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
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28 #include <sys/types.h>
30 /* Default unix group name for tracing. */
31 #define LTTNG_DEFAULT_TRACING_GROUP "tracing"
33 /* Environment variable to set session daemon binary path. */
34 #define LTTNG_SESSIOND_PATH_ENV "LTTNG_SESSIOND_PATH"
36 /* Default trace output directory name */
37 #define LTTNG_DEFAULT_TRACE_DIR_NAME "lttng-traces"
40 * Event symbol length. Copied from LTTng kernel ABI.
42 #define LTTNG_SYMBOL_NAME_LEN 256
45 * Every lttng_event_* structure both apply to kernel event and user-space
50 * Domain type are the different possible tracers.
52 enum lttng_domain_type
{
53 LTTNG_DOMAIN_KERNEL
= 1,
57 * For now, the domains below are not implemented. However, we keep them
58 * here in order to retain their enum values for future development. Note
59 * that it is on the roadmap to implement them.
61 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
62 LTTNG_DOMAIN_UST_PID = 4,
63 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
68 * Instrumentation type of tracing event.
70 enum lttng_event_type
{
72 LTTNG_EVENT_TRACEPOINT
= 0,
73 LTTNG_EVENT_PROBE
= 1,
74 LTTNG_EVENT_FUNCTION
= 2,
75 LTTNG_EVENT_FUNCTION_ENTRY
= 3,
77 LTTNG_EVENT_SYSCALL
= 5,
78 LTTNG_EVENT_TRACEPOINT_LOGLEVEL
= 6,
84 enum lttng_event_output
{
85 LTTNG_EVENT_SPLICE
= 0,
89 /* Event context possible type */
90 enum lttng_event_context_type
{
91 LTTNG_EVENT_CONTEXT_PID
= 0,
92 LTTNG_EVENT_CONTEXT_PERF_COUNTER
= 1,
93 LTTNG_EVENT_CONTEXT_COMM
= 2,
94 LTTNG_EVENT_CONTEXT_PRIO
= 3,
95 LTTNG_EVENT_CONTEXT_NICE
= 4,
96 LTTNG_EVENT_CONTEXT_VPID
= 5,
97 LTTNG_EVENT_CONTEXT_TID
= 6,
98 LTTNG_EVENT_CONTEXT_VTID
= 7,
99 LTTNG_EVENT_CONTEXT_PPID
= 8,
100 LTTNG_EVENT_CONTEXT_VPPID
= 9,
103 enum lttng_calibrate_type
{
104 LTTNG_CALIBRATE_FUNCTION
= 0,
107 struct lttng_domain
{
108 enum lttng_domain_type type
;
111 char exec_name
[NAME_MAX
];
115 /* Perf counter attributes */
116 struct lttng_event_perf_counter_ctx
{
119 char name
[LTTNG_SYMBOL_NAME_LEN
];
122 /* Event/Channel context */
123 struct lttng_event_context
{
124 enum lttng_event_context_type ctx
;
126 struct lttng_event_perf_counter_ctx perf_counter
;
133 * Either addr is used or symbol_name and offset.
135 struct lttng_event_probe_attr
{
139 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
145 struct lttng_event_function_attr
{
146 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
150 * Generic lttng event
153 char name
[LTTNG_SYMBOL_NAME_LEN
];
154 char loglevel
[LTTNG_SYMBOL_NAME_LEN
];
155 int64_t loglevel_value
;
156 enum lttng_event_type type
;
159 /* Per event type configuration */
161 struct lttng_event_probe_attr probe
;
162 struct lttng_event_function_attr ftrace
;
167 * Tracer channel attributes. For both kernel and user-space.
169 struct lttng_channel_attr
{
170 int overwrite
; /* 1: overwrite, 0: discard */
171 uint64_t subbuf_size
; /* bytes */
172 uint64_t num_subbuf
; /* power of 2 */
173 unsigned int switch_timer_interval
; /* usec */
174 unsigned int read_timer_interval
; /* usec */
175 enum lttng_event_output output
; /* splice, mmap */
179 * Channel information structure. For both kernel and user-space.
181 struct lttng_channel
{
182 char name
[LTTNG_SYMBOL_NAME_LEN
];
184 struct lttng_channel_attr attr
;
187 struct lttng_calibrate
{
188 enum lttng_calibrate_type type
;
192 * Basic session information.
194 * This is an 'output data' meaning that it only comes *from* the session
195 * daemon *to* the lttng client. It's basically a 'human' representation of
196 * tracing entities (here a session).
198 struct lttng_session
{
200 /* The path where traces are written */
202 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
206 * Handle used as a context for commands.
208 struct lttng_handle
{
209 char session_name
[NAME_MAX
];
210 struct lttng_domain domain
;
214 * Public LTTng control API
216 * For functions having a lttng domain type as parameter, if a bad value is
217 * given, NO default is applied and an error is returned.
219 * On success, all functions of the API return 0 or the size of the allocated
222 * On error, a negative value is returned being a specific lttng-tools error
223 * code which can be humanly interpreted with lttng_strerror(err).
227 * Create an handle used as a context for every request made to the library.
229 * This handle contains the session name and lttng domain on which the command
230 * will be executed on.
232 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
233 struct lttng_domain
*domain
);
236 * Destroy an handle. This will simply free(3) the data pointer returned by
237 * lttng_create_handle() and rendering it unsuable.
239 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
242 * Create tracing session using a name and a path where trace will be written.
244 extern int lttng_create_session(const char *name
, const char *path
);
247 * Destroy tracing session.
249 * The session will not be useable anymore, tracing will stopped for all
250 * registered trace and tracing buffers will be flushed.
252 extern int lttng_destroy_session(const char *name
);
255 * List all tracing sessions.
257 * Return the size of the "lttng_session" array. Caller must free(3).
259 extern int lttng_list_sessions(struct lttng_session
**sessions
);
262 * List registered domain(s) of a session.
264 * Return the size of the "lttng_domain" array. Caller must free(3).
266 extern int lttng_list_domains(const char *session_name
,
267 struct lttng_domain
**domains
);
270 * List channel(s) of a session.
272 * Return the size of the "lttng_channel" array. Caller must free(3).
274 extern int lttng_list_channels(struct lttng_handle
*handle
,
275 struct lttng_channel
**channels
);
278 * List event(s) of a session channel.
280 * Return the size of the "lttng_event" array. Caller must free(3).
282 extern int lttng_list_events(struct lttng_handle
*handle
,
283 const char *channel_name
, struct lttng_event
**events
);
286 * List available tracepoints of a specific lttng domain.
288 * Return the size of the "lttng_event" array. Caller must free(3).
290 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
291 struct lttng_event
**events
);
294 * Check if a session daemon is alive.
296 extern int lttng_session_daemon_alive(void);
299 * Set tracing group for the *current* flow of execution.
301 extern int lttng_set_tracing_group(const char *name
);
304 * Return a human readable error message of a lttng-tools error code.
306 * Parameter MUST be a negative value or else you'll get a generic message.
308 extern const char *lttng_strerror(int code
);
311 * This call permits to register an "outside consumer" to a session and a lttng
312 * domain. No consumer will be spawned and all fds/commands will go through the
313 * socket path given (socket_path).
315 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
316 * command socket. The error socket is not supported yet for roaming consumers.
318 extern int lttng_register_consumer(struct lttng_handle
*handle
,
319 const char *socket_path
);
322 * Start tracing for *all* registered trace (kernel and user-space).
324 extern int lttng_start_tracing(const char *session_name
);
327 * Stop tracing for *all* registered trace (kernel and user-space).
329 extern int lttng_stop_tracing(const char *session_name
);
332 * Add context to event for a specific channel.
334 * If event_name is NULL, the context is applied to all event of the channel.
335 * If channel_name is NULL, a lookup of the event's channel is done.
336 * If both are NULL, the context is applied on all events of all channels.
338 extern int lttng_add_context(struct lttng_handle
*handle
,
339 struct lttng_event_context
*ctx
, const char *event_name
,
340 const char *channel_name
);
343 * Create or enable a kernel event.
345 * If the event you are trying to enable does not exist, it will be created,
346 * else it is enabled.
348 * If channel_name is NULL, the default channel is used (channel0).
350 extern int lttng_enable_event(struct lttng_handle
*handle
,
351 struct lttng_event
*ev
, const char *channel_name
);
354 * Create or enable a kernel channel.
356 * If name is NULL, the default channel is enabled (channel0).
358 extern int lttng_enable_channel(struct lttng_handle
*handle
,
359 struct lttng_channel
*chan
);
362 * Disable kernel event.
364 * If channel_name is NULL, the default channel is used (channel0).
366 extern int lttng_disable_event(struct lttng_handle
*handle
,
367 const char *name
, const char *channel_name
);
370 * Disable kernel channel.
372 * If channel_name is NULL, the default channel is disabled (channel0).
374 extern int lttng_disable_channel(struct lttng_handle
*handle
,
378 * Calibrate LTTng overhead.
380 extern int lttng_calibrate(struct lttng_handle
*handle
,
381 struct lttng_calibrate
*calibrate
);
384 * Set the default channel attributes for a specific domain and an allocated
385 * lttng_channel_attr pointer.
387 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
388 struct lttng_channel_attr
*attr
);
390 #endif /* _LTTNG_H */