2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 #ifndef _LTT_SESSION_H
19 #define _LTT_SESSION_H
23 #include <urcu/list.h>
25 #include <common/hashtable/hashtable.h>
26 #include <lttng/rotation.h>
27 #include <lttng/location.h>
28 #include <lttng/lttng-error.h>
31 #include "trace-kernel.h"
34 struct ltt_ust_session
;
37 * Tracing session list
39 * Statically declared in session.c and can be accessed by using
40 * session_get_list() function that returns the pointer to the list.
42 struct ltt_session_list
{
44 * This lock protects any read/write access to the list and
45 * next_uuid. All public functions in session.c acquire this
46 * lock and release it before returning. If none of those
47 * functions are used, the lock MUST be acquired in order to
48 * iterate or/and do any actions on that list.
52 * This condition variable is signaled on every removal from
55 pthread_cond_t removal_cond
;
58 * Session unique ID generator. The session list lock MUST be
59 * upon update and read of this counter.
63 /* Linked list head */
64 struct cds_list_head head
;
68 * This data structure contains information needed to identify a tracing
69 * session for both LTTng and UST.
73 bool has_auto_generated_name
;
74 char hostname
[HOST_NAME_MAX
]; /* Local hostname. */
76 struct ltt_kernel_session
*kernel_session
;
77 struct ltt_ust_session
*ust_session
;
80 * Protect any read/write on this session data structure. This lock must be
81 * acquired *before* using any public functions declared below. Use
82 * session_lock() and session_unlock() for that.
85 struct cds_list_head list
;
86 uint64_t id
; /* session unique identifier */
87 /* Indicates if the session has been added to the session list and ht.*/
89 /* Indicates if a destroy command has been applied to this session. */
91 /* UID/GID of the user owning the session */
95 * Network session handle. A value of 0 means that there is no remote
96 * session established.
100 * This consumer is only set when the create_session_uri call is made.
101 * This contains the temporary information for a consumer output. Upon
102 * creation of the UST or kernel session, this consumer, if available, is
103 * copied into those sessions.
105 struct consumer_output
*consumer
;
107 * Indicates whether or not the user has specified an output directory
108 * or if it was configured using the default configuration.
110 bool has_user_specified_directory
;
111 /* Did at least ONE start command has been triggered?. */
112 unsigned int has_been_started
:1;
114 * Is the session active? Start trace command sets this to 1 and the stop
115 * command reset it to 0.
117 unsigned int active
:1;
119 /* Snapshot representation in a session. */
120 struct snapshot snapshot
;
121 /* Indicate if the session has to output the traces or not. */
122 unsigned int output_traces
;
124 * This session is in snapshot mode. This means that channels enabled
125 * will be set in overwrite mode by default and must be in mmap
126 * output mode. Note that snapshots can be taken on a session that
127 * is not in "snapshot_mode". This parameter only affects channel
130 unsigned int snapshot_mode
;
132 * A session that has channels that don't use 'mmap' output can't be
133 * used to capture snapshots. This is set to true whenever a
134 * 'splice' kernel channel is enabled.
136 bool has_non_mmap_channel
;
138 * Timer set when the session is created for live reading.
140 unsigned int live_timer
;
142 * Path where to keep the shared memory files.
144 char shm_path
[PATH_MAX
];
146 * Node in ltt_sessions_ht_by_id.
148 struct lttng_ht_node_u64 node
;
150 * Timer to check periodically if a relay and/or consumer has completed
153 bool rotation_pending_check_timer_enabled
;
154 timer_t rotation_pending_check_timer
;
155 /* Timer to periodically rotate a session. */
156 bool rotation_schedule_timer_enabled
;
157 timer_t rotation_schedule_timer
;
158 /* Value for periodic rotations, 0 if disabled. */
159 uint64_t rotate_timer_period
;
160 /* Value for size-based rotations, 0 if disabled. */
161 uint64_t rotate_size
;
163 * Keep a state if this session was rotated after the last stop command.
164 * We only allow one rotation after a stop. At destroy, we also need to
165 * know if a rotation occurred since the last stop to rename the current
168 bool rotated_after_last_stop
;
170 * Condition and trigger for size-based rotations.
172 struct lttng_condition
*rotate_condition
;
173 struct lttng_trigger
*rotate_trigger
;
174 LTTNG_OPTIONAL(uint64_t) most_recent_chunk_id
;
175 struct lttng_trace_chunk
*current_trace_chunk
;
176 struct lttng_trace_chunk
*chunk_being_archived
;
177 /* Current state of a rotation. */
178 enum lttng_rotation_state rotation_state
;
179 char *last_archived_chunk_name
;
180 LTTNG_OPTIONAL(uint64_t) last_archived_chunk_id
;
184 enum lttng_error_code
session_create(const char *name
, uid_t uid
, gid_t gid
,
185 struct ltt_session
**out_session
);
186 void session_lock(struct ltt_session
*session
);
187 void session_lock_list(void);
188 int session_trylock_list(void);
189 void session_unlock(struct ltt_session
*session
);
190 void session_unlock_list(void);
192 void session_destroy(struct ltt_session
*session
);
194 bool session_get(struct ltt_session
*session
);
195 void session_put(struct ltt_session
*session
);
197 enum consumer_dst_type
session_get_consumer_destination_type(
198 const struct ltt_session
*session
);
199 const char *session_get_net_consumer_hostname(
200 const struct ltt_session
*session
);
201 void session_get_net_consumer_ports(
202 const struct ltt_session
*session
,
203 uint16_t *control_port
, uint16_t *data_port
);
204 struct lttng_trace_archive_location
*session_get_trace_archive_location(
205 struct ltt_session
*session
);
207 struct ltt_session
*session_find_by_name(const char *name
);
208 struct ltt_session
*session_find_by_id(uint64_t id
);
210 struct ltt_session_list
*session_get_list(void);
211 void session_list_wait_empty(void);
213 int session_access_ok(struct ltt_session
*session
, uid_t uid
, gid_t gid
);
215 int session_reset_rotation_state(struct ltt_session
*session
,
216 enum lttng_rotation_state result
);
218 /* Create a new trace chunk object from the session's configuration. */
219 struct lttng_trace_chunk
*session_create_new_trace_chunk(
220 struct ltt_session
*session
,
221 const char *session_base_path_override
,
222 const char *chunk_name_override
);
225 * Set `new_trace_chunk` as the session's current trace chunk. A reference
226 * to `new_trace_chunk` is acquired by the session. The chunk is created
227 * on remote peers (consumer and relay daemons).
229 * A reference to the session's current trace chunk is returned through
230 * `current_session_trace_chunk` on success.
232 int session_set_trace_chunk(struct ltt_session
*session
,
233 struct lttng_trace_chunk
*new_trace_chunk
,
234 struct lttng_trace_chunk
**current_session_trace_chunk
);
237 * Close a chunk on the remote peers of a session. Has no effect on the
238 * ltt_session itself.
240 int session_close_trace_chunk(const struct ltt_session
*session
,
241 struct lttng_trace_chunk
*trace_chunk
);
243 #endif /* _LTT_SESSION_H */