[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>

/*
 * Event symbol length. Copied from LTTng kernel ABI.
 */
#define LTTNG_SYMBOL_NAME_LEN 256

/*
 * 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,

	/*
	 * For now, the domains below are not implemented. However, we keep them
	 * here in order to retain their enum values for future development. Note
	 * that it is on the roadmap to implement them.
	 *
	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_EVENT_TRACEPOINT_LOGLEVEL       = 6,
};

/*
 * 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];
	char loglevel[LTTNG_SYMBOL_NAME_LEN];
	int64_t loglevel_value;
	enum lttng_event_type type;
	uint32_t enabled;
	pid_t pid;
	/* 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[LTTNG_SYMBOL_NAME_LEN];
	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];
	uint32_t enabled;	/* enabled/started: 1, disabled/stopped: 0 */
};

/*
 * 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_strerror(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(const char *name);

/*
 * 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(const char *session_name,
		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_strerror(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(const char *session_name);

/*
 * Stop tracing for *all* registered trace (kernel and user-space).
 */
extern int lttng_stop_tracing(const char *session_name);

/*
 * 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);

/*
 * Set the default channel attributes for a specific domain and an allocated
 * lttng_channel_attr pointer.
 */
extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
		struct lttng_channel_attr *attr);

#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	/*
	31	* Event symbol length. Copied from LTTng kernel ABI.
	32	*/
	33	#define LTTNG_SYMBOL_NAME_LEN 256
	34
	35	/*
	36	* Every lttng_event_* structure both apply to kernel event and user-space
	37	* event.
	38	*/
	39
	40	/*
	41	* Domain type are the different possible tracers.
	42	*/
	43	enum lttng_domain_type {
	44	LTTNG_DOMAIN_KERNEL = 1,
	45	LTTNG_DOMAIN_UST = 2,
	46
	47	/*
	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.
	51	*
	52	LTTNG_DOMAIN_UST_EXEC_NAME = 3,
	53	LTTNG_DOMAIN_UST_PID = 4,
	54	LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5,
	55	*/
	56	};
	57
	58	/*
	59	* Instrumentation type of tracing event.
	60	*/
	61	enum lttng_event_type {
	62	LTTNG_EVENT_ALL = -1,
	63	LTTNG_EVENT_TRACEPOINT = 0,
	64	LTTNG_EVENT_PROBE = 1,
	65	LTTNG_EVENT_FUNCTION = 2,
	66	LTTNG_EVENT_FUNCTION_ENTRY = 3,
	67	LTTNG_EVENT_NOOP = 4,
	68	LTTNG_EVENT_SYSCALL = 5,
	69	LTTNG_EVENT_TRACEPOINT_LOGLEVEL = 6,
	70	};
	71
	72	/*
	73	* LTTng consumer mode
	74	*/
	75	enum lttng_event_output {
	76	LTTNG_EVENT_SPLICE = 0,
	77	LTTNG_EVENT_MMAP = 1,
	78	};
	79
	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,
	92	};
	93
	94	enum lttng_calibrate_type {
	95	LTTNG_CALIBRATE_FUNCTION = 0,
	96	};
	97
	98	struct lttng_domain {
	99	enum lttng_domain_type type;
	100	union {
	101	pid_t pid;
	102	char exec_name[NAME_MAX];
	103	} attr;
	104	};
	105
	106	/* Perf counter attributes */
	107	struct lttng_event_perf_counter_ctx {
	108	uint32_t type;
	109	uint64_t config;
	110	char name[LTTNG_SYMBOL_NAME_LEN];
	111	};
	112
	113	/* Event/Channel context */
	114	struct lttng_event_context {
	115	enum lttng_event_context_type ctx;
	116	union {
	117	struct lttng_event_perf_counter_ctx perf_counter;
	118	} u;
	119	};
	120
	121	/*
	122	* Event probe.
	123	*
	124	* Either addr is used or symbol_name and offset.
	125	*/
	126	struct lttng_event_probe_attr {
	127	uint64_t addr;
	128
	129	uint64_t offset;
	130	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	131	};
	132
	133	/*
	134	* Function tracer
	135	*/
	136	struct lttng_event_function_attr {
	137	char symbol_name[LTTNG_SYMBOL_NAME_LEN];
	138	};
	139
	140	/*
	141	* Generic lttng event
	142	*/
	143	struct 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;
	148	uint32_t enabled;
	149	pid_t pid;
	150	/* Per event type configuration */
	151	union {
	152	struct lttng_event_probe_attr probe;
	153	struct lttng_event_function_attr ftrace;
	154	} attr;
	155	};
	156
	157	/*
	158	* Tracer channel attributes. For both kernel and user-space.
	159	*/
	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 */
	167	};
	168
	169	/*
	170	* Channel information structure. For both kernel and user-space.
	171	*/
	172	struct lttng_channel {
	173	char name[LTTNG_SYMBOL_NAME_LEN];
	174	uint32_t enabled;
	175	struct lttng_channel_attr attr;
	176	};
	177
	178	struct lttng_calibrate {
	179	enum lttng_calibrate_type type;
	180	};
	181
	182	/*
	183	* Basic session information.
	184	*
	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).
	188	*/
	189	struct lttng_session {
	190	char name[NAME_MAX];
	191	/* The path where traces are written */
	192	char path[PATH_MAX];
	193	uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
	194	};
	195
	196	/*
	197	* Handle used as a context for commands.
	198	*/
	199	struct lttng_handle {
	200	char session_name[NAME_MAX];
	201	struct lttng_domain domain;
	202	};
	203
	204	/*
	205	* Public LTTng control API
	206	*
	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.
	209	*
	210	* On success, all functions of the API return 0 or the size of the allocated
	211	* array.
	212	*
	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).
	215	*/
	216
	217	/*
	218	* Create an handle used as a context for every request made to the library.
	219	*
	220	* This handle contains the session name and lttng domain on which the command
	221	* will be executed on.
	222	*/
	223	extern struct lttng_handle lttng_create_handle(const char session_name,
	224	struct lttng_domain *domain);
	225
	226	/*
	227	* Destroy an handle. This will simply free(3) the data pointer returned by
	228	* lttng_create_handle() and rendering it unsuable.
	229	*/
	230	extern void lttng_destroy_handle(struct lttng_handle *handle);
	231
	232	/*
	233	* Create tracing session using a name and a path where trace will be written.
	234	*/
	235	extern int lttng_create_session(const char name, const char path);
	236
	237	/*
	238	* Destroy tracing session.
	239	*
	240	* The session will not be useable anymore, tracing will stopped for all
	241	* registered trace and tracing buffers will be flushed.
	242	*/
	243	extern int lttng_destroy_session(const char *name);
	244
	245	/*
	246	* List all tracing sessions.
	247	*
	248	* Return the size of the "lttng_session" array. Caller must free(3).
	249	*/
	250	extern int lttng_list_sessions(struct lttng_session **sessions);
	251
	252	/*
	253	* List registered domain(s) of a session.
	254	*
	255	* Return the size of the "lttng_domain" array. Caller must free(3).
	256	*/
	257	extern int lttng_list_domains(const char *session_name,
	258	struct lttng_domain **domains);
	259
	260	/*
	261	* List channel(s) of a session.
	262	*
	263	* Return the size of the "lttng_channel" array. Caller must free(3).
	264	*/
	265	extern int lttng_list_channels(struct lttng_handle *handle,
	266	struct lttng_channel **channels);
	267
	268	/*
	269	* List event(s) of a session channel.
	270	*
	271	* Return the size of the "lttng_event" array. Caller must free(3).
	272	*/
	273	extern int lttng_list_events(struct lttng_handle *handle,
	274	const char channel_name, struct lttng_event *events);
	275
	276	/*
	277	* List available tracepoints of a specific lttng domain.
	278	*
	279	* Return the size of the "lttng_event" array. Caller must free(3).
	280	*/
	281	extern int lttng_list_tracepoints(struct lttng_handle *handle,
	282	struct lttng_event **events);
	283
	284	/*
	285	* Check if a session daemon is alive.
	286	*/
	287	extern int lttng_session_daemon_alive(void);
	288
	289	/*
	290	* Set tracing group for the current flow of execution.
	291	*/
	292	extern int lttng_set_tracing_group(const char *name);
	293
	294	/*
	295	* Return a human readable error message of a lttng-tools error code.
	296	*
	297	* Parameter MUST be a negative value or else you'll get a generic message.
	298	*/
	299	extern const char *lttng_strerror(int code);
	300
	301	/*
	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).
	305	*
	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.
	308	*/
	309	extern int lttng_register_consumer(struct lttng_handle *handle,
	310	const char *socket_path);
	311
	312	/*
	313	* Start tracing for all registered trace (kernel and user-space).
	314	*/
	315	extern int lttng_start_tracing(const char *session_name);
	316
	317	/*
	318	* Stop tracing for all registered trace (kernel and user-space).
	319	*/
	320	extern int lttng_stop_tracing(const char *session_name);
	321
	322	/*
	323	* Add context to event for a specific channel.
	324	*
	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.
	328	*/
	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);
	332
	333	/*
	334	* Create or enable a kernel event.
	335	*
	336	* If the event you are trying to enable does not exist, it will be created,
	337	* else it is enabled.
	338	*
	339	* If channel_name is NULL, the default channel is used (channel0).
	340	*/
	341	extern int lttng_enable_event(struct lttng_handle *handle,
	342	struct lttng_event ev, const char channel_name);
	343
	344	/*
	345	* Create or enable a kernel channel.
	346	*
	347	* If name is NULL, the default channel is enabled (channel0).
	348	*/
	349	extern int lttng_enable_channel(struct lttng_handle *handle,
	350	struct lttng_channel *chan);
	351
	352	/*
	353	* Disable kernel event.
	354	*
	355	* If channel_name is NULL, the default channel is used (channel0).
	356	*/
	357	extern int lttng_disable_event(struct lttng_handle *handle,
	358	const char name, const char channel_name);
	359
	360	/*
	361	* Disable kernel channel.
	362	*
	363	* If channel_name is NULL, the default channel is disabled (channel0).
	364	*/
	365	extern int lttng_disable_channel(struct lttng_handle *handle,
	366	const char *name);
	367
	368	/*
	369	* Calibrate LTTng overhead.
	370	*/
	371	extern int lttng_calibrate(struct lttng_handle *handle,
	372	struct lttng_calibrate *calibrate);
	373
	374	/*
	375	* Set the default channel attributes for a specific domain and an allocated
	376	* lttng_channel_attr pointer.
	377	*/
	378	extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
	379	struct lttng_channel_attr *attr);
	380
	381	#endif /* _LTTNG_H */