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
22 #include <urcu/list.h>
24 #include <common/hashtable/hashtable.h>
27 #include "trace-kernel.h"
29 struct ltt_ust_session
;
32 * Tracing session list
34 * Statically declared in session.c and can be accessed by using
35 * session_get_list() function that returns the pointer to the list.
37 struct ltt_session_list
{
39 * This lock protects any read/write access to the list and
40 * next_uuid. All public functions in session.c acquire this
41 * lock and release it before returning. If none of those
42 * functions are used, the lock MUST be acquired in order to
43 * iterate or/and do any actions on that list.
48 * Session unique ID generator. The session list lock MUST be
49 * upon update and read of this counter.
53 /* Linked list head */
54 struct cds_list_head head
;
57 struct ltt_session_chunk
{
59 * When the rotation is in progress, the temporary path name is
60 * stored here. When the rotation is complete, the final path name
61 * is here and can be queried with the rotate_pending call.
63 char current_rotate_path
[PATH_MAX
];
65 * The path where the consumer is currently writing after the first
68 char active_tracing_path
[PATH_MAX
];
72 * This data structure contains information needed to identify a tracing
73 * session for both LTTng and UST.
77 char hostname
[HOST_NAME_MAX
]; /* Local hostname. */
78 struct ltt_kernel_session
*kernel_session
;
79 struct ltt_ust_session
*ust_session
;
81 * Protect any read/write on this session data structure. This lock must be
82 * acquired *before* using any public functions declared below. Use
83 * session_lock() and session_unlock() for that.
86 struct cds_list_head list
;
87 uint64_t id
; /* session unique identifier */
88 /* UID/GID of the user owning the session */
92 * Network session handle. A value of 0 means that there is no remote
93 * session established.
97 * This consumer is only set when the create_session_uri call is made.
98 * This contains the temporary information for a consumer output. Upon
99 * creation of the UST or kernel session, this consumer, if available, is
100 * copied into those sessions.
102 struct consumer_output
*consumer
;
104 /* Did at least ONE start command has been triggered?. */
105 unsigned int has_been_started
:1;
107 * Is the session active? Start trace command sets this to 1 and the stop
108 * command reset it to 0.
110 unsigned int active
:1;
112 /* Snapshot representation in a session. */
113 struct snapshot snapshot
;
114 /* Indicate if the session has to output the traces or not. */
115 unsigned int output_traces
;
117 * This session is in snapshot mode. This means that every channel enabled
118 * will be set in overwrite mode and mmap. It is considered exclusively for
121 unsigned int snapshot_mode
;
123 * Timer set when the session is created for live reading.
125 unsigned int live_timer
;
127 * Path where to keep the shared memory files.
129 char shm_path
[PATH_MAX
];
131 * Node in ltt_sessions_ht_by_id.
133 struct lttng_ht_node_u64 node
;
135 * Number of session rotation for this session.
137 uint64_t rotate_count
;
138 unsigned int rotate_pending
:1;
139 enum lttng_rotate_status rotate_status
;
141 * Number of channels waiting for a rotate.
142 * When this number reaches 0, we can handle the rename of the chunk
143 * folder and inform the client that the rotate is finished.
145 * TODO: replace rotate_pending checks by that.
147 unsigned int nr_chan_rotate_pending
;
148 struct ltt_session_chunk rotation_chunk
;
150 * The timestamp of the beginning of the previous chunk. For the
151 * first chunk, this is the "lttng start" timestamp. For the
152 * subsequent ones, this copies the current_chunk_start_ts value when
153 * a new rotation starts. This value is used to set the name of a
154 * complete chunk directory, ex: "last_chunk_start_ts-now()".
156 time_t last_chunk_start_ts
;
158 * This is the timestamp when a new chunk starts. When a new rotation
159 * starts, we copy this value to last_chunk_start_ts and override it
160 * with the current timestamp.
162 time_t current_chunk_start_ts
;
163 time_t session_last_stop_ts
;
164 time_t last_begin_rotation_ts
;
168 int session_create(char *name
, uid_t uid
, gid_t gid
);
169 int session_destroy(struct ltt_session
*session
);
171 void session_lock(struct ltt_session
*session
);
172 void session_lock_list(void);
173 void session_unlock(struct ltt_session
*session
);
174 void session_unlock_list(void);
176 struct ltt_session
*session_find_by_name(const char *name
);
177 struct ltt_session
*session_find_by_id(uint64_t id
);
178 struct ltt_session_list
*session_get_list(void);
180 int session_access_ok(struct ltt_session
*session
, uid_t uid
, gid_t gid
);
182 #endif /* _LTT_SESSION_H */