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 + 12
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 */
295 /* LTTng 2.3 padding limit */
296 unsigned int live_timer_interval
; /* usec */
298 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
302 * Channel information structure. For both kernel and user-space.
304 * The structures should be initialized to zero before use.
306 #define LTTNG_CHANNEL_PADDING1 16
307 struct lttng_channel
{
308 char name
[LTTNG_SYMBOL_NAME_LEN
];
310 struct lttng_channel_attr attr
;
312 char padding
[LTTNG_CHANNEL_PADDING1
];
315 #define LTTNG_CALIBRATE_PADDING1 16
316 struct lttng_calibrate
{
317 enum lttng_calibrate_type type
;
319 char padding
[LTTNG_CALIBRATE_PADDING1
];
323 * Basic session information.
325 * This is an 'output data' meaning that it only comes *from* the session
326 * daemon *to* the lttng client. It's basically a 'human' representation of
327 * tracing entities (here a session).
329 * The structures should be initialized to zero before use.
331 #define LTTNG_SESSION_PADDING1 12
332 struct lttng_session
{
334 /* The path where traces are written */
336 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
337 uint32_t snapshot_mode
;
338 unsigned int live_timer_interval
; /* usec */
340 char padding
[LTTNG_SESSION_PADDING1
];
344 * Handle used as a context for commands.
346 * The structures should be initialized to zero before use.
348 #define LTTNG_HANDLE_PADDING1 16
349 struct lttng_handle
{
350 char session_name
[NAME_MAX
];
351 struct lttng_domain domain
;
353 char padding
[LTTNG_HANDLE_PADDING1
];
357 * Public LTTng control API
359 * For functions having an lttng domain type as parameter, if a bad value is
360 * given, NO default is applied and an error is returned.
362 * On success, all functions of the API return 0 or the size of the allocated
365 * On error, a negative value is returned being a specific lttng-tools error
366 * code which can be humanly interpreted with lttng_strerror(err).
368 * Exceptions to this are noted below.
372 * Create a handle used as a context for every request made to the library.
374 * This handle contains the session name and lttng domain on which the command
376 * The returned pointer will be NULL in case of malloc() error.
378 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
379 struct lttng_domain
*domain
);
384 * It free(3) the data pointer returned by lttng_create_handle(), rendering it
387 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
390 * Create a tracing session using a name and an optional URL.
392 * If _url_ is NULL, no consumer is created for the session. The name can't be
395 extern int lttng_create_session(const char *name
, const char *url
);
398 * Create a tracing session that will exclusively be used for snapshot meaning
399 * the session will be in no output mode and every channel enabled for that
400 * session will be set in overwrite mode and in mmap output since splice is not
403 * If an url is given, it will be used to create a default snapshot output
404 * using it as a destination. If NULL, no output will be defined and an
405 * add-output call will be needed.
407 * Name can't be NULL.
409 extern int lttng_create_session_snapshot(const char *name
,
410 const char *snapshot_url
);
413 * Create a session exclusively used for live reading.
415 * In this mode, the switch-timer parameter is forced for each UST channel, a
416 * live-switch-timer is enabled for kernel channels, manually setting
417 * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
418 * indexes are sent and metadata is checked for each packet.
420 * Returns LTTNG_OK on success or a negative error code.
422 extern int lttng_create_session_live(const char *name
, const char *url
,
423 unsigned int timer_interval
);
426 * Destroy a tracing session.
428 * The session will not be usable anymore, tracing will be stopped for all
429 * registered traces, and the tracing buffers will be flushed.
431 * The name can't be NULL here.
433 extern int lttng_destroy_session(const char *name
);
436 * List all the tracing sessions.
438 * Return the size (number of entries) of the "lttng_session" array. Caller
441 extern int lttng_list_sessions(struct lttng_session
**sessions
);
444 * List the registered domain(s) of a session.
446 * Return the size (number of entries) of the "lttng_domain" array. Caller
449 extern int lttng_list_domains(const char *session_name
,
450 struct lttng_domain
**domains
);
453 * List the channel(s) of a session.
455 * Return the size (number of entries) of the "lttng_channel" array. Caller
458 extern int lttng_list_channels(struct lttng_handle
*handle
,
459 struct lttng_channel
**channels
);
462 * List the event(s) of a session channel.
464 * Return the size (number of entries) of the "lttng_event" array.
465 * Caller must free(3).
467 extern int lttng_list_events(struct lttng_handle
*handle
,
468 const char *channel_name
, struct lttng_event
**events
);
471 * List the available tracepoints of a specific lttng domain.
473 * Return the size (number of entries) of the "lttng_event" array.
474 * Caller must free(3).
476 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
477 struct lttng_event
**events
);
480 * List the available tracepoints fields of a specific lttng domain.
482 * Return the size (number of entries) of the "lttng_event_field" array.
483 * Caller must free(3).
485 extern int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
486 struct lttng_event_field
**fields
);
489 * Check if a session daemon is alive.
491 * Return 1 if alive or 0 if not. On error returns a negative value.
493 extern int lttng_session_daemon_alive(void);
496 * Set the tracing group for the *current* flow of execution.
498 * On success, returns 0 else a negative value on error being a lttng error
499 * code found in lttng-error.h
501 extern int lttng_set_tracing_group(const char *name
);
504 * Return a human-readable error message for an lttng-tools error code.
506 * Parameter MUST be a negative value or else you'll get a generic message.
508 extern const char *lttng_strerror(int code
);
511 * This call registers an "outside consumer" for a session and an lttng domain.
512 * No consumer will be spawned and all fds/commands will go through the socket
513 * path given (socket_path).
515 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
516 * command socket. The error socket is not supported yet for roaming consumers.
518 extern int lttng_register_consumer(struct lttng_handle
*handle
,
519 const char *socket_path
);
522 * Start tracing for *all* registered traces (kernel and user-space).
524 extern int lttng_start_tracing(const char *session_name
);
527 * Stop tracing for *all* registered traces (kernel and user-space).
529 * This call will wait for data availability for each domain of the session so
530 * this can take an abritrary amount of time. However, when returning you have
531 * the guarantee that the data is ready to be read and analyse. Use the
532 * _no_wait call below to avoid this behavior.
534 * The session_name can't be NULL.
536 extern int lttng_stop_tracing(const char *session_name
);
539 * Behave exactly like lttng_stop_tracing but does not wait for data
542 extern int lttng_stop_tracing_no_wait(const char *session_name
);
545 * Add context to event(s) for a specific channel (or for all).
547 * If channel_name is NULL, a lookup of the event's channel is done. If both
548 * are NULL, the context is applied to all events of all channels.
550 * Note that whatever event_name value is, a context can not be added to an
551 * event, so we just ignore it for now.
553 extern int lttng_add_context(struct lttng_handle
*handle
,
554 struct lttng_event_context
*ctx
, const char *event_name
,
555 const char *channel_name
);
558 * Create or enable an event (or events) for a channel.
560 * If the event you are trying to enable does not exist, it will be created,
561 * else it is enabled.
562 * If channel_name is NULL, the default channel is used (channel0).
564 * The handle and ev params can not be NULL.
566 extern int lttng_enable_event(struct lttng_handle
*handle
,
567 struct lttng_event
*ev
, const char *channel_name
);
570 * Create or enable an event with a specific filter.
572 * If the event you are trying to enable does not exist, it will be created,
573 * else it is enabled.
574 * If ev is NULL, all events are enabled with that filter.
575 * If channel_name is NULL, the default channel is used (channel0) and created
577 * If filter_expression is NULL, an event without associated filter is
580 extern int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
581 struct lttng_event
*event
, const char *channel_name
,
582 const char *filter_expression
);
585 * Create or enable a channel.
587 * The chan and handle params can not be NULL.
589 extern int lttng_enable_channel(struct lttng_handle
*handle
,
590 struct lttng_channel
*chan
);
593 * Disable event(s) of a channel and domain.
595 * If name is NULL, all events are disabled.
596 * If channel_name is NULL, the default channel is used (channel0).
598 extern int lttng_disable_event(struct lttng_handle
*handle
,
599 const char *name
, const char *channel_name
);
605 extern int lttng_disable_channel(struct lttng_handle
*handle
,
609 * Calibrate LTTng overhead.
611 * The chan and handle params can not be NULL.
613 extern int lttng_calibrate(struct lttng_handle
*handle
,
614 struct lttng_calibrate
*calibrate
);
617 * Set the default channel attributes for a specific domain and an allocated
618 * lttng_channel_attr pointer.
620 * If one or both arguments are NULL, nothing happens.
622 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
623 struct lttng_channel_attr
*attr
);
626 * Set URL for a consumer for a session and domain.
628 * Both data and control URL must be defined. If both URLs are the same, only
629 * the control URL is used even for network streaming.
631 * Default port are 5342 and 5343 respectively for control and data which uses
634 extern int lttng_set_consumer_url(struct lttng_handle
*handle
,
635 const char *control_url
, const char *data_url
);
638 * Enable the consumer for a session and domain.
640 extern LTTNG_DEPRECATED("This call is now obsolete.")
641 int lttng_enable_consumer(struct lttng_handle
*handle
);
644 * Disable consumer for a session and domain.
646 extern LTTNG_DEPRECATED("This call is now obsolete.")
647 int lttng_disable_consumer(struct lttng_handle
*handle
);
650 * Check session daemon health for a specific component.
652 * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
653 * the control library was not able to connect to the session daemon health
656 * Any other positive value is an lttcomm error which can be translate with
659 * Please see lttng-health-check(3) man page for more information.
661 extern LTTNG_DEPRECATED("This call is now obsolete.")
662 int lttng_health_check(enum lttng_health_component c
);
665 * For a given session name, this call checks if the data is ready to be read
666 * or is still being extracted by the consumer(s) (pending) hence not ready to
667 * be used by any readers.
669 * Return 0 if there is _no_ data pending in the buffers thus having a
670 * guarantee that the data can be read safely. Else, return 1 if there is still
671 * traced data is pending. On error, a negative value is returned and readable
672 * by lttng_strerror().
674 extern int lttng_data_pending(const char *session_name
);