[lttng-tools.git] / include / lttng / lttng.h

/*
 * lttng.h
 *
 * Linux Trace Toolkit Control Library Header File
 *
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _LTTNG_H
#define _LTTNG_H

#include <limits.h>
#include <stdint.h>
#include <sys/types.h>

/* Default unix group name for tracing. */
#define LTTNG_DEFAULT_TRACING_GROUP "tracing"

/* Environment variable to set session daemon binary path. */
#define LTTNG_SESSIOND_PATH_ENV "LTTNG_SESSIOND_PATH"

/* Default trace output directory name */
#define LTTNG_DEFAULT_TRACE_DIR_NAME "lttng-traces"

/*
 * Event symbol length. Copied from LTTng kernel ABI.
 */
#define LTTNG_SYMBOL_NAME_LEN 128

/*
 * Every lttng_event_* structure both apply to kernel event and user-space
 * event.
 */

/*
 * Domain type are the different possible tracers.
 */
enum lttng_domain_type {
	LTTNG_DOMAIN_KERNEL                   = 1,
	LTTNG_DOMAIN_UST                      = 2,
	LTTNG_DOMAIN_UST_EXEC_NAME            = 3,
	LTTNG_DOMAIN_UST_PID                  = 4,
	LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN  = 5,
};

/*
 * Instrumentation type of tracing event.
 */
enum lttng_event_type {
	LTTNG_EVENT_TRACEPOINT,
	LTTNG_EVENT_PROBE,
	LTTNG_EVENT_FUNCTION,
	LTTNG_EVENT_FUNCTION_ENTRY,
};

/*
 * LTTng consumer mode
 */
enum lttng_event_output {
	LTTNG_EVENT_SPLICE = 0,
	LTTNG_EVENT_MMAP   = 1,
};

/* Event context possible type */
enum lttng_event_context_type {
	LTTNG_EVENT_CONTEXT_PID                = 0,
	LTTNG_EVENT_CONTEXT_PERF_COUNTER       = 1,
	LTTNG_EVENT_CONTEXT_COMM               = 2,
	LTTNG_EVENT_CONTEXT_PRIO               = 3,
	LTTNG_EVENT_CONTEXT_NICE               = 4,
	LTTNG_EVENT_CONTEXT_VPID               = 5,
	LTTNG_EVENT_CONTEXT_TID                = 6,
	LTTNG_EVENT_CONTEXT_VTID               = 7,
	LTTNG_EVENT_CONTEXT_PPID               = 8,
	LTTNG_EVENT_CONTEXT_VPPID              = 9,
};

enum lttng_calibrate_type {
	LTTNG_CALIBRATE_FUNCTION               = 0,
};

struct lttng_domain {
	enum lttng_domain_type type;
	union {
		pid_t pid;
		char exec_name[NAME_MAX];
	} attr;
};

/* Perf counter attributes */
struct lttng_event_perf_counter_ctx {
	uint32_t type;
	uint64_t config;
	char name[LTTNG_SYMBOL_NAME_LEN];
};

/* Event/Channel context */
struct lttng_event_context {
	enum lttng_event_context_type ctx;
	union {
		struct lttng_event_perf_counter_ctx perf_counter;
	} u;
};

/*
 * Event probe.
 *
 * Either addr is used or symbol_name and offset.
 */
struct lttng_event_probe_attr {
	uint64_t addr;

	uint64_t offset;
	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
};

/*
 * Function tracer
 */
struct lttng_event_function_attr {
	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
};

/*
 * Generic lttng event
 */
struct lttng_event {
	char name[LTTNG_SYMBOL_NAME_LEN];
	enum lttng_event_type type;
	uint32_t enabled;
	/* Per event type configuration */
	union {
		struct lttng_event_probe_attr probe;
		struct lttng_event_function_attr ftrace;
	} attr;
};

/*
 * Tracer channel attributes. For both kernel and user-space.
 */
struct lttng_channel_attr {
	int overwrite;                      /* 1: overwrite, 0: discard */
	uint64_t subbuf_size;               /* bytes */
	uint64_t num_subbuf;                /* power of 2 */
	unsigned int switch_timer_interval; /* usec */
	unsigned int read_timer_interval;   /* usec */
	enum lttng_event_output output;     /* splice, mmap */
};

/*
 * Channel information structure. For both kernel and user-space.
 */
struct lttng_channel {
	char name[NAME_MAX];
	uint32_t enabled;
	struct lttng_channel_attr attr;
};

struct lttng_calibrate {
	enum lttng_calibrate_type type;
};

/*
 * Basic session information.
 *
 * This is an 'output data' meaning that it only comes *from* the session
 * daemon *to* the lttng client. It's basically a 'human' representation of
 * tracing entities (here a session).
 */
struct lttng_session {
	char name[NAME_MAX];
	/* The path where traces are written */
	char path[PATH_MAX];
};

/*
 * Handle used as a context for commands.
 */
struct lttng_handle {
	char session_name[NAME_MAX];
	struct lttng_domain domain;
};

/*
 * Public LTTng control API
 *
 * For functions having a lttng domain type as parameter, if a bad value is
 * given, NO default is applied and an error is returned.
 *
 * On success, all functions of the API return 0 or the size of the allocated
 * array.
 *
 * On error, a negative value is returned being a specific lttng-tools error
 * code which can be humanly interpreted with lttng_get_readable_code(err).
 */

/*
 * Create an handle used as a context for every request made to the library.
 *
 * This handle contains the session name and lttng domain on which the command
 * will be executed on.
 */
extern struct lttng_handle *lttng_create_handle(const char *session_name,
		struct lttng_domain *domain);

/*
 * Destroy an handle. This will simply free(3) the data pointer returned by
 * lttng_create_handle() and rendering it unsuable.
 */
extern void lttng_destroy_handle(struct lttng_handle *handle);

/*
 * Create tracing session using a name and a path where trace will be written.
 */
extern int lttng_create_session(const char *name, const char *path);

/*
 * Destroy tracing session.
 *
 * The session will not be useable anymore, tracing will stopped for all
 * registered trace and tracing buffers will be flushed.
 */
extern int lttng_destroy_session(struct lttng_handle *handle);

/*
 * List all tracing sessions.
 *
 * Return the size of the "lttng_session" array. Caller must free(3).
 */
extern int lttng_list_sessions(struct lttng_session **sessions);

/*
 * List registered domain(s) of a session.
 *
 * Return the size of the "lttng_domain" array. Caller must free(3).
 */
extern int lttng_list_domains(struct lttng_handle *handle,
		struct lttng_domain **domains);

/*
 * List channel(s) of a session.
 *
 * Return the size of the "lttng_channel" array. Caller must free(3).
 */
extern int lttng_list_channels(struct lttng_handle *handle,
		struct lttng_channel **channels);

/*
 * List event(s) of a session channel.
 *
 * Return the size of the "lttng_event" array. Caller must free(3).
 */
extern int lttng_list_events(struct lttng_handle *handle,
		const char *channel_name, struct lttng_event **events);

/*
 * List available tracepoints of a specific lttng domain.
 *
 * Return the size of the "lttng_event" array. Caller must free(3).
 */
extern int lttng_list_tracepoints(struct lttng_handle *handle,
		struct lttng_event **events);

/*
 * Check if a session daemon is alive.
 */
extern int lttng_session_daemon_alive(void);

/*
 * Set tracing group for the *current* flow of execution.
 */
extern int lttng_set_tracing_group(const char *name);

/*
 * Return a human readable error message of a lttng-tools error code.
 *
 * Parameter MUST be a negative value or else you'll get a generic message.
 */
extern const char *lttng_get_readable_code(int code);

/*
 * This call permits to register an "outside consumer" to a session and a lttng
 * domain. No consumer will be spawned and all fds/commands will go through the
 * socket path given (socket_path).
 *
 * NOTE: At the moment, if you use the liblttngkconsumerd, you can only use the
 * command socket. The error socket is not supported yet for roaming consumers.
 */
extern int lttng_register_consumer(struct lttng_handle *handle,
		const char *socket_path);

/*
 * Start tracing for *all* registered trace (kernel and user-space).
 */
extern int lttng_start_tracing(struct lttng_handle *handle);

/*
 * Stop tracing for *all* registered trace (kernel and user-space).
 */
extern int lttng_stop_tracing(struct lttng_handle *handle);

/*
 * Add context to event for a specific channel.
 *
 * If event_name is NULL, the context is applied to all event of the channel.
 * If channel_name is NULL, a lookup of the event's channel is done.
 * If both are NULL, the context is applied on all events of all channels.
 */
extern int lttng_add_context(struct lttng_handle *handle,
		struct lttng_event_context *ctx, const char *event_name,
		const char *channel_name);

/*
 * Create or enable a kernel event.
 *
 * If the event you are trying to enable does not exist, it will be created,
 * else it is enabled.
 *
 * If channel_name is NULL, the default channel is used (channel0).
 */
extern int lttng_enable_event(struct lttng_handle *handle,
		struct lttng_event *ev, const char *channel_name);

/*
 * Create or enable a kernel channel.
 *
 * If name is NULL, the default channel is enabled (channel0).
 */
extern int lttng_enable_channel(struct lttng_handle *handle,
		struct lttng_channel *chan);

/*
 * Disable kernel event.
 *
 * If channel_name is NULL, the default channel is used (channel0).
 */
extern int lttng_disable_event(struct lttng_handle *handle,
		const char *name, const char *channel_name);

/*
 * Disable kernel channel.
 *
 * If channel_name is NULL, the default channel is disabled (channel0).
 */
extern int lttng_disable_channel(struct lttng_handle *handle,
		const char *name);

/*
 * Calibrate LTTng overhead.
 */
extern int lttng_calibrate(struct lttng_handle *handle,
		struct lttng_calibrate *calibrate);

#endif /* _LTTNG_H */
Commit	Line	Data
	1	/*
	2	* lttng.h
	3	*
	4	* Linux Trace Toolkit Control Library Header File
	5	*
	6	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	7	*
	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.
	12	*
	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.
	17	*
	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
	21	*/
	22
	23	#ifndef _LTTNG_H
	24	#define _LTTNG_H
	25
	26	#include <limits.h>
	27	#include <stdint.h>
	28	#include <sys/types.h>
	29
	30	/* Default unix group name for tracing. */
	31	#define LTTNG_DEFAULT_TRACING_GROUP "tracing"
	32
	33	/* Environment variable to set session daemon binary path. */
	34	#define LTTNG_SESSIOND_PATH_ENV "LTTNG_SESSIOND_PATH"
	35
	36	/* Default trace output directory name */
	37	#define LTTNG_DEFAULT_TRACE_DIR_NAME "lttng-traces"
	38
	39	/*
	40	* Event symbol length. Copied from LTTng kernel ABI.
	41	*/
	42	#define LTTNG_SYMBOL_NAME_LEN 128
	43
	44	/*
	45	* Every lttng_event_* structure both apply to kernel event and user-space
	46	* event.
	47	*/
	48
	49	/*
	50	* Domain type are the different possible tracers.
	51	*/
	52	enum lttng_domain_type {
	53	LTTNG_DOMAIN_KERNEL = 1,
	54	LTTNG_DOMAIN_UST = 2,
	55	LTTNG_DOMAIN_UST_EXEC_NAME = 3,
	56	LTTNG_DOMAIN_UST_PID = 4,
	57	LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
	58	};
	59
	60	/*
	61	* Instrumentation type of tracing event.
	62	*/
	63	enum lttng_event_type {
	64	LTTNG_EVENT_TRACEPOINT,
	65	LTTNG_EVENT_PROBE,
	66	LTTNG_EVENT_FUNCTION,
	67	LTTNG_EVENT_FUNCTION_ENTRY,
	68	};
	69
	70	/*
	71	* LTTng consumer mode
	72	*/
	73	enum lttng_event_output {
	74	LTTNG_EVENT_SPLICE = 0,
	75	LTTNG_EVENT_MMAP = 1,
	76	};
	77
	78	/* Event context possible type */
	79	enum lttng_event_context_type {
	80	LTTNG_EVENT_CONTEXT_PID = 0,
	81	LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1,
	82	LTTNG_EVENT_CONTEXT_COMM = 2,
	83	LTTNG_EVENT_CONTEXT_PRIO = 3,
	84	LTTNG_EVENT_CONTEXT_NICE = 4,
	85	LTTNG_EVENT_CONTEXT_VPID = 5,
	86	LTTNG_EVENT_CONTEXT_TID = 6,
	87	LTTNG_EVENT_CONTEXT_VTID = 7,
	88	LTTNG_EVENT_CONTEXT_PPID = 8,
	89	LTTNG_EVENT_CONTEXT_VPPID = 9,
	90	};
	91
	92	enum lttng_calibrate_type {
	93	LTTNG_CALIBRATE_FUNCTION = 0,
	94	};
	95
	96	struct lttng_domain {
	97	enum lttng_domain_type type;
	98	union {
	99	pid_t pid;
	100	char exec_name[NAME_MAX];
	101	} attr;
	102	};
	103
	104	/* Perf counter attributes */
	105	struct lttng_event_perf_counter_ctx {
	106	uint32_t type;
	107	uint64_t config;
	108	char name[LTTNG_SYMBOL_NAME_LEN];
	109	};
	110
	111	/* Event/Channel context */
	112	struct lttng_event_context {
	113	enum lttng_event_context_type ctx;
	114	union {
	115	struct lttng_event_perf_counter_ctx perf_counter;
	116	} u;
	117	};
	118
	119	/*
	120	* Event probe.
	121	*
	122	* Either addr is used or symbol_name and offset.
	123	*/
	124	struct lttng_event_probe_attr {
	125	uint64_t addr;
	126
	127	uint64_t offset;
	128	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	129	};
	130
	131	/*
	132	* Function tracer
	133	*/
	134	struct lttng_event_function_attr {
	135	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	136	};
	137
	138	/*
	139	* Generic lttng event
	140	*/
	141	struct lttng_event {
	142	char name[LTTNG_SYMBOL_NAME_LEN];
	143	enum lttng_event_type type;
	144	uint32_t enabled;
	145	/* Per event type configuration */
	146	union {
	147	struct lttng_event_probe_attr probe;
	148	struct lttng_event_function_attr ftrace;
	149	} attr;
	150	};
	151
	152	/*
	153	* Tracer channel attributes. For both kernel and user-space.
	154	*/
	155	struct lttng_channel_attr {
	156	int overwrite; /* 1: overwrite, 0: discard */
	157	uint64_t subbuf_size; /* bytes */
	158	uint64_t num_subbuf; /* power of 2 */
	159	unsigned int switch_timer_interval; /* usec */
	160	unsigned int read_timer_interval; /* usec */
	161	enum lttng_event_output output; /* splice, mmap */
	162	};
	163
	164	/*
	165	* Channel information structure. For both kernel and user-space.
	166	*/
	167	struct lttng_channel {
	168	char name[NAME_MAX];
	169	uint32_t enabled;
	170	struct lttng_channel_attr attr;
	171	};
	172
	173	struct lttng_calibrate {
	174	enum lttng_calibrate_type type;
	175	};
	176
	177	/*
	178	* Basic session information.
	179	*
	180	* This is an 'output data' meaning that it only comes from the session
	181	* daemon to the lttng client. It's basically a 'human' representation of
	182	* tracing entities (here a session).
	183	*/
	184	struct lttng_session {
	185	char name[NAME_MAX];
	186	/* The path where traces are written */
	187	char path[PATH_MAX];
	188	};
	189
	190	/*
	191	* Handle used as a context for commands.
	192	*/
	193	struct lttng_handle {
	194	char session_name[NAME_MAX];
	195	struct lttng_domain domain;
	196	};
	197
	198	/*
	199	* Public LTTng control API
	200	*
	201	* For functions having a lttng domain type as parameter, if a bad value is
	202	* given, NO default is applied and an error is returned.
	203	*
	204	* On success, all functions of the API return 0 or the size of the allocated
	205	* array.
	206	*
	207	* On error, a negative value is returned being a specific lttng-tools error
	208	* code which can be humanly interpreted with lttng_get_readable_code(err).
	209	*/
	210
	211	/*
	212	* Create an handle used as a context for every request made to the library.
	213	*
	214	* This handle contains the session name and lttng domain on which the command
	215	* will be executed on.
	216	*/
	217	extern struct lttng_handle lttng_create_handle(const char session_name,
	218	struct lttng_domain *domain);
	219
	220	/*
	221	* Destroy an handle. This will simply free(3) the data pointer returned by
	222	* lttng_create_handle() and rendering it unsuable.
	223	*/
	224	extern void lttng_destroy_handle(struct lttng_handle *handle);
	225
	226	/*
	227	* Create tracing session using a name and a path where trace will be written.
	228	*/
	229	extern int lttng_create_session(const char name, const char path);
	230
	231	/*
	232	* Destroy tracing session.
	233	*
	234	* The session will not be useable anymore, tracing will stopped for all
	235	* registered trace and tracing buffers will be flushed.
	236	*/
	237	extern int lttng_destroy_session(struct lttng_handle *handle);
	238
	239	/*
	240	* List all tracing sessions.
	241	*
	242	* Return the size of the "lttng_session" array. Caller must free(3).
	243	*/
	244	extern int lttng_list_sessions(struct lttng_session **sessions);
	245
	246	/*
	247	* List registered domain(s) of a session.
	248	*
	249	* Return the size of the "lttng_domain" array. Caller must free(3).
	250	*/
	251	extern int lttng_list_domains(struct lttng_handle *handle,
	252	struct lttng_domain **domains);
	253
	254	/*
	255	* List channel(s) of a session.
	256	*
	257	* Return the size of the "lttng_channel" array. Caller must free(3).
	258	*/
	259	extern int lttng_list_channels(struct lttng_handle *handle,
	260	struct lttng_channel **channels);
	261
	262	/*
	263	* List event(s) of a session channel.
	264	*
	265	* Return the size of the "lttng_event" array. Caller must free(3).
	266	*/
	267	extern int lttng_list_events(struct lttng_handle *handle,
	268	const char channel_name, struct lttng_event *events);
	269
	270	/*
	271	* List available tracepoints of a specific lttng domain.
	272	*
	273	* Return the size of the "lttng_event" array. Caller must free(3).
	274	*/
	275	extern int lttng_list_tracepoints(struct lttng_handle *handle,
	276	struct lttng_event **events);
	277
	278	/*
	279	* Check if a session daemon is alive.
	280	*/
	281	extern int lttng_session_daemon_alive(void);
	282
	283	/*
	284	* Set tracing group for the current flow of execution.
	285	*/
	286	extern int lttng_set_tracing_group(const char *name);
	287
	288	/*
	289	* Return a human readable error message of a lttng-tools error code.
	290	*
	291	* Parameter MUST be a negative value or else you'll get a generic message.
	292	*/
	293	extern const char *lttng_get_readable_code(int code);
	294
	295	/*
	296	* This call permits to register an "outside consumer" to a session and a lttng
	297	* domain. No consumer will be spawned and all fds/commands will go through the
	298	* socket path given (socket_path).
	299	*
	300	* NOTE: At the moment, if you use the liblttngkconsumerd, you can only use the
	301	* command socket. The error socket is not supported yet for roaming consumers.
	302	*/
	303	extern int lttng_register_consumer(struct lttng_handle *handle,
	304	const char *socket_path);
	305
	306	/*
	307	* Start tracing for all registered trace (kernel and user-space).
	308	*/
	309	extern int lttng_start_tracing(struct lttng_handle *handle);
	310
	311	/*
	312	* Stop tracing for all registered trace (kernel and user-space).
	313	*/
	314	extern int lttng_stop_tracing(struct lttng_handle *handle);
	315
	316	/*
	317	* Add context to event for a specific channel.
	318	*
	319	* If event_name is NULL, the context is applied to all event of the channel.
	320	* If channel_name is NULL, a lookup of the event's channel is done.
	321	* If both are NULL, the context is applied on all events of all channels.
	322	*/
	323	extern int lttng_add_context(struct lttng_handle *handle,
	324	struct lttng_event_context ctx, const char event_name,
	325	const char *channel_name);
	326
	327	/*
	328	* Create or enable a kernel event.
	329	*
	330	* If the event you are trying to enable does not exist, it will be created,
	331	* else it is enabled.
	332	*
	333	* If channel_name is NULL, the default channel is used (channel0).
	334	*/
	335	extern int lttng_enable_event(struct lttng_handle *handle,
	336	struct lttng_event ev, const char channel_name);
	337
	338	/*
	339	* Create or enable a kernel channel.
	340	*
	341	* If name is NULL, the default channel is enabled (channel0).
	342	*/
	343	extern int lttng_enable_channel(struct lttng_handle *handle,
	344	struct lttng_channel *chan);
	345
	346	/*
	347	* Disable kernel event.
	348	*
	349	* If channel_name is NULL, the default channel is used (channel0).
	350	*/
	351	extern int lttng_disable_event(struct lttng_handle *handle,
	352	const char name, const char channel_name);
	353
	354	/*
	355	* Disable kernel channel.
	356	*
	357	* If channel_name is NULL, the default channel is disabled (channel0).
	358	*/
	359	extern int lttng_disable_channel(struct lttng_handle *handle,
	360	const char *name);
	361
	362	/*
	363	* Calibrate LTTng overhead.
	364	*/
	365	extern int lttng_calibrate(struct lttng_handle *handle,
	366	struct lttng_calibrate *calibrate);
	367
	368	#endif /* _LTTNG_H */