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91d76f53 | 1 | /* |
21cf9b6b | 2 | * Copyright (C) 2011 EfficiOS Inc. |
5b74c7b1 | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: GPL-2.0-only |
5b74c7b1 | 5 | * |
5b74c7b1 DG |
6 | */ |
7 | ||
8 | #ifndef _LTT_SESSION_H | |
9 | #define _LTT_SESSION_H | |
10 | ||
73184835 | 11 | #include <limits.h> |
5c408ad8 | 12 | #include <stdbool.h> |
20fe2104 | 13 | #include <urcu/list.h> |
d4a2a84a | 14 | |
c9e313bc SM |
15 | #include <common/hashtable/hashtable.hpp> |
16 | #include <common/dynamic-array.hpp> | |
e99e3664 | 17 | #include <common/make-unique-wrapper.hpp> |
d7bfb9b0 | 18 | #include <common/pthread-lock.hpp> |
db66e574 | 19 | #include <lttng/rotation.h> |
5d65beab | 20 | #include <lttng/location.h> |
82b69413 | 21 | #include <lttng/lttng-error.h> |
6dc3064a | 22 | |
c9e313bc SM |
23 | #include "snapshot.hpp" |
24 | #include "trace-kernel.hpp" | |
25 | #include "consumer.hpp" | |
7972aab2 | 26 | |
3130a40c JG |
27 | #define ASSERT_SESSION_LIST_LOCKED() LTTNG_ASSERT(session_trylock_list()) |
28 | ||
7972aab2 | 29 | struct ltt_ust_session; |
00187dd4 | 30 | |
3e3665b8 JG |
31 | typedef void (*ltt_session_destroy_notifier)(const struct ltt_session *session, |
32 | void *user_data); | |
ccbdaca4 MD |
33 | typedef void (*ltt_session_clear_notifier)(const struct ltt_session *session, |
34 | void *user_data); | |
3e3665b8 | 35 | |
e99e3664 JG |
36 | namespace lttng { |
37 | namespace sessiond { | |
38 | namespace details { | |
39 | void locked_session_release(ltt_session *session); | |
40 | } /* namespace details */ | |
41 | } /* namespace sessiond */ | |
42 | } /* namespace lttng */ | |
43 | ||
b5541356 DG |
44 | /* |
45 | * Tracing session list | |
46 | * | |
47 | * Statically declared in session.c and can be accessed by using | |
54d01ffb | 48 | * session_get_list() function that returns the pointer to the list. |
b5541356 | 49 | */ |
5b74c7b1 | 50 | struct ltt_session_list { |
b5541356 | 51 | /* |
a24f7994 MD |
52 | * This lock protects any read/write access to the list and |
53 | * next_uuid. All public functions in session.c acquire this | |
54 | * lock and release it before returning. If none of those | |
55 | * functions are used, the lock MUST be acquired in order to | |
56 | * iterate or/and do any actions on that list. | |
b5541356 DG |
57 | */ |
58 | pthread_mutex_t lock; | |
99d688f2 JG |
59 | /* |
60 | * This condition variable is signaled on every removal from | |
61 | * the session list. | |
62 | */ | |
63 | pthread_cond_t removal_cond; | |
6c9cc2ab | 64 | |
b5541356 | 65 | /* |
a24f7994 MD |
66 | * Session unique ID generator. The session list lock MUST be |
67 | * upon update and read of this counter. | |
b5541356 | 68 | */ |
d022620a | 69 | uint64_t next_uuid; |
6c9cc2ab DG |
70 | |
71 | /* Linked list head */ | |
5b74c7b1 DG |
72 | struct cds_list_head head; |
73 | }; | |
74 | ||
b5541356 DG |
75 | /* |
76 | * This data structure contains information needed to identify a tracing | |
77 | * session for both LTTng and UST. | |
5b74c7b1 DG |
78 | */ |
79 | struct ltt_session { | |
e99e3664 JG |
80 | using id_t = uint64_t; |
81 | using locked_ptr = std::unique_ptr<ltt_session, | |
82 | lttng::details::create_unique_class<ltt_session, | |
83 | lttng::sessiond::details::locked_session_release>::deleter>; | |
84 | using sptr = std::shared_ptr<ltt_session>; | |
85 | ||
9fa5211e JR |
86 | ltt_session() |
87 | { | |
88 | has_been_started = 0; | |
89 | active = 0; | |
90 | }; | |
91 | ~ltt_session() = default; | |
92 | ||
93 | char name[NAME_MAX]{0}; | |
94 | bool has_auto_generated_name{false}; | |
95 | bool name_contains_creation_time{false}; | |
96 | char hostname[LTTNG_HOST_NAME_MAX]{0}; /* Local hostname. */ | |
ecd1a12f | 97 | /* Path of the last closed chunk. */ |
9fa5211e JR |
98 | char last_chunk_path[LTTNG_PATH_MAX]{0}; |
99 | time_t creation_time{}; | |
100 | struct ltt_kernel_session *kernel_session{}; | |
101 | struct ltt_ust_session *ust_session{}; | |
102 | struct urcu_ref ref {}; | |
b5541356 DG |
103 | /* |
104 | * Protect any read/write on this session data structure. This lock must be | |
105 | * acquired *before* using any public functions declared below. Use | |
54d01ffb | 106 | * session_lock() and session_unlock() for that. |
b5541356 | 107 | */ |
9fa5211e JR |
108 | pthread_mutex_t lock{}; |
109 | struct cds_list_head list {}; | |
110 | id_t id{}; /* session unique identifier */ | |
f4cc5e83 | 111 | /* Indicates if the session has been added to the session list and ht.*/ |
9fa5211e | 112 | bool published{false}; |
e32d7f27 | 113 | /* Indicates if a destroy command has been applied to this session. */ |
9fa5211e | 114 | bool destroyed{false}; |
6df2e2c9 | 115 | /* UID/GID of the user owning the session */ |
9fa5211e JR |
116 | uid_t uid{}; |
117 | gid_t gid{}; | |
00e2e675 DG |
118 | /* |
119 | * Network session handle. A value of 0 means that there is no remote | |
120 | * session established. | |
121 | */ | |
9fa5211e | 122 | uint64_t net_handle{}; |
00e2e675 DG |
123 | /* |
124 | * This consumer is only set when the create_session_uri call is made. | |
125 | * This contains the temporary information for a consumer output. Upon | |
126 | * creation of the UST or kernel session, this consumer, if available, is | |
127 | * copied into those sessions. | |
128 | */ | |
9fa5211e | 129 | struct consumer_output *consumer{}; |
b178f53e JG |
130 | /* |
131 | * Indicates whether or not the user has specified an output directory | |
132 | * or if it was configured using the default configuration. | |
133 | */ | |
9fa5211e | 134 | bool has_user_specified_directory{false}; |
8382cf6f | 135 | /* Did at least ONE start command has been triggered?. */ |
9fa5211e | 136 | bool has_been_started{false}; |
8382cf6f | 137 | /* |
9fa5211e JR |
138 | * Is the session active? Start trace command sets this to true and the stop |
139 | * command reset it to false. | |
8382cf6f | 140 | */ |
9fa5211e | 141 | bool active{false}; |
6dc3064a DG |
142 | |
143 | /* Snapshot representation in a session. */ | |
9fa5211e | 144 | struct snapshot snapshot {}; |
6dc3064a | 145 | /* Indicate if the session has to output the traces or not. */ |
9fa5211e | 146 | unsigned int output_traces{}; |
27babd3a | 147 | /* |
92fe5ca1 JG |
148 | * This session is in snapshot mode. This means that channels enabled |
149 | * will be set in overwrite mode by default and must be in mmap | |
150 | * output mode. Note that snapshots can be taken on a session that | |
151 | * is not in "snapshot_mode". This parameter only affects channel | |
152 | * creation defaults. | |
27babd3a | 153 | */ |
9fa5211e | 154 | unsigned int snapshot_mode{}; |
54213acc JG |
155 | /* |
156 | * A session that has channels that don't use 'mmap' output can't be | |
157 | * used to capture snapshots. This is set to true whenever a | |
158 | * 'splice' kernel channel is enabled. | |
159 | */ | |
9fa5211e | 160 | bool has_non_mmap_channel{false}; |
ecc48a90 JD |
161 | /* |
162 | * Timer set when the session is created for live reading. | |
163 | */ | |
9fa5211e | 164 | unsigned int live_timer{0}; |
d7ba1388 MD |
165 | /* |
166 | * Path where to keep the shared memory files. | |
167 | */ | |
9fa5211e | 168 | char shm_path[PATH_MAX]{}; |
23324029 JD |
169 | /* |
170 | * Node in ltt_sessions_ht_by_id. | |
171 | */ | |
9fa5211e | 172 | struct lttng_ht_node_u64 node {}; |
e1bbf989 JR |
173 | /* |
174 | * Node in ltt_sessions_ht_by_name. | |
175 | */ | |
9fa5211e | 176 | struct lttng_ht_node_str node_by_name {}; |
d88744a4 | 177 | /* |
92816cc3 JG |
178 | * Timer to check periodically if a relay and/or consumer has completed |
179 | * the last rotation. | |
d88744a4 | 180 | */ |
9fa5211e JR |
181 | bool rotation_pending_check_timer_enabled{false}; |
182 | timer_t rotation_pending_check_timer{}; | |
259c2674 | 183 | /* Timer to periodically rotate a session. */ |
9fa5211e JR |
184 | bool rotation_schedule_timer_enabled{false}; |
185 | timer_t rotation_schedule_timer{}; | |
66ea93b1 | 186 | /* Value for periodic rotations, 0 if disabled. */ |
9fa5211e | 187 | uint64_t rotate_timer_period{}; |
66ea93b1 | 188 | /* Value for size-based rotations, 0 if disabled. */ |
9fa5211e | 189 | uint64_t rotate_size{}; |
5c408ad8 JD |
190 | /* |
191 | * Keep a state if this session was rotated after the last stop command. | |
192 | * We only allow one rotation after a stop. At destroy, we also need to | |
a9577b76 | 193 | * know if a rotation occurred since the last stop to rename the current |
a2b988e2 MD |
194 | * chunk. After a stop followed by rotate, all subsequent clear |
195 | * (without prior start) will succeed, but will be effect-less. | |
5c408ad8 | 196 | */ |
9fa5211e | 197 | bool rotated_after_last_stop{false}; |
b02f5986 MD |
198 | /* |
199 | * Track whether the session was cleared after last stop. All subsequent | |
200 | * clear (without prior start) will succeed, but will be effect-less. A | |
201 | * subsequent rotate (without prior start) will return an error. | |
202 | */ | |
9fa5211e | 203 | bool cleared_after_last_stop{false}; |
a7ceb342 MD |
204 | /* |
205 | * True if the session has had an explicit non-quiet rotation. | |
206 | */ | |
9fa5211e | 207 | bool rotated{false}; |
90936dcf | 208 | /* |
c08136a3 | 209 | * Trigger for size-based rotations. |
90936dcf | 210 | */ |
9fa5211e JR |
211 | struct lttng_trigger *rotate_trigger{}; |
212 | LTTNG_OPTIONAL(uint64_t) most_recent_chunk_id{}; | |
213 | struct lttng_trace_chunk *current_trace_chunk{}; | |
214 | struct lttng_trace_chunk *chunk_being_archived{}; | |
d2956687 | 215 | /* Current state of a rotation. */ |
9fa5211e JR |
216 | enum lttng_rotation_state rotation_state { LTTNG_ROTATION_STATE_NO_ROTATION }; |
217 | bool quiet_rotation{false}; | |
218 | char *last_archived_chunk_name{}; | |
219 | LTTNG_OPTIONAL(uint64_t) last_archived_chunk_id{}; | |
220 | struct lttng_dynamic_array destroy_notifiers {}; | |
221 | struct lttng_dynamic_array clear_notifiers {}; | |
6fa5fe7c | 222 | /* Session base path override. Set non-null. */ |
9fa5211e | 223 | char *base_path{}; |
5b74c7b1 DG |
224 | }; |
225 | ||
b178f53e | 226 | enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid, |
e3876bf0 | 227 | struct ltt_session **out_session); |
54d01ffb | 228 | void session_lock(struct ltt_session *session); |
733c9165 JG |
229 | void session_unlock(struct ltt_session *session); |
230 | ||
231 | /* | |
232 | * The session list lock covers more ground than its name implies. While | |
233 | * it does protect against concurent mutations of the session list, it is | |
234 | * also used as a multi-session lock when synchronizing newly-registered | |
235 | * 'user space tracer' and 'agent' applications. | |
236 | * | |
9b7cbebd | 237 | * In other words, it prevents tracer configurations from changing while they |
733c9165 JG |
238 | * are being transmitted to the various applications. |
239 | */ | |
54d01ffb | 240 | void session_lock_list(void); |
71e0a100 | 241 | int session_trylock_list(void); |
54d01ffb | 242 | void session_unlock_list(void); |
6c9cc2ab | 243 | |
e32d7f27 | 244 | void session_destroy(struct ltt_session *session); |
3e3665b8 JG |
245 | int session_add_destroy_notifier(struct ltt_session *session, |
246 | ltt_session_destroy_notifier notifier, void *user_data); | |
e32d7f27 | 247 | |
ccbdaca4 MD |
248 | int session_add_clear_notifier(struct ltt_session *session, |
249 | ltt_session_clear_notifier notifier, void *user_data); | |
250 | void session_notify_clear(struct ltt_session *session); | |
251 | ||
e32d7f27 JG |
252 | bool session_get(struct ltt_session *session); |
253 | void session_put(struct ltt_session *session); | |
254 | ||
dd73d57b JG |
255 | enum consumer_dst_type session_get_consumer_destination_type( |
256 | const struct ltt_session *session); | |
257 | const char *session_get_net_consumer_hostname( | |
258 | const struct ltt_session *session); | |
259 | void session_get_net_consumer_ports( | |
260 | const struct ltt_session *session, | |
261 | uint16_t *control_port, uint16_t *data_port); | |
5d65beab | 262 | struct lttng_trace_archive_location *session_get_trace_archive_location( |
3e3665b8 | 263 | const struct ltt_session *session); |
dd73d57b | 264 | |
58a1a227 | 265 | struct ltt_session *session_find_by_name(const char *name); |
e99e3664 | 266 | struct ltt_session *session_find_by_id(ltt_session::id_t id); |
99d688f2 | 267 | |
54d01ffb | 268 | struct ltt_session_list *session_get_list(void); |
99d688f2 | 269 | void session_list_wait_empty(void); |
5b74c7b1 | 270 | |
d7b377ed | 271 | bool session_access_ok(struct ltt_session *session, uid_t uid); |
2f77fc4b | 272 | |
2961f09e JG |
273 | int session_reset_rotation_state(struct ltt_session *session, |
274 | enum lttng_rotation_state result); | |
275 | ||
d2956687 JG |
276 | /* Create a new trace chunk object from the session's configuration. */ |
277 | struct lttng_trace_chunk *session_create_new_trace_chunk( | |
348a81dc JG |
278 | const struct ltt_session *session, |
279 | const struct consumer_output *consumer_output_override, | |
82b69413 JG |
280 | const char *session_base_path_override, |
281 | const char *chunk_name_override); | |
d2956687 JG |
282 | |
283 | /* | |
284 | * Set `new_trace_chunk` as the session's current trace chunk. A reference | |
285 | * to `new_trace_chunk` is acquired by the session. The chunk is created | |
286 | * on remote peers (consumer and relay daemons). | |
287 | * | |
288 | * A reference to the session's current trace chunk is returned through | |
289 | * `current_session_trace_chunk` on success. | |
290 | */ | |
82b69413 | 291 | int session_set_trace_chunk(struct ltt_session *session, |
d2956687 JG |
292 | struct lttng_trace_chunk *new_trace_chunk, |
293 | struct lttng_trace_chunk **current_session_trace_chunk); | |
294 | ||
295 | /* | |
296 | * Close a chunk on the remote peers of a session. Has no effect on the | |
297 | * ltt_session itself. | |
298 | */ | |
343defc2 | 299 | int session_close_trace_chunk(struct ltt_session *session, |
bbc4768c | 300 | struct lttng_trace_chunk *trace_chunk, |
343defc2 | 301 | enum lttng_trace_chunk_command_type close_command, |
ecd1a12f | 302 | char *path); |
82b69413 | 303 | |
04ed9e10 JG |
304 | /* Open a packet in all channels of a given session. */ |
305 | enum lttng_error_code session_open_packets(struct ltt_session *session); | |
306 | ||
e2b6b28e JG |
307 | bool session_output_supports_trace_chunks(const struct ltt_session *session); |
308 | ||
e1bbf989 JR |
309 | /* |
310 | * Sample the id of a session looked up via its name. | |
311 | * Here the term "sampling" hint the caller that this return the id at a given | |
312 | * point in time with no guarantee that the session for which the id was | |
313 | * sampled still exist at that point. | |
314 | * | |
315 | * Return 0 when the session is not found, | |
316 | * Return 1 when the session is found and set `id`. | |
317 | */ | |
318 | bool sample_session_id_by_name(const char *name, uint64_t *id); | |
319 | ||
e99e3664 JG |
320 | namespace lttng { |
321 | namespace sessiond { | |
322 | ||
323 | /* | |
324 | * Session list lock must be acquired by the caller. | |
325 | * The caller must not keep the ownership of the returned locked session | |
326 | * for longer than strictly necessary. If your intention is to acquire | |
327 | * a reference to an ltt_session, see `find_session_by_id()`. | |
328 | */ | |
329 | ltt_session::locked_ptr find_locked_session_by_id(ltt_session::id_t id); | |
330 | ||
331 | /* | |
332 | * Session list lock must be acquired by the caller. | |
333 | * The caller must not keep the ownership of the returned locked session | |
334 | * for longer than strictly necessary. If your intention is to acquire | |
335 | * a reference to an ltt_session, see `find_session_by_id()`. | |
336 | */ | |
337 | ltt_session::sptr find_session_by_id(ltt_session::id_t id); | |
338 | ||
339 | } /* namespace sessiond */ | |
340 | } /* namespace lttng */ | |
341 | ||
5b74c7b1 | 342 | #endif /* _LTT_SESSION_H */ |