4171cde41c998d123fac3b407a337ec622b42cfe
[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 a handle. This will simply free(3) the data pointer returned by
364 * lttng_create_handle(), rendering it unusable.
365 */
366 extern void lttng_destroy_handle(struct lttng_handle *handle);
367
368 /*
369 * Create a tracing session using a name and an optional URL.
370 *
371 * If _url_ is NULL, no consumer is created for the session.
372 */
373 extern int lttng_create_session(const char *name, const char *url);
374
375 /*
376 * Destroy a tracing session.
377 *
378 * The session will not be usable anymore, tracing will be stopped for all
379 * registered traces, and the tracing buffers will be flushed.
380 */
381 extern int lttng_destroy_session(const char *name);
382
383 /*
384 * List all the tracing sessions.
385 *
386 * Return the size (number of entries) of the "lttng_session" array. Caller
387 * must free(3).
388 */
389 extern int lttng_list_sessions(struct lttng_session **sessions);
390
391 /*
392 * List the registered domain(s) of a session.
393 *
394 * Return the size (number of entries) of the "lttng_domain" array. Caller
395 * must free(3).
396 */
397 extern int lttng_list_domains(const char *session_name,
398 struct lttng_domain **domains);
399
400 /*
401 * List the channel(s) of a session.
402 *
403 * Return the size (number of entries) of the "lttng_channel" array. Caller
404 * must free(3).
405 */
406 extern int lttng_list_channels(struct lttng_handle *handle,
407 struct lttng_channel **channels);
408
409 /*
410 * List the event(s) of a session channel.
411 *
412 * Return the size (number of entries) of the "lttng_event" array.
413 * Caller must free(3).
414 */
415 extern int lttng_list_events(struct lttng_handle *handle,
416 const char *channel_name, struct lttng_event **events);
417
418 /*
419 * List the available tracepoints of a specific lttng domain.
420 *
421 * Return the size (number of entries) of the "lttng_event" array.
422 * Caller must free(3).
423 */
424 extern int lttng_list_tracepoints(struct lttng_handle *handle,
425 struct lttng_event **events);
426
427 /*
428 * List the available tracepoints fields of a specific lttng domain.
429 *
430 * Return the size (number of entries) of the "lttng_event_field" array.
431 * Caller must free(3).
432 */
433 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
434 struct lttng_event_field **fields);
435
436 /*
437 * Check if a session daemon is alive.
438 *
439 * Return 1 if alive or 0 if not. On error returns a negative value.
440 */
441 extern int lttng_session_daemon_alive(void);
442
443 /*
444 * Set the tracing group for the *current* flow of execution.
445 *
446 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
447 */
448 extern int lttng_set_tracing_group(const char *name);
449
450 /*
451 * Return a human-readable error message for an lttng-tools error code.
452 *
453 * Parameter MUST be a negative value or else you'll get a generic message.
454 */
455 extern const char *lttng_strerror(int code);
456
457 /*
458 * This call registers an "outside consumer" for a session and an lttng domain.
459 * No consumer will be spawned and all fds/commands will go through the socket
460 * path given (socket_path).
461 *
462 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
463 * command socket. The error socket is not supported yet for roaming consumers.
464 */
465 extern int lttng_register_consumer(struct lttng_handle *handle,
466 const char *socket_path);
467
468 /*
469 * Start tracing for *all* registered traces (kernel and user-space).
470 */
471 extern int lttng_start_tracing(const char *session_name);
472
473 /*
474 * Stop tracing for *all* registered traces (kernel and user-space).
475 */
476 extern int lttng_stop_tracing(const char *session_name);
477
478 /*
479 * Add context to event(s) for a specific channel (or for all).
480 *
481 * If event_name is NULL, the context is applied to all events of the channel.
482 * If channel_name is NULL, a lookup of the event's channel is done.
483 * If both are NULL, the context is applied to all events of all channels.
484 */
485 extern int lttng_add_context(struct lttng_handle *handle,
486 struct lttng_event_context *ctx, const char *event_name,
487 const char *channel_name);
488
489 /*
490 * Create or enable an event (or events) for a channel.
491 *
492 * If the event you are trying to enable does not exist, it will be created,
493 * else it is enabled.
494 * If event_name is NULL, all events are enabled.
495 * If channel_name is NULL, the default channel is used (channel0).
496 */
497 extern int lttng_enable_event(struct lttng_handle *handle,
498 struct lttng_event *ev, const char *channel_name);
499
500 /*
501 * Apply a filter expression to an event.
502 *
503 * If event_name is NULL, the filter is applied to all events of the channel.
504 * If channel_name is NULL, a lookup of the event's channel is done.
505 * If both are NULL, the filter is applied to all events of all channels.
506 */
507 extern int lttng_set_event_filter(struct lttng_handle *handle,
508 const char *event_name,
509 const char *channel_name,
510 const char *filter_expression);
511 /*
512 * Create or enable a channel.
513 * The channel name cannot be NULL.
514 */
515 extern int lttng_enable_channel(struct lttng_handle *handle,
516 struct lttng_channel *chan);
517
518 /*
519 * Disable event(s) of a channel and domain.
520 *
521 * If event_name is NULL, all events are disabled.
522 * If channel_name is NULL, the default channel is used (channel0).
523 */
524 extern int lttng_disable_event(struct lttng_handle *handle,
525 const char *name, const char *channel_name);
526
527 /*
528 * Disable channel.
529 *
530 * The channel name cannot be NULL.
531 */
532 extern int lttng_disable_channel(struct lttng_handle *handle,
533 const char *name);
534
535 /*
536 * Calibrate LTTng overhead.
537 */
538 extern int lttng_calibrate(struct lttng_handle *handle,
539 struct lttng_calibrate *calibrate);
540
541 /*
542 * Set the default channel attributes for a specific domain and an allocated
543 * lttng_channel_attr pointer.
544 *
545 * If either or both of the arguments are NULL, nothing happens.
546 */
547 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
548 struct lttng_channel_attr *attr);
549
550 /*
551 * Set URL for a consumer for a session and domain.
552 *
553 * Both data and control URL must be defined. If both URLs are the same, only
554 * the control URL is used even for network streaming.
555 *
556 * Default port are 5342 and 5343 respectively for control and data which uses
557 * the TCP protocol.
558 */
559 extern int lttng_set_consumer_url(struct lttng_handle *handle,
560 const char *control_url, const char *data_url);
561
562 /*
563 * Enable the consumer for a session and domain.
564 */
565 extern int lttng_enable_consumer(struct lttng_handle *handle);
566
567 /*
568 * Disable consumer for a session and domain.
569 */
570 extern int lttng_disable_consumer(struct lttng_handle *handle);
571
572 /*
573 * Check session daemon health for a specific component.
574 *
575 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
576 * the control library was not able to connect to the session daemon health
577 * socket.
578 *
579 * Any other positive value is an lttcomm error which can be translate with
580 * lttng_strerror().
581 */
582 extern int lttng_health_check(enum lttng_health_component c);
583
584 /*
585 * For a given session name, this call checks if the data is ready to be read
586 * or is still being extracted by the consumer(s) hence not ready to be used by
587 * any readers.
588 *
589 * Return 0 if the data is _NOT_ available else 1 if the data is ready. On
590 * error, a negative value is returned and readable by lttng_strerror().
591 */
592 extern int lttng_data_available(const char *session_name);
593
594 #ifdef __cplusplus
595 }
596 #endif
597
598 #endif /* LTTNG_H */
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