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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 | ||
28f23191 JG |
11 | #include "consumer.hpp" |
12 | #include "snapshot.hpp" | |
13 | #include "trace-kernel.hpp" | |
d4a2a84a | 14 | |
c9e313bc | 15 | #include <common/dynamic-array.hpp> |
d9a970b7 | 16 | #include <common/exception.hpp> |
28f23191 | 17 | #include <common/hashtable/hashtable.hpp> |
e99e3664 | 18 | #include <common/make-unique-wrapper.hpp> |
d7bfb9b0 | 19 | #include <common/pthread-lock.hpp> |
a0a4f314 | 20 | #include <common/reference.hpp> |
28f23191 | 21 | |
5d65beab | 22 | #include <lttng/location.h> |
82b69413 | 23 | #include <lttng/lttng-error.h> |
28f23191 | 24 | #include <lttng/rotation.h> |
6dc3064a | 25 | |
1a496780 | 26 | #include <condition_variable> |
28f23191 | 27 | #include <limits.h> |
1a496780 | 28 | #include <mutex> |
28f23191 JG |
29 | #include <stdbool.h> |
30 | #include <urcu/list.h> | |
7972aab2 | 31 | |
3130a40c JG |
32 | #define ASSERT_SESSION_LIST_LOCKED() LTTNG_ASSERT(session_trylock_list()) |
33 | ||
7972aab2 | 34 | struct ltt_ust_session; |
00187dd4 | 35 | |
d9a970b7 JG |
36 | struct ltt_session; |
37 | struct ltt_session_list; | |
38 | ||
39 | enum lttng_error_code | |
40 | session_create(const char *name, uid_t uid, gid_t gid, struct ltt_session **out_session); | |
41 | void session_lock(struct ltt_session *session); | |
42 | void session_unlock(struct ltt_session *session); | |
43 | ||
44 | bool session_get(struct ltt_session *session); | |
45 | void session_put(struct ltt_session *session); | |
46 | ||
47 | /* | |
48 | * The session list lock covers more ground than its name implies. While | |
49 | * it does protect against concurent mutations of the session list, it is | |
50 | * also used as a multi-session lock when synchronizing newly-registered | |
51 | * 'user space tracer' and 'agent' applications. | |
52 | * | |
53 | * In other words, it prevents tracer configurations from changing while they | |
54 | * are being transmitted to the various applications. | |
55 | */ | |
56 | int session_trylock_list() noexcept; | |
57 | ||
58 | #define LTTNG_THROW_SESSION_NOT_FOUND_BY_NAME_ERROR(session_name) \ | |
59 | throw lttng::sessiond::exceptions::session_not_found_error(session_name, \ | |
60 | LTTNG_SOURCE_LOCATION()) | |
61 | #define LTTNG_THROW_SESSION_NOT_FOUND_BY_ID_ERROR(id) \ | |
62 | throw lttng::sessiond::exceptions::session_not_found_error(id, LTTNG_SOURCE_LOCATION()) | |
63 | ||
b5541356 DG |
64 | /* |
65 | * Tracing session list | |
66 | * | |
67 | * Statically declared in session.c and can be accessed by using | |
54d01ffb | 68 | * session_get_list() function that returns the pointer to the list. |
b5541356 | 69 | */ |
5b74c7b1 | 70 | struct ltt_session_list { |
b5541356 | 71 | /* |
a24f7994 MD |
72 | * This lock protects any read/write access to the list and |
73 | * next_uuid. All public functions in session.c acquire this | |
74 | * lock and release it before returning. If none of those | |
75 | * functions are used, the lock MUST be acquired in order to | |
76 | * iterate or/and do any actions on that list. | |
b5541356 | 77 | */ |
1a496780 | 78 | std::mutex lock; |
99d688f2 JG |
79 | /* |
80 | * This condition variable is signaled on every removal from | |
81 | * the session list. | |
82 | */ | |
1a496780 | 83 | std::condition_variable removal_cond; |
6c9cc2ab | 84 | |
b5541356 | 85 | /* |
a24f7994 MD |
86 | * Session unique ID generator. The session list lock MUST be |
87 | * upon update and read of this counter. | |
b5541356 | 88 | */ |
1a496780 | 89 | uint64_t next_uuid = 0; |
6c9cc2ab DG |
90 | |
91 | /* Linked list head */ | |
1a496780 | 92 | struct cds_list_head head = CDS_LIST_HEAD_INIT(head); |
5b74c7b1 DG |
93 | }; |
94 | ||
b5541356 DG |
95 | /* |
96 | * This data structure contains information needed to identify a tracing | |
97 | * session for both LTTng and UST. | |
5b74c7b1 DG |
98 | */ |
99 | struct ltt_session { | |
e99e3664 | 100 | using id_t = uint64_t; |
d9a970b7 JG |
101 | |
102 | private: | |
103 | static void _locked_session_release(ltt_session *session); | |
104 | static void _locked_const_session_release(const ltt_session *session); | |
105 | static void _const_session_put(const ltt_session *session); | |
a0a4f314 | 106 | static void _const_session_unlock(const ltt_session& session); |
d9a970b7 JG |
107 | |
108 | public: | |
a0a4f314 JG |
109 | using locked_ref = lttng::non_copyable_reference< |
110 | ltt_session, | |
111 | lttng::memory::create_deleter_class<ltt_session, | |
112 | ltt_session::_locked_session_release>::deleter>; | |
113 | using ref = lttng::non_copyable_reference< | |
d9a970b7 JG |
114 | ltt_session, |
115 | lttng::memory::create_deleter_class<ltt_session, session_put>::deleter>; | |
a0a4f314 JG |
116 | using const_locked_ref = lttng::non_copyable_reference< |
117 | const ltt_session, | |
118 | lttng::memory::create_deleter_class< | |
119 | const ltt_session, | |
120 | ltt_session::_locked_const_session_release>::deleter>; | |
121 | using const_ref = lttng::non_copyable_reference< | |
d9a970b7 | 122 | const ltt_session, |
a0a4f314 JG |
123 | lttng::memory::create_deleter_class<const ltt_session, |
124 | ltt_session::_const_session_put>::deleter>; | |
d9a970b7 JG |
125 | |
126 | void lock() const noexcept; | |
127 | void unlock() const noexcept; | |
128 | ||
129 | /* | |
130 | * Session list lock must be acquired by the caller. | |
131 | * | |
132 | * The caller must not keep the ownership of the returned locked session | |
133 | * for longer than strictly necessary. If your intention is to acquire | |
134 | * a reference to an ltt_session, see `find_session()`. | |
135 | */ | |
136 | static locked_ref find_locked_session(ltt_session::id_t id); | |
137 | static locked_ref find_locked_session(lttng::c_string_view name); | |
138 | static const_locked_ref find_locked_const_session(ltt_session::id_t id); | |
139 | static const_locked_ref find_locked_const_session(lttng::c_string_view name); | |
140 | ||
141 | static ref find_session(ltt_session::id_t id); | |
142 | static ref find_session(lttng::c_string_view name); | |
143 | static const_ref find_const_session(ltt_session::id_t id); | |
144 | static const_ref find_const_session(lttng::c_string_view name); | |
e99e3664 | 145 | |
74babd95 | 146 | char name[NAME_MAX]; |
b178f53e | 147 | bool has_auto_generated_name; |
46ef2188 | 148 | bool name_contains_creation_time; |
32aef76c | 149 | char hostname[LTTNG_HOST_NAME_MAX]; /* Local hostname. */ |
ecd1a12f MD |
150 | /* Path of the last closed chunk. */ |
151 | char last_chunk_path[LTTNG_PATH_MAX]; | |
b178f53e | 152 | time_t creation_time; |
20fe2104 | 153 | struct ltt_kernel_session *kernel_session; |
f6a9efaa | 154 | struct ltt_ust_session *ust_session; |
d9a970b7 | 155 | mutable struct urcu_ref ref_count; |
b5541356 DG |
156 | /* |
157 | * Protect any read/write on this session data structure. This lock must be | |
158 | * acquired *before* using any public functions declared below. Use | |
54d01ffb | 159 | * session_lock() and session_unlock() for that. |
b5541356 | 160 | */ |
d9a970b7 | 161 | mutable pthread_mutex_t _lock; |
b5541356 | 162 | struct cds_list_head list; |
e99e3664 JG |
163 | /* session unique identifier */ |
164 | id_t id; | |
f4cc5e83 JG |
165 | /* Indicates if the session has been added to the session list and ht.*/ |
166 | bool published; | |
e32d7f27 JG |
167 | /* Indicates if a destroy command has been applied to this session. */ |
168 | bool destroyed; | |
6df2e2c9 MD |
169 | /* UID/GID of the user owning the session */ |
170 | uid_t uid; | |
171 | gid_t gid; | |
00e2e675 DG |
172 | /* |
173 | * Network session handle. A value of 0 means that there is no remote | |
174 | * session established. | |
175 | */ | |
176 | uint64_t net_handle; | |
177 | /* | |
178 | * This consumer is only set when the create_session_uri call is made. | |
179 | * This contains the temporary information for a consumer output. Upon | |
180 | * creation of the UST or kernel session, this consumer, if available, is | |
181 | * copied into those sessions. | |
182 | */ | |
183 | struct consumer_output *consumer; | |
b178f53e JG |
184 | /* |
185 | * Indicates whether or not the user has specified an output directory | |
186 | * or if it was configured using the default configuration. | |
187 | */ | |
188 | bool has_user_specified_directory; | |
8382cf6f | 189 | /* Did at least ONE start command has been triggered?. */ |
66cefebd JG |
190 | bool has_been_started; |
191 | /* Is the session active? */ | |
192 | bool active; | |
6dc3064a DG |
193 | |
194 | /* Snapshot representation in a session. */ | |
195 | struct snapshot snapshot; | |
196 | /* Indicate if the session has to output the traces or not. */ | |
197 | unsigned int output_traces; | |
27babd3a | 198 | /* |
92fe5ca1 JG |
199 | * This session is in snapshot mode. This means that channels enabled |
200 | * will be set in overwrite mode by default and must be in mmap | |
201 | * output mode. Note that snapshots can be taken on a session that | |
202 | * is not in "snapshot_mode". This parameter only affects channel | |
203 | * creation defaults. | |
27babd3a DG |
204 | */ |
205 | unsigned int snapshot_mode; | |
54213acc JG |
206 | /* |
207 | * A session that has channels that don't use 'mmap' output can't be | |
208 | * used to capture snapshots. This is set to true whenever a | |
209 | * 'splice' kernel channel is enabled. | |
210 | */ | |
211 | bool has_non_mmap_channel; | |
ecc48a90 JD |
212 | /* |
213 | * Timer set when the session is created for live reading. | |
214 | */ | |
d98ad589 | 215 | unsigned int live_timer; |
d7ba1388 MD |
216 | /* |
217 | * Path where to keep the shared memory files. | |
218 | */ | |
219 | char shm_path[PATH_MAX]; | |
23324029 JD |
220 | /* |
221 | * Node in ltt_sessions_ht_by_id. | |
222 | */ | |
223 | struct lttng_ht_node_u64 node; | |
e1bbf989 JR |
224 | /* |
225 | * Node in ltt_sessions_ht_by_name. | |
226 | */ | |
227 | struct lttng_ht_node_str node_by_name; | |
d88744a4 | 228 | /* |
92816cc3 JG |
229 | * Timer to check periodically if a relay and/or consumer has completed |
230 | * the last rotation. | |
d88744a4 | 231 | */ |
92816cc3 JG |
232 | bool rotation_pending_check_timer_enabled; |
233 | timer_t rotation_pending_check_timer; | |
259c2674 | 234 | /* Timer to periodically rotate a session. */ |
92816cc3 JG |
235 | bool rotation_schedule_timer_enabled; |
236 | timer_t rotation_schedule_timer; | |
66ea93b1 | 237 | /* Value for periodic rotations, 0 if disabled. */ |
259c2674 | 238 | uint64_t rotate_timer_period; |
66ea93b1 | 239 | /* Value for size-based rotations, 0 if disabled. */ |
259c2674 | 240 | uint64_t rotate_size; |
5c408ad8 JD |
241 | /* |
242 | * Keep a state if this session was rotated after the last stop command. | |
243 | * We only allow one rotation after a stop. At destroy, we also need to | |
a9577b76 | 244 | * know if a rotation occurred since the last stop to rename the current |
a2b988e2 MD |
245 | * chunk. After a stop followed by rotate, all subsequent clear |
246 | * (without prior start) will succeed, but will be effect-less. | |
5c408ad8 JD |
247 | */ |
248 | bool rotated_after_last_stop; | |
b02f5986 MD |
249 | /* |
250 | * Track whether the session was cleared after last stop. All subsequent | |
251 | * clear (without prior start) will succeed, but will be effect-less. A | |
252 | * subsequent rotate (without prior start) will return an error. | |
253 | */ | |
254 | bool cleared_after_last_stop; | |
a7ceb342 MD |
255 | /* |
256 | * True if the session has had an explicit non-quiet rotation. | |
257 | */ | |
258 | bool rotated; | |
90936dcf | 259 | /* |
c08136a3 | 260 | * Trigger for size-based rotations. |
90936dcf | 261 | */ |
90936dcf | 262 | struct lttng_trigger *rotate_trigger; |
d2956687 | 263 | LTTNG_OPTIONAL(uint64_t) most_recent_chunk_id; |
82b69413 | 264 | struct lttng_trace_chunk *current_trace_chunk; |
d2956687 JG |
265 | struct lttng_trace_chunk *chunk_being_archived; |
266 | /* Current state of a rotation. */ | |
267 | enum lttng_rotation_state rotation_state; | |
7fdbed1c | 268 | bool quiet_rotation; |
d2956687 JG |
269 | char *last_archived_chunk_name; |
270 | LTTNG_OPTIONAL(uint64_t) last_archived_chunk_id; | |
3e3665b8 | 271 | struct lttng_dynamic_array destroy_notifiers; |
ccbdaca4 | 272 | struct lttng_dynamic_array clear_notifiers; |
6fa5fe7c MD |
273 | /* Session base path override. Set non-null. */ |
274 | char *base_path; | |
d9a970b7 | 275 | }; |
e1bbf989 | 276 | |
a0a4f314 JG |
277 | /* |
278 | * Destruction notifiers are invoked in an exclusive context. There is no need for the session to be | |
279 | * locked nor for a reference to be acquired. | |
280 | */ | |
281 | using ltt_session_destroy_notifier = void (*)(const ltt_session::locked_ref&, void *); | |
282 | using ltt_session_clear_notifier = void (*)(const ltt_session::locked_ref&, void *); | |
283 | ||
e99e3664 JG |
284 | namespace lttng { |
285 | namespace sessiond { | |
286 | ||
d9a970b7 | 287 | std::unique_lock<std::mutex> lock_session_list(); |
e99e3664 | 288 | |
d9a970b7 JG |
289 | namespace exceptions { |
290 | /** | |
291 | * @class session_not_found_error | |
292 | * @brief Represents a session-not-found error and provides the parameters used to query the session | |
293 | * for use by error-reporting code. | |
294 | */ | |
295 | class session_not_found_error : public lttng::runtime_error { | |
296 | public: | |
297 | class query_parameter { | |
298 | public: | |
299 | enum class query_type : std::uint8_t { BY_NAME, BY_ID }; | |
300 | ||
301 | /* | |
302 | * Intentionally not explicit to allow construction from c-style strings, | |
303 | * std::string, and lttng::c_string_view. | |
304 | * | |
305 | * NOLINTBEGIN(google-explicit-constructor) | |
306 | */ | |
307 | query_parameter(const std::string& session_name) : | |
308 | type(query_type::BY_NAME), parameter(session_name) | |
309 | { | |
310 | } | |
311 | /* NOLINTEND(google-explicit-constructor) */ | |
312 | ||
a0a4f314 JG |
313 | explicit query_parameter(ltt_session::id_t id_) : |
314 | type(query_type::BY_ID), parameter(id_) | |
d9a970b7 JG |
315 | { |
316 | } | |
317 | ||
318 | query_parameter(const query_parameter& other) : type(other.type) | |
319 | { | |
320 | if (type == query_type::BY_NAME) { | |
321 | new (¶meter.name) std::string(other.parameter.name); | |
322 | } else { | |
323 | parameter.id = other.parameter.id; | |
324 | } | |
325 | } | |
326 | ||
327 | ~query_parameter() | |
328 | { | |
329 | if (type == query_type::BY_NAME) { | |
330 | parameter.name.~basic_string(); | |
331 | } | |
332 | } | |
333 | ||
334 | query_type type; | |
335 | union parameter { | |
336 | explicit parameter(std::string name_) : name(std::move(name_)) | |
337 | { | |
338 | } | |
339 | ||
340 | explicit parameter(ltt_session::id_t id_) : id(id_) | |
341 | { | |
342 | } | |
343 | ||
344 | /* | |
345 | * parameter doesn't have enough information to do this safely; it it | |
346 | * delegated to its parent which uses placement new. | |
347 | */ | |
348 | parameter() | |
349 | { | |
350 | } | |
351 | ||
352 | parameter(const parameter&) = delete; | |
353 | parameter(const parameter&&) = delete; | |
354 | parameter& operator=(parameter&) = delete; | |
355 | parameter& operator=(parameter&&) = delete; | |
356 | ||
357 | ~parameter() | |
358 | { | |
359 | } | |
360 | ||
361 | std::string name; | |
362 | ltt_session::id_t id; | |
363 | } parameter; | |
364 | }; | |
365 | ||
366 | session_not_found_error(const std::string& session_name, | |
367 | const lttng::source_location& source_location_) : | |
368 | lttng::runtime_error(fmt::format("Session not found: name=`{}`", session_name), | |
369 | source_location_), | |
370 | query_parameter(session_name) | |
371 | { | |
372 | } | |
373 | ||
374 | session_not_found_error(ltt_session::id_t session_id, | |
375 | const lttng::source_location& source_location_) : | |
376 | lttng::runtime_error("Session not found: id=" + std::to_string(session_id), | |
377 | source_location_), | |
378 | query_parameter(session_id) | |
379 | { | |
380 | } | |
381 | ||
382 | session_not_found_error(const session_not_found_error& other) = default; | |
383 | ~session_not_found_error() noexcept override = default; | |
384 | ||
385 | query_parameter query_parameter; | |
386 | }; | |
387 | } // namespace exceptions | |
e99e3664 JG |
388 | } /* namespace sessiond */ |
389 | } /* namespace lttng */ | |
390 | ||
a0a4f314 JG |
391 | void session_destroy(struct ltt_session *session); |
392 | int session_add_destroy_notifier(const ltt_session::locked_ref& session, | |
393 | ltt_session_destroy_notifier notifier, | |
394 | void *user_data); | |
395 | ||
396 | int session_add_clear_notifier(const ltt_session::locked_ref& session, | |
397 | ltt_session_clear_notifier notifier, | |
398 | void *user_data); | |
399 | void session_notify_clear(const ltt_session::locked_ref& session); | |
400 | ||
401 | enum consumer_dst_type | |
402 | session_get_consumer_destination_type(const ltt_session::locked_ref& session); | |
403 | const char *session_get_net_consumer_hostname(const ltt_session::locked_ref& session); | |
404 | void session_get_net_consumer_ports(const ltt_session::locked_ref& session, | |
405 | uint16_t *control_port, | |
406 | uint16_t *data_port); | |
407 | struct lttng_trace_archive_location * | |
408 | session_get_trace_archive_location(const ltt_session::locked_ref& session); | |
409 | ||
410 | struct ltt_session_list *session_get_list(); | |
411 | void session_list_wait_empty(std::unique_lock<std::mutex> list_lock); | |
412 | ||
413 | bool session_access_ok(const ltt_session::locked_ref& session, uid_t uid); | |
414 | ||
415 | int session_reset_rotation_state(const ltt_session::locked_ref& session, | |
416 | enum lttng_rotation_state result); | |
417 | ||
418 | /* Create a new trace chunk object from the session's configuration. */ | |
419 | struct lttng_trace_chunk * | |
420 | session_create_new_trace_chunk(const ltt_session::locked_ref& session, | |
421 | const struct consumer_output *consumer_output_override, | |
422 | const char *session_base_path_override, | |
423 | const char *chunk_name_override); | |
424 | ||
425 | /* | |
426 | * Set `new_trace_chunk` as the session's current trace chunk. A reference | |
427 | * to `new_trace_chunk` is acquired by the session. The chunk is created | |
428 | * on remote peers (consumer and relay daemons). | |
429 | * | |
430 | * A reference to the session's current trace chunk is returned through | |
431 | * `current_session_trace_chunk` on success. | |
432 | */ | |
433 | int session_set_trace_chunk(const ltt_session::locked_ref& session, | |
434 | struct lttng_trace_chunk *new_trace_chunk, | |
435 | struct lttng_trace_chunk **current_session_trace_chunk); | |
436 | ||
437 | /* | |
438 | * Close a chunk on the remote peers of a session. Has no effect on the | |
439 | * ltt_session itself. | |
440 | */ | |
441 | int session_close_trace_chunk(const ltt_session::locked_ref& session, | |
442 | struct lttng_trace_chunk *trace_chunk, | |
443 | enum lttng_trace_chunk_command_type close_command, | |
444 | char *path); | |
445 | ||
446 | /* Open a packet in all channels of a given session. */ | |
447 | enum lttng_error_code session_open_packets(const ltt_session::locked_ref& session); | |
448 | ||
449 | bool session_output_supports_trace_chunks(const struct ltt_session *session); | |
450 | ||
451 | /* | |
452 | * Sample the id of a session looked up via its name. | |
453 | * Here the term "sampling" hint the caller that this return the id at a given | |
454 | * point in time with no guarantee that the session for which the id was | |
455 | * sampled still exist at that point. | |
456 | * | |
457 | * Return 0 when the session is not found, | |
458 | * Return 1 when the session is found and set `id`. | |
459 | */ | |
460 | bool sample_session_id_by_name(const char *name, uint64_t *id); | |
461 | ||
5b74c7b1 | 462 | #endif /* _LTT_SESSION_H */ |