[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 <asm/types.h>
#include <sys/types.h>
#include <stdint.h>
#include <limits.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,
};

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;
};

/*
 * 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];
};

/*
 * 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).
 */

/*
 * Session daemon control
 */

/*
 * 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_domain *domain,
		const char *session_name, 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_domain *domain,
		const char *session_name, const char *channel_name,
		struct lttng_event **events);

/*
 * List available tracepoints of domain.
 *
 * Return the size of the "lttng_event" array. Caller must free(3).
 */
extern int lttng_list_tracepoints(struct lttng_domain *domain,
		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);

/*
 * Set the session name of the *current* flow of execution.
 *
 * This is a VERY important things to do before doing any tracing actions. If
 * it's not done, you'll get an error saying that the session is not found.
 * It avoids the use of a session name on every API call.
 */
extern void lttng_set_session_name(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);

/*
 * 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_domain *domain,
		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_domain *domain, 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_domain *domain,
		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_domain *domain, 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_domain *domain,
		const char *name);

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