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

/*
 * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
 * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License, version 2.1 only,
 * as published by the Free Software Foundation.
 *
 * 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_SESSION_H
#define LTTNG_SESSION_H

#ifdef __cplusplus
extern "C" {
#endif

enum lttng_tracker_type {
	LTTNG_TRACKER_PID = 0,
	LTTNG_TRACKER_VPID = 1,
	LTTNG_TRACKER_UID = 2,
	LTTNG_TRACKER_GID = 3,
	LTTNG_TRACKER_VUID = 4,
	LTTNG_TRACKER_VGID = 5,
};

enum lttng_tracker_id_type {
	LTTNG_ID_UNKNOWN = -1,
	LTTNG_ID_ALL = 0,
	LTTNG_ID_VALUE = 1,
	LTTNG_ID_STRING = 2,
};

struct lttng_tracker_id {
	enum lttng_tracker_id_type type;
	int value;
	char *string;
};

struct lttng_session_descriptor;
struct lttng_destruction_handle;

/*
 * Basic session information.
 *
 * The "enabled" field is only used when listing the sessions which indicate if
 * it's started or not.
 *
 * The structures should be initialized to zero before use.
 */
#define LTTNG_SESSION_PADDING1             8
struct lttng_session {
	char name[LTTNG_NAME_MAX];
	/*
	 * Human-readable representation of the trace's destination.
	 * In the case of a local tracing session, a path is provided:
	 *     /path/to/the/output
	 *
	 * In the case of a remote (network) tracing session, the string has
	 * the following format:
	 *     net://hostname/path:ctrl_port [data: data_port]
	 */
	char path[PATH_MAX];
	uint32_t enabled;	/* enabled/started: 1, disabled/stopped: 0 */
	uint32_t snapshot_mode;
	unsigned int live_timer_interval;	/* usec */

	/*
	 * End of public attributes.
	 * The remaining fields are used to deal with ABI management concerns.
	 */

	/*
	 * 32-bit architectures are already naturally aligned on 4 bytes after
	 * 'live_timer_interval'. However, the offset does not result in a
	 * natural alignment on 64-bit architectures. Adding 4 bytes of
	 * padding here results in an aligned offset after 'alignement_padding'
	 * for both bitnesses.
	 *
	 * This was added since not all compilers appear to align unions in the
	 * same way. Some (e.g. MSVC) do not seem to impose an alignement
	 * constraint while others (e.g. gcc, clang, icc) seem to align it to
	 * ensure 'ptr' is naturally aligned.
	 */
	char alignment_padding[4];
	union {
		/*
		 * Ensure the 'extended' union has the same size for both
		 * 32-bit and 64-bit builds.
		 */
		char padding[LTTNG_SESSION_PADDING1];
		void *ptr;
	} extended;
};

/*
 * Create a session on the session daemon from a session descriptor.
 *
 * See the session descriptor API description in session-descriptor.h
 *
 * Note that unspecified session descriptor parameters, such as a session's
 * name, are updated in the session descriptor if the creation of the session
 * succeeds. This allows users to query the session's auto-generated name
 * after its creation. Note that other attributes can be queried using the
 * session listing API.
 *
 * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
 * return codes.
 */
extern enum lttng_error_code lttng_create_session_ext(
		struct lttng_session_descriptor *session_descriptor);

/*
 * Create a tracing session using a name and an optional URL.
 *
 * If _url_ is NULL, no consumer is created for the session. The name can't be
 * NULL here.
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_create_session(const char *name, const char *url);

/*
 * Create a tracing session that will exclusively be used for snapshot meaning
 * the session will be in no output mode and every channel enabled for that
 * session will be set in overwrite mode and in mmap output since splice is not
 * supported.
 *
 * Name can't be NULL. If an url is given, it will be used to create a default
 * snapshot output using it as a destination. If NULL, no output will be
 * defined and an add-output call will be needed.
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_create_session_snapshot(const char *name,
		const char *snapshot_url);

/*
 * Create a session exclusively used for live reading.
 *
 * In this mode, the switch-timer parameter is forced for each UST channel, a
 * live-switch-timer is enabled for kernel channels, manually setting
 * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
 * indexes are sent and metadata is checked for each packet.
 *
 * Name can't be NULL. If no URL is given, the default is to send the data to
 * net://127.0.0.1. The timer_interval is in usec.
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_create_session_live(const char *name, const char *url,
		unsigned int timer_interval);

/*
 * Destroy a tracing session.
 *
 * The session will not be usable, tracing will be stopped thus buffers will be
 * flushed.
 *
 * This call will wait for data availability for each domain of the session,
 * which can take an arbitrary amount of time. However, when returning the
 * tracing data is guaranteed to be ready to be read and analyzed.
 *
 * lttng_destroy_session_no_wait() may be used if such a guarantee is not
 * needed.
 *
 * The name can't be NULL here.
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_destroy_session(const char *name);

/*
 * Destroy a tracing session.
 *
 * Performs the same function as lttng_destroy_session(), but provides
 * an lttng_destruction_handle which can be used to wait for the completion
 * of the session's destruction. The lttng_destroy_handle can also be used
 * obtain the status and archive location of any implicit session
 * rotation that may have occurred during the session's destruction.
 *
 * Returns LTTNG_OK on success. The returned handle is owned by the caller
 * and must be free'd using lttng_destruction_handle_destroy().
 */
extern enum lttng_error_code lttng_destroy_session_ext(const char *session_name,
		struct lttng_destruction_handle **handle);

/*
 * Behaves exactly like lttng_destroy_session but does not wait for data
 * availability.
 */
extern int lttng_destroy_session_no_wait(const char *name);

/*
 * List all the tracing sessions.
 *
 * Return the number of entries of the "lttng_session" array. The caller
 * must free the returned sessions array directly using free().
 *
 * On error, a negative LTTng error code is returned.
 */
extern int lttng_list_sessions(struct lttng_session **sessions);

/*
 * Get the creation time of an lttng_session object on the session daemon.
 *
 * This function must only be used with lttng_session objects returned
 * by lttng_list_sessions() or lttng_session_create().
 *
 * The creation time returned is a UNIX timestamp; the number of seconds since
 * Epoch (1970-01-01 00:00:00 +0000 (UTC)).
 *
 * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
 * return codes.
 */
extern enum lttng_error_code lttng_session_get_creation_time(
		const struct lttng_session *session, uint64_t *creation_time);

/*
 * Set the shared memory path for a session.
 *
 * Sets the (optional) file system path where shared memory buffers will
 * be created for the session. This is useful for buffer extraction on
 * crash, when used with filesystems like pramfs.
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_set_session_shm_path(const char *session_name,
		const char *shm_path);

/*
 * Add PID to session tracker.
 *
 * A pid argument >= 0 adds the PID to the session tracker.
 * A pid argument of -1 means "track all PIDs".
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_track_pid(struct lttng_handle *handle, int pid);

/*
 * Remove PID from session tracker.
 *
 * A pid argument >= 0 removes the PID from the session tracker.
 * A pid argument of -1 means "untrack all PIDs".
 *
 * Return 0 on success else a negative LTTng error code.
 */
extern int lttng_untrack_pid(struct lttng_handle *handle, int pid);

/*
 * List PIDs in the tracker.
 *
 * enabled is set to whether the PID tracker is enabled.
 * pids is set to an allocated array of PIDs currently tracked. On
 * success, pids must be freed by the caller.
 * nr_pids is set to the number of entries contained by the pids array.
 *
 * Returns 0 on success, else a negative LTTng error code.
 */
extern int lttng_list_tracker_pids(struct lttng_handle *handle,
		int *enabled, int32_t **pids, size_t *nr_pids);

#ifdef __cplusplus
}
#endif

#endif /* LTTNG_SESSION_H */
Commit	Line	Data
1239a312 DG	1	/*
1239a312 DG	2	* Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
3e3665b8	3	* Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
1239a312 DG	4	*
	5	* This library is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU Lesser General Public License, version 2.1 only,
	7	* as published by the Free Software Foundation.
	8	*
	9	* This library is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
	12	* for more details.
	13	*
	14	* You should have received a copy of the GNU Lesser General Public License
	15	* along with this library; if not, write to the Free Software Foundation,
	16	* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	17	*/
	18
	19	#ifndef LTTNG_SESSION_H
	20	#define LTTNG_SESSION_H
	21
	22	#ifdef __cplusplus
	23	extern "C" {
	24	#endif
	25
41ef8f63 JR	26	enum lttng_tracker_type {
	27	LTTNG_TRACKER_PID = 0,
	28	LTTNG_TRACKER_VPID = 1,
	29	LTTNG_TRACKER_UID = 2,
	30	LTTNG_TRACKER_GID = 3,
	31	LTTNG_TRACKER_VUID = 4,
	32	LTTNG_TRACKER_VGID = 5,
	33	};
	34
	35	enum lttng_tracker_id_type {
	36	LTTNG_ID_UNKNOWN = -1,
	37	LTTNG_ID_ALL = 0,
	38	LTTNG_ID_VALUE = 1,
	39	LTTNG_ID_STRING = 2,
	40	};
	41
	42	struct lttng_tracker_id {
	43	enum lttng_tracker_id_type type;
	44	int value;
	45	char *string;
	46	};
	47
b178f53e	48	struct lttng_session_descriptor;
3e3665b8	49	struct lttng_destruction_handle;
b178f53e	50
1239a312 DG	51	/*
	52	* Basic session information.
	53	*
	54	* The "enabled" field is only used when listing the sessions which indicate if
	55	* it's started or not.
	56	*
	57	* The structures should be initialized to zero before use.
	58	*/
e9af56b3	59	#define LTTNG_SESSION_PADDING1 8
1239a312	60	struct lttng_session {
36d2e35d	61	char name[LTTNG_NAME_MAX];
beede00c JG	62	/*
	63	* Human-readable representation of the trace's destination.
	64	* In the case of a local tracing session, a path is provided:
	65	* /path/to/the/output
	66	*
	67	* In the case of a remote (network) tracing session, the string has
	68	* the following format:
	69	* net://hostname/path:ctrl_port [data: data_port]
	70	*/
1239a312 DG	71	char path[PATH_MAX];
	72	uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
	73	uint32_t snapshot_mode;
	74	unsigned int live_timer_interval; /* usec */
	75
e9af56b3 JG	76	/*
	77	* End of public attributes.
	78	* The remaining fields are used to deal with ABI management concerns.
	79	*/
	80
	81	/*
	82	* 32-bit architectures are already naturally aligned on 4 bytes after
	83	* 'live_timer_interval'. However, the offset does not result in a
	84	* natural alignment on 64-bit architectures. Adding 4 bytes of
	85	* padding here results in an aligned offset after 'alignement_padding'
	86	* for both bitnesses.
	87	*
	88	* This was added since not all compilers appear to align unions in the
	89	* same way. Some (e.g. MSVC) do not seem to impose an alignement
	90	* constraint while others (e.g. gcc, clang, icc) seem to align it to
	91	* ensure 'ptr' is naturally aligned.
	92	*/
	93	char alignment_padding[4];
b178f53e	94	union {
e9af56b3 JG	95	/*
	96	* Ensure the 'extended' union has the same size for both
	97	* 32-bit and 64-bit builds.
	98	*/
b178f53e JG	99	char padding[LTTNG_SESSION_PADDING1];
	100	void *ptr;
	101	} extended;
1239a312 DG	102	};
1239a312 DG	103
b178f53e JG	104	/*
	105	* Create a session on the session daemon from a session descriptor.
	106	*
	107	* See the session descriptor API description in session-descriptor.h
	108	*
	109	* Note that unspecified session descriptor parameters, such as a session's
	110	* name, are updated in the session descriptor if the creation of the session
	111	* succeeds. This allows users to query the session's auto-generated name
	112	* after its creation. Note that other attributes can be queried using the
	113	* session listing API.
	114	*
	115	* Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
	116	* return codes.
	117	*/
	118	extern enum lttng_error_code lttng_create_session_ext(
	119	struct lttng_session_descriptor *session_descriptor);
	120
1239a312 DG	121	/*
	122	* Create a tracing session using a name and an optional URL.
	123	*
	124	* If _url_ is NULL, no consumer is created for the session. The name can't be
	125	* NULL here.
	126	*
	127	* Return 0 on success else a negative LTTng error code.
	128	*/
	129	extern int lttng_create_session(const char name, const char url);
	130
	131	/*
	132	* Create a tracing session that will exclusively be used for snapshot meaning
	133	* the session will be in no output mode and every channel enabled for that
	134	* session will be set in overwrite mode and in mmap output since splice is not
	135	* supported.
	136	*
	137	* Name can't be NULL. If an url is given, it will be used to create a default
	138	* snapshot output using it as a destination. If NULL, no output will be
	139	* defined and an add-output call will be needed.
	140	*
	141	* Return 0 on success else a negative LTTng error code.
	142	*/
	143	extern int lttng_create_session_snapshot(const char *name,
	144	const char *snapshot_url);
	145
	146	/*
	147	* Create a session exclusively used for live reading.
	148	*
	149	* In this mode, the switch-timer parameter is forced for each UST channel, a
	150	* live-switch-timer is enabled for kernel channels, manually setting
	151	* switch-timer is forbidden. Synchronization beacons are sent to the relayd,
	152	* indexes are sent and metadata is checked for each packet.
	153	*
	154	* Name can't be NULL. If no URL is given, the default is to send the data to
1aacaae2	155	* net://127.0.0.1. The timer_interval is in usec.
1239a312 DG	156	*
	157	* Return 0 on success else a negative LTTng error code.
	158	*/
	159	extern int lttng_create_session_live(const char name, const char url,
	160	unsigned int timer_interval);
	161
	162	/*
	163	* Destroy a tracing session.
	164	*
	165	* The session will not be usable, tracing will be stopped thus buffers will be
	166	* flushed.
	167	*
e20ee7c2 JD	168	* This call will wait for data availability for each domain of the session,
	169	* which can take an arbitrary amount of time. However, when returning the
	170	* tracing data is guaranteed to be ready to be read and analyzed.
	171	*
	172	* lttng_destroy_session_no_wait() may be used if such a guarantee is not
	173	* needed.
	174	*
1239a312 DG	175	* The name can't be NULL here.
1239a312 DG	176	*
780d4bb8	177	* Return 0 on success else a negative LTTng error code.
1239a312 DG	178	*/
	179	extern int lttng_destroy_session(const char *name);
	180
3e3665b8 JG	181	/*
	182	* Destroy a tracing session.
	183	*
	184	* Performs the same function as lttng_destroy_session(), but provides
	185	* an lttng_destruction_handle which can be used to wait for the completion
	186	* of the session's destruction. The lttng_destroy_handle can also be used
	187	* obtain the status and archive location of any implicit session
83ed9e90	188	* rotation that may have occurred during the session's destruction.
3e3665b8 JG	189	*
	190	* Returns LTTNG_OK on success. The returned handle is owned by the caller
	191	* and must be free'd using lttng_destruction_handle_destroy().
	192	*/
	193	extern enum lttng_error_code lttng_destroy_session_ext(const char *session_name,
	194	struct lttng_destruction_handle **handle);
	195
e20ee7c2 JD	196	/*
	197	* Behaves exactly like lttng_destroy_session but does not wait for data
	198	* availability.
	199	*/
	200	extern int lttng_destroy_session_no_wait(const char *name);
	201
1239a312 DG	202	/*
	203	* List all the tracing sessions.
	204	*
b178f53e JG	205	* Return the number of entries of the "lttng_session" array. The caller
	206	* must free the returned sessions array directly using free().
	207	*
	208	* On error, a negative LTTng error code is returned.
1239a312 DG	209	*/
	210	extern int lttng_list_sessions(struct lttng_session **sessions);
	211
b178f53e JG	212	/*
	213	* Get the creation time of an lttng_session object on the session daemon.
	214	*
	215	* This function must only be used with lttng_session objects returned
	216	* by lttng_list_sessions() or lttng_session_create().
	217	*
	218	* The creation time returned is a UNIX timestamp; the number of seconds since
	219	* Epoch (1970-01-01 00:00:00 +0000 (UTC)).
	220	*
	221	* Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
	222	* return codes.
	223	*/
	224	extern enum lttng_error_code lttng_session_get_creation_time(
	225	const struct lttng_session session, uint64_t creation_time);
	226
d7ba1388 MD	227	/*
	228	* Set the shared memory path for a session.
	229	*
	230	* Sets the (optional) file system path where shared memory buffers will
	231	* be created for the session. This is useful for buffer extraction on
	232	* crash, when used with filesystems like pramfs.
	233	*
	234	* Return 0 on success else a negative LTTng error code.
	235	*/
	236	extern int lttng_set_session_shm_path(const char *session_name,
	237	const char *shm_path);
	238
ccf10263 MD	239	/*
	240	* Add PID to session tracker.
	241	*
	242	* A pid argument >= 0 adds the PID to the session tracker.
	243	* A pid argument of -1 means "track all PIDs".
	244	*
	245	* Return 0 on success else a negative LTTng error code.
	246	*/
	247	extern int lttng_track_pid(struct lttng_handle *handle, int pid);
	248
	249	/*
	250	* Remove PID from session tracker.
	251	*
	252	* A pid argument >= 0 removes the PID from the session tracker.
	253	* A pid argument of -1 means "untrack all PIDs".
	254	*
	255	* Return 0 on success else a negative LTTng error code.
	256	*/
	257	extern int lttng_untrack_pid(struct lttng_handle *handle, int pid);
	258
a5dfbb9d MD	259	/*
	260	* List PIDs in the tracker.
	261	*
36dc4128 JG	262	* enabled is set to whether the PID tracker is enabled.
	263	* pids is set to an allocated array of PIDs currently tracked. On
	264	* success, pids must be freed by the caller.
	265	* nr_pids is set to the number of entries contained by the pids array.
a5dfbb9d MD	266	*
	267	* Returns 0 on success, else a negative LTTng error code.
	268	*/
	269	extern int lttng_list_tracker_pids(struct lttng_handle *handle,
	270	int enabled, int32_t pids, size_t nr_pids);
	271
1239a312 DG	272	#ifdef __cplusplus
	273	}
	274	#endif
	275
	276	#endif /* LTTNG_SESSION_H */