[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_ALL                       = -1,
	LTTNG_EVENT_TRACEPOINT                = 0,
	LTTNG_EVENT_PROBE                     = 1,
	LTTNG_EVENT_FUNCTION                  = 2,
	LTTNG_EVENT_FUNCTION_ENTRY            = 3,
	LTTNG_EVENT_NOOP                      = 4,
	LTTNG_EVENT_SYSCALL                   = 5,
};

/*
 * 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 liblttng-kconsumer, 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_ALL = -1,
	65	LTTNG_EVENT_TRACEPOINT = 0,
	66	LTTNG_EVENT_PROBE = 1,
	67	LTTNG_EVENT_FUNCTION = 2,
	68	LTTNG_EVENT_FUNCTION_ENTRY = 3,
	69	LTTNG_EVENT_NOOP = 4,
	70	LTTNG_EVENT_SYSCALL = 5,
	71	};
	72
	73	/*
	74	* LTTng consumer mode
	75	*/
	76	enum lttng_event_output {
	77	LTTNG_EVENT_SPLICE = 0,
	78	LTTNG_EVENT_MMAP = 1,
	79	};
	80
	81	/* Event context possible type */
	82	enum lttng_event_context_type {
	83	LTTNG_EVENT_CONTEXT_PID = 0,
	84	LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1,
	85	LTTNG_EVENT_CONTEXT_COMM = 2,
	86	LTTNG_EVENT_CONTEXT_PRIO = 3,
	87	LTTNG_EVENT_CONTEXT_NICE = 4,
	88	LTTNG_EVENT_CONTEXT_VPID = 5,
	89	LTTNG_EVENT_CONTEXT_TID = 6,
	90	LTTNG_EVENT_CONTEXT_VTID = 7,
	91	LTTNG_EVENT_CONTEXT_PPID = 8,
	92	LTTNG_EVENT_CONTEXT_VPPID = 9,
	93	};
	94
	95	enum lttng_calibrate_type {
	96	LTTNG_CALIBRATE_FUNCTION = 0,
	97	};
	98
	99	struct lttng_domain {
	100	enum lttng_domain_type type;
	101	union {
	102	pid_t pid;
	103	char exec_name[NAME_MAX];
	104	} attr;
	105	};
	106
	107	/* Perf counter attributes */
	108	struct lttng_event_perf_counter_ctx {
	109	uint32_t type;
	110	uint64_t config;
	111	char name[LTTNG_SYMBOL_NAME_LEN];
	112	};
	113
	114	/* Event/Channel context */
	115	struct lttng_event_context {
	116	enum lttng_event_context_type ctx;
	117	union {
	118	struct lttng_event_perf_counter_ctx perf_counter;
	119	} u;
	120	};
	121
	122	/*
	123	* Event probe.
	124	*
	125	* Either addr is used or symbol_name and offset.
	126	*/
	127	struct lttng_event_probe_attr {
	128	uint64_t addr;
	129
	130	uint64_t offset;
	131	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	132	};
	133
	134	/*
	135	* Function tracer
	136	*/
	137	struct lttng_event_function_attr {
	138	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	139	};
	140
	141	/*
	142	* Generic lttng event
	143	*/
	144	struct lttng_event {
	145	char name[LTTNG_SYMBOL_NAME_LEN];
	146	enum lttng_event_type type;
	147	uint32_t enabled;
	148	/* Per event type configuration */
	149	union {
	150	struct lttng_event_probe_attr probe;
	151	struct lttng_event_function_attr ftrace;
	152	} attr;
	153	};
	154
	155	/*
	156	* Tracer channel attributes. For both kernel and user-space.
	157	*/
	158	struct lttng_channel_attr {
	159	int overwrite; /* 1: overwrite, 0: discard */
	160	uint64_t subbuf_size; /* bytes */
	161	uint64_t num_subbuf; /* power of 2 */
	162	unsigned int switch_timer_interval; /* usec */
	163	unsigned int read_timer_interval; /* usec */
	164	enum lttng_event_output output; /* splice, mmap */
	165	};
	166
	167	/*
	168	* Channel information structure. For both kernel and user-space.
	169	*/
	170	struct lttng_channel {
	171	char name[NAME_MAX];
	172	uint32_t enabled;
	173	struct lttng_channel_attr attr;
	174	};
	175
	176	struct lttng_calibrate {
	177	enum lttng_calibrate_type type;
	178	};
	179
	180	/*
	181	* Basic session information.
	182	*
	183	* This is an 'output data' meaning that it only comes from the session
	184	* daemon to the lttng client. It's basically a 'human' representation of
	185	* tracing entities (here a session).
	186	*/
	187	struct lttng_session {
	188	char name[NAME_MAX];
	189	/* The path where traces are written */
	190	char path[PATH_MAX];
	191	};
	192
	193	/*
	194	* Handle used as a context for commands.
	195	*/
	196	struct lttng_handle {
	197	char session_name[NAME_MAX];
	198	struct lttng_domain domain;
	199	};
	200
	201	/*
	202	* Public LTTng control API
	203	*
	204	* For functions having a lttng domain type as parameter, if a bad value is
	205	* given, NO default is applied and an error is returned.
	206	*
	207	* On success, all functions of the API return 0 or the size of the allocated
	208	* array.
	209	*
	210	* On error, a negative value is returned being a specific lttng-tools error
	211	* code which can be humanly interpreted with lttng_get_readable_code(err).
	212	*/
	213
	214	/*
	215	* Create an handle used as a context for every request made to the library.
	216	*
	217	* This handle contains the session name and lttng domain on which the command
	218	* will be executed on.
	219	*/
	220	extern struct lttng_handle lttng_create_handle(const char session_name,
	221	struct lttng_domain *domain);
	222
	223	/*
	224	* Destroy an handle. This will simply free(3) the data pointer returned by
	225	* lttng_create_handle() and rendering it unsuable.
	226	*/
	227	extern void lttng_destroy_handle(struct lttng_handle *handle);
	228
	229	/*
	230	* Create tracing session using a name and a path where trace will be written.
	231	*/
	232	extern int lttng_create_session(const char name, const char path);
	233
	234	/*
	235	* Destroy tracing session.
	236	*
	237	* The session will not be useable anymore, tracing will stopped for all
	238	* registered trace and tracing buffers will be flushed.
	239	*/
	240	extern int lttng_destroy_session(struct lttng_handle *handle);
	241
	242	/*
	243	* List all tracing sessions.
	244	*
	245	* Return the size of the "lttng_session" array. Caller must free(3).
	246	*/
	247	extern int lttng_list_sessions(struct lttng_session **sessions);
	248
	249	/*
	250	* List registered domain(s) of a session.
	251	*
	252	* Return the size of the "lttng_domain" array. Caller must free(3).
	253	*/
	254	extern int lttng_list_domains(struct lttng_handle *handle,
	255	struct lttng_domain **domains);
	256
	257	/*
	258	* List channel(s) of a session.
	259	*
	260	* Return the size of the "lttng_channel" array. Caller must free(3).
	261	*/
	262	extern int lttng_list_channels(struct lttng_handle *handle,
	263	struct lttng_channel **channels);
	264
	265	/*
	266	* List event(s) of a session channel.
	267	*
	268	* Return the size of the "lttng_event" array. Caller must free(3).
	269	*/
	270	extern int lttng_list_events(struct lttng_handle *handle,
	271	const char channel_name, struct lttng_event *events);
	272
	273	/*
	274	* List available tracepoints of a specific lttng domain.
	275	*
	276	* Return the size of the "lttng_event" array. Caller must free(3).
	277	*/
	278	extern int lttng_list_tracepoints(struct lttng_handle *handle,
	279	struct lttng_event **events);
	280
	281	/*
	282	* Check if a session daemon is alive.
	283	*/
	284	extern int lttng_session_daemon_alive(void);
	285
	286	/*
	287	* Set tracing group for the current flow of execution.
	288	*/
	289	extern int lttng_set_tracing_group(const char *name);
	290
	291	/*
	292	* Return a human readable error message of a lttng-tools error code.
	293	*
	294	* Parameter MUST be a negative value or else you'll get a generic message.
	295	*/
	296	extern const char *lttng_get_readable_code(int code);
	297
	298	/*
	299	* This call permits to register an "outside consumer" to a session and a lttng
	300	* domain. No consumer will be spawned and all fds/commands will go through the
	301	* socket path given (socket_path).
	302	*
	303	* NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
	304	* command socket. The error socket is not supported yet for roaming consumers.
	305	*/
	306	extern int lttng_register_consumer(struct lttng_handle *handle,
	307	const char *socket_path);
	308
	309	/*
	310	* Start tracing for all registered trace (kernel and user-space).
	311	*/
	312	extern int lttng_start_tracing(struct lttng_handle *handle);
	313
	314	/*
	315	* Stop tracing for all registered trace (kernel and user-space).
	316	*/
	317	extern int lttng_stop_tracing(struct lttng_handle *handle);
	318
	319	/*
	320	* Add context to event for a specific channel.
	321	*
	322	* If event_name is NULL, the context is applied to all event of the channel.
	323	* If channel_name is NULL, a lookup of the event's channel is done.
	324	* If both are NULL, the context is applied on all events of all channels.
	325	*/
	326	extern int lttng_add_context(struct lttng_handle *handle,
	327	struct lttng_event_context ctx, const char event_name,
	328	const char *channel_name);
	329
	330	/*
	331	* Create or enable a kernel event.
	332	*
	333	* If the event you are trying to enable does not exist, it will be created,
	334	* else it is enabled.
	335	*
	336	* If channel_name is NULL, the default channel is used (channel0).
	337	*/
	338	extern int lttng_enable_event(struct lttng_handle *handle,
	339	struct lttng_event ev, const char channel_name);
	340
	341	/*
	342	* Create or enable a kernel channel.
	343	*
	344	* If name is NULL, the default channel is enabled (channel0).
	345	*/
	346	extern int lttng_enable_channel(struct lttng_handle *handle,
	347	struct lttng_channel *chan);
	348
	349	/*
	350	* Disable kernel event.
	351	*
	352	* If channel_name is NULL, the default channel is used (channel0).
	353	*/
	354	extern int lttng_disable_event(struct lttng_handle *handle,
	355	const char name, const char channel_name);
	356
	357	/*
	358	* Disable kernel channel.
	359	*
	360	* If channel_name is NULL, the default channel is disabled (channel0).
	361	*/
	362	extern int lttng_disable_channel(struct lttng_handle *handle,
	363	const char *name);
	364
	365	/*
	366	* Calibrate LTTng overhead.
	367	*/
	368	extern int lttng_calibrate(struct lttng_handle *handle,
	369	struct lttng_calibrate *calibrate);
	370
	371	#endif /* _LTTNG_H */