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 #define LTTNG_PACKED __attribute__((__packed__))
41 * Event symbol length. Copied from LTTng kernel ABI.
43 #define LTTNG_SYMBOL_NAME_LEN 256
46 * Every lttng_event_* structure both apply to kernel event and user-space
51 * Domain types: the different possible tracers.
53 enum lttng_domain_type
{
54 LTTNG_DOMAIN_KERNEL
= 1,
58 * For now, the domains below are not implemented. However, we keep them
59 * here in order to retain their enum values for future development. Note
60 * that it is on the roadmap to implement them.
62 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
63 LTTNG_DOMAIN_UST_PID = 4,
64 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
69 * Instrumentation type of tracing event.
71 enum lttng_event_type
{
73 LTTNG_EVENT_TRACEPOINT
= 0,
74 LTTNG_EVENT_PROBE
= 1,
75 LTTNG_EVENT_FUNCTION
= 2,
76 LTTNG_EVENT_FUNCTION_ENTRY
= 3,
78 LTTNG_EVENT_SYSCALL
= 5,
82 * Loglevel information.
84 enum lttng_loglevel_type
{
85 LTTNG_EVENT_LOGLEVEL_ALL
= 0,
86 LTTNG_EVENT_LOGLEVEL_RANGE
= 1,
87 LTTNG_EVENT_LOGLEVEL_SINGLE
= 2,
91 * Available loglevels.
94 LTTNG_LOGLEVEL_EMERG
= 0,
95 LTTNG_LOGLEVEL_ALERT
= 1,
96 LTTNG_LOGLEVEL_CRIT
= 2,
97 LTTNG_LOGLEVEL_ERR
= 3,
98 LTTNG_LOGLEVEL_WARNING
= 4,
99 LTTNG_LOGLEVEL_NOTICE
= 5,
100 LTTNG_LOGLEVEL_INFO
= 6,
101 LTTNG_LOGLEVEL_DEBUG_SYSTEM
= 7,
102 LTTNG_LOGLEVEL_DEBUG_PROGRAM
= 8,
103 LTTNG_LOGLEVEL_DEBUG_PROCESS
= 9,
104 LTTNG_LOGLEVEL_DEBUG_MODULE
= 10,
105 LTTNG_LOGLEVEL_DEBUG_UNIT
= 11,
106 LTTNG_LOGLEVEL_DEBUG_FUNCTION
= 12,
107 LTTNG_LOGLEVEL_DEBUG_LINE
= 13,
108 LTTNG_LOGLEVEL_DEBUG
= 14,
112 * LTTng consumer mode
114 enum lttng_event_output
{
115 LTTNG_EVENT_SPLICE
= 0,
116 LTTNG_EVENT_MMAP
= 1,
119 /* Event context possible type */
120 enum lttng_event_context_type
{
121 LTTNG_EVENT_CONTEXT_PID
= 0,
122 LTTNG_EVENT_CONTEXT_PERF_COUNTER
= 1,
123 LTTNG_EVENT_CONTEXT_PROCNAME
= 2,
124 LTTNG_EVENT_CONTEXT_PRIO
= 3,
125 LTTNG_EVENT_CONTEXT_NICE
= 4,
126 LTTNG_EVENT_CONTEXT_VPID
= 5,
127 LTTNG_EVENT_CONTEXT_TID
= 6,
128 LTTNG_EVENT_CONTEXT_VTID
= 7,
129 LTTNG_EVENT_CONTEXT_PPID
= 8,
130 LTTNG_EVENT_CONTEXT_VPPID
= 9,
131 LTTNG_EVENT_CONTEXT_PTHREAD_ID
= 10,
132 LTTNG_EVENT_CONTEXT_HOSTNAME
= 11,
135 enum lttng_calibrate_type
{
136 LTTNG_CALIBRATE_FUNCTION
= 0,
139 /* Health component for the health check function. */
140 enum lttng_health_component
{
142 LTTNG_HEALTH_APP_MANAGE
,
143 LTTNG_HEALTH_APP_REG
,
145 LTTNG_HEALTH_CONSUMER
,
150 * The structures should be initialized to zero before use.
152 #define LTTNG_DOMAIN_PADDING1 16
153 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
154 struct lttng_domain
{
155 enum lttng_domain_type type
;
156 char padding
[LTTNG_DOMAIN_PADDING1
];
160 char exec_name
[NAME_MAX
];
161 char padding
[LTTNG_DOMAIN_PADDING2
];
166 * Perf counter attributes
168 * The structures should be initialized to zero before use.
170 #define LTTNG_PERF_EVENT_PADDING1 16
171 struct lttng_event_perf_counter_ctx
{
174 char name
[LTTNG_SYMBOL_NAME_LEN
];
176 char padding
[LTTNG_PERF_EVENT_PADDING1
];
180 * Event/channel context
182 * The structures should be initialized to zero before use.
184 #define LTTNG_EVENT_CONTEXT_PADDING1 16
185 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
186 struct lttng_event_context
{
187 enum lttng_event_context_type ctx
;
188 char padding
[LTTNG_EVENT_CONTEXT_PADDING1
];
191 struct lttng_event_perf_counter_ctx perf_counter
;
192 char padding
[LTTNG_EVENT_CONTEXT_PADDING2
];
199 * Either addr is used or symbol_name and offset.
201 * The structures should be initialized to zero before use.
203 #define LTTNG_EVENT_PROBE_PADDING1 16
204 struct lttng_event_probe_attr
{
208 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
210 char padding
[LTTNG_EVENT_PROBE_PADDING1
];
216 * The structures should be initialized to zero before use.
218 #define LTTNG_EVENT_FUNCTION_PADDING1 16
219 struct lttng_event_function_attr
{
220 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
222 char padding
[LTTNG_EVENT_FUNCTION_PADDING1
];
226 * Generic lttng event
228 * The structures should be initialized to zero before use.
230 #define LTTNG_EVENT_PADDING1 15
231 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
233 enum lttng_event_type type
;
234 char name
[LTTNG_SYMBOL_NAME_LEN
];
236 enum lttng_loglevel_type loglevel_type
;
239 int32_t enabled
; /* Does not apply: -1 */
241 unsigned char filter
; /* filter enabled ? */
243 char padding
[LTTNG_EVENT_PADDING1
];
245 /* Per event type configuration */
247 struct lttng_event_probe_attr probe
;
248 struct lttng_event_function_attr ftrace
;
250 char padding
[LTTNG_EVENT_PADDING2
];
254 enum lttng_event_field_type
{
255 LTTNG_EVENT_FIELD_OTHER
= 0,
256 LTTNG_EVENT_FIELD_INTEGER
= 1,
257 LTTNG_EVENT_FIELD_ENUM
= 2,
258 LTTNG_EVENT_FIELD_FLOAT
= 3,
259 LTTNG_EVENT_FIELD_STRING
= 4,
262 #define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32
263 struct lttng_event_field
{
264 char field_name
[LTTNG_SYMBOL_NAME_LEN
];
265 enum lttng_event_field_type type
;
266 char padding
[LTTNG_EVENT_FIELD_PADDING
];
267 struct lttng_event event
;
272 * Tracer channel attributes. For both kernel and user-space.
274 * The structures should be initialized to zero before use.
276 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32
277 struct lttng_channel_attr
{
278 int overwrite
; /* 1: overwrite, 0: discard */
279 uint64_t subbuf_size
; /* bytes */
280 uint64_t num_subbuf
; /* power of 2 */
281 unsigned int switch_timer_interval
; /* usec */
282 unsigned int read_timer_interval
; /* usec */
283 enum lttng_event_output output
; /* splice, mmap */
285 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
289 * Channel information structure. For both kernel and user-space.
291 * The structures should be initialized to zero before use.
293 #define LTTNG_CHANNEL_PADDING1 16
294 struct lttng_channel
{
295 char name
[LTTNG_SYMBOL_NAME_LEN
];
297 struct lttng_channel_attr attr
;
299 char padding
[LTTNG_CHANNEL_PADDING1
];
302 #define LTTNG_CALIBRATE_PADDING1 16
303 struct lttng_calibrate
{
304 enum lttng_calibrate_type type
;
306 char padding
[LTTNG_CALIBRATE_PADDING1
];
310 * Basic session information.
312 * This is an 'output data' meaning that it only comes *from* the session
313 * daemon *to* the lttng client. It's basically a 'human' representation of
314 * tracing entities (here a session).
316 * The structures should be initialized to zero before use.
318 #define LTTNG_SESSION_PADDING1 16
319 struct lttng_session
{
321 /* The path where traces are written */
323 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
325 char padding
[LTTNG_SESSION_PADDING1
];
329 * Handle used as a context for commands.
331 * The structures should be initialized to zero before use.
333 #define LTTNG_HANDLE_PADDING1 16
334 struct lttng_handle
{
335 char session_name
[NAME_MAX
];
336 struct lttng_domain domain
;
338 char padding
[LTTNG_HANDLE_PADDING1
];
342 * Public LTTng control API
344 * For functions having an lttng domain type as parameter, if a bad value is
345 * given, NO default is applied and an error is returned.
347 * On success, all functions of the API return 0 or the size of the allocated
350 * On error, a negative value is returned being a specific lttng-tools error
351 * code which can be humanly interpreted with lttng_strerror(err).
353 * Exceptions to this are noted below.
357 * Create a handle used as a context for every request made to the library.
359 * This handle contains the session name and lttng domain on which the command
361 * The returned pointer will be NULL in case of malloc() error.
363 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
364 struct lttng_domain
*domain
);
369 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
372 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
375 * Create a tracing session using a name and an optional URL.
377 * If _url_ is NULL, no consumer is created for the session. The name can't be
380 extern int lttng_create_session(const char *name
, const char *url
);
383 * Destroy a tracing session.
385 * The session will not be usable anymore, tracing will be stopped for all
386 * registered traces, and the tracing buffers will be flushed.
388 * The name can't be NULL here.
390 extern int lttng_destroy_session(const char *name
);
393 * List all the tracing sessions.
395 * Return the size (number of entries) of the "lttng_session" array. Caller
398 extern int lttng_list_sessions(struct lttng_session
**sessions
);
401 * List the registered domain(s) of a session.
403 * Return the size (number of entries) of the "lttng_domain" array. Caller
406 extern int lttng_list_domains(const char *session_name
,
407 struct lttng_domain
**domains
);
410 * List the channel(s) of a session.
412 * Return the size (number of entries) of the "lttng_channel" array. Caller
415 extern int lttng_list_channels(struct lttng_handle
*handle
,
416 struct lttng_channel
**channels
);
419 * List the event(s) of a session channel.
421 * Return the size (number of entries) of the "lttng_event" array.
422 * Caller must free(3).
424 extern int lttng_list_events(struct lttng_handle
*handle
,
425 const char *channel_name
, struct lttng_event
**events
);
428 * List the available tracepoints of a specific lttng domain.
430 * Return the size (number of entries) of the "lttng_event" array.
431 * Caller must free(3).
433 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
434 struct lttng_event
**events
);
437 * List the available tracepoints fields of a specific lttng domain.
439 * Return the size (number of entries) of the "lttng_event_field" array.
440 * Caller must free(3).
442 extern int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
443 struct lttng_event_field
**fields
);
446 * Check if a session daemon is alive.
448 * Return 1 if alive or 0 if not. On error returns a negative value.
450 extern int lttng_session_daemon_alive(void);
453 * Set the tracing group for the *current* flow of execution.
455 * On success, returns 0 else a negative value on error being a lttng error
456 * code found in lttng-error.h
458 extern int lttng_set_tracing_group(const char *name
);
461 * Return a human-readable error message for an lttng-tools error code.
463 * Parameter MUST be a negative value or else you'll get a generic message.
465 extern const char *lttng_strerror(int code
);
468 * This call registers an "outside consumer" for a session and an lttng domain.
469 * No consumer will be spawned and all fds/commands will go through the socket
470 * path given (socket_path).
472 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
473 * command socket. The error socket is not supported yet for roaming consumers.
475 extern int lttng_register_consumer(struct lttng_handle
*handle
,
476 const char *socket_path
);
479 * Start tracing for *all* registered traces (kernel and user-space).
481 extern int lttng_start_tracing(const char *session_name
);
484 * Stop tracing for *all* registered traces (kernel and user-space).
486 * This call will wait for data availability for each domain of the session so
487 * this can take an abritrary amount of time. However, when returning you have
488 * the guarantee that the data is ready to be read and analyse. Use the
489 * _no_wait call below to avoid this behavior.
491 * The session_name can't be NULL.
493 extern int lttng_stop_tracing(const char *session_name
);
496 * Behave exactly like lttng_stop_tracing but does not wait for data
499 extern int lttng_stop_tracing_no_wait(const char *session_name
);
502 * Add context to event(s) for a specific channel (or for all).
504 * If channel_name is NULL, a lookup of the event's channel is done. If both
505 * are NULL, the context is applied to all events of all channels.
507 * Note that whatever event_name value is, a context can not be added to an
508 * event, so we just ignore it for now.
510 extern int lttng_add_context(struct lttng_handle
*handle
,
511 struct lttng_event_context
*ctx
, const char *event_name
,
512 const char *channel_name
);
515 * Create or enable an event (or events) for a channel.
517 * If the event you are trying to enable does not exist, it will be created,
518 * else it is enabled.
519 * If channel_name is NULL, the default channel is used (channel0).
521 * The handle and ev params can not be NULL.
523 extern int lttng_enable_event(struct lttng_handle
*handle
,
524 struct lttng_event
*ev
, const char *channel_name
);
527 * Create or enable an event with a specific filter.
529 * If the event you are trying to enable does not exist, it will be created,
530 * else it is enabled.
531 * If ev is NULL, all events are enabled with that filter.
532 * If channel_name is NULL, the default channel is used (channel0) and created
534 * If filter_expression is NULL, an event without associated filter is
537 extern int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
538 struct lttng_event
*event
, const char *channel_name
,
539 const char *filter_expression
);
542 * Create or enable a channel.
544 * The chan and handle params can not be NULL.
546 extern int lttng_enable_channel(struct lttng_handle
*handle
,
547 struct lttng_channel
*chan
);
550 * Disable event(s) of a channel and domain.
552 * If name is NULL, all events are disabled.
553 * If channel_name is NULL, the default channel is used (channel0).
555 extern int lttng_disable_event(struct lttng_handle
*handle
,
556 const char *name
, const char *channel_name
);
562 extern int lttng_disable_channel(struct lttng_handle
*handle
,
566 * Calibrate LTTng overhead.
568 * The chan and handle params can not be NULL.
570 extern int lttng_calibrate(struct lttng_handle
*handle
,
571 struct lttng_calibrate
*calibrate
);
574 * Set the default channel attributes for a specific domain and an allocated
575 * lttng_channel_attr pointer.
577 * If one or both arguments are NULL, nothing happens.
579 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
580 struct lttng_channel_attr
*attr
);
583 * Set URL for a consumer for a session and domain.
585 * Both data and control URL must be defined. If both URLs are the same, only
586 * the control URL is used even for network streaming.
588 * Default port are 5342 and 5343 respectively for control and data which uses
591 extern int lttng_set_consumer_url(struct lttng_handle
*handle
,
592 const char *control_url
, const char *data_url
);
595 * Enable the consumer for a session and domain.
597 extern int lttng_enable_consumer(struct lttng_handle
*handle
);
600 * Disable consumer for a session and domain.
602 extern int lttng_disable_consumer(struct lttng_handle
*handle
);
605 * Check session daemon health for a specific component.
607 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
608 * the control library was not able to connect to the session daemon health
611 * Any other positive value is an lttcomm error which can be translate with
614 * Please see lttng-health-check(3) man page for more information.
616 extern int lttng_health_check(enum lttng_health_component c
);
619 * For a given session name, this call checks if the data is ready to be read
620 * or is still being extracted by the consumer(s) (pending) hence not ready to
621 * be used by any readers.
623 * Return 0 if there is _no_ data pending in the buffers thus having a
624 * guarantee that the data can be read safely. Else, return 1 if there is still
625 * traced data is pending. On error, a negative value is returned and readable
626 * by lttng_strerror().
628 extern int lttng_data_pending(const char *session_name
);