4 * Linux Trace Toolkit Control Library Header File
6 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
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.
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
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
27 #include <sys/types.h>
29 /* Error codes that can be returned by API calls */
30 #include <lttng/lttng-error.h>
37 * Event symbol length. Copied from LTTng kernel ABI.
39 #define LTTNG_SYMBOL_NAME_LEN 256
42 * Every lttng_event_* structure both apply to kernel event and user-space
47 * Domain types: the different possible tracers.
49 enum lttng_domain_type
{
50 LTTNG_DOMAIN_KERNEL
= 1,
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.
58 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
59 LTTNG_DOMAIN_UST_PID = 4,
60 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
65 * Instrumentation type of tracing event.
67 enum lttng_event_type
{
69 LTTNG_EVENT_TRACEPOINT
= 0,
70 LTTNG_EVENT_PROBE
= 1,
71 LTTNG_EVENT_FUNCTION
= 2,
72 LTTNG_EVENT_FUNCTION_ENTRY
= 3,
74 LTTNG_EVENT_SYSCALL
= 5,
78 * Loglevel information.
80 enum lttng_loglevel_type
{
81 LTTNG_EVENT_LOGLEVEL_ALL
= 0,
82 LTTNG_EVENT_LOGLEVEL_RANGE
= 1,
83 LTTNG_EVENT_LOGLEVEL_SINGLE
= 2,
87 * Available loglevels.
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,
108 * LTTng consumer mode
110 enum lttng_event_output
{
111 LTTNG_EVENT_SPLICE
= 0,
112 LTTNG_EVENT_MMAP
= 1,
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,
131 enum lttng_calibrate_type
{
132 LTTNG_CALIBRATE_FUNCTION
= 0,
135 /* Health component for the health check function. */
136 enum lttng_health_component
{
138 LTTNG_HEALTH_APP_MANAGE
,
139 LTTNG_HEALTH_APP_REG
,
141 LTTNG_HEALTH_CONSUMER
,
146 * The structures should be initialized to zero before use.
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
];
156 char exec_name
[NAME_MAX
];
157 char padding
[LTTNG_DOMAIN_PADDING2
];
162 * Perf counter attributes
164 * The structures should be initialized to zero before use.
166 #define LTTNG_PERF_EVENT_PADDING1 16
167 struct lttng_event_perf_counter_ctx
{
170 char name
[LTTNG_SYMBOL_NAME_LEN
];
172 char padding
[LTTNG_PERF_EVENT_PADDING1
];
176 * Event/channel context
178 * The structures should be initialized to zero before use.
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
];
187 struct lttng_event_perf_counter_ctx perf_counter
;
188 char padding
[LTTNG_EVENT_CONTEXT_PADDING2
];
195 * Either addr is used or symbol_name and offset.
197 * The structures should be initialized to zero before use.
199 #define LTTNG_EVENT_PROBE_PADDING1 16
200 struct lttng_event_probe_attr
{
204 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
206 char padding
[LTTNG_EVENT_PROBE_PADDING1
];
212 * The structures should be initialized to zero before use.
214 #define LTTNG_EVENT_FUNCTION_PADDING1 16
215 struct lttng_event_function_attr
{
216 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
218 char padding
[LTTNG_EVENT_FUNCTION_PADDING1
];
222 * Generic lttng event
224 * The structures should be initialized to zero before use.
226 #define LTTNG_EVENT_PADDING1 15
227 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
229 enum lttng_event_type type
;
230 char name
[LTTNG_SYMBOL_NAME_LEN
];
232 enum lttng_loglevel_type loglevel_type
;
235 int32_t enabled
; /* Does not apply: -1 */
237 unsigned char filter
; /* filter enabled ? */
239 char padding
[LTTNG_EVENT_PADDING1
];
241 /* Per event type configuration */
243 struct lttng_event_probe_attr probe
;
244 struct lttng_event_function_attr ftrace
;
246 char padding
[LTTNG_EVENT_PADDING2
];
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,
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
;
268 * Tracer channel attributes. For both kernel and user-space.
270 * The structures should be initialized to zero before use.
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 */
281 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
285 * Channel information structure. For both kernel and user-space.
287 * The structures should be initialized to zero before use.
289 #define LTTNG_CHANNEL_PADDING1 16
290 struct lttng_channel
{
291 char name
[LTTNG_SYMBOL_NAME_LEN
];
293 struct lttng_channel_attr attr
;
295 char padding
[LTTNG_CHANNEL_PADDING1
];
298 #define LTTNG_CALIBRATE_PADDING1 16
299 struct lttng_calibrate
{
300 enum lttng_calibrate_type type
;
302 char padding
[LTTNG_CALIBRATE_PADDING1
];
306 * Basic session information.
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).
312 * The structures should be initialized to zero before use.
314 #define LTTNG_SESSION_PADDING1 16
315 struct lttng_session
{
317 /* The path where traces are written */
319 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
321 char padding
[LTTNG_SESSION_PADDING1
];
325 * Handle used as a context for commands.
327 * The structures should be initialized to zero before use.
329 #define LTTNG_HANDLE_PADDING1 16
330 struct lttng_handle
{
331 char session_name
[NAME_MAX
];
332 struct lttng_domain domain
;
334 char padding
[LTTNG_HANDLE_PADDING1
];
338 * Public LTTng control API
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.
343 * On success, all functions of the API return 0 or the size of the allocated
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).
349 * Exceptions to this are noted below.
353 * Create a handle used as a context for every request made to the library.
355 * This handle contains the session name and lttng domain on which the command
357 * The returned pointer will be NULL in case of malloc() error.
359 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
360 struct lttng_domain
*domain
);
363 * Destroy a handle. This will simply free(3) the data pointer returned by
364 * lttng_create_handle(), rendering it unusable.
366 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
369 * Create a tracing session using a name and an optional URL.
371 * If _url_ is NULL, no consumer is created for the session.
373 extern int lttng_create_session(const char *name
, const char *url
);
376 * Destroy a tracing session.
378 * The session will not be usable anymore, tracing will be stopped for all
379 * registered traces, and the tracing buffers will be flushed.
381 extern int lttng_destroy_session(const char *name
);
384 * List all the tracing sessions.
386 * Return the size (number of entries) of the "lttng_session" array. Caller
389 extern int lttng_list_sessions(struct lttng_session
**sessions
);
392 * List the registered domain(s) of a session.
394 * Return the size (number of entries) of the "lttng_domain" array. Caller
397 extern int lttng_list_domains(const char *session_name
,
398 struct lttng_domain
**domains
);
401 * List the channel(s) of a session.
403 * Return the size (number of entries) of the "lttng_channel" array. Caller
406 extern int lttng_list_channels(struct lttng_handle
*handle
,
407 struct lttng_channel
**channels
);
410 * List the event(s) of a session channel.
412 * Return the size (number of entries) of the "lttng_event" array.
413 * Caller must free(3).
415 extern int lttng_list_events(struct lttng_handle
*handle
,
416 const char *channel_name
, struct lttng_event
**events
);
419 * List the available tracepoints of a specific lttng domain.
421 * Return the size (number of entries) of the "lttng_event" array.
422 * Caller must free(3).
424 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
425 struct lttng_event
**events
);
428 * List the available tracepoints fields of a specific lttng domain.
430 * Return the size (number of entries) of the "lttng_event_field" array.
431 * Caller must free(3).
433 extern int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
434 struct lttng_event_field
**fields
);
437 * Check if a session daemon is alive.
439 * Return 1 if alive or 0 if not. On error returns a negative value.
441 extern int lttng_session_daemon_alive(void);
444 * Set the tracing group for the *current* flow of execution.
446 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
448 extern int lttng_set_tracing_group(const char *name
);
451 * Return a human-readable error message for an lttng-tools error code.
453 * Parameter MUST be a negative value or else you'll get a generic message.
455 extern const char *lttng_strerror(int code
);
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).
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.
465 extern int lttng_register_consumer(struct lttng_handle
*handle
,
466 const char *socket_path
);
469 * Start tracing for *all* registered traces (kernel and user-space).
471 extern int lttng_start_tracing(const char *session_name
);
474 * Stop tracing for *all* registered traces (kernel and user-space).
476 * This call will wait for data availability for each domain of the session so
477 * this can take an abritrary amount of time. However, when returning you have
478 * the guarantee that the data is ready to be read and analyse. Use the
479 * _no_wait call below to avoid this behavior.
481 extern int lttng_stop_tracing(const char *session_name
);
484 * Behave exactly like lttng_stop_tracing but does not wait for data
487 extern int lttng_stop_tracing_no_wait(const char *session_name
);
490 * Add context to event(s) for a specific channel (or for all).
492 * If event_name is NULL, the context is applied to all events of the channel.
493 * If channel_name is NULL, a lookup of the event's channel is done.
494 * If both are NULL, the context is applied to all events of all channels.
496 extern int lttng_add_context(struct lttng_handle
*handle
,
497 struct lttng_event_context
*ctx
, const char *event_name
,
498 const char *channel_name
);
501 * Create or enable an event (or events) for a channel.
503 * If the event you are trying to enable does not exist, it will be created,
504 * else it is enabled.
505 * If event_name is NULL, all events are enabled.
506 * If channel_name is NULL, the default channel is used (channel0).
508 extern int lttng_enable_event(struct lttng_handle
*handle
,
509 struct lttng_event
*ev
, const char *channel_name
);
512 * Apply a filter expression to an event.
514 * If event is NULL, the filter is applied to all events of the channel.
515 * If channel_name is NULL, a lookup of the event's channel is done.
516 * If both are NULL, the filter is applied to all events of all channels.
518 extern int lttng_set_event_filter(struct lttng_handle
*handle
,
519 struct lttng_event
*event
, const char *channel_name
,
520 const char *filter_expression
);
523 * Create or enable a channel.
524 * The channel name cannot be NULL.
526 extern int lttng_enable_channel(struct lttng_handle
*handle
,
527 struct lttng_channel
*chan
);
530 * Disable event(s) of a channel and domain.
532 * If event_name is NULL, all events are disabled.
533 * If channel_name is NULL, the default channel is used (channel0).
535 extern int lttng_disable_event(struct lttng_handle
*handle
,
536 const char *name
, const char *channel_name
);
541 * The channel name cannot be NULL.
543 extern int lttng_disable_channel(struct lttng_handle
*handle
,
547 * Calibrate LTTng overhead.
549 extern int lttng_calibrate(struct lttng_handle
*handle
,
550 struct lttng_calibrate
*calibrate
);
553 * Set the default channel attributes for a specific domain and an allocated
554 * lttng_channel_attr pointer.
556 * If either or both of the arguments are NULL, nothing happens.
558 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
559 struct lttng_channel_attr
*attr
);
562 * Set URL for a consumer for a session and domain.
564 * Both data and control URL must be defined. If both URLs are the same, only
565 * the control URL is used even for network streaming.
567 * Default port are 5342 and 5343 respectively for control and data which uses
570 extern int lttng_set_consumer_url(struct lttng_handle
*handle
,
571 const char *control_url
, const char *data_url
);
574 * Enable the consumer for a session and domain.
576 extern int lttng_enable_consumer(struct lttng_handle
*handle
);
579 * Disable consumer for a session and domain.
581 extern int lttng_disable_consumer(struct lttng_handle
*handle
);
584 * Check session daemon health for a specific component.
586 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
587 * the control library was not able to connect to the session daemon health
590 * Any other positive value is an lttcomm error which can be translate with
593 extern int lttng_health_check(enum lttng_health_component c
);
596 * For a given session name, this call checks if the data is ready to be read
597 * or is still being extracted by the consumer(s) (pending) hence not ready to
598 * be used by any readers.
600 * Return 0 if there is _no_ data pending in the buffers thus having a
601 * guarantee that the data can be read safely. Else, return 1 if there is still
602 * traced data is pending. On error, a negative value is returned and readable
603 * by lttng_strerror().
605 extern int lttng_data_pending(const char *session_name
);