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,
72 * Loglevel information.
74 enum lttng_loglevel_type
{
75 LTTNG_EVENT_LOGLEVEL
= 0,
76 LTTNG_EVENT_LOGLEVEL_ONLY
= 1,
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 struct lttng_domain
{
107 enum lttng_domain_type type
;
110 char exec_name
[NAME_MAX
];
114 /* Perf counter attributes */
115 struct lttng_event_perf_counter_ctx
{
118 char name
[LTTNG_SYMBOL_NAME_LEN
];
121 /* Event/Channel context */
122 struct lttng_event_context
{
123 enum lttng_event_context_type ctx
;
125 struct lttng_event_perf_counter_ctx perf_counter
;
132 * Either addr is used or symbol_name and offset.
134 struct lttng_event_probe_attr
{
138 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
144 struct lttng_event_function_attr
{
145 char symbol_name
[LTTNG_SYMBOL_NAME_LEN
];
149 * Generic lttng event
152 enum lttng_event_type type
;
153 char name
[LTTNG_SYMBOL_NAME_LEN
];
155 enum lttng_loglevel_type loglevel_type
;
156 char loglevel
[LTTNG_SYMBOL_NAME_LEN
];
157 int64_t loglevel_value
; /* for printing */
161 /* Per event type configuration */
163 struct lttng_event_probe_attr probe
;
164 struct lttng_event_function_attr ftrace
;
169 * Tracer channel attributes. For both kernel and user-space.
171 struct lttng_channel_attr
{
172 int overwrite
; /* 1: overwrite, 0: discard */
173 uint64_t subbuf_size
; /* bytes */
174 uint64_t num_subbuf
; /* power of 2 */
175 unsigned int switch_timer_interval
; /* usec */
176 unsigned int read_timer_interval
; /* usec */
177 enum lttng_event_output output
; /* splice, mmap */
181 * Channel information structure. For both kernel and user-space.
183 struct lttng_channel
{
184 char name
[LTTNG_SYMBOL_NAME_LEN
];
186 struct lttng_channel_attr attr
;
189 struct lttng_calibrate
{
190 enum lttng_calibrate_type type
;
194 * Basic session information.
196 * This is an 'output data' meaning that it only comes *from* the session
197 * daemon *to* the lttng client. It's basically a 'human' representation of
198 * tracing entities (here a session).
200 struct lttng_session
{
202 /* The path where traces are written */
204 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
208 * Handle used as a context for commands.
210 struct lttng_handle
{
211 char session_name
[NAME_MAX
];
212 struct lttng_domain domain
;
216 * Public LTTng control API
218 * For functions having a lttng domain type as parameter, if a bad value is
219 * given, NO default is applied and an error is returned.
221 * On success, all functions of the API return 0 or the size of the allocated
224 * On error, a negative value is returned being a specific lttng-tools error
225 * code which can be humanly interpreted with lttng_strerror(err).
229 * Create an handle used as a context for every request made to the library.
231 * This handle contains the session name and lttng domain on which the command
232 * will be executed on.
234 extern struct lttng_handle
*lttng_create_handle(const char *session_name
,
235 struct lttng_domain
*domain
);
238 * Destroy an handle. This will simply free(3) the data pointer returned by
239 * lttng_create_handle() and rendering it unsuable.
241 extern void lttng_destroy_handle(struct lttng_handle
*handle
);
244 * Create tracing session using a name and a path where trace will be written.
246 extern int lttng_create_session(const char *name
, const char *path
);
249 * Destroy tracing session.
251 * The session will not be useable anymore, tracing will stopped for all
252 * registered trace and tracing buffers will be flushed.
254 extern int lttng_destroy_session(const char *name
);
257 * List all tracing sessions.
259 * Return the size of the "lttng_session" array. Caller must free(3).
261 extern int lttng_list_sessions(struct lttng_session
**sessions
);
264 * List registered domain(s) of a session.
266 * Return the size of the "lttng_domain" array. Caller must free(3).
268 extern int lttng_list_domains(const char *session_name
,
269 struct lttng_domain
**domains
);
272 * List channel(s) of a session.
274 * Return the size of the "lttng_channel" array. Caller must free(3).
276 extern int lttng_list_channels(struct lttng_handle
*handle
,
277 struct lttng_channel
**channels
);
280 * List event(s) of a session channel.
282 * Return the size of the "lttng_event" array. Caller must free(3).
284 extern int lttng_list_events(struct lttng_handle
*handle
,
285 const char *channel_name
, struct lttng_event
**events
);
288 * List available tracepoints of a specific lttng domain.
290 * Return the size of the "lttng_event" array. Caller must free(3).
292 extern int lttng_list_tracepoints(struct lttng_handle
*handle
,
293 struct lttng_event
**events
);
296 * Check if a session daemon is alive.
298 extern int lttng_session_daemon_alive(void);
301 * Set tracing group for the *current* flow of execution.
303 extern int lttng_set_tracing_group(const char *name
);
306 * Return a human readable error message of a lttng-tools error code.
308 * Parameter MUST be a negative value or else you'll get a generic message.
310 extern const char *lttng_strerror(int code
);
313 * This call permits to register an "outside consumer" to a session and a lttng
314 * domain. No consumer will be spawned and all fds/commands will go through the
315 * socket path given (socket_path).
317 * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
318 * command socket. The error socket is not supported yet for roaming consumers.
320 extern int lttng_register_consumer(struct lttng_handle
*handle
,
321 const char *socket_path
);
324 * Start tracing for *all* registered trace (kernel and user-space).
326 extern int lttng_start_tracing(const char *session_name
);
329 * Stop tracing for *all* registered trace (kernel and user-space).
331 extern int lttng_stop_tracing(const char *session_name
);
334 * Add context to event for a specific channel.
336 * If event_name is NULL, the context is applied to all event of the channel.
337 * If channel_name is NULL, a lookup of the event's channel is done.
338 * If both are NULL, the context is applied on all events of all channels.
340 extern int lttng_add_context(struct lttng_handle
*handle
,
341 struct lttng_event_context
*ctx
, const char *event_name
,
342 const char *channel_name
);
345 * Create or enable a kernel event.
347 * If the event you are trying to enable does not exist, it will be created,
348 * else it is enabled.
350 * If channel_name is NULL, the default channel is used (channel0).
352 extern int lttng_enable_event(struct lttng_handle
*handle
,
353 struct lttng_event
*ev
, const char *channel_name
);
356 * Create or enable a kernel channel.
358 * If name is NULL, the default channel is enabled (channel0).
360 extern int lttng_enable_channel(struct lttng_handle
*handle
,
361 struct lttng_channel
*chan
);
364 * Disable kernel event.
366 * If channel_name is NULL, the default channel is used (channel0).
368 extern int lttng_disable_event(struct lttng_handle
*handle
,
369 const char *name
, const char *channel_name
);
372 * Disable kernel channel.
374 * If channel_name is NULL, the default channel is disabled (channel0).
376 extern int lttng_disable_channel(struct lttng_handle
*handle
,
380 * Calibrate LTTng overhead.
382 extern int lttng_calibrate(struct lttng_handle
*handle
,
383 struct lttng_calibrate
*calibrate
);
386 * Set the default channel attributes for a specific domain and an allocated
387 * lttng_channel_attr pointer.
389 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
390 struct lttng_channel_attr
*attr
);
392 #endif /* _LTTNG_H */