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,
129 LTTNG_EVENT_CONTEXT_IP
= 12,
132 enum lttng_calibrate_type
{
133 LTTNG_CALIBRATE_FUNCTION
= 0,
136 /* Health component for the health check function. */
137 enum lttng_health_component
{
139 LTTNG_HEALTH_APP_MANAGE
,
140 LTTNG_HEALTH_APP_REG
,
142 LTTNG_HEALTH_CONSUMER
,
143 LTTNG_HEALTH_HT_CLEANUP
,
144 LTTNG_HEALTH_APP_MANAGE_NOTIFY
,
145 LTTNG_HEALTH_APP_REG_DISPATCH
,
149 /* Buffer type for a specific domain. */
150 enum lttng_buffer_type
{
151 LTTNG_BUFFER_PER_PID
, /* Only supported by UST being the default. */
152 LTTNG_BUFFER_PER_UID
, /* Only supported by UST. */
153 LTTNG_BUFFER_GLOBAL
, /* Only supported by the Kernel. */
157 * The structures should be initialized to zero before use.
159 #define LTTNG_DOMAIN_PADDING1 12
160 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
161 struct lttng_domain
{
162 enum lttng_domain_type type
;
163 enum lttng_buffer_type buf_type
;
164 char padding
[LTTNG_DOMAIN_PADDING1
];
168 char exec_name
[NAME_MAX
];
169 char padding
[LTTNG_DOMAIN_PADDING2
];
174 * Perf counter attributes
176 * The structures should be initialized to zero before use.
178 #define LTTNG_PERF_EVENT_PADDING1 16
179 struct lttng_event_perf_counter_ctx
{
182 char name
[LTTNG_SYMBOL_NAME_LEN
];
184 char padding
[LTTNG_PERF_EVENT_PADDING1
];
188 * Event/channel context
190 * The structures should be initialized to zero before use.
192 #define LTTNG_EVENT_CONTEXT_PADDING1 16
193 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
194 struct lttng_event_context
{
195 enum lttng_event_context_type ctx
;
196 char padding
[LTTNG_EVENT_CONTEXT_PADDING1
];
199 struct lttng_event_perf_counter_ctx perf_counter
;
200 char padding
[LTTNG_EVENT_CONTEXT_PADDING2
];
207 * Either addr is used or symbol_name and offset.
209 * The structures should be initialized to zero before use.
211 #define LTTNG_EVENT_PROBE_PADDING1 16
212 struct lttng_event_probe_attr
{
216 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
218 char padding
[LTTNG_EVENT_PROBE_PADDING1
];
224 * The structures should be initialized to zero before use.
226 #define LTTNG_EVENT_FUNCTION_PADDING1 16
227 struct lttng_event_function_attr
{
228 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
230 char padding
[LTTNG_EVENT_FUNCTION_PADDING1
];
234 * Generic lttng event
236 * The structures should be initialized to zero before use.
238 #define LTTNG_EVENT_PADDING1 15
239 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
241 enum lttng_event_type type
;
242 char name
[LTTNG_SYMBOL_NAME_LEN
];
244 enum lttng_loglevel_type loglevel_type
;
247 int32_t enabled
; /* Does not apply: -1 */
249 unsigned char filter
; /* filter enabled ? */
251 char padding
[LTTNG_EVENT_PADDING1
];
253 /* Per event type configuration */
255 struct lttng_event_probe_attr probe
;
256 struct lttng_event_function_attr ftrace
;
258 char padding
[LTTNG_EVENT_PADDING2
];
262 enum lttng_event_field_type
{
263 LTTNG_EVENT_FIELD_OTHER
= 0,
264 LTTNG_EVENT_FIELD_INTEGER
= 1,
265 LTTNG_EVENT_FIELD_ENUM
= 2,
266 LTTNG_EVENT_FIELD_FLOAT
= 3,
267 LTTNG_EVENT_FIELD_STRING
= 4,
270 #define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32
271 struct lttng_event_field
{
272 char field_name
[LTTNG_SYMBOL_NAME_LEN
];
273 enum lttng_event_field_type type
;
274 char padding
[LTTNG_EVENT_FIELD_PADDING
];
275 struct lttng_event event
;
280 * Tracer channel attributes. For both kernel and user-space.
282 * The structures should be initialized to zero before use.
284 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 16
285 struct lttng_channel_attr
{
286 int overwrite
; /* 1: overwrite, 0: discard */
287 uint64_t subbuf_size
; /* bytes */
288 uint64_t num_subbuf
; /* power of 2 */
289 unsigned int switch_timer_interval
; /* usec */
290 unsigned int read_timer_interval
; /* usec */
291 enum lttng_event_output output
; /* splice, mmap */
292 /* LTTng 2.1 padding limit */
293 uint64_t tracefile_size
; /* bytes */
294 uint64_t tracefile_count
; /* number of tracefiles */
296 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
300 * Channel information structure. For both kernel and user-space.
302 * The structures should be initialized to zero before use.
304 #define LTTNG_CHANNEL_PADDING1 16
305 struct lttng_channel
{
306 char name
[LTTNG_SYMBOL_NAME_LEN
];
308 struct lttng_channel_attr attr
;
310 char padding
[LTTNG_CHANNEL_PADDING1
];
313 #define LTTNG_CALIBRATE_PADDING1 16
314 struct lttng_calibrate
{
315 enum lttng_calibrate_type type
;
317 char padding
[LTTNG_CALIBRATE_PADDING1
];
321 * Basic session information.
323 * This is an 'output data' meaning that it only comes *from* the session
324 * daemon *to* the lttng client. It's basically a 'human' representation of
325 * tracing entities (here a session).
327 * The structures should be initialized to zero before use.
329 #define LTTNG_SESSION_PADDING1 12
330 struct lttng_session
{
332 /* The path where traces are written */
334 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
335 uint32_t snapshot_mode
;
337 char padding
[LTTNG_SESSION_PADDING1
];
341 * Handle used as a context for commands.
343 * The structures should be initialized to zero before use.
345 #define LTTNG_HANDLE_PADDING1 16
346 struct lttng_handle
{
347 char session_name
[NAME_MAX
];
348 struct lttng_domain domain
;
350 char padding
[LTTNG_HANDLE_PADDING1
];
354 * Public LTTng control API
356 * For functions having an lttng domain type as parameter, if a bad value is
357 * given, NO default is applied and an error is returned.
359 * On success, all functions of the API return 0 or the size of the allocated
362 * On error, a negative value is returned being a specific lttng-tools error
363 * code which can be humanly interpreted with lttng_strerror(err).
365 * Exceptions to this are noted below.
369 * Create a handle used as a context for every request made to the library.
371 * This handle contains the session name and lttng domain on which the command
373 * The returned pointer will be NULL in case of malloc() error.
375 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
376 struct lttng_domain
*domain
);
381 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
384 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
387 * Create a tracing session using a name and an optional URL.
389 * If _url_ is NULL, no consumer is created for the session. The name can't be
392 extern int lttng_create_session(const char *name
, const char *url
);
395 * Create a tracing session that will exclusively be used for snapshot meaning
396 * the session will be in no output mode and every channel enabled for that
397 * session will be set in overwrite mode and in mmap output since splice is not
400 * If an url is given, it will be used to create a default snapshot output
401 * using it as a destination. If NULL, no output will be defined and an
402 * add-output call will be needed.
404 * Name can't be NULL.
406 extern int lttng_create_session_snapshot(const char *name
,
407 const char *snapshot_url
);
410 * Destroy a tracing session.
412 * The session will not be usable anymore, tracing will be stopped for all
413 * registered traces, and the tracing buffers will be flushed.
415 * The name can't be NULL here.
417 extern int lttng_destroy_session(const char *name
);
420 * List all the tracing sessions.
422 * Return the size (number of entries) of the "lttng_session" array. Caller
425 extern int lttng_list_sessions(struct lttng_session
**sessions
);
428 * List the registered domain(s) of a session.
430 * Return the size (number of entries) of the "lttng_domain" array. Caller
433 extern int lttng_list_domains(const char *session_name
,
434 struct lttng_domain
**domains
);
437 * List the channel(s) of a session.
439 * Return the size (number of entries) of the "lttng_channel" array. Caller
442 extern int lttng_list_channels(struct lttng_handle
*handle
,
443 struct lttng_channel
**channels
);
446 * List the event(s) of a session channel.
448 * Return the size (number of entries) of the "lttng_event" array.
449 * Caller must free(3).
451 extern int lttng_list_events(struct lttng_handle
*handle
,
452 const char *channel_name
, struct lttng_event
**events
);
455 * List the available tracepoints of a specific lttng domain.
457 * Return the size (number of entries) of the "lttng_event" array.
458 * Caller must free(3).
460 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
461 struct lttng_event
**events
);
464 * List the available tracepoints fields of a specific lttng domain.
466 * Return the size (number of entries) of the "lttng_event_field" array.
467 * Caller must free(3).
469 extern int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
470 struct lttng_event_field
**fields
);
473 * Check if a session daemon is alive.
475 * Return 1 if alive or 0 if not. On error returns a negative value.
477 extern int lttng_session_daemon_alive(void);
480 * Set the tracing group for the *current* flow of execution.
482 * On success, returns 0 else a negative value on error being a lttng error
483 * code found in lttng-error.h
485 extern int lttng_set_tracing_group(const char *name
);
488 * Return a human-readable error message for an lttng-tools error code.
490 * Parameter MUST be a negative value or else you'll get a generic message.
492 extern const char *lttng_strerror(int code
);
495 * This call registers an "outside consumer" for a session and an lttng domain.
496 * No consumer will be spawned and all fds/commands will go through the socket
497 * path given (socket_path).
499 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
500 * command socket. The error socket is not supported yet for roaming consumers.
502 extern int lttng_register_consumer(struct lttng_handle
*handle
,
503 const char *socket_path
);
506 * Start tracing for *all* registered traces (kernel and user-space).
508 extern int lttng_start_tracing(const char *session_name
);
511 * Stop tracing for *all* registered traces (kernel and user-space).
513 * This call will wait for data availability for each domain of the session so
514 * this can take an abritrary amount of time. However, when returning you have
515 * the guarantee that the data is ready to be read and analyse. Use the
516 * _no_wait call below to avoid this behavior.
518 * The session_name can't be NULL.
520 extern int lttng_stop_tracing(const char *session_name
);
523 * Behave exactly like lttng_stop_tracing but does not wait for data
526 extern int lttng_stop_tracing_no_wait(const char *session_name
);
529 * Add context to event(s) for a specific channel (or for all).
531 * If channel_name is NULL, a lookup of the event's channel is done. If both
532 * are NULL, the context is applied to all events of all channels.
534 * Note that whatever event_name value is, a context can not be added to an
535 * event, so we just ignore it for now.
537 extern int lttng_add_context(struct lttng_handle
*handle
,
538 struct lttng_event_context
*ctx
, const char *event_name
,
539 const char *channel_name
);
542 * Create or enable an event (or events) for a channel.
544 * If the event you are trying to enable does not exist, it will be created,
545 * else it is enabled.
546 * If channel_name is NULL, the default channel is used (channel0).
548 * The handle and ev params can not be NULL.
550 extern int lttng_enable_event(struct lttng_handle
*handle
,
551 struct lttng_event
*ev
, const char *channel_name
);
554 * Create or enable an event with a specific filter.
556 * If the event you are trying to enable does not exist, it will be created,
557 * else it is enabled.
558 * If ev is NULL, all events are enabled with that filter.
559 * If channel_name is NULL, the default channel is used (channel0) and created
561 * If filter_expression is NULL, an event without associated filter is
564 extern int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
565 struct lttng_event
*event
, const char *channel_name
,
566 const char *filter_expression
);
569 * Create or enable a channel.
571 * The chan and handle params can not be NULL.
573 extern int lttng_enable_channel(struct lttng_handle
*handle
,
574 struct lttng_channel
*chan
);
577 * Disable event(s) of a channel and domain.
579 * If name is NULL, all events are disabled.
580 * If channel_name is NULL, the default channel is used (channel0).
582 extern int lttng_disable_event(struct lttng_handle
*handle
,
583 const char *name
, const char *channel_name
);
589 extern int lttng_disable_channel(struct lttng_handle
*handle
,
593 * Calibrate LTTng overhead.
595 * The chan and handle params can not be NULL.
597 extern int lttng_calibrate(struct lttng_handle
*handle
,
598 struct lttng_calibrate
*calibrate
);
601 * Set the default channel attributes for a specific domain and an allocated
602 * lttng_channel_attr pointer.
604 * If one or both arguments are NULL, nothing happens.
606 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
607 struct lttng_channel_attr
*attr
);
610 * Set URL for a consumer for a session and domain.
612 * Both data and control URL must be defined. If both URLs are the same, only
613 * the control URL is used even for network streaming.
615 * Default port are 5342 and 5343 respectively for control and data which uses
618 extern int lttng_set_consumer_url(struct lttng_handle
*handle
,
619 const char *control_url
, const char *data_url
);
622 * Enable the consumer for a session and domain.
624 extern LTTNG_DEPRECATED("This call is now obsolete.")
625 int lttng_enable_consumer(struct lttng_handle
*handle
);
628 * Disable consumer for a session and domain.
630 extern LTTNG_DEPRECATED("This call is now obsolete.")
631 int lttng_disable_consumer(struct lttng_handle
*handle
);
634 * Check session daemon health for a specific component.
636 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
637 * the control library was not able to connect to the session daemon health
640 * Any other positive value is an lttcomm error which can be translate with
643 * Please see lttng-health-check(3) man page for more information.
645 extern int lttng_health_check(enum lttng_health_component c
);
648 * For a given session name, this call checks if the data is ready to be read
649 * or is still being extracted by the consumer(s) (pending) hence not ready to
650 * be used by any readers.
652 * Return 0 if there is _no_ data pending in the buffers thus having a
653 * guarantee that the data can be read safely. Else, return 1 if there is still
654 * traced data is pending. On error, a negative value is returned and readable
655 * by lttng_strerror().
657 extern int lttng_data_pending(const char *session_name
);