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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> |
2b6001b5 | 12 | #include <memory> |
5c408ad8 | 13 | #include <stdbool.h> |
20fe2104 | 14 | #include <urcu/list.h> |
d4a2a84a | 15 | |
c9e313bc | 16 | #include <common/dynamic-array.hpp> |
2b6001b5 | 17 | #include <common/hashtable/hashtable.hpp> |
e99e3664 | 18 | #include <common/make-unique-wrapper.hpp> |
d7bfb9b0 | 19 | #include <common/pthread-lock.hpp> |
5d65beab | 20 | #include <lttng/location.h> |
82b69413 | 21 | #include <lttng/lttng-error.h> |
2b6001b5 JR |
22 | #include <lttng/rotation.h> |
23 | #include <lttng/trace-format-descriptor-internal.hpp> | |
6dc3064a | 24 | |
c9e313bc SM |
25 | #include "snapshot.hpp" |
26 | #include "trace-kernel.hpp" | |
27 | #include "consumer.hpp" | |
7972aab2 | 28 | |
3130a40c JG |
29 | #define ASSERT_SESSION_LIST_LOCKED() LTTNG_ASSERT(session_trylock_list()) |
30 | ||
7972aab2 | 31 | struct ltt_ust_session; |
00187dd4 | 32 | |
3e3665b8 JG |
33 | typedef void (*ltt_session_destroy_notifier)(const struct ltt_session *session, |
34 | void *user_data); | |
ccbdaca4 MD |
35 | typedef void (*ltt_session_clear_notifier)(const struct ltt_session *session, |
36 | void *user_data); | |
3e3665b8 | 37 | |
e99e3664 JG |
38 | namespace lttng { |
39 | namespace sessiond { | |
40 | namespace details { | |
41 | void locked_session_release(ltt_session *session); | |
42 | } /* namespace details */ | |
43 | } /* namespace sessiond */ | |
44 | } /* namespace lttng */ | |
45 | ||
b5541356 DG |
46 | /* |
47 | * Tracing session list | |
48 | * | |
49 | * Statically declared in session.c and can be accessed by using | |
54d01ffb | 50 | * session_get_list() function that returns the pointer to the list. |
b5541356 | 51 | */ |
5b74c7b1 | 52 | struct ltt_session_list { |
b5541356 | 53 | /* |
a24f7994 MD |
54 | * This lock protects any read/write access to the list and |
55 | * next_uuid. All public functions in session.c acquire this | |
56 | * lock and release it before returning. If none of those | |
57 | * functions are used, the lock MUST be acquired in order to | |
58 | * iterate or/and do any actions on that list. | |
b5541356 DG |
59 | */ |
60 | pthread_mutex_t lock; | |
99d688f2 JG |
61 | /* |
62 | * This condition variable is signaled on every removal from | |
63 | * the session list. | |
64 | */ | |
65 | pthread_cond_t removal_cond; | |
6c9cc2ab | 66 | |
b5541356 | 67 | /* |
a24f7994 MD |
68 | * Session unique ID generator. The session list lock MUST be |
69 | * upon update and read of this counter. | |
b5541356 | 70 | */ |
d022620a | 71 | uint64_t next_uuid; |
6c9cc2ab DG |
72 | |
73 | /* Linked list head */ | |
5b74c7b1 DG |
74 | struct cds_list_head head; |
75 | }; | |
76 | ||
b5541356 DG |
77 | /* |
78 | * This data structure contains information needed to identify a tracing | |
79 | * session for both LTTng and UST. | |
5b74c7b1 DG |
80 | */ |
81 | struct ltt_session { | |
e99e3664 JG |
82 | using id_t = uint64_t; |
83 | using locked_ptr = std::unique_ptr<ltt_session, | |
84 | lttng::details::create_unique_class<ltt_session, | |
85 | lttng::sessiond::details::locked_session_release>::deleter>; | |
86 | using sptr = std::shared_ptr<ltt_session>; | |
87 | ||
9fa5211e JR |
88 | ltt_session() |
89 | { | |
90 | has_been_started = 0; | |
91 | active = 0; | |
92 | }; | |
93 | ~ltt_session() = default; | |
94 | ||
95 | char name[NAME_MAX]{0}; | |
96 | bool has_auto_generated_name{false}; | |
97 | bool name_contains_creation_time{false}; | |
98 | char hostname[LTTNG_HOST_NAME_MAX]{0}; /* Local hostname. */ | |
ecd1a12f | 99 | /* Path of the last closed chunk. */ |
9fa5211e JR |
100 | char last_chunk_path[LTTNG_PATH_MAX]{0}; |
101 | time_t creation_time{}; | |
102 | struct ltt_kernel_session *kernel_session{}; | |
103 | struct ltt_ust_session *ust_session{}; | |
104 | struct urcu_ref ref {}; | |
b5541356 DG |
105 | /* |
106 | * Protect any read/write on this session data structure. This lock must be | |
107 | * acquired *before* using any public functions declared below. Use | |
54d01ffb | 108 | * session_lock() and session_unlock() for that. |
b5541356 | 109 | */ |
9fa5211e JR |
110 | pthread_mutex_t lock{}; |
111 | struct cds_list_head list {}; | |
112 | id_t id{}; /* session unique identifier */ | |
f4cc5e83 | 113 | /* Indicates if the session has been added to the session list and ht.*/ |
9fa5211e | 114 | bool published{false}; |
e32d7f27 | 115 | /* Indicates if a destroy command has been applied to this session. */ |
9fa5211e | 116 | bool destroyed{false}; |
6df2e2c9 | 117 | /* UID/GID of the user owning the session */ |
9fa5211e JR |
118 | uid_t uid{}; |
119 | gid_t gid{}; | |
00e2e675 DG |
120 | /* |
121 | * Network session handle. A value of 0 means that there is no remote | |
122 | * session established. | |
123 | */ | |
9fa5211e | 124 | uint64_t net_handle{}; |
00e2e675 DG |
125 | /* |
126 | * This consumer is only set when the create_session_uri call is made. | |
127 | * This contains the temporary information for a consumer output. Upon | |
128 | * creation of the UST or kernel session, this consumer, if available, is | |
129 | * copied into those sessions. | |
130 | */ | |
9fa5211e | 131 | struct consumer_output *consumer{}; |
b178f53e JG |
132 | /* |
133 | * Indicates whether or not the user has specified an output directory | |
134 | * or if it was configured using the default configuration. | |
135 | */ | |
9fa5211e | 136 | bool has_user_specified_directory{false}; |
8382cf6f | 137 | /* Did at least ONE start command has been triggered?. */ |
9fa5211e | 138 | bool has_been_started{false}; |
8382cf6f | 139 | /* |
9fa5211e JR |
140 | * Is the session active? Start trace command sets this to true and the stop |
141 | * command reset it to false. | |
8382cf6f | 142 | */ |
9fa5211e | 143 | bool active{false}; |
6dc3064a DG |
144 | |
145 | /* Snapshot representation in a session. */ | |
9fa5211e | 146 | struct snapshot snapshot {}; |
6dc3064a | 147 | /* Indicate if the session has to output the traces or not. */ |
9fa5211e | 148 | unsigned int output_traces{}; |
27babd3a | 149 | /* |
92fe5ca1 JG |
150 | * This session is in snapshot mode. This means that channels enabled |
151 | * will be set in overwrite mode by default and must be in mmap | |
152 | * output mode. Note that snapshots can be taken on a session that | |
153 | * is not in "snapshot_mode". This parameter only affects channel | |
154 | * creation defaults. | |
27babd3a | 155 | */ |
9fa5211e | 156 | unsigned int snapshot_mode{}; |
54213acc JG |
157 | /* |
158 | * A session that has channels that don't use 'mmap' output can't be | |
159 | * used to capture snapshots. This is set to true whenever a | |
160 | * 'splice' kernel channel is enabled. | |
161 | */ | |
9fa5211e | 162 | bool has_non_mmap_channel{false}; |
ecc48a90 JD |
163 | /* |
164 | * Timer set when the session is created for live reading. | |
165 | */ | |
9fa5211e | 166 | unsigned int live_timer{0}; |
d7ba1388 MD |
167 | /* |
168 | * Path where to keep the shared memory files. | |
169 | */ | |
9fa5211e | 170 | char shm_path[PATH_MAX]{}; |
23324029 JD |
171 | /* |
172 | * Node in ltt_sessions_ht_by_id. | |
173 | */ | |
9fa5211e | 174 | struct lttng_ht_node_u64 node {}; |
e1bbf989 JR |
175 | /* |
176 | * Node in ltt_sessions_ht_by_name. | |
177 | */ | |
9fa5211e | 178 | struct lttng_ht_node_str node_by_name {}; |
d88744a4 | 179 | /* |
92816cc3 JG |
180 | * Timer to check periodically if a relay and/or consumer has completed |
181 | * the last rotation. | |
d88744a4 | 182 | */ |
9fa5211e JR |
183 | bool rotation_pending_check_timer_enabled{false}; |
184 | timer_t rotation_pending_check_timer{}; | |
259c2674 | 185 | /* Timer to periodically rotate a session. */ |
9fa5211e JR |
186 | bool rotation_schedule_timer_enabled{false}; |
187 | timer_t rotation_schedule_timer{}; | |
66ea93b1 | 188 | /* Value for periodic rotations, 0 if disabled. */ |
9fa5211e | 189 | uint64_t rotate_timer_period{}; |
66ea93b1 | 190 | /* Value for size-based rotations, 0 if disabled. */ |
9fa5211e | 191 | uint64_t rotate_size{}; |
5c408ad8 JD |
192 | /* |
193 | * Keep a state if this session was rotated after the last stop command. | |
194 | * We only allow one rotation after a stop. At destroy, we also need to | |
a9577b76 | 195 | * know if a rotation occurred since the last stop to rename the current |
a2b988e2 MD |
196 | * chunk. After a stop followed by rotate, all subsequent clear |
197 | * (without prior start) will succeed, but will be effect-less. | |
5c408ad8 | 198 | */ |
9fa5211e | 199 | bool rotated_after_last_stop{false}; |
b02f5986 MD |
200 | /* |
201 | * Track whether the session was cleared after last stop. All subsequent | |
202 | * clear (without prior start) will succeed, but will be effect-less. A | |
203 | * subsequent rotate (without prior start) will return an error. | |
204 | */ | |
9fa5211e | 205 | bool cleared_after_last_stop{false}; |
a7ceb342 MD |
206 | /* |
207 | * True if the session has had an explicit non-quiet rotation. | |
208 | */ | |
9fa5211e | 209 | bool rotated{false}; |
90936dcf | 210 | /* |
c08136a3 | 211 | * Trigger for size-based rotations. |
90936dcf | 212 | */ |
9fa5211e JR |
213 | struct lttng_trigger *rotate_trigger{}; |
214 | LTTNG_OPTIONAL(uint64_t) most_recent_chunk_id{}; | |
215 | struct lttng_trace_chunk *current_trace_chunk{}; | |
216 | struct lttng_trace_chunk *chunk_being_archived{}; | |
d2956687 | 217 | /* Current state of a rotation. */ |
9fa5211e JR |
218 | enum lttng_rotation_state rotation_state { LTTNG_ROTATION_STATE_NO_ROTATION }; |
219 | bool quiet_rotation{false}; | |
220 | char *last_archived_chunk_name{}; | |
221 | LTTNG_OPTIONAL(uint64_t) last_archived_chunk_id{}; | |
222 | struct lttng_dynamic_array destroy_notifiers {}; | |
223 | struct lttng_dynamic_array clear_notifiers {}; | |
6fa5fe7c | 224 | /* Session base path override. Set non-null. */ |
9fa5211e | 225 | char *base_path{}; |
2b6001b5 JR |
226 | /* Trace output format */ |
227 | lttng::trace_format_descriptor::sptr trace_format; | |
5b74c7b1 DG |
228 | }; |
229 | ||
2b6001b5 JR |
230 | enum lttng_error_code session_create(const char *name, |
231 | uid_t uid, | |
232 | gid_t gid, | |
233 | lttng::trace_format_descriptor::uptr& trace_format, | |
e3876bf0 | 234 | struct ltt_session **out_session); |
54d01ffb | 235 | void session_lock(struct ltt_session *session); |
733c9165 JG |
236 | void session_unlock(struct ltt_session *session); |
237 | ||
238 | /* | |
239 | * The session list lock covers more ground than its name implies. While | |
240 | * it does protect against concurent mutations of the session list, it is | |
241 | * also used as a multi-session lock when synchronizing newly-registered | |
242 | * 'user space tracer' and 'agent' applications. | |
243 | * | |
9b7cbebd | 244 | * In other words, it prevents tracer configurations from changing while they |
733c9165 JG |
245 | * are being transmitted to the various applications. |
246 | */ | |
54d01ffb | 247 | void session_lock_list(void); |
71e0a100 | 248 | int session_trylock_list(void); |
54d01ffb | 249 | void session_unlock_list(void); |
6c9cc2ab | 250 | |
e32d7f27 | 251 | void session_destroy(struct ltt_session *session); |
3e3665b8 JG |
252 | int session_add_destroy_notifier(struct ltt_session *session, |
253 | ltt_session_destroy_notifier notifier, void *user_data); | |
e32d7f27 | 254 | |
ccbdaca4 MD |
255 | int session_add_clear_notifier(struct ltt_session *session, |
256 | ltt_session_clear_notifier notifier, void *user_data); | |
257 | void session_notify_clear(struct ltt_session *session); | |
258 | ||
e32d7f27 JG |
259 | bool session_get(struct ltt_session *session); |
260 | void session_put(struct ltt_session *session); | |
261 | ||
dd73d57b JG |
262 | enum consumer_dst_type session_get_consumer_destination_type( |
263 | const struct ltt_session *session); | |
264 | const char *session_get_net_consumer_hostname( | |
265 | const struct ltt_session *session); | |
266 | void session_get_net_consumer_ports( | |
267 | const struct ltt_session *session, | |
268 | uint16_t *control_port, uint16_t *data_port); | |
5d65beab | 269 | struct lttng_trace_archive_location *session_get_trace_archive_location( |
3e3665b8 | 270 | const struct ltt_session *session); |
dd73d57b | 271 | |
58a1a227 | 272 | struct ltt_session *session_find_by_name(const char *name); |
e99e3664 | 273 | struct ltt_session *session_find_by_id(ltt_session::id_t id); |
99d688f2 | 274 | |
54d01ffb | 275 | struct ltt_session_list *session_get_list(void); |
99d688f2 | 276 | void session_list_wait_empty(void); |
5b74c7b1 | 277 | |
d7b377ed | 278 | bool session_access_ok(struct ltt_session *session, uid_t uid); |
2f77fc4b | 279 | |
2961f09e JG |
280 | int session_reset_rotation_state(struct ltt_session *session, |
281 | enum lttng_rotation_state result); | |
282 | ||
d2956687 JG |
283 | /* Create a new trace chunk object from the session's configuration. */ |
284 | struct lttng_trace_chunk *session_create_new_trace_chunk( | |
348a81dc JG |
285 | const struct ltt_session *session, |
286 | const struct consumer_output *consumer_output_override, | |
82b69413 JG |
287 | const char *session_base_path_override, |
288 | const char *chunk_name_override); | |
d2956687 JG |
289 | |
290 | /* | |
291 | * Set `new_trace_chunk` as the session's current trace chunk. A reference | |
292 | * to `new_trace_chunk` is acquired by the session. The chunk is created | |
293 | * on remote peers (consumer and relay daemons). | |
294 | * | |
295 | * A reference to the session's current trace chunk is returned through | |
296 | * `current_session_trace_chunk` on success. | |
297 | */ | |
82b69413 | 298 | int session_set_trace_chunk(struct ltt_session *session, |
d2956687 JG |
299 | struct lttng_trace_chunk *new_trace_chunk, |
300 | struct lttng_trace_chunk **current_session_trace_chunk); | |
301 | ||
302 | /* | |
303 | * Close a chunk on the remote peers of a session. Has no effect on the | |
304 | * ltt_session itself. | |
305 | */ | |
343defc2 | 306 | int session_close_trace_chunk(struct ltt_session *session, |
bbc4768c | 307 | struct lttng_trace_chunk *trace_chunk, |
343defc2 | 308 | enum lttng_trace_chunk_command_type close_command, |
ecd1a12f | 309 | char *path); |
82b69413 | 310 | |
04ed9e10 JG |
311 | /* Open a packet in all channels of a given session. */ |
312 | enum lttng_error_code session_open_packets(struct ltt_session *session); | |
313 | ||
e2b6b28e JG |
314 | bool session_output_supports_trace_chunks(const struct ltt_session *session); |
315 | ||
e1bbf989 JR |
316 | /* |
317 | * Sample the id of a session looked up via its name. | |
318 | * Here the term "sampling" hint the caller that this return the id at a given | |
319 | * point in time with no guarantee that the session for which the id was | |
320 | * sampled still exist at that point. | |
321 | * | |
322 | * Return 0 when the session is not found, | |
323 | * Return 1 when the session is found and set `id`. | |
324 | */ | |
325 | bool sample_session_id_by_name(const char *name, uint64_t *id); | |
326 | ||
e99e3664 JG |
327 | namespace lttng { |
328 | namespace sessiond { | |
329 | ||
330 | /* | |
331 | * Session list lock must be acquired by the caller. | |
332 | * The caller must not keep the ownership of the returned locked session | |
333 | * for longer than strictly necessary. If your intention is to acquire | |
334 | * a reference to an ltt_session, see `find_session_by_id()`. | |
335 | */ | |
336 | ltt_session::locked_ptr find_locked_session_by_id(ltt_session::id_t id); | |
337 | ||
338 | /* | |
339 | * Session list lock must be acquired by the caller. | |
340 | * The caller must not keep the ownership of the returned locked session | |
341 | * for longer than strictly necessary. If your intention is to acquire | |
342 | * a reference to an ltt_session, see `find_session_by_id()`. | |
343 | */ | |
344 | ltt_session::sptr find_session_by_id(ltt_session::id_t id); | |
345 | ||
346 | } /* namespace sessiond */ | |
347 | } /* namespace lttng */ | |
348 | ||
5b74c7b1 | 349 | #endif /* _LTT_SESSION_H */ |