Docs: lttng-ctl has no default live timer period
[lttng-tools.git] / include / lttng / session.h
CommitLineData
1239a312
DG
1/*
2 * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
3 *
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.
7 *
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
11 * for more details.
12 *
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
16 */
17
18#ifndef LTTNG_SESSION_H
19#define LTTNG_SESSION_H
20
21#ifdef __cplusplus
22extern "C" {
23#endif
24
25/*
26 * Basic session information.
27 *
28 * The "enabled" field is only used when listing the sessions which indicate if
29 * it's started or not.
30 *
31 * The structures should be initialized to zero before use.
32 */
33#define LTTNG_SESSION_PADDING1 12
34struct lttng_session {
36d2e35d 35 char name[LTTNG_NAME_MAX];
1239a312
DG
36 /* The path where traces are written */
37 char path[PATH_MAX];
38 uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */
39 uint32_t snapshot_mode;
40 unsigned int live_timer_interval; /* usec */
41
42 char padding[LTTNG_SESSION_PADDING1];
43};
44
45/*
46 * Create a tracing session using a name and an optional URL.
47 *
48 * If _url_ is NULL, no consumer is created for the session. The name can't be
49 * NULL here.
50 *
51 * Return 0 on success else a negative LTTng error code.
52 */
53extern int lttng_create_session(const char *name, const char *url);
54
55/*
56 * Create a tracing session that will exclusively be used for snapshot meaning
57 * the session will be in no output mode and every channel enabled for that
58 * session will be set in overwrite mode and in mmap output since splice is not
59 * supported.
60 *
61 * Name can't be NULL. If an url is given, it will be used to create a default
62 * snapshot output using it as a destination. If NULL, no output will be
63 * defined and an add-output call will be needed.
64 *
65 * Return 0 on success else a negative LTTng error code.
66 */
67extern int lttng_create_session_snapshot(const char *name,
68 const char *snapshot_url);
69
70/*
71 * Create a session exclusively used for live reading.
72 *
73 * In this mode, the switch-timer parameter is forced for each UST channel, a
74 * live-switch-timer is enabled for kernel channels, manually setting
75 * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
76 * indexes are sent and metadata is checked for each packet.
77 *
78 * Name can't be NULL. If no URL is given, the default is to send the data to
1aacaae2 79 * net://127.0.0.1. The timer_interval is in usec.
1239a312
DG
80 *
81 * Return 0 on success else a negative LTTng error code.
82 */
83extern int lttng_create_session_live(const char *name, const char *url,
84 unsigned int timer_interval);
85
86/*
87 * Destroy a tracing session.
88 *
89 * The session will not be usable, tracing will be stopped thus buffers will be
90 * flushed.
91 *
e20ee7c2
JD
92 * This call will wait for data availability for each domain of the session,
93 * which can take an arbitrary amount of time. However, when returning the
94 * tracing data is guaranteed to be ready to be read and analyzed.
95 *
96 * lttng_destroy_session_no_wait() may be used if such a guarantee is not
97 * needed.
98 *
1239a312
DG
99 * The name can't be NULL here.
100 *
101 * Return 0 on success else a negative LTTng error code.
102 */
103extern int lttng_destroy_session(const char *name);
104
e20ee7c2
JD
105/*
106 * Behaves exactly like lttng_destroy_session but does not wait for data
107 * availability.
108 */
109extern int lttng_destroy_session_no_wait(const char *name);
110
1239a312
DG
111/*
112 * List all the tracing sessions.
113 *
114 * Return the size (number of entries) of the "lttng_session" array. Caller
115 * must free sessions. On error, a negative LTTng error code is returned.
116 */
117extern int lttng_list_sessions(struct lttng_session **sessions);
118
d7ba1388
MD
119/*
120 * Set the shared memory path for a session.
121 *
122 * Sets the (optional) file system path where shared memory buffers will
123 * be created for the session. This is useful for buffer extraction on
124 * crash, when used with filesystems like pramfs.
125 *
126 * Return 0 on success else a negative LTTng error code.
127 */
128extern int lttng_set_session_shm_path(const char *session_name,
129 const char *shm_path);
130
ccf10263
MD
131/*
132 * Add PID to session tracker.
133 *
134 * A pid argument >= 0 adds the PID to the session tracker.
135 * A pid argument of -1 means "track all PIDs".
136 *
137 * Return 0 on success else a negative LTTng error code.
138 */
139extern int lttng_track_pid(struct lttng_handle *handle, int pid);
140
141/*
142 * Remove PID from session tracker.
143 *
144 * A pid argument >= 0 removes the PID from the session tracker.
145 * A pid argument of -1 means "untrack all PIDs".
146 *
147 * Return 0 on success else a negative LTTng error code.
148 */
149extern int lttng_untrack_pid(struct lttng_handle *handle, int pid);
150
a5dfbb9d
MD
151/*
152 * List PIDs in the tracker.
153 *
36dc4128
JG
154 * enabled is set to whether the PID tracker is enabled.
155 * pids is set to an allocated array of PIDs currently tracked. On
156 * success, pids must be freed by the caller.
157 * nr_pids is set to the number of entries contained by the pids array.
a5dfbb9d
MD
158 *
159 * Returns 0 on success, else a negative LTTng error code.
160 */
161extern int lttng_list_tracker_pids(struct lttng_handle *handle,
162 int *enabled, int32_t **pids, size_t *nr_pids);
163
1239a312
DG
164#ifdef __cplusplus
165}
166#endif
167
168#endif /* LTTNG_SESSION_H */
This page took 0.067931 seconds and 5 git commands to generate.