dd5d936c5faaed64910f4220e04025b691606028
[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 /*
33 * Event symbol length. Copied from LTTng kernel ABI.
34 */
35 #define LTTNG_SYMBOL_NAME_LEN 256
36
37 /*
38 * Every lttng_event_* structure both apply to kernel event and user-space
39 * event.
40 */
41
42 /*
43 * Domain types: the different possible tracers.
44 */
45 enum lttng_domain_type {
46 LTTNG_DOMAIN_KERNEL = 1,
47 LTTNG_DOMAIN_UST = 2,
48
49 /*
50 * For now, the domains below are not implemented. However, we keep them
51 * here in order to retain their enum values for future development. Note
52 * that it is on the roadmap to implement them.
53 *
54 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
55 LTTNG_DOMAIN_UST_PID = 4,
56 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
57 */
58 };
59
60 /*
61 * Instrumentation type of tracing event.
62 */
63 enum lttng_event_type {
64 LTTNG_EVENT_ALL = -1,
65 LTTNG_EVENT_TRACEPOINT = 0,
66 LTTNG_EVENT_PROBE = 1,
67 LTTNG_EVENT_FUNCTION = 2,
68 LTTNG_EVENT_FUNCTION_ENTRY = 3,
69 LTTNG_EVENT_NOOP = 4,
70 LTTNG_EVENT_SYSCALL = 5,
71 };
72
73 /*
74 * Loglevel information.
75 */
76 enum lttng_loglevel_type {
77 LTTNG_EVENT_LOGLEVEL_ALL = 0,
78 LTTNG_EVENT_LOGLEVEL_RANGE = 1,
79 LTTNG_EVENT_LOGLEVEL_SINGLE = 2,
80 };
81
82 /*
83 * Available loglevels.
84 */
85 enum lttng_loglevel {
86 LTTNG_LOGLEVEL_EMERG = 0,
87 LTTNG_LOGLEVEL_ALERT = 1,
88 LTTNG_LOGLEVEL_CRIT = 2,
89 LTTNG_LOGLEVEL_ERR = 3,
90 LTTNG_LOGLEVEL_WARNING = 4,
91 LTTNG_LOGLEVEL_NOTICE = 5,
92 LTTNG_LOGLEVEL_INFO = 6,
93 LTTNG_LOGLEVEL_DEBUG_SYSTEM = 7,
94 LTTNG_LOGLEVEL_DEBUG_PROGRAM = 8,
95 LTTNG_LOGLEVEL_DEBUG_PROCESS = 9,
96 LTTNG_LOGLEVEL_DEBUG_MODULE = 10,
97 LTTNG_LOGLEVEL_DEBUG_UNIT = 11,
98 LTTNG_LOGLEVEL_DEBUG_FUNCTION = 12,
99 LTTNG_LOGLEVEL_DEBUG_LINE = 13,
100 LTTNG_LOGLEVEL_DEBUG = 14,
101 };
102
103 /*
104 * LTTng consumer mode
105 */
106 enum lttng_event_output {
107 LTTNG_EVENT_SPLICE = 0,
108 LTTNG_EVENT_MMAP = 1,
109 };
110
111 /* Event context possible type */
112 enum lttng_event_context_type {
113 LTTNG_EVENT_CONTEXT_PID = 0,
114 LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1,
115 LTTNG_EVENT_CONTEXT_PROCNAME = 2,
116 LTTNG_EVENT_CONTEXT_PRIO = 3,
117 LTTNG_EVENT_CONTEXT_NICE = 4,
118 LTTNG_EVENT_CONTEXT_VPID = 5,
119 LTTNG_EVENT_CONTEXT_TID = 6,
120 LTTNG_EVENT_CONTEXT_VTID = 7,
121 LTTNG_EVENT_CONTEXT_PPID = 8,
122 LTTNG_EVENT_CONTEXT_VPPID = 9,
123 LTTNG_EVENT_CONTEXT_PTHREAD_ID = 10,
124 LTTNG_EVENT_CONTEXT_HOSTNAME = 11,
125 };
126
127 enum lttng_calibrate_type {
128 LTTNG_CALIBRATE_FUNCTION = 0,
129 };
130
131 /* Health component for the health check function. */
132 enum lttng_health_component {
133 LTTNG_HEALTH_CMD,
134 LTTNG_HEALTH_APP_MANAGE,
135 LTTNG_HEALTH_APP_REG,
136 LTTNG_HEALTH_KERNEL,
137 LTTNG_HEALTH_CONSUMER,
138 LTTNG_HEALTH_ALL,
139 };
140
141 /*
142 * The structures should be initialized to zero before use.
143 */
144 #define LTTNG_DOMAIN_PADDING1 16
145 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
146 struct lttng_domain {
147 enum lttng_domain_type type;
148 char padding[LTTNG_DOMAIN_PADDING1];
149
150 union {
151 pid_t pid;
152 char exec_name[NAME_MAX];
153 char padding[LTTNG_DOMAIN_PADDING2];
154 } attr;
155 };
156
157 /*
158 * Perf counter attributes
159 *
160 * The structures should be initialized to zero before use.
161 */
162 #define LTTNG_PERF_EVENT_PADDING1 16
163 struct lttng_event_perf_counter_ctx {
164 uint32_t type;
165 uint64_t config;
166 char name[LTTNG_SYMBOL_NAME_LEN];
167
168 char padding[LTTNG_PERF_EVENT_PADDING1];
169 };
170
171 /*
172 * Event/channel context
173 *
174 * The structures should be initialized to zero before use.
175 */
176 #define LTTNG_EVENT_CONTEXT_PADDING1 16
177 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
178 struct lttng_event_context {
179 enum lttng_event_context_type ctx;
180 char padding[LTTNG_EVENT_CONTEXT_PADDING1];
181
182 union {
183 struct lttng_event_perf_counter_ctx perf_counter;
184 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
185 } u;
186 };
187
188 /*
189 * Event probe.
190 *
191 * Either addr is used or symbol_name and offset.
192 *
193 * The structures should be initialized to zero before use.
194 */
195 #define LTTNG_EVENT_PROBE_PADDING1 16
196 struct lttng_event_probe_attr {
197 uint64_t addr;
198
199 uint64_t offset;
200 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
201
202 char padding[LTTNG_EVENT_PROBE_PADDING1];
203 };
204
205 /*
206 * Function tracer
207 *
208 * The structures should be initialized to zero before use.
209 */
210 #define LTTNG_EVENT_FUNCTION_PADDING1 16
211 struct lttng_event_function_attr {
212 char symbol_name[LTTNG_SYMBOL_NAME_LEN];
213
214 char padding[LTTNG_EVENT_FUNCTION_PADDING1];
215 };
216
217 /*
218 * Generic lttng event
219 *
220 * The structures should be initialized to zero before use.
221 */
222 #define LTTNG_EVENT_PADDING1 15
223 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
224 struct lttng_event {
225 enum lttng_event_type type;
226 char name[LTTNG_SYMBOL_NAME_LEN];
227
228 enum lttng_loglevel_type loglevel_type;
229 int loglevel;
230
231 int32_t enabled; /* Does not apply: -1 */
232 pid_t pid;
233 unsigned char filter; /* filter enabled ? */
234
235 char padding[LTTNG_EVENT_PADDING1];
236
237 /* Per event type configuration */
238 union {
239 struct lttng_event_probe_attr probe;
240 struct lttng_event_function_attr ftrace;
241
242 char padding[LTTNG_EVENT_PADDING2];
243 } attr;
244 };
245
246 enum lttng_event_field_type {
247 LTTNG_EVENT_FIELD_OTHER = 0,
248 LTTNG_EVENT_FIELD_INTEGER = 1,
249 LTTNG_EVENT_FIELD_ENUM = 2,
250 LTTNG_EVENT_FIELD_FLOAT = 3,
251 LTTNG_EVENT_FIELD_STRING = 4,
252 };
253
254 #define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32
255 struct lttng_event_field {
256 char field_name[LTTNG_SYMBOL_NAME_LEN];
257 enum lttng_event_field_type type;
258 char padding[LTTNG_EVENT_FIELD_PADDING];
259 struct lttng_event event;
260 };
261
262 /*
263 * Tracer channel attributes. For both kernel and user-space.
264 *
265 * The structures should be initialized to zero before use.
266 */
267 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32
268 struct lttng_channel_attr {
269 int overwrite; /* 1: overwrite, 0: discard */
270 uint64_t subbuf_size; /* bytes */
271 uint64_t num_subbuf; /* power of 2 */
272 unsigned int switch_timer_interval; /* usec */
273 unsigned int read_timer_interval; /* usec */
274 enum lttng_event_output output; /* splice, mmap */
275
276 char padding[LTTNG_CHANNEL_ATTR_PADDING1];
277 };
278
279 /*
280 * Channel information structure. For both kernel and user-space.
281 *
282 * The structures should be initialized to zero before use.
283 */
284 #define LTTNG_CHANNEL_PADDING1 16
285 struct lttng_channel {
286 char name[LTTNG_SYMBOL_NAME_LEN];
287 uint32_t enabled;
288 struct lttng_channel_attr attr;
289
290 char padding[LTTNG_CHANNEL_PADDING1];
291 };
292
293 #define LTTNG_CALIBRATE_PADDING1 16
294 struct lttng_calibrate {
295 enum lttng_calibrate_type type;
296
297 char padding[LTTNG_CALIBRATE_PADDING1];
298 };
299
300 /*
301 * Basic session information.
302 *
303 * This is an 'output data' meaning that it only comes *from* the session
304 * daemon *to* the lttng client. It's basically a 'human' representation of
305 * tracing entities (here a session).
306 *
307 * The structures should be initialized to zero before use.
308 */
309 #define LTTNG_SESSION_PADDING1 16
310 struct lttng_session {
311 char name[NAME_MAX];
312 /* The path where traces are written */
313 char path[PATH_MAX];
314 uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
315
316 char padding[LTTNG_SESSION_PADDING1];
317 };
318
319 /*
320 * Handle used as a context for commands.
321 *
322 * The structures should be initialized to zero before use.
323 */
324 #define LTTNG_HANDLE_PADDING1 16
325 struct lttng_handle {
326 char session_name[NAME_MAX];
327 struct lttng_domain domain;
328
329 char padding[LTTNG_HANDLE_PADDING1];
330 };
331
332 /*
333 * Public LTTng control API
334 *
335 * For functions having an lttng domain type as parameter, if a bad value is
336 * given, NO default is applied and an error is returned.
337 *
338 * On success, all functions of the API return 0 or the size of the allocated
339 * array (in bytes).
340 *
341 * On error, a negative value is returned being a specific lttng-tools error
342 * code which can be humanly interpreted with lttng_strerror(err).
343 *
344 * Exceptions to this are noted below.
345 */
346
347 /*
348 * Create a handle used as a context for every request made to the library.
349 *
350 * This handle contains the session name and lttng domain on which the command
351 * will be executed.
352 * The returned pointer will be NULL in case of malloc() error.
353 */
354 extern struct lttng_handle *lttng_create_handle(const char *session_name,
355 struct lttng_domain *domain);
356
357 /*
358 * Destroy a handle. This will simply free(3) the data pointer returned by
359 * lttng_create_handle(), rendering it unusable.
360 */
361 extern void lttng_destroy_handle(struct lttng_handle *handle);
362
363 /*
364 * Create a tracing session using a name and an optional URL.
365 *
366 * If _url_ is NULL, no consumer is created for the session.
367 */
368 extern int lttng_create_session(const char *name, const char *url);
369
370 /*
371 * Destroy a tracing session.
372 *
373 * The session will not be usable anymore, tracing will be stopped for all
374 * registered traces, and the tracing buffers will be flushed.
375 */
376 extern int lttng_destroy_session(const char *name);
377
378 /*
379 * List all the tracing sessions.
380 *
381 * Return the size (number of entries) of the "lttng_session" array. Caller
382 * must free(3).
383 */
384 extern int lttng_list_sessions(struct lttng_session **sessions);
385
386 /*
387 * List the registered domain(s) of a session.
388 *
389 * Return the size (number of entries) of the "lttng_domain" array. Caller
390 * must free(3).
391 */
392 extern int lttng_list_domains(const char *session_name,
393 struct lttng_domain **domains);
394
395 /*
396 * List the channel(s) of a session.
397 *
398 * Return the size (number of entries) of the "lttng_channel" array. Caller
399 * must free(3).
400 */
401 extern int lttng_list_channels(struct lttng_handle *handle,
402 struct lttng_channel **channels);
403
404 /*
405 * List the event(s) of a session channel.
406 *
407 * Return the size (number of entries) of the "lttng_event" array.
408 * Caller must free(3).
409 */
410 extern int lttng_list_events(struct lttng_handle *handle,
411 const char *channel_name, struct lttng_event **events);
412
413 /*
414 * List the available tracepoints of a specific lttng domain.
415 *
416 * Return the size (number of entries) of the "lttng_event" array.
417 * Caller must free(3).
418 */
419 extern int lttng_list_tracepoints(struct lttng_handle *handle,
420 struct lttng_event **events);
421
422 /*
423 * List the available tracepoints fields of a specific lttng domain.
424 *
425 * Return the size (number of entries) of the "lttng_event_field" array.
426 * Caller must free(3).
427 */
428 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
429 struct lttng_event_field **fields);
430
431 /*
432 * Check if a session daemon is alive.
433 *
434 * Return 1 if alive or 0 if not. On error returns a negative value.
435 */
436 extern int lttng_session_daemon_alive(void);
437
438 /*
439 * Set the tracing group for the *current* flow of execution.
440 *
441 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
442 */
443 extern int lttng_set_tracing_group(const char *name);
444
445 /*
446 * Return a human-readable error message for an lttng-tools error code.
447 *
448 * Parameter MUST be a negative value or else you'll get a generic message.
449 */
450 extern const char *lttng_strerror(int code);
451
452 /*
453 * This call registers an "outside consumer" for a session and an lttng domain.
454 * No consumer will be spawned and all fds/commands will go through the socket
455 * path given (socket_path).
456 *
457 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
458 * command socket. The error socket is not supported yet for roaming consumers.
459 */
460 extern int lttng_register_consumer(struct lttng_handle *handle,
461 const char *socket_path);
462
463 /*
464 * Start tracing for *all* registered traces (kernel and user-space).
465 */
466 extern int lttng_start_tracing(const char *session_name);
467
468 /*
469 * Stop tracing for *all* registered traces (kernel and user-space).
470 */
471 extern int lttng_stop_tracing(const char *session_name);
472
473 /*
474 * Add context to event(s) for a specific channel (or for all).
475 *
476 * If event_name is NULL, the context is applied to all events of the channel.
477 * If channel_name is NULL, a lookup of the event's channel is done.
478 * If both are NULL, the context is applied to all events of all channels.
479 */
480 extern int lttng_add_context(struct lttng_handle *handle,
481 struct lttng_event_context *ctx, const char *event_name,
482 const char *channel_name);
483
484 /*
485 * Create or enable an event (or events) for a channel.
486 *
487 * If the event you are trying to enable does not exist, it will be created,
488 * else it is enabled.
489 * If event_name is NULL, all events are enabled.
490 * If channel_name is NULL, the default channel is used (channel0).
491 */
492 extern int lttng_enable_event(struct lttng_handle *handle,
493 struct lttng_event *ev, const char *channel_name);
494
495 /*
496 * Apply a filter expression to an event.
497 *
498 * If event_name is NULL, the filter is applied to all events of the channel.
499 * If channel_name is NULL, a lookup of the event's channel is done.
500 * If both are NULL, the filter is applied to all events of all channels.
501 */
502 extern int lttng_set_event_filter(struct lttng_handle *handle,
503 const char *event_name,
504 const char *channel_name,
505 const char *filter_expression);
506 /*
507 * Create or enable a channel.
508 * The channel name cannot be NULL.
509 */
510 extern int lttng_enable_channel(struct lttng_handle *handle,
511 struct lttng_channel *chan);
512
513 /*
514 * Disable event(s) of a channel and domain.
515 *
516 * If event_name is NULL, all events are disabled.
517 * If channel_name is NULL, the default channel is used (channel0).
518 */
519 extern int lttng_disable_event(struct lttng_handle *handle,
520 const char *name, const char *channel_name);
521
522 /*
523 * Disable channel.
524 *
525 * The channel name cannot be NULL.
526 */
527 extern int lttng_disable_channel(struct lttng_handle *handle,
528 const char *name);
529
530 /*
531 * Calibrate LTTng overhead.
532 */
533 extern int lttng_calibrate(struct lttng_handle *handle,
534 struct lttng_calibrate *calibrate);
535
536 /*
537 * Set the default channel attributes for a specific domain and an allocated
538 * lttng_channel_attr pointer.
539 *
540 * If either or both of the arguments are NULL, nothing happens.
541 */
542 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
543 struct lttng_channel_attr *attr);
544
545 /*
546 * Set URL for a consumer for a session and domain.
547 *
548 * Both data and control URL must be defined. If both URLs are the same, only
549 * the control URL is used even for network streaming.
550 *
551 * Default port are 5342 and 5343 respectively for control and data which uses
552 * the TCP protocol.
553 */
554 extern int lttng_set_consumer_url(struct lttng_handle *handle,
555 const char *control_url, const char *data_url);
556
557 /*
558 * Enable the consumer for a session and domain.
559 */
560 extern int lttng_enable_consumer(struct lttng_handle *handle);
561
562 /*
563 * Disable consumer for a session and domain.
564 */
565 extern int lttng_disable_consumer(struct lttng_handle *handle);
566
567 /*
568 * Check session daemon health for a specific component.
569 *
570 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
571 * the control library was not able to connect to the session daemon health
572 * socket.
573 *
574 * Any other positive value is an lttcomm error which can be translate with
575 * lttng_strerror().
576 */
577 extern int lttng_health_check(enum lttng_health_component c);
578
579 #endif /* LTTNG_H */
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