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 * The current archive id corresponds to the number of session rotations
151 * that have occurred for this session. The archive id
152 * is used to tag the "generation" of a stream. This tag allows the
153 * consumer and relay daemons to track when a given stream was created
154 * during the lifetime of a session.
156 * For instance, if a stream is created after a session rotation was
157 * launched, the consumer and relay daemons must not check its position
158 * to determine if that specific session rotation was completed. It is
159 * implicitly "completed" since the stream appeared _after_ the session
160 * rotation was initiated.
162 uint64_t current_archive_id
;
164 * Rotation is considered pending between the time it is launched up
165 * until the moment when the data has been writen at the destination
166 * and the trace archive has been renamed.
168 * When tracing locally, only 'rotation_pending_local' is used since
169 * no remote checks are needed. However, when tracing to a relay daemon,
170 * a second check is needed to ensure that the data has been
171 * commited at the remote destination.
173 bool rotation_pending_local
;
174 bool rotation_pending_relay
;
175 /* Current state of a rotation. */
176 enum lttng_rotation_state rotation_state
;
179 * When the rotation is in progress, the temporary path name is
180 * stored here. When the rotation is complete, the final path name
181 * is here and can be queried with the rotate_pending call.
183 char current_rotate_path
[LTTNG_PATH_MAX
];
185 * The path where the consumer is currently writing after the first
188 char active_tracing_path
[LTTNG_PATH_MAX
];
191 * The timestamp of the beginning of the previous chunk. For the
192 * first chunk, this is the "lttng start" timestamp. For the
193 * subsequent ones, this copies the current_chunk_start_ts value when
194 * a new rotation starts. This value is used to set the name of a
195 * complete chunk directory, ex: "last_chunk_start_ts-now()".
197 time_t last_chunk_start_ts
;
199 * This is the timestamp when a new chunk starts. When a new rotation
200 * starts, we copy this value to last_chunk_start_ts and replace it
201 * with the current timestamp.
203 time_t current_chunk_start_ts
;
205 * Timer to check periodically if a relay and/or consumer has completed
208 bool rotation_pending_check_timer_enabled
;
209 timer_t rotation_pending_check_timer
;
210 /* Timer to periodically rotate a session. */
211 bool rotation_schedule_timer_enabled
;
212 timer_t rotation_schedule_timer
;
213 /* Value for periodic rotations, 0 if disabled. */
214 uint64_t rotate_timer_period
;
215 /* Value for size-based rotations, 0 if disabled. */
216 uint64_t rotate_size
;
218 * Keep a state if this session was rotated after the last stop command.
219 * We only allow one rotation after a stop. At destroy, we also need to
220 * know if a rotation occurred since the last stop to rename the current
223 bool rotated_after_last_stop
;
225 * Condition and trigger for size-based rotations.
227 struct lttng_condition
*rotate_condition
;
228 struct lttng_trigger
*rotate_trigger
;
229 LTTNG_OPTIONAL(uint64_t) last_trace_chunk_id
;
230 struct lttng_trace_chunk
*current_trace_chunk
;
234 enum lttng_error_code
session_create(const char *name
, uid_t uid
, gid_t gid
,
235 struct ltt_session
**out_session
);
236 void session_lock(struct ltt_session
*session
);
237 void session_lock_list(void);
238 int session_trylock_list(void);
239 void session_unlock(struct ltt_session
*session
);
240 void session_unlock_list(void);
242 void session_destroy(struct ltt_session
*session
);
244 bool session_get(struct ltt_session
*session
);
245 void session_put(struct ltt_session
*session
);
247 enum consumer_dst_type
session_get_consumer_destination_type(
248 const struct ltt_session
*session
);
249 const char *session_get_net_consumer_hostname(
250 const struct ltt_session
*session
);
251 void session_get_net_consumer_ports(
252 const struct ltt_session
*session
,
253 uint16_t *control_port
, uint16_t *data_port
);
254 struct lttng_trace_archive_location
*session_get_trace_archive_location(
255 struct ltt_session
*session
);
257 struct ltt_session
*session_find_by_name(const char *name
);
258 struct ltt_session
*session_find_by_id(uint64_t id
);
260 struct ltt_session_list
*session_get_list(void);
261 void session_list_wait_empty(void);
263 int session_access_ok(struct ltt_session
*session
, uid_t uid
, gid_t gid
);
265 int session_reset_rotation_state(struct ltt_session
*session
,
266 enum lttng_rotation_state result
);
268 enum lttng_error_code
session_switch_trace_chunk(struct ltt_session
*session
,
269 const char *session_base_path_override
,
270 const char *chunk_name_override
);
271 int session_set_trace_chunk(struct ltt_session
*session
,
272 struct lttng_trace_chunk
*current_trace_chunk
);
274 #endif /* _LTT_SESSION_H */