549 * If channel_name is NULL, the default channel is used (channel0).
550 */
551 extern int lttng_disable_event(struct lttng_handle *handle,
552 const char *name, const char *channel_name);
553
554 /*
555 * Disable channel.
556 *
557 */
558 extern int lttng_disable_channel(struct lttng_handle *handle,
559 const char *name);
560
561 /*
562 * Calibrate LTTng overhead.
563 *
564 * The chan and handle params can not be NULL.
565 */
566 extern int lttng_calibrate(struct lttng_handle *handle,
567 struct lttng_calibrate *calibrate);
568
569 /*
570 * Set the default channel attributes for a specific domain and an allocated
571 * lttng_channel_attr pointer.
572 *
573 * If one or both arguments are NULL, nothing happens.
574 */
575 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
576 struct lttng_channel_attr *attr);
577
578 /*
579 * Set URL for a consumer for a session and domain.
580 *
581 * Both data and control URL must be defined. If both URLs are the same, only
582 * the control URL is used even for network streaming.
583 *
584 * Default port are 5342 and 5343 respectively for control and data which uses
585 * the TCP protocol.
586 */
587 extern int lttng_set_consumer_url(struct lttng_handle *handle,
588 const char *control_url, const char *data_url);
589
590 /*
591 * Enable the consumer for a session and domain.
592 */
593 extern int lttng_enable_consumer(struct lttng_handle *handle);
594
595 /*
596 * Disable consumer for a session and domain.
597 */
598 extern int lttng_disable_consumer(struct lttng_handle *handle);
599
600 /*
601 * Check session daemon health for a specific component.
602 *
603 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
604 * the control library was not able to connect to the session daemon health
605 * socket.
606 *
607 * Any other positive value is an lttcomm error which can be translate with
608 * lttng_strerror().
609 *
610 * Please see lttng-health-check(3) man page for more information.
611 */
612 extern int lttng_health_check(enum lttng_health_component c);
613
614 /*
615 * For a given session name, this call checks if the data is ready to be read
616 * or is still being extracted by the consumer(s) (pending) hence not ready to
617 * be used by any readers.
618 *
619 * Return 0 if there is _no_ data pending in the buffers thus having a
620 * guarantee that the data can be read safely. Else, return 1 if there is still
621 * traced data is pending. On error, a negative value is returned and readable
622 * by lttng_strerror().
623 */
624 extern int lttng_data_pending(const char *session_name);
625
626 #ifdef __cplusplus
627 }
628 #endif
629
630 #endif /* LTTNG_H */
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