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 as published by the
10 * Free Software Foundation; only version 2.1 of the License.
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,
82 enum lttng_event_output
{
83 LTTNG_EVENT_SPLICE
= 0,
87 /* Event context possible type */
88 enum lttng_event_context_type
{
89 LTTNG_EVENT_CONTEXT_PID
= 0,
90 LTTNG_EVENT_CONTEXT_PERF_COUNTER
= 1,
91 LTTNG_EVENT_CONTEXT_PROCNAME
= 2,
92 LTTNG_EVENT_CONTEXT_PRIO
= 3,
93 LTTNG_EVENT_CONTEXT_NICE
= 4,
94 LTTNG_EVENT_CONTEXT_VPID
= 5,
95 LTTNG_EVENT_CONTEXT_TID
= 6,
96 LTTNG_EVENT_CONTEXT_VTID
= 7,
97 LTTNG_EVENT_CONTEXT_PPID
= 8,
98 LTTNG_EVENT_CONTEXT_VPPID
= 9,
99 LTTNG_EVENT_CONTEXT_PTHREAD_ID
= 10,
102 enum lttng_calibrate_type
{
103 LTTNG_CALIBRATE_FUNCTION
= 0,
106 #define LTTNG_DOMAIN_PADDING1 16
107 #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
108 struct lttng_domain
{
109 enum lttng_domain_type type
;
110 char padding
[LTTNG_DOMAIN_PADDING1
];
114 char exec_name
[NAME_MAX
];
115 char padding
[LTTNG_DOMAIN_PADDING2
];
119 /* Perf counter attributes */
120 #define LTTNG_PERF_EVENT_PADDING1 16
121 struct lttng_event_perf_counter_ctx
{
124 char name
[LTTNG_SYMBOL_NAME_LEN
];
126 char padding
[LTTNG_PERF_EVENT_PADDING1
];
129 /* Event/Channel context */
130 #define LTTNG_EVENT_CONTEXT_PADDING1 16
131 #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
132 struct lttng_event_context
{
133 enum lttng_event_context_type ctx
;
134 char padding
[LTTNG_EVENT_CONTEXT_PADDING1
];
137 struct lttng_event_perf_counter_ctx perf_counter
;
138 char padding
[LTTNG_EVENT_CONTEXT_PADDING2
];
145 * Either addr is used or symbol_name and offset.
147 #define LTTNG_EVENT_PROBE_PADDING1 16
148 struct lttng_event_probe_attr
{
152 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
154 char padding
[LTTNG_EVENT_PROBE_PADDING1
];
160 #define LTTNG_EVENT_FUNCTION_PADDING1 16
161 struct lttng_event_function_attr
{
162 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
164 char padding
[LTTNG_EVENT_FUNCTION_PADDING1
];
168 * Generic lttng event
170 #define LTTNG_EVENT_PADDING1 16
171 #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32
173 enum lttng_event_type type
;
174 char name
[LTTNG_SYMBOL_NAME_LEN
];
176 enum lttng_loglevel_type loglevel_type
;
182 char padding
[LTTNG_EVENT_PADDING1
];
184 /* Per event type configuration */
186 struct lttng_event_probe_attr probe
;
187 struct lttng_event_function_attr ftrace
;
189 char padding
[LTTNG_EVENT_PADDING2
];
194 * Tracer channel attributes. For both kernel and user-space.
196 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32
197 struct lttng_channel_attr
{
198 int overwrite
; /* 1: overwrite, 0: discard */
199 uint64_t subbuf_size
; /* bytes */
200 uint64_t num_subbuf
; /* power of 2 */
201 unsigned int switch_timer_interval
; /* usec */
202 unsigned int read_timer_interval
; /* usec */
203 enum lttng_event_output output
; /* splice, mmap */
205 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
209 * Channel information structure. For both kernel and user-space.
211 #define LTTNG_CHANNEL_PADDING1 16
212 struct lttng_channel
{
213 char name
[LTTNG_SYMBOL_NAME_LEN
];
215 struct lttng_channel_attr attr
;
217 char padding
[LTTNG_CHANNEL_PADDING1
];
220 #define LTTNG_CALIBRATE_PADDING1 16
221 struct lttng_calibrate
{
222 enum lttng_calibrate_type type
;
224 char padding
[LTTNG_CALIBRATE_PADDING1
];
228 * Basic session information.
230 * This is an 'output data' meaning that it only comes *from* the session
231 * daemon *to* the lttng client. It's basically a 'human' representation of
232 * tracing entities (here a session).
234 #define LTTNG_SESSION_PADDING1 16
235 struct lttng_session
{
237 /* The path where traces are written */
239 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
241 char padding
[LTTNG_SESSION_PADDING1
];
245 * Handle used as a context for commands.
247 #define LTTNG_HANDLE_PADDING1 16
248 struct lttng_handle
{
249 char session_name
[NAME_MAX
];
250 struct lttng_domain domain
;
252 char padding
[LTTNG_HANDLE_PADDING1
];
256 * Public LTTng control API
258 * For functions having an lttng domain type as parameter, if a bad value is
259 * given, NO default is applied and an error is returned.
261 * On success, all functions of the API return 0 or the size of the allocated
264 * On error, a negative value is returned being a specific lttng-tools error
265 * code which can be humanly interpreted with lttng_strerror(err).
267 * Exceptions to this are noted below.
271 * Create a handle used as a context for every request made to the library.
273 * This handle contains the session name and lttng domain on which the command
275 * The returned pointer will be NULL in case of malloc() error.
277 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
278 struct lttng_domain
*domain
);
281 * Destroy a handle. This will simply free(3) the data pointer returned by
282 * lttng_create_handle(), rendering it unusable.
284 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
287 * Create a tracing session using a name and a path where the trace will be
290 extern int lttng_create_session(const char *name
, const char *path
);
293 * Destroy a tracing session.
295 * The session will not be usable anymore, tracing will be stopped for all
296 * registered traces, and the tracing buffers will be flushed.
298 extern int lttng_destroy_session(const char *name
);
301 * List all the tracing sessions.
303 * Return the size (number of entries) of the "lttng_session" array. Caller
306 extern int lttng_list_sessions(struct lttng_session
**sessions
);
309 * List the registered domain(s) of a session.
311 * Return the size (number of entries) of the "lttng_domain" array. Caller
314 extern int lttng_list_domains(const char *session_name
,
315 struct lttng_domain
**domains
);
318 * List the channel(s) of a session.
320 * Return the size (number of entries) of the "lttng_channel" array. Caller
323 extern int lttng_list_channels(struct lttng_handle
*handle
,
324 struct lttng_channel
**channels
);
327 * List the event(s) of a session channel.
329 * Return the size (number of entries) of the "lttng_event" array.
330 * Caller must free(3).
332 extern int lttng_list_events(struct lttng_handle
*handle
,
333 const char *channel_name
, struct lttng_event
**events
);
336 * List the available tracepoints of a specific lttng domain.
338 * Return the size (number of entries) of the "lttng_event" array.
339 * Caller must free(3).
341 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
342 struct lttng_event
**events
);
345 * Check if a session daemon is alive.
347 * Return 1 if alive or 0 if not. On error returns a negative value.
349 extern int lttng_session_daemon_alive(void);
352 * Set the tracing group for the *current* flow of execution.
354 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
356 extern int lttng_set_tracing_group(const char *name
);
359 * Return a human-readable error message for an lttng-tools error code.
361 * Parameter MUST be a negative value or else you'll get a generic message.
363 extern const char *lttng_strerror(int code
);
366 * This call registers an "outside consumer" for a session and an lttng domain.
367 * No consumer will be spawned and all fds/commands will go through the socket
368 * path given (socket_path).
370 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
371 * command socket. The error socket is not supported yet for roaming consumers.
373 extern int lttng_register_consumer(struct lttng_handle
*handle
,
374 const char *socket_path
);
377 * Start tracing for *all* registered traces (kernel and user-space).
379 extern int lttng_start_tracing(const char *session_name
);
382 * Stop tracing for *all* registered traces (kernel and user-space).
384 extern int lttng_stop_tracing(const char *session_name
);
387 * Add context to event(s) for a specific channel (or for all).
389 * If event_name is NULL, the context is applied to all events of the channel.
390 * If channel_name is NULL, a lookup of the event's channel is done.
391 * If both are NULL, the context is applied to all events of all channels.
393 extern int lttng_add_context(struct lttng_handle
*handle
,
394 struct lttng_event_context
*ctx
, const char *event_name
,
395 const char *channel_name
);
398 * Create or enable a kernel event (or events) for a channel.
400 * If the event you are trying to enable does not exist, it will be created,
401 * else it is enabled.
402 * If event_name is NULL, all events are enabled.
403 * If channel_name is NULL, the default channel is used (channel0).
405 extern int lttng_enable_event(struct lttng_handle
*handle
,
406 struct lttng_event
*ev
, const char *channel_name
);
409 * Create or enable a kernel channel.
410 * The channel name cannot be NULL.
412 extern int lttng_enable_channel(struct lttng_handle
*handle
,
413 struct lttng_channel
*chan
);
416 * Disable kernel event(s) of a channel and domain.
418 * If event_name is NULL, all events are disabled.
419 * If channel_name is NULL, the default channel is used (channel0).
421 extern int lttng_disable_event(struct lttng_handle
*handle
,
422 const char *name
, const char *channel_name
);
425 * Disable kernel channel.
427 * The channel name cannot be NULL.
429 extern int lttng_disable_channel(struct lttng_handle
*handle
,
433 * Calibrate LTTng overhead.
435 extern int lttng_calibrate(struct lttng_handle
*handle
,
436 struct lttng_calibrate
*calibrate
);
439 * Set the default channel attributes for a specific domain and an allocated
440 * lttng_channel_attr pointer.
442 * If either or both of the arguments are NULL, nothing happens.
444 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
445 struct lttng_channel_attr
*attr
);
447 #endif /* _LTTNG_H */