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>
30 #include "trace-kernel.h"
33 struct ltt_ust_session
;
36 * Tracing session list
38 * Statically declared in session.c and can be accessed by using
39 * session_get_list() function that returns the pointer to the list.
41 struct ltt_session_list
{
43 * This lock protects any read/write access to the list and
44 * next_uuid. All public functions in session.c acquire this
45 * lock and release it before returning. If none of those
46 * functions are used, the lock MUST be acquired in order to
47 * iterate or/and do any actions on that list.
52 * Session unique ID generator. The session list lock MUST be
53 * upon update and read of this counter.
57 /* Linked list head */
58 struct cds_list_head head
;
62 * This data structure contains information needed to identify a tracing
63 * session for both LTTng and UST.
67 char hostname
[HOST_NAME_MAX
]; /* Local hostname. */
68 struct ltt_kernel_session
*kernel_session
;
69 struct ltt_ust_session
*ust_session
;
71 * Protect any read/write on this session data structure. This lock must be
72 * acquired *before* using any public functions declared below. Use
73 * session_lock() and session_unlock() for that.
76 struct cds_list_head list
;
77 uint64_t id
; /* session unique identifier */
78 /* UID/GID of the user owning the session */
82 * Network session handle. A value of 0 means that there is no remote
83 * session established.
87 * This consumer is only set when the create_session_uri call is made.
88 * This contains the temporary information for a consumer output. Upon
89 * creation of the UST or kernel session, this consumer, if available, is
90 * copied into those sessions.
92 struct consumer_output
*consumer
;
94 /* Did at least ONE start command has been triggered?. */
95 unsigned int has_been_started
:1;
97 * Is the session active? Start trace command sets this to 1 and the stop
98 * command reset it to 0.
100 unsigned int active
:1;
102 /* Snapshot representation in a session. */
103 struct snapshot snapshot
;
104 /* Indicate if the session has to output the traces or not. */
105 unsigned int output_traces
;
107 * This session is in snapshot mode. This means that every channel enabled
108 * will be set in overwrite mode and mmap. It is considered exclusively for
111 unsigned int snapshot_mode
;
113 * Timer set when the session is created for live reading.
115 unsigned int live_timer
;
117 * Path where to keep the shared memory files.
119 char shm_path
[PATH_MAX
];
121 * Node in ltt_sessions_ht_by_id.
123 struct lttng_ht_node_u64 node
;
125 * The current archive id corresponds to the number of session rotations
126 * that have occured for this session. The archive id
127 * is used to tag the "generation" of a stream. This tag allows the
128 * consumer and relay daemons to track when a given stream was created
129 * during the lifetime of a session.
131 * For instance, if a stream is created after a session rotation was
132 * launched, the consumer and relay daemons must not check its position
133 * to determine if that specific session rotation was completed. It is
134 * implicitly "completed" since the stream appeared _after_ the session
135 * rotation was initiated.
137 uint64_t current_archive_id
;
139 * Rotation is pending between the time it starts until the consumer has
140 * finished extracting the data. If the session uses a relay, data related
141 * to a rotation can still be in flight after that, see
142 * rotate_pending_relay.
146 * True until the relay has finished the rotation of all the streams.
148 bool rotate_pending_relay
;
149 /* Current state of a rotation. */
150 enum lttng_rotation_state rotation_state
;
152 * Number of channels waiting for a rotation.
153 * When this number reaches 0, we can handle the rename of the chunk
154 * folder and inform the client that the rotate is finished.
156 unsigned int nr_chan_rotate_pending
;
159 * When the rotation is in progress, the temporary path name is
160 * stored here. When the rotation is complete, the final path name
161 * is here and can be queried with the rotate_pending call.
163 char current_rotate_path
[LTTNG_PATH_MAX
];
165 * The path where the consumer is currently writing after the first
168 char active_tracing_path
[LTTNG_PATH_MAX
];
171 * The timestamp of the beginning of the previous chunk. For the
172 * first chunk, this is the "lttng start" timestamp. For the
173 * subsequent ones, this copies the current_chunk_start_ts value when
174 * a new rotation starts. This value is used to set the name of a
175 * complete chunk directory, ex: "last_chunk_start_ts-now()".
177 time_t last_chunk_start_ts
;
179 * This is the timestamp when a new chunk starts. When a new rotation
180 * starts, we copy this value to last_chunk_start_ts and replace it
181 * with the current timestamp.
183 time_t current_chunk_start_ts
;
185 * Timer to check periodically if a relay has completed the last
188 bool rotate_relay_pending_timer_enabled
;
189 timer_t rotate_relay_pending_timer
;
190 /* Timer to periodically rotate a session. */
191 bool rotate_timer_enabled
;
192 timer_t rotate_timer
;
193 /* Value for periodic rotations, 0 if disabled. */
194 uint64_t rotate_timer_period
;
195 /* Value for size-based rotations, 0 if disabled. */
196 uint64_t rotate_size
;
198 * Keep a state if this session was rotated after the last stop command.
199 * We only allow one rotation after a stop. At destroy, we also need to
200 * know if a rotation occured since the last stop to rename the current
203 bool rotated_after_last_stop
;
205 * Condition and trigger for size-based rotations.
207 struct lttng_condition
*rotate_condition
;
208 struct lttng_trigger
*rotate_trigger
;
212 int session_create(char *name
, uid_t uid
, gid_t gid
);
213 int session_destroy(struct ltt_session
*session
);
215 void session_lock(struct ltt_session
*session
);
216 void session_lock_list(void);
217 int session_trylock_list(void);
218 void session_unlock(struct ltt_session
*session
);
219 void session_unlock_list(void);
221 enum consumer_dst_type
session_get_consumer_destination_type(
222 const struct ltt_session
*session
);
223 const char *session_get_net_consumer_hostname(
224 const struct ltt_session
*session
);
225 void session_get_net_consumer_ports(
226 const struct ltt_session
*session
,
227 uint16_t *control_port
, uint16_t *data_port
);
228 struct lttng_trace_archive_location
*session_get_trace_archive_location(
229 struct ltt_session
*session
);
231 struct ltt_session
*session_find_by_name(const char *name
);
232 struct ltt_session
*session_find_by_id(uint64_t id
);
233 struct ltt_session_list
*session_get_list(void);
235 int session_access_ok(struct ltt_session
*session
, uid_t uid
, gid_t gid
);
237 #endif /* _LTT_SESSION_H */