2 * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
4 * This library is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License, version 2.1 only,
6 * as published by the Free Software Foundation.
8 * This library is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this library; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 #ifndef LTTNG_SESSION_H
19 #define LTTNG_SESSION_H
25 #include <lttng/constant.h>
27 enum lttng_tracker_type
{
28 LTTNG_TRACKER_PID
= 0,
36 enum lttng_tracker_id_type
{
37 LTTNG_ID_UNKNOWN
= -1,
44 struct lttng_tracker_id
{
45 enum lttng_tracker_id_type type
;
53 * Basic session information.
55 * The "enabled" field is only used when listing the sessions which indicate if
56 * it's started or not.
58 * The structures should be initialized to zero before use.
60 #define LTTNG_SESSION_PADDING1 12
61 struct lttng_session
{
62 char name
[LTTNG_NAME_MAX
];
63 /* The path where traces are written */
65 uint32_t enabled
; /* enabled/started: 1, disabled/stopped: 0 */
66 uint32_t snapshot_mode
;
67 unsigned int live_timer_interval
; /* usec */
69 char padding
[LTTNG_SESSION_PADDING1
];
73 * Create a tracing session using a name and an optional URL.
75 * If _url_ is NULL, no consumer is created for the session. The name can't be
78 * Return 0 on success else a negative LTTng error code.
80 extern int lttng_create_session(const char *name
, const char *url
);
83 * Create a tracing session that will exclusively be used for snapshot meaning
84 * the session will be in no output mode and every channel enabled for that
85 * session will be set in overwrite mode and in mmap output since splice is not
88 * Name can't be NULL. If an url is given, it will be used to create a default
89 * snapshot output using it as a destination. If NULL, no output will be
90 * defined and an add-output call will be needed.
92 * Return 0 on success else a negative LTTng error code.
94 extern int lttng_create_session_snapshot(const char *name
,
95 const char *snapshot_url
);
98 * Create a session exclusively used for live reading.
100 * In this mode, the switch-timer parameter is forced for each UST channel, a
101 * live-switch-timer is enabled for kernel channels, manually setting
102 * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
103 * indexes are sent and metadata is checked for each packet.
105 * Name can't be NULL. If no URL is given, the default is to send the data to
106 * net://127.0.0.1. The timer_interval is in usec and by default set to 1000000
109 * Return 0 on success else a negative LTTng error code.
111 extern int lttng_create_session_live(const char *name
, const char *url
,
112 unsigned int timer_interval
);
115 * Destroy a tracing session.
117 * The session will not be usable, tracing will be stopped thus buffers will be
120 * This call will wait for data availability for each domain of the session,
121 * which can take an arbitrary amount of time. However, when returning the
122 * tracing data is guaranteed to be ready to be read and analyzed.
124 * lttng_destroy_session_no_wait() may be used if such a guarantee is not
127 * The name can't be NULL here.
129 * Return 0 on success else a negative LTTng error code.
131 extern int lttng_destroy_session(const char *name
);
134 * Behaves exactly like lttng_destroy_session but does not wait for data
137 extern int lttng_destroy_session_no_wait(const char *name
);
140 * List all the tracing sessions.
142 * Return the size (number of entries) of the "lttng_session" array. Caller
143 * must free sessions. On error, a negative LTTng error code is returned.
145 extern int lttng_list_sessions(struct lttng_session
**sessions
);
148 * Set the shared memory path for a session.
150 * Sets the (optional) file system path where shared memory buffers will
151 * be created for the session. This is useful for buffer extraction on
152 * crash, when used with filesystems like pramfs.
154 * Return 0 on success else a negative LTTng error code.
156 extern int lttng_set_session_shm_path(const char *session_name
,
157 const char *shm_path
);
160 * Add ID to session tracker.
162 * tracker_type is the type of tracker.
163 * An id argument >= 0 adds the ID to the session tracker.
164 * An id argument of -1 means "track all IDs".
166 * Return 0 on success else a negative LTTng error code.
168 extern int lttng_track_id(struct lttng_handle
*handle
,
169 enum lttng_tracker_type tracker_type
,
170 struct lttng_tracker_id
*id
);
173 * Remove ID from session tracker.
175 * tracker_type is the type of tracker.
176 * An id argument >= 0 removes the ID from the session tracker.
177 * An id argument of -1 means "untrack all IDs".
179 * Return 0 on success else a negative LTTng error code.
181 extern int lttng_untrack_id(struct lttng_handle
*handle
,
182 enum lttng_tracker_type tracker_type
,
183 struct lttng_tracker_id
*id
);
186 * List IDs in the tracker.
188 * tracker_type is the type of tracker.
189 * ids is set to an allocated array of IDs currently tracked. On
190 * success, ids and the strings it contains must be freed by the
192 * nr_ids is set to the number of entries contained by the ids array.
194 * Returns 0 on success, else a negative LTTng error code.
196 extern int lttng_list_tracker_ids(struct lttng_handle
*handle
,
197 enum lttng_tracker_type tracker_type
,
198 struct lttng_tracker_id
**ids
,
202 * Add PID to session tracker.
204 * A pid argument >= 0 adds the PID to the session tracker.
205 * A pid argument of -1 means "track all PIDs".
207 * Return 0 on success else a negative LTTng error code.
209 extern int lttng_track_pid(struct lttng_handle
*handle
, int pid
);
212 * Remove PID from session tracker.
214 * A pid argument >= 0 removes the PID from the session tracker.
215 * A pid argument of -1 means "untrack all PIDs".
217 * Return 0 on success else a negative LTTng error code.
219 extern int lttng_untrack_pid(struct lttng_handle
*handle
, int pid
);
222 * List PIDs in the tracker.
224 * enabled is set to whether the PID tracker is enabled.
225 * pids is set to an allocated array of PIDs currently tracked. On
226 * success, pids must be freed by the caller.
227 * nr_pids is set to the number of entries contained by the pids array.
229 * Returns 0 on success, else a negative LTTng error code.
231 extern int lttng_list_tracker_pids(struct lttng_handle
*handle
,
232 int *enabled
, int32_t **pids
, size_t *nr_pids
);
238 #endif /* LTTNG_SESSION_H */