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>
30 * Event symbol length. Copied from LTTng kernel ABI.
32 #define LTTNG_SYMBOL_NAME_LEN 256
35 * Every lttng_event_* structure both apply to kernel event and user-space
40 * Domain types: the different possible tracers.
42 enum lttng_domain_type
{
43 LTTNG_DOMAIN_KERNEL
= 1,
47 * For now, the domains below are not implemented. However, we keep them
48 * here in order to retain their enum values for future development. Note
49 * that it is on the roadmap to implement them.
51 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
52 LTTNG_DOMAIN_UST_PID = 4,
53 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
58 * Instrumentation type of tracing event.
60 enum lttng_event_type
{
62 LTTNG_EVENT_TRACEPOINT
= 0,
63 LTTNG_EVENT_PROBE
= 1,
64 LTTNG_EVENT_FUNCTION
= 2,
65 LTTNG_EVENT_FUNCTION_ENTRY
= 3,
67 LTTNG_EVENT_SYSCALL
= 5,
71 * Loglevel information.
73 enum lttng_loglevel_type
{
74 LTTNG_EVENT_LOGLEVEL_ALL
= 0,
75 LTTNG_EVENT_LOGLEVEL_RANGE
= 1,
76 LTTNG_EVENT_LOGLEVEL_SINGLE
= 2,
80 * Available loglevels.
83 LTTNG_LOGLEVEL_EMERG
= 0,
84 LTTNG_LOGLEVEL_ALERT
= 1,
85 LTTNG_LOGLEVEL_CRIT
= 2,
86 LTTNG_LOGLEVEL_ERR
= 3,
87 LTTNG_LOGLEVEL_WARNING
= 4,
88 LTTNG_LOGLEVEL_NOTICE
= 5,
89 LTTNG_LOGLEVEL_INFO
= 6,
90 LTTNG_LOGLEVEL_DEBUG_SYSTEM
= 7,
91 LTTNG_LOGLEVEL_DEBUG_PROGRAM
= 8,
92 LTTNG_LOGLEVEL_DEBUG_PROCESS
= 9,
93 LTTNG_LOGLEVEL_DEBUG_MODULE
= 10,
94 LTTNG_LOGLEVEL_DEBUG_UNIT
= 11,
95 LTTNG_LOGLEVEL_DEBUG_FUNCTION
= 12,
96 LTTNG_LOGLEVEL_DEBUG_LINE
= 13,
97 LTTNG_LOGLEVEL_DEBUG
= 14,
101 * LTTng consumer mode
103 enum lttng_event_output
{
104 LTTNG_EVENT_SPLICE
= 0,
105 LTTNG_EVENT_MMAP
= 1,
108 /* Event context possible type */
109 enum lttng_event_context_type
{
110 LTTNG_EVENT_CONTEXT_PID
= 0,
111 LTTNG_EVENT_CONTEXT_PERF_COUNTER
= 1,
112 LTTNG_EVENT_CONTEXT_PROCNAME
= 2,
113 LTTNG_EVENT_CONTEXT_PRIO
= 3,
114 LTTNG_EVENT_CONTEXT_NICE
= 4,
115 LTTNG_EVENT_CONTEXT_VPID
= 5,
116 LTTNG_EVENT_CONTEXT_TID
= 6,
117 LTTNG_EVENT_CONTEXT_VTID
= 7,
118 LTTNG_EVENT_CONTEXT_PPID
= 8,
119 LTTNG_EVENT_CONTEXT_VPPID
= 9,
120 LTTNG_EVENT_CONTEXT_PTHREAD_ID
= 10,
123 enum lttng_calibrate_type
{
124 LTTNG_CALIBRATE_FUNCTION
= 0,
128 * The structures should be initialized to zero before use.
130 #define LTTNG_DOMAIN_PADDING1 16
131 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
132 struct lttng_domain
{
133 enum lttng_domain_type type
;
134 char padding
[LTTNG_DOMAIN_PADDING1
];
138 char exec_name
[NAME_MAX
];
139 char padding
[LTTNG_DOMAIN_PADDING2
];
144 * Perf counter attributes
146 * The structures should be initialized to zero before use.
148 #define LTTNG_PERF_EVENT_PADDING1 16
149 struct lttng_event_perf_counter_ctx
{
152 char name
[LTTNG_SYMBOL_NAME_LEN
];
154 char padding
[LTTNG_PERF_EVENT_PADDING1
];
158 * Event/channel context
160 * The structures should be initialized to zero before use.
162 #define LTTNG_EVENT_CONTEXT_PADDING1 16
163 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
164 struct lttng_event_context
{
165 enum lttng_event_context_type ctx
;
166 char padding
[LTTNG_EVENT_CONTEXT_PADDING1
];
169 struct lttng_event_perf_counter_ctx perf_counter
;
170 char padding
[LTTNG_EVENT_CONTEXT_PADDING2
];
177 * Either addr is used or symbol_name and offset.
179 * The structures should be initialized to zero before use.
181 #define LTTNG_EVENT_PROBE_PADDING1 16
182 struct lttng_event_probe_attr
{
186 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
188 char padding
[LTTNG_EVENT_PROBE_PADDING1
];
194 * The structures should be initialized to zero before use.
196 #define LTTNG_EVENT_FUNCTION_PADDING1 16
197 struct lttng_event_function_attr
{
198 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
200 char padding
[LTTNG_EVENT_FUNCTION_PADDING1
];
204 * Generic lttng event
206 * The structures should be initialized to zero before use.
208 #define LTTNG_EVENT_PADDING1 16
209 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
211 enum lttng_event_type type
;
212 char name
[LTTNG_SYMBOL_NAME_LEN
];
214 enum lttng_loglevel_type loglevel_type
;
220 char padding
[LTTNG_EVENT_PADDING1
];
222 /* Per event type configuration */
224 struct lttng_event_probe_attr probe
;
225 struct lttng_event_function_attr ftrace
;
227 char padding
[LTTNG_EVENT_PADDING2
];
232 * Tracer channel attributes. For both kernel and user-space.
234 * The structures should be initialized to zero before use.
236 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32
237 struct lttng_channel_attr
{
238 int overwrite
; /* 1: overwrite, 0: discard */
239 uint64_t subbuf_size
; /* bytes */
240 uint64_t num_subbuf
; /* power of 2 */
241 unsigned int switch_timer_interval
; /* usec */
242 unsigned int read_timer_interval
; /* usec */
243 enum lttng_event_output output
; /* splice, mmap */
245 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
249 * Channel information structure. For both kernel and user-space.
251 * The structures should be initialized to zero before use.
253 #define LTTNG_CHANNEL_PADDING1 16
254 struct lttng_channel
{
255 char name
[LTTNG_SYMBOL_NAME_LEN
];
257 struct lttng_channel_attr attr
;
259 char padding
[LTTNG_CHANNEL_PADDING1
];
262 #define LTTNG_CALIBRATE_PADDING1 16
263 struct lttng_calibrate
{
264 enum lttng_calibrate_type type
;
266 char padding
[LTTNG_CALIBRATE_PADDING1
];
270 * Basic session information.
272 * This is an 'output data' meaning that it only comes *from* the session
273 * daemon *to* the lttng client. It's basically a 'human' representation of
274 * tracing entities (here a session).
276 * The structures should be initialized to zero before use.
278 #define LTTNG_SESSION_PADDING1 16
279 struct lttng_session
{
281 /* The path where traces are written */
283 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
285 char padding
[LTTNG_SESSION_PADDING1
];
289 * Handle used as a context for commands.
291 * The structures should be initialized to zero before use.
293 #define LTTNG_HANDLE_PADDING1 16
294 struct lttng_handle
{
295 char session_name
[NAME_MAX
];
296 struct lttng_domain domain
;
298 char padding
[LTTNG_HANDLE_PADDING1
];
302 * Public LTTng control API
304 * For functions having an lttng domain type as parameter, if a bad value is
305 * given, NO default is applied and an error is returned.
307 * On success, all functions of the API return 0 or the size of the allocated
310 * On error, a negative value is returned being a specific lttng-tools error
311 * code which can be humanly interpreted with lttng_strerror(err).
313 * Exceptions to this are noted below.
317 * Create a handle used as a context for every request made to the library.
319 * This handle contains the session name and lttng domain on which the command
321 * The returned pointer will be NULL in case of malloc() error.
323 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
324 struct lttng_domain
*domain
);
327 * Destroy a handle. This will simply free(3) the data pointer returned by
328 * lttng_create_handle(), rendering it unusable.
330 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
333 * Create a tracing session using a name and a path where the trace will be
336 extern int lttng_create_session(const char *name
, const char *path
);
339 * Destroy a tracing session.
341 * The session will not be usable anymore, tracing will be stopped for all
342 * registered traces, and the tracing buffers will be flushed.
344 extern int lttng_destroy_session(const char *name
);
347 * List all the tracing sessions.
349 * Return the size (number of entries) of the "lttng_session" array. Caller
352 extern int lttng_list_sessions(struct lttng_session
**sessions
);
355 * List the registered domain(s) of a session.
357 * Return the size (number of entries) of the "lttng_domain" array. Caller
360 extern int lttng_list_domains(const char *session_name
,
361 struct lttng_domain
**domains
);
364 * List the channel(s) of a session.
366 * Return the size (number of entries) of the "lttng_channel" array. Caller
369 extern int lttng_list_channels(struct lttng_handle
*handle
,
370 struct lttng_channel
**channels
);
373 * List the event(s) of a session channel.
375 * Return the size (number of entries) of the "lttng_event" array.
376 * Caller must free(3).
378 extern int lttng_list_events(struct lttng_handle
*handle
,
379 const char *channel_name
, struct lttng_event
**events
);
382 * List the available tracepoints of a specific lttng domain.
384 * Return the size (number of entries) of the "lttng_event" array.
385 * Caller must free(3).
387 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
388 struct lttng_event
**events
);
391 * Check if a session daemon is alive.
393 * Return 1 if alive or 0 if not. On error returns a negative value.
395 extern int lttng_session_daemon_alive(void);
398 * Set the tracing group for the *current* flow of execution.
400 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
402 extern int lttng_set_tracing_group(const char *name
);
405 * Return a human-readable error message for an lttng-tools error code.
407 * Parameter MUST be a negative value or else you'll get a generic message.
409 extern const char *lttng_strerror(int code
);
412 * This call registers an "outside consumer" for a session and an lttng domain.
413 * No consumer will be spawned and all fds/commands will go through the socket
414 * path given (socket_path).
416 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
417 * command socket. The error socket is not supported yet for roaming consumers.
419 extern int lttng_register_consumer(struct lttng_handle
*handle
,
420 const char *socket_path
);
423 * Start tracing for *all* registered traces (kernel and user-space).
425 extern int lttng_start_tracing(const char *session_name
);
428 * Stop tracing for *all* registered traces (kernel and user-space).
430 extern int lttng_stop_tracing(const char *session_name
);
433 * Add context to event(s) for a specific channel (or for all).
435 * If event_name is NULL, the context is applied to all events of the channel.
436 * If channel_name is NULL, a lookup of the event's channel is done.
437 * If both are NULL, the context is applied to all events of all channels.
439 extern int lttng_add_context(struct lttng_handle
*handle
,
440 struct lttng_event_context
*ctx
, const char *event_name
,
441 const char *channel_name
);
444 * Create or enable an event (or events) for a channel.
446 * If the event you are trying to enable does not exist, it will be created,
447 * else it is enabled.
448 * If event_name is NULL, all events are enabled.
449 * If channel_name is NULL, the default channel is used (channel0).
451 extern int lttng_enable_event(struct lttng_handle
*handle
,
452 struct lttng_event
*ev
, const char *channel_name
);
455 * Create or enable a channel.
456 * The channel name cannot be NULL.
458 extern int lttng_enable_channel(struct lttng_handle
*handle
,
459 struct lttng_channel
*chan
);
462 * Disable event(s) of a channel and domain.
464 * If event_name is NULL, all events are disabled.
465 * If channel_name is NULL, the default channel is used (channel0).
467 extern int lttng_disable_event(struct lttng_handle
*handle
,
468 const char *name
, const char *channel_name
);
473 * The channel name cannot be NULL.
475 extern int lttng_disable_channel(struct lttng_handle
*handle
,
479 * Calibrate LTTng overhead.
481 extern int lttng_calibrate(struct lttng_handle
*handle
,
482 struct lttng_calibrate
*calibrate
);
485 * Set the default channel attributes for a specific domain and an allocated
486 * lttng_channel_attr pointer.
488 * If either or both of the arguments are NULL, nothing happens.
490 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
491 struct lttng_channel_attr
*attr
);
493 #endif /* _LTTNG_H */