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>
31 * Event symbol length. Copied from LTTng kernel ABI.
33 #define LTTNG_SYMBOL_NAME_LEN 256
36 * Every lttng_event_* structure both apply to kernel event and user-space
41 * Domain type are the different possible tracers.
43 enum lttng_domain_type
{
44 LTTNG_DOMAIN_KERNEL
= 1,
48 * For now, the domains below are not implemented. However, we keep them
49 * here in order to retain their enum values for future development. Note
50 * that it is on the roadmap to implement them.
52 LTTNG_DOMAIN_UST_EXEC_NAME = 3,
53 LTTNG_DOMAIN_UST_PID = 4,
54 LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
59 * Instrumentation type of tracing event.
61 enum lttng_event_type
{
63 LTTNG_EVENT_TRACEPOINT
= 0,
64 LTTNG_EVENT_PROBE
= 1,
65 LTTNG_EVENT_FUNCTION
= 2,
66 LTTNG_EVENT_FUNCTION_ENTRY
= 3,
68 LTTNG_EVENT_SYSCALL
= 5,
69 LTTNG_EVENT_TRACEPOINT_LOGLEVEL
= 6,
75 enum lttng_event_output
{
76 LTTNG_EVENT_SPLICE
= 0,
80 /* Event context possible type */
81 enum lttng_event_context_type
{
82 LTTNG_EVENT_CONTEXT_PID
= 0,
83 LTTNG_EVENT_CONTEXT_PERF_COUNTER
= 1,
84 LTTNG_EVENT_CONTEXT_COMM
= 2,
85 LTTNG_EVENT_CONTEXT_PRIO
= 3,
86 LTTNG_EVENT_CONTEXT_NICE
= 4,
87 LTTNG_EVENT_CONTEXT_VPID
= 5,
88 LTTNG_EVENT_CONTEXT_TID
= 6,
89 LTTNG_EVENT_CONTEXT_VTID
= 7,
90 LTTNG_EVENT_CONTEXT_PPID
= 8,
91 LTTNG_EVENT_CONTEXT_VPPID
= 9,
94 enum lttng_calibrate_type
{
95 LTTNG_CALIBRATE_FUNCTION
= 0,
99 enum lttng_domain_type type
;
102 char exec_name
[NAME_MAX
];
106 /* Perf counter attributes */
107 struct lttng_event_perf_counter_ctx
{
110 char name
[LTTNG_SYMBOL_NAME_LEN
];
113 /* Event/Channel context */
114 struct lttng_event_context
{
115 enum lttng_event_context_type ctx
;
117 struct lttng_event_perf_counter_ctx perf_counter
;
124 * Either addr is used or symbol_name and offset.
126 struct lttng_event_probe_attr
{
130 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
136 struct lttng_event_function_attr
{
137 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
141 * Generic lttng event
144 char name
[LTTNG_SYMBOL_NAME_LEN
];
145 char loglevel
[LTTNG_SYMBOL_NAME_LEN
];
146 int64_t loglevel_value
;
147 enum lttng_event_type type
;
150 /* Per event type configuration */
152 struct lttng_event_probe_attr probe
;
153 struct lttng_event_function_attr ftrace
;
158 * Tracer channel attributes. For both kernel and user-space.
160 struct lttng_channel_attr
{
161 int overwrite
; /* 1: overwrite, 0: discard */
162 uint64_t subbuf_size
; /* bytes */
163 uint64_t num_subbuf
; /* power of 2 */
164 unsigned int switch_timer_interval
; /* usec */
165 unsigned int read_timer_interval
; /* usec */
166 enum lttng_event_output output
; /* splice, mmap */
170 * Channel information structure. For both kernel and user-space.
172 struct lttng_channel
{
173 char name
[LTTNG_SYMBOL_NAME_LEN
];
175 struct lttng_channel_attr attr
;
178 struct lttng_calibrate
{
179 enum lttng_calibrate_type type
;
183 * Basic session information.
185 * This is an 'output data' meaning that it only comes *from* the session
186 * daemon *to* the lttng client. It's basically a 'human' representation of
187 * tracing entities (here a session).
189 struct lttng_session
{
191 /* The path where traces are written */
193 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
197 * Handle used as a context for commands.
199 struct lttng_handle
{
200 char session_name
[NAME_MAX
];
201 struct lttng_domain domain
;
205 * Public LTTng control API
207 * For functions having a lttng domain type as parameter, if a bad value is
208 * given, NO default is applied and an error is returned.
210 * On success, all functions of the API return 0 or the size of the allocated
213 * On error, a negative value is returned being a specific lttng-tools error
214 * code which can be humanly interpreted with lttng_strerror(err).
218 * Create an handle used as a context for every request made to the library.
220 * This handle contains the session name and lttng domain on which the command
221 * will be executed on.
223 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
224 struct lttng_domain
*domain
);
227 * Destroy an handle. This will simply free(3) the data pointer returned by
228 * lttng_create_handle() and rendering it unsuable.
230 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
233 * Create tracing session using a name and a path where trace will be written.
235 extern int lttng_create_session(const char *name
, const char *path
);
238 * Destroy tracing session.
240 * The session will not be useable anymore, tracing will stopped for all
241 * registered trace and tracing buffers will be flushed.
243 extern int lttng_destroy_session(const char *name
);
246 * List all tracing sessions.
248 * Return the size of the "lttng_session" array. Caller must free(3).
250 extern int lttng_list_sessions(struct lttng_session
**sessions
);
253 * List registered domain(s) of a session.
255 * Return the size of the "lttng_domain" array. Caller must free(3).
257 extern int lttng_list_domains(const char *session_name
,
258 struct lttng_domain
**domains
);
261 * List channel(s) of a session.
263 * Return the size of the "lttng_channel" array. Caller must free(3).
265 extern int lttng_list_channels(struct lttng_handle
*handle
,
266 struct lttng_channel
**channels
);
269 * List event(s) of a session channel.
271 * Return the size of the "lttng_event" array. Caller must free(3).
273 extern int lttng_list_events(struct lttng_handle
*handle
,
274 const char *channel_name
, struct lttng_event
**events
);
277 * List available tracepoints of a specific lttng domain.
279 * Return the size of the "lttng_event" array. Caller must free(3).
281 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
282 struct lttng_event
**events
);
285 * Check if a session daemon is alive.
287 extern int lttng_session_daemon_alive(void);
290 * Set tracing group for the *current* flow of execution.
292 extern int lttng_set_tracing_group(const char *name
);
295 * Return a human readable error message of a lttng-tools error code.
297 * Parameter MUST be a negative value or else you'll get a generic message.
299 extern const char *lttng_strerror(int code
);
302 * This call permits to register an "outside consumer" to a session and a lttng
303 * domain. No consumer will be spawned and all fds/commands will go through the
304 * socket path given (socket_path).
306 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
307 * command socket. The error socket is not supported yet for roaming consumers.
309 extern int lttng_register_consumer(struct lttng_handle
*handle
,
310 const char *socket_path
);
313 * Start tracing for *all* registered trace (kernel and user-space).
315 extern int lttng_start_tracing(const char *session_name
);
318 * Stop tracing for *all* registered trace (kernel and user-space).
320 extern int lttng_stop_tracing(const char *session_name
);
323 * Add context to event for a specific channel.
325 * If event_name is NULL, the context is applied to all event of the channel.
326 * If channel_name is NULL, a lookup of the event's channel is done.
327 * If both are NULL, the context is applied on all events of all channels.
329 extern int lttng_add_context(struct lttng_handle
*handle
,
330 struct lttng_event_context
*ctx
, const char *event_name
,
331 const char *channel_name
);
334 * Create or enable a kernel event.
336 * If the event you are trying to enable does not exist, it will be created,
337 * else it is enabled.
339 * If channel_name is NULL, the default channel is used (channel0).
341 extern int lttng_enable_event(struct lttng_handle
*handle
,
342 struct lttng_event
*ev
, const char *channel_name
);
345 * Create or enable a kernel channel.
347 * If name is NULL, the default channel is enabled (channel0).
349 extern int lttng_enable_channel(struct lttng_handle
*handle
,
350 struct lttng_channel
*chan
);
353 * Disable kernel event.
355 * If channel_name is NULL, the default channel is used (channel0).
357 extern int lttng_disable_event(struct lttng_handle
*handle
,
358 const char *name
, const char *channel_name
);
361 * Disable kernel channel.
363 * If channel_name is NULL, the default channel is disabled (channel0).
365 extern int lttng_disable_channel(struct lttng_handle
*handle
,
369 * Calibrate LTTng overhead.
371 extern int lttng_calibrate(struct lttng_handle
*handle
,
372 struct lttng_calibrate
*calibrate
);
375 * Set the default channel attributes for a specific domain and an allocated
376 * lttng_channel_attr pointer.
378 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
379 struct lttng_channel_attr
*attr
);
381 #endif /* _LTTNG_H */