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f2b3ef9f JG |
1 | /* |
2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0-only | |
5 | * | |
6 | */ | |
7 | ||
c9e313bc SM |
8 | #include "action-executor.hpp" |
9 | #include "cmd.hpp" | |
10 | #include "health-sessiond.hpp" | |
11 | #include "lttng-sessiond.hpp" | |
12 | #include "notification-thread-internal.hpp" | |
13 | #include "session.hpp" | |
14 | #include "thread.hpp" | |
28ab034a | 15 | |
c9e313bc SM |
16 | #include <common/dynamic-array.hpp> |
17 | #include <common/macros.hpp> | |
18 | #include <common/optional.hpp> | |
56047f5a | 19 | #include <common/urcu.hpp> |
28ab034a | 20 | |
c9e313bc SM |
21 | #include <lttng/action/action-internal.hpp> |
22 | #include <lttng/action/list-internal.hpp> | |
ad63a966 | 23 | #include <lttng/action/list.h> |
c9e313bc | 24 | #include <lttng/action/notify-internal.hpp> |
f2b3ef9f JG |
25 | #include <lttng/action/notify.h> |
26 | #include <lttng/action/rotate-session.h> | |
27 | #include <lttng/action/snapshot-session.h> | |
28 | #include <lttng/action/start-session.h> | |
29 | #include <lttng/action/stop-session.h> | |
30 | #include <lttng/condition/evaluation.h> | |
c9e313bc | 31 | #include <lttng/condition/event-rule-matches-internal.hpp> |
f2b3ef9f | 32 | #include <lttng/lttng-error.h> |
c9e313bc | 33 | #include <lttng/trigger/trigger-internal.hpp> |
28ab034a | 34 | |
f2b3ef9f JG |
35 | #include <pthread.h> |
36 | #include <stdbool.h> | |
37 | #include <stddef.h> | |
38 | #include <urcu/list.h> | |
39 | ||
28ab034a | 40 | #define THREAD_NAME "Action Executor" |
f2b3ef9f JG |
41 | #define MAX_QUEUED_WORK_COUNT 8192 |
42 | ||
f1494934 JG |
43 | struct action_executor { |
44 | struct lttng_thread *thread; | |
45 | struct notification_thread_handle *notification_thread_handle; | |
46 | struct { | |
47 | uint64_t pending_count; | |
48 | struct cds_list_head list; | |
49 | pthread_cond_t cond; | |
50 | pthread_mutex_t lock; | |
51 | } work; | |
52 | bool should_quit; | |
53 | uint64_t next_work_item_id; | |
54 | }; | |
55 | ||
56 | namespace { | |
72365501 JR |
57 | /* |
58 | * A work item is composed of a dynamic array of sub-items which | |
59 | * represent a flattened, and augmented, version of a trigger's actions. | |
60 | * | |
61 | * We cannot rely solely on the trigger's actions since each action can have an | |
62 | * execution context we need to comply with. | |
63 | * | |
64 | * The notion of execution context is required since for some actions the | |
65 | * associated object are referenced by name and not by id. This can lead to | |
66 | * a number of ambiguities when executing an action work item. | |
67 | * | |
68 | * For example, let's take a simple trigger such as: | |
69 | * - condition: ust event a | |
70 | * - action: start session S | |
71 | * | |
72 | * At time T, session S exists. | |
73 | * At T + 1, the event A is hit. | |
74 | * At T + 2, the tracer event notification is received and the work item is | |
75 | * queued. Here session S have an id of 1. | |
76 | * At T + 3, the session S is destroyed and a new session S is created, with a | |
77 | * resulting id of 200. | |
78 | * At T +4, the work item is popped from the queue and begin execution and will | |
79 | * start session S with an id of 200 instead of the session S id 1 that was | |
80 | * present at the queuing phase. | |
81 | * | |
82 | * The context to be respected is the one when the work item is queued. If the | |
83 | * execution context is not the same at the moment of execution, we skip the | |
84 | * execution of that sub-item. | |
85 | * | |
86 | * It is the same policy in regards to the validity of the associated | |
87 | * trigger object at the moment of execution, if the trigger is found to be | |
88 | * unregistered, the execution is skipped. | |
89 | */ | |
f2b3ef9f JG |
90 | struct action_work_item { |
91 | uint64_t id; | |
72365501 JR |
92 | |
93 | /* | |
94 | * The actions to be executed with their respective execution context. | |
95 | * See struct `action_work_subitem`. | |
96 | */ | |
be65f802 | 97 | struct lttng_dynamic_array subitems; |
72365501 JR |
98 | |
99 | /* Execution context data */ | |
f2b3ef9f JG |
100 | struct lttng_trigger *trigger; |
101 | struct lttng_evaluation *evaluation; | |
102 | struct notification_client_list *client_list; | |
103 | LTTNG_OPTIONAL(struct lttng_credentials) object_creds; | |
104 | struct cds_list_head list_node; | |
105 | }; | |
106 | ||
72365501 JR |
107 | struct action_work_subitem { |
108 | struct lttng_action *action; | |
109 | struct { | |
110 | /* Used by actions targeting a session. */ | |
111 | LTTNG_OPTIONAL(uint64_t) session_id; | |
112 | } context; | |
113 | }; | |
f1494934 | 114 | } /* namespace */ |
72365501 | 115 | |
f2b3ef9f JG |
116 | /* |
117 | * Only return non-zero on a fatal error that should shut down the action | |
118 | * executor. | |
119 | */ | |
e665dfbc JG |
120 | using action_executor_handler = int (*)(struct action_executor *, |
121 | const struct action_work_item *, | |
122 | struct action_work_subitem *); | |
f2b3ef9f JG |
123 | |
124 | static int action_executor_notify_handler(struct action_executor *executor, | |
28ab034a JG |
125 | const struct action_work_item *, |
126 | struct action_work_subitem *); | |
127 | static int action_executor_start_session_handler(struct action_executor *executor, | |
128 | const struct action_work_item *, | |
129 | struct action_work_subitem *); | |
130 | static int action_executor_stop_session_handler(struct action_executor *executor, | |
131 | const struct action_work_item *, | |
132 | struct action_work_subitem *); | |
133 | static int action_executor_rotate_session_handler(struct action_executor *executor, | |
134 | const struct action_work_item *, | |
135 | struct action_work_subitem *); | |
136 | static int action_executor_snapshot_session_handler(struct action_executor *executor, | |
137 | const struct action_work_item *, | |
138 | struct action_work_subitem *); | |
7c2fae7c | 139 | static int action_executor_list_handler(struct action_executor *executor, |
28ab034a JG |
140 | const struct action_work_item *, |
141 | struct action_work_subitem *); | |
f2b3ef9f | 142 | static int action_executor_generic_handler(struct action_executor *executor, |
28ab034a JG |
143 | const struct action_work_item *, |
144 | struct action_work_subitem *); | |
f2b3ef9f JG |
145 | |
146 | static const action_executor_handler action_executors[] = { | |
28ab034a JG |
147 | action_executor_notify_handler, action_executor_start_session_handler, |
148 | action_executor_stop_session_handler, action_executor_rotate_session_handler, | |
149 | action_executor_snapshot_session_handler, action_executor_list_handler, | |
f2b3ef9f JG |
150 | }; |
151 | ||
72365501 JR |
152 | /* Forward declaration */ |
153 | static int add_action_to_subitem_array(struct lttng_action *action, | |
28ab034a | 154 | struct lttng_dynamic_array *subitems); |
72365501 JR |
155 | |
156 | static int populate_subitem_array_from_trigger(struct lttng_trigger *trigger, | |
28ab034a | 157 | struct lttng_dynamic_array *subitems); |
72365501 JR |
158 | |
159 | static void action_work_subitem_destructor(void *element) | |
160 | { | |
7966af57 | 161 | struct action_work_subitem *subitem = (action_work_subitem *) element; |
72365501 JR |
162 | |
163 | lttng_action_put(subitem->action); | |
164 | } | |
165 | ||
f2b3ef9f JG |
166 | static const char *get_action_name(const struct lttng_action *action) |
167 | { | |
0e43bcbf JG |
168 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
169 | ||
a0377dfe | 170 | LTTNG_ASSERT(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
0e43bcbf | 171 | |
c0e2990d | 172 | return lttng_action_type_string(action_type); |
f2b3ef9f JG |
173 | } |
174 | ||
175 | /* Check if this trigger allowed to interect with a given session. */ | |
176 | static bool is_trigger_allowed_for_session(const struct lttng_trigger *trigger, | |
a0a4f314 | 177 | const ltt_session::locked_ref& session) |
f2b3ef9f JG |
178 | { |
179 | bool is_allowed = false; | |
180 | const struct lttng_credentials session_creds = { | |
ff588497 JR |
181 | .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid), |
182 | .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid), | |
f2b3ef9f JG |
183 | }; |
184 | /* Can never be NULL. */ | |
28ab034a | 185 | const struct lttng_credentials *trigger_creds = lttng_trigger_get_credentials(trigger); |
f2b3ef9f | 186 | |
ff588497 | 187 | is_allowed = (lttng_credentials_is_equal_uid(trigger_creds, &session_creds)) || |
28ab034a | 188 | (lttng_credentials_get_uid(trigger_creds) == 0); |
f2b3ef9f | 189 | if (!is_allowed) { |
ff588497 | 190 | WARN("Trigger is not allowed to interact with session `%s`: session uid = %ld, session gid = %ld, trigger uid = %ld", |
28ab034a JG |
191 | session->name, |
192 | (long int) session->uid, | |
193 | (long int) session->gid, | |
194 | (long int) lttng_credentials_get_uid(trigger_creds)); | |
f2b3ef9f JG |
195 | } |
196 | ||
197 | return is_allowed; | |
198 | } | |
199 | ||
34f87583 JR |
200 | static const char *get_trigger_name(const struct lttng_trigger *trigger) |
201 | { | |
202 | const char *trigger_name; | |
203 | enum lttng_trigger_status trigger_status; | |
204 | ||
205 | trigger_status = lttng_trigger_get_name(trigger, &trigger_name); | |
0efb2ad7 JG |
206 | switch (trigger_status) { |
207 | case LTTNG_TRIGGER_STATUS_OK: | |
208 | break; | |
209 | case LTTNG_TRIGGER_STATUS_UNSET: | |
210 | trigger_name = "(anonymous)"; | |
211 | break; | |
212 | default: | |
213 | trigger_name = "(failed to get name)"; | |
214 | break; | |
215 | } | |
34f87583 JR |
216 | |
217 | return trigger_name; | |
218 | } | |
219 | ||
28ab034a JG |
220 | static int client_handle_transmission_status(struct notification_client *client, |
221 | enum client_transmission_status status, | |
222 | void *user_data) | |
f2b3ef9f JG |
223 | { |
224 | int ret = 0; | |
7966af57 | 225 | struct action_executor *executor = (action_executor *) user_data; |
f2b3ef9f JG |
226 | bool update_communication = true; |
227 | ||
f2b3ef9f JG |
228 | switch (status) { |
229 | case CLIENT_TRANSMISSION_STATUS_COMPLETE: | |
230 | DBG("Successfully sent full notification to client, client_id = %" PRIu64, | |
28ab034a | 231 | client->id); |
9016dbfc JG |
232 | /* |
233 | * There is no need to wake the (e)poll thread. If it was waiting for | |
234 | * "out" events on the client's socket, it will see that no payload | |
235 | * in queued and will unsubscribe from that event. | |
236 | * | |
237 | * In the other cases, we have to wake the the (e)poll thread to either | |
238 | * handle the error on the client or to get it to monitor the client "out" | |
239 | * events. | |
240 | */ | |
f2b3ef9f JG |
241 | update_communication = false; |
242 | break; | |
243 | case CLIENT_TRANSMISSION_STATUS_QUEUED: | |
244 | DBG("Queued notification in client outgoing buffer, client_id = %" PRIu64, | |
28ab034a | 245 | client->id); |
f2b3ef9f JG |
246 | break; |
247 | case CLIENT_TRANSMISSION_STATUS_FAIL: | |
248 | DBG("Communication error occurred while sending notification to client, client_id = %" PRIu64, | |
28ab034a | 249 | client->id); |
f2b3ef9f JG |
250 | break; |
251 | default: | |
252 | ERR("Fatal error encoutered while sending notification to client, client_id = %" PRIu64, | |
28ab034a | 253 | client->id); |
f2b3ef9f JG |
254 | ret = -1; |
255 | goto end; | |
256 | } | |
257 | ||
258 | if (!update_communication) { | |
259 | goto end; | |
260 | } | |
261 | ||
6c24d3fd | 262 | /* Safe to read client's id without locking as it is immutable. */ |
f2b3ef9f | 263 | ret = notification_thread_client_communication_update( |
28ab034a | 264 | executor->notification_thread_handle, client->id, status); |
f2b3ef9f JG |
265 | end: |
266 | return ret; | |
267 | } | |
268 | ||
269 | static int action_executor_notify_handler(struct action_executor *executor, | |
28ab034a JG |
270 | const struct action_work_item *work_item, |
271 | struct action_work_subitem *item __attribute__((unused))) | |
f2b3ef9f | 272 | { |
28ab034a JG |
273 | return notification_client_list_send_evaluation( |
274 | work_item->client_list, | |
275 | work_item->trigger, | |
276 | work_item->evaluation, | |
cd9adb8b | 277 | work_item->object_creds.is_set ? &(work_item->object_creds.value) : nullptr, |
28ab034a JG |
278 | client_handle_transmission_status, |
279 | executor); | |
f2b3ef9f JG |
280 | } |
281 | ||
28ab034a JG |
282 | static int action_executor_start_session_handler(struct action_executor *executor |
283 | __attribute__((unused)), | |
284 | const struct action_work_item *work_item, | |
285 | struct action_work_subitem *item) | |
f2b3ef9f | 286 | { |
f2b3ef9f JG |
287 | const char *session_name; |
288 | enum lttng_action_status action_status; | |
f2b3ef9f | 289 | enum lttng_error_code cmd_ret; |
72365501 | 290 | struct lttng_action *action = item->action; |
f2b3ef9f | 291 | |
56047f5a JG |
292 | lttng::urcu::read_lock_guard read_lock; |
293 | ||
28ab034a | 294 | action_status = lttng_action_start_session_get_session_name(action, &session_name); |
f2b3ef9f | 295 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
28ab034a | 296 | ERR("Failed to get session name from `%s` action", get_action_name(action)); |
d9a970b7 | 297 | return -1; |
f2b3ef9f JG |
298 | } |
299 | ||
72365501 JR |
300 | /* |
301 | * Validate if at the moment of the action was queued the session | |
302 | * existed. If not skip the action altogether. | |
303 | */ | |
304 | if (!item->context.session_id.is_set) { | |
4ec6f5b6 | 305 | DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`", |
28ab034a JG |
306 | session_name, |
307 | get_action_name(action), | |
308 | get_trigger_name(work_item->trigger)); | |
72365501 | 309 | lttng_action_increase_execution_failure_count(action); |
d9a970b7 | 310 | return 0; |
72365501 JR |
311 | } |
312 | ||
d9a970b7 | 313 | /* |
a0a4f314 | 314 | * Mind the order of the declaration of list_lock vs session: |
d9a970b7 JG |
315 | * the session list lock must always be released _after_ the release of |
316 | * a session's reference (the destruction of a ref/locked_ref) to ensure | |
317 | * since the reference's release may unpublish the session from the list of | |
318 | * sessions. | |
319 | */ | |
320 | const auto list_lock = lttng::sessiond::lock_session_list(); | |
d9a970b7 | 321 | try { |
a0a4f314 | 322 | const auto session = ltt_session::find_locked_session( |
d9a970b7 | 323 | LTTNG_OPTIONAL_GET(item->context.session_id)); |
a0a4f314 JG |
324 | |
325 | if (session->destroyed) { | |
326 | DBG("Session `%s` with id = %" PRIu64 | |
327 | " is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`", | |
328 | session->name, | |
329 | session->id, | |
330 | get_action_name(action), | |
331 | get_trigger_name(work_item->trigger)); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { | |
336 | return 0; | |
337 | } | |
338 | ||
339 | cmd_ret = (lttng_error_code) cmd_start_trace(session); | |
340 | switch (cmd_ret) { | |
341 | case LTTNG_OK: | |
342 | DBG("Successfully started session `%s` on behalf of trigger `%s`", | |
343 | session_name, | |
344 | get_trigger_name(work_item->trigger)); | |
345 | break; | |
346 | case LTTNG_ERR_TRACE_ALREADY_STARTED: | |
347 | DBG("Attempted to start session `%s` on behalf of trigger `%s` but it was already started", | |
348 | session_name, | |
349 | get_trigger_name(work_item->trigger)); | |
350 | break; | |
351 | default: | |
352 | WARN("Failed to start session `%s` on behalf of trigger `%s`: %s", | |
353 | session_name, | |
354 | get_trigger_name(work_item->trigger), | |
355 | lttng_strerror(-cmd_ret)); | |
356 | lttng_action_increase_execution_failure_count(action); | |
357 | break; | |
358 | } | |
d9a970b7 JG |
359 | } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) { |
360 | DBG_FMT("Failed to execution trigger action: {}, action=`{}`, trigger_name=`{}`, location='{}'", | |
361 | ex.what(), | |
362 | session_name, | |
363 | get_action_name(action), | |
364 | get_trigger_name(work_item->trigger), | |
365 | ex.source_location); | |
4a467a84 | 366 | lttng_action_increase_execution_failure_count(action); |
f2b3ef9f JG |
367 | } |
368 | ||
d9a970b7 | 369 | return 0; |
f2b3ef9f JG |
370 | } |
371 | ||
28ab034a JG |
372 | static int action_executor_stop_session_handler(struct action_executor *executor |
373 | __attribute__((unused)), | |
374 | const struct action_work_item *work_item, | |
375 | struct action_work_subitem *item) | |
f2b3ef9f | 376 | { |
f2b3ef9f JG |
377 | const char *session_name; |
378 | enum lttng_action_status action_status; | |
f2b3ef9f | 379 | enum lttng_error_code cmd_ret; |
72365501 | 380 | struct lttng_action *action = item->action; |
f2b3ef9f | 381 | |
56047f5a JG |
382 | lttng::urcu::read_lock_guard read_lock; |
383 | ||
28ab034a | 384 | action_status = lttng_action_stop_session_get_session_name(action, &session_name); |
f2b3ef9f | 385 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
28ab034a | 386 | ERR("Failed to get session name from `%s` action", get_action_name(action)); |
d9a970b7 | 387 | return -1; |
f2b3ef9f JG |
388 | } |
389 | ||
72365501 JR |
390 | /* |
391 | * Validate if, at the moment the action was queued, the target session | |
392 | * existed. If not, skip the action altogether. | |
393 | */ | |
394 | if (!item->context.session_id.is_set) { | |
4ec6f5b6 | 395 | DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`", |
28ab034a JG |
396 | session_name, |
397 | get_action_name(action), | |
398 | get_trigger_name(work_item->trigger)); | |
72365501 | 399 | lttng_action_increase_execution_failure_count(action); |
d9a970b7 | 400 | return 0; |
72365501 JR |
401 | } |
402 | ||
d9a970b7 | 403 | /* |
a0a4f314 | 404 | * Mind the order of the declaration of list_lock vs session: |
d9a970b7 JG |
405 | * the session list lock must always be released _after_ the release of |
406 | * a session's reference (the destruction of a ref/locked_ref) to ensure | |
407 | * since the reference's release may unpublish the session from the list of | |
408 | * sessions. | |
409 | */ | |
410 | const auto list_lock = lttng::sessiond::lock_session_list(); | |
d9a970b7 JG |
411 | |
412 | try { | |
a0a4f314 | 413 | const auto session = ltt_session::find_locked_session( |
d9a970b7 | 414 | LTTNG_OPTIONAL_GET(item->context.session_id)); |
a0a4f314 JG |
415 | |
416 | if (session->destroyed) { | |
417 | DBG("Session `%s` with id = %" PRIu64 | |
418 | " is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`", | |
419 | session->name, | |
420 | session->id, | |
421 | get_action_name(action), | |
422 | get_trigger_name(work_item->trigger)); | |
423 | return 0; | |
424 | } | |
425 | ||
426 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { | |
427 | return 0; | |
428 | } | |
429 | ||
430 | cmd_ret = (lttng_error_code) cmd_stop_trace(session); | |
431 | switch (cmd_ret) { | |
432 | case LTTNG_OK: | |
433 | DBG("Successfully stopped session `%s` on behalf of trigger `%s`", | |
434 | session_name, | |
435 | get_trigger_name(work_item->trigger)); | |
436 | break; | |
437 | case LTTNG_ERR_TRACE_ALREADY_STOPPED: | |
438 | DBG("Attempted to stop session `%s` on behalf of trigger `%s` but it was already stopped", | |
439 | session_name, | |
440 | get_trigger_name(work_item->trigger)); | |
441 | break; | |
442 | default: | |
443 | WARN("Failed to stop session `%s` on behalf of trigger `%s`: %s", | |
444 | session_name, | |
445 | get_trigger_name(work_item->trigger), | |
446 | lttng_strerror(-cmd_ret)); | |
447 | lttng_action_increase_execution_failure_count(action); | |
448 | break; | |
449 | } | |
d9a970b7 JG |
450 | } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) { |
451 | DBG_FMT("Failed to execution trigger action: {}, action=`{}`, trigger_name=`{}`, location='{}'", | |
452 | ex.what(), | |
453 | session_name, | |
454 | get_action_name(action), | |
455 | get_trigger_name(work_item->trigger), | |
456 | ex.source_location); | |
2d57482c | 457 | lttng_action_increase_execution_failure_count(action); |
f2b3ef9f JG |
458 | } |
459 | ||
d9a970b7 | 460 | return 0; |
f2b3ef9f JG |
461 | } |
462 | ||
28ab034a JG |
463 | static int action_executor_rotate_session_handler(struct action_executor *executor |
464 | __attribute__((unused)), | |
465 | const struct action_work_item *work_item, | |
466 | struct action_work_subitem *item) | |
f2b3ef9f | 467 | { |
f2b3ef9f JG |
468 | const char *session_name; |
469 | enum lttng_action_status action_status; | |
f2b3ef9f | 470 | enum lttng_error_code cmd_ret; |
72365501 | 471 | struct lttng_action *action = item->action; |
f2b3ef9f | 472 | |
56047f5a JG |
473 | lttng::urcu::read_lock_guard read_lock; |
474 | ||
28ab034a | 475 | action_status = lttng_action_rotate_session_get_session_name(action, &session_name); |
f2b3ef9f | 476 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
28ab034a | 477 | ERR("Failed to get session name from `%s` action", get_action_name(action)); |
d9a970b7 | 478 | return -1; |
f2b3ef9f JG |
479 | } |
480 | ||
72365501 JR |
481 | /* |
482 | * Validate if, at the moment the action was queued, the target session | |
483 | * existed. If not, skip the action altogether. | |
484 | */ | |
485 | if (!item->context.session_id.is_set) { | |
4ec6f5b6 | 486 | DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`", |
28ab034a JG |
487 | session_name, |
488 | get_action_name(action), | |
489 | get_trigger_name(work_item->trigger)); | |
72365501 | 490 | lttng_action_increase_execution_failure_count(action); |
d9a970b7 | 491 | return 0; |
72365501 JR |
492 | } |
493 | ||
d9a970b7 | 494 | /* |
a0a4f314 | 495 | * Mind the order of the declaration of list_lock vs session: |
d9a970b7 JG |
496 | * the session list lock must always be released _after_ the release of |
497 | * a session's reference (the destruction of a ref/locked_ref) to ensure | |
498 | * since the reference's release may unpublish the session from the list of | |
499 | * sessions. | |
500 | */ | |
501 | const auto list_lock = lttng::sessiond::lock_session_list(); | |
d9a970b7 | 502 | try { |
a0a4f314 | 503 | const auto session = ltt_session::find_locked_session( |
d9a970b7 | 504 | LTTNG_OPTIONAL_GET(item->context.session_id)); |
a0a4f314 JG |
505 | |
506 | if (session->destroyed) { | |
507 | DBG("Session `%s` with id = %" PRIu64 | |
508 | " is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`", | |
509 | session->name, | |
510 | session->id, | |
511 | get_action_name(action), | |
512 | get_trigger_name(work_item->trigger)); | |
513 | return 0; | |
514 | } | |
515 | ||
516 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { | |
517 | return 0; | |
518 | } | |
519 | ||
520 | cmd_ret = (lttng_error_code) cmd_rotate_session( | |
521 | session, nullptr, false, LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED); | |
522 | switch (cmd_ret) { | |
523 | case LTTNG_OK: | |
524 | DBG("Successfully started rotation of session `%s` on behalf of trigger `%s`", | |
525 | session_name, | |
526 | get_trigger_name(work_item->trigger)); | |
527 | break; | |
528 | case LTTNG_ERR_ROTATION_PENDING: | |
529 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation is already ongoing", | |
530 | session_name, | |
531 | get_trigger_name(work_item->trigger)); | |
532 | lttng_action_increase_execution_failure_count(action); | |
533 | break; | |
534 | case LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP: | |
535 | case LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR: | |
536 | DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation has already been completed since the last stop or clear", | |
537 | session_name, | |
538 | get_trigger_name(work_item->trigger)); | |
539 | break; | |
540 | default: | |
541 | WARN("Failed to start a rotation of session `%s` on behalf of trigger `%s`: %s", | |
542 | session_name, | |
543 | get_trigger_name(work_item->trigger), | |
544 | lttng_strerror(-cmd_ret)); | |
545 | lttng_action_increase_execution_failure_count(action); | |
546 | break; | |
547 | } | |
d9a970b7 JG |
548 | } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) { |
549 | DBG_FMT("Failed to execution trigger action: {}, action=`{}`, trigger_name=`{}`, location='{}'", | |
550 | ex.what(), | |
551 | session_name, | |
552 | get_action_name(action), | |
553 | get_trigger_name(work_item->trigger), | |
554 | ex.source_location); | |
2d57482c | 555 | lttng_action_increase_execution_failure_count(action); |
f2b3ef9f JG |
556 | } |
557 | ||
d9a970b7 | 558 | return 0; |
f2b3ef9f JG |
559 | } |
560 | ||
28ab034a JG |
561 | static int action_executor_snapshot_session_handler(struct action_executor *executor |
562 | __attribute__((unused)), | |
563 | const struct action_work_item *work_item, | |
564 | struct action_work_subitem *item) | |
f2b3ef9f | 565 | { |
f2b3ef9f JG |
566 | const char *session_name; |
567 | enum lttng_action_status action_status; | |
7966af57 | 568 | lttng_snapshot_output default_snapshot_output; |
28ab034a | 569 | const struct lttng_snapshot_output *snapshot_output = &default_snapshot_output; |
f2b3ef9f | 570 | enum lttng_error_code cmd_ret; |
72365501 JR |
571 | struct lttng_action *action = item->action; |
572 | ||
7966af57 SM |
573 | default_snapshot_output.max_size = UINT64_MAX; |
574 | ||
56047f5a JG |
575 | lttng::urcu::read_lock_guard read_lock; |
576 | ||
72365501 JR |
577 | /* |
578 | * Validate if, at the moment the action was queued, the target session | |
579 | * existed. If not, skip the action altogether. | |
580 | */ | |
581 | if (!item->context.session_id.is_set) { | |
4ec6f5b6 | 582 | DBG("Session was not present at the moment the work item was enqueued for `%s` action of trigger `%s`", |
28ab034a JG |
583 | get_action_name(action), |
584 | get_trigger_name(work_item->trigger)); | |
72365501 | 585 | lttng_action_increase_execution_failure_count(action); |
d9a970b7 | 586 | return 0; |
72365501 | 587 | } |
f2b3ef9f | 588 | |
28ab034a | 589 | action_status = lttng_action_snapshot_session_get_session_name(action, &session_name); |
f2b3ef9f | 590 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
28ab034a | 591 | ERR("Failed to get session name from `%s` action", get_action_name(action)); |
d9a970b7 | 592 | return -1; |
f2b3ef9f JG |
593 | } |
594 | ||
28ab034a JG |
595 | action_status = lttng_action_snapshot_session_get_output(action, &snapshot_output); |
596 | if (action_status != LTTNG_ACTION_STATUS_OK && action_status != LTTNG_ACTION_STATUS_UNSET) { | |
597 | ERR("Failed to get output from `%s` action", get_action_name(action)); | |
d9a970b7 | 598 | return -1; |
f2b3ef9f JG |
599 | } |
600 | ||
d9a970b7 JG |
601 | /* |
602 | * Mind the order of the declaration of list_lock vs session: | |
603 | * the session list lock must always be released _after_ the release of | |
604 | * a session's reference (the destruction of a ref/locked_ref) to ensure | |
605 | * since the reference's release may unpublish the session from the list of | |
606 | * sessions. | |
607 | */ | |
608 | const auto list_lock = lttng::sessiond::lock_session_list(); | |
d9a970b7 | 609 | try { |
a0a4f314 | 610 | const auto session = ltt_session::find_locked_session( |
d9a970b7 | 611 | LTTNG_OPTIONAL_GET(item->context.session_id)); |
a0a4f314 JG |
612 | |
613 | if (session->destroyed) { | |
614 | DBG("Session `%s` with id = %" PRIu64 | |
615 | " is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`", | |
616 | session->name, | |
617 | session->id, | |
618 | get_action_name(action), | |
619 | get_trigger_name(work_item->trigger)); | |
620 | return 0; | |
621 | } | |
622 | ||
623 | if (!is_trigger_allowed_for_session(work_item->trigger, session)) { | |
624 | return 0; | |
625 | } | |
626 | ||
627 | cmd_ret = (lttng_error_code) cmd_snapshot_record(session, snapshot_output, 0); | |
628 | switch (cmd_ret) { | |
629 | case LTTNG_OK: | |
630 | DBG("Successfully recorded snapshot of session `%s` on behalf of trigger `%s`", | |
631 | session_name, | |
632 | get_trigger_name(work_item->trigger)); | |
633 | break; | |
634 | default: | |
635 | WARN("Failed to record snapshot of session `%s` on behalf of trigger `%s`: %s", | |
636 | session_name, | |
637 | get_trigger_name(work_item->trigger), | |
638 | lttng_strerror(-cmd_ret)); | |
639 | lttng_action_increase_execution_failure_count(action); | |
640 | break; | |
641 | } | |
642 | ||
d9a970b7 JG |
643 | } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) { |
644 | DBG_FMT("Failed to execution trigger action: {}, action=`{}`, trigger_name=`{}`, location='{}'", | |
645 | ex.what(), | |
646 | session_name, | |
647 | get_action_name(action), | |
648 | get_trigger_name(work_item->trigger), | |
649 | ex.source_location); | |
2d57482c | 650 | lttng_action_increase_execution_failure_count(action); |
f2b3ef9f JG |
651 | } |
652 | ||
d9a970b7 | 653 | return 0; |
f2b3ef9f JG |
654 | } |
655 | ||
28ab034a JG |
656 | static int action_executor_list_handler(struct action_executor *executor __attribute__((unused)), |
657 | const struct action_work_item *work_item | |
658 | __attribute__((unused)), | |
659 | struct action_work_subitem *item __attribute__((unused))) | |
f2b3ef9f | 660 | { |
7c2fae7c | 661 | ERR("Execution of a list action by the action executor should never occur"); |
72365501 | 662 | abort(); |
f2b3ef9f JG |
663 | } |
664 | ||
665 | static int action_executor_generic_handler(struct action_executor *executor, | |
28ab034a JG |
666 | const struct action_work_item *work_item, |
667 | struct action_work_subitem *item) | |
f2b3ef9f | 668 | { |
2d57482c | 669 | int ret; |
72365501 | 670 | struct lttng_action *action = item->action; |
0e43bcbf JG |
671 | const enum lttng_action_type action_type = lttng_action_get_type(action); |
672 | ||
a0377dfe | 673 | LTTNG_ASSERT(action_type != LTTNG_ACTION_TYPE_UNKNOWN); |
0e43bcbf | 674 | |
2d57482c JR |
675 | lttng_action_increase_execution_request_count(action); |
676 | if (!lttng_action_should_execute(action)) { | |
677 | DBG("Policy prevented execution of action `%s` of trigger `%s` action work item %" PRIu64, | |
28ab034a JG |
678 | get_action_name(action), |
679 | get_trigger_name(work_item->trigger), | |
680 | work_item->id); | |
2d57482c JR |
681 | ret = 0; |
682 | goto end; | |
683 | } | |
684 | ||
685 | lttng_action_increase_execution_count(action); | |
2516f2d8 | 686 | DBG("Executing action `%s` of trigger `%s` action work item %" PRIu64, |
28ab034a JG |
687 | get_action_name(action), |
688 | get_trigger_name(work_item->trigger), | |
689 | work_item->id); | |
72365501 | 690 | ret = action_executors[action_type](executor, work_item, item); |
2d57482c JR |
691 | end: |
692 | return ret; | |
f2b3ef9f JG |
693 | } |
694 | ||
695 | static int action_work_item_execute(struct action_executor *executor, | |
28ab034a | 696 | struct action_work_item *work_item) |
f2b3ef9f JG |
697 | { |
698 | int ret; | |
72365501 | 699 | size_t count, i; |
f2b3ef9f | 700 | |
34f87583 | 701 | DBG("Starting execution of action work item %" PRIu64 " of trigger `%s`", |
28ab034a JG |
702 | work_item->id, |
703 | get_trigger_name(work_item->trigger)); | |
72365501 | 704 | |
be65f802 | 705 | count = lttng_dynamic_array_get_count(&work_item->subitems); |
72365501 JR |
706 | for (i = 0; i < count; i++) { |
707 | struct action_work_subitem *item; | |
708 | ||
28ab034a JG |
709 | item = (action_work_subitem *) lttng_dynamic_array_get_element(&work_item->subitems, |
710 | i); | |
711 | ret = action_executor_generic_handler(executor, work_item, item); | |
72365501 JR |
712 | if (ret) { |
713 | goto end; | |
714 | } | |
715 | } | |
716 | end: | |
34f87583 | 717 | DBG("Completed execution of action work item %" PRIu64 " of trigger `%s`", |
28ab034a JG |
718 | work_item->id, |
719 | get_trigger_name(work_item->trigger)); | |
f2b3ef9f JG |
720 | return ret; |
721 | } | |
722 | ||
723 | static void action_work_item_destroy(struct action_work_item *work_item) | |
724 | { | |
725 | lttng_trigger_put(work_item->trigger); | |
726 | lttng_evaluation_destroy(work_item->evaluation); | |
727 | notification_client_list_put(work_item->client_list); | |
be65f802 | 728 | lttng_dynamic_array_reset(&work_item->subitems); |
f2b3ef9f JG |
729 | free(work_item); |
730 | } | |
731 | ||
732 | static void *action_executor_thread(void *_data) | |
733 | { | |
7966af57 | 734 | struct action_executor *executor = (action_executor *) _data; |
f2b3ef9f | 735 | |
a0377dfe | 736 | LTTNG_ASSERT(executor); |
f2b3ef9f | 737 | |
28ab034a | 738 | health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR); |
f2b3ef9f JG |
739 | |
740 | rcu_register_thread(); | |
741 | rcu_thread_online(); | |
742 | ||
743 | DBG("Entering work execution loop"); | |
744 | pthread_mutex_lock(&executor->work.lock); | |
745 | while (!executor->should_quit) { | |
da247508 | 746 | int ret = 0; |
f2b3ef9f JG |
747 | struct action_work_item *work_item; |
748 | ||
749 | health_code_update(); | |
750 | if (executor->work.pending_count == 0) { | |
751 | health_poll_entry(); | |
752 | DBG("No work items enqueued, entering wait"); | |
28ab034a | 753 | pthread_cond_wait(&executor->work.cond, &executor->work.lock); |
f2b3ef9f JG |
754 | DBG("Woke-up from wait"); |
755 | health_poll_exit(); | |
756 | continue; | |
757 | } | |
758 | ||
0db0f8e0 | 759 | /* Pop item from front of the list with work lock held. */ |
28ab034a JG |
760 | work_item = cds_list_first_entry( |
761 | &executor->work.list, struct action_work_item, list_node); | |
f2b3ef9f JG |
762 | cds_list_del(&work_item->list_node); |
763 | executor->work.pending_count--; | |
764 | ||
765 | /* | |
766 | * Work can be performed without holding the work lock, | |
767 | * allowing new items to be queued. | |
768 | */ | |
769 | pthread_mutex_unlock(&executor->work.lock); | |
d2a28b27 JR |
770 | |
771 | /* Execute item only if a trigger is registered. */ | |
772 | lttng_trigger_lock(work_item->trigger); | |
773 | if (!lttng_trigger_is_registered(work_item->trigger)) { | |
cd9adb8b | 774 | const char *trigger_name = nullptr; |
d2a28b27 JR |
775 | uid_t trigger_owner_uid; |
776 | enum lttng_trigger_status trigger_status; | |
777 | ||
0efb2ad7 | 778 | trigger_name = get_trigger_name(work_item->trigger); |
d2a28b27 | 779 | |
28ab034a JG |
780 | trigger_status = |
781 | lttng_trigger_get_owner_uid(work_item->trigger, &trigger_owner_uid); | |
a0377dfe | 782 | LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK); |
d2a28b27 | 783 | |
28ab034a JG |
784 | DBG("Work item skipped since the associated trigger is no longer registered: work item id = %" PRIu64 |
785 | ", trigger name = `%s`, trigger owner uid = %d", | |
786 | work_item->id, | |
787 | trigger_name, | |
788 | (int) trigger_owner_uid); | |
d2a28b27 JR |
789 | ret = 0; |
790 | goto skip_execute; | |
791 | } | |
792 | ||
f2b3ef9f | 793 | ret = action_work_item_execute(executor, work_item); |
d2a28b27 JR |
794 | |
795 | skip_execute: | |
796 | lttng_trigger_unlock(work_item->trigger); | |
f2b3ef9f JG |
797 | action_work_item_destroy(work_item); |
798 | if (ret) { | |
799 | /* Fatal error. */ | |
800 | break; | |
801 | } | |
802 | ||
803 | health_code_update(); | |
804 | pthread_mutex_lock(&executor->work.lock); | |
805 | } | |
806 | ||
f5f5c54d JG |
807 | if (executor->should_quit) { |
808 | pthread_mutex_unlock(&executor->work.lock); | |
809 | } | |
f2b3ef9f JG |
810 | DBG("Left work execution loop"); |
811 | ||
812 | health_code_update(); | |
813 | ||
814 | rcu_thread_offline(); | |
815 | rcu_unregister_thread(); | |
412d7227 | 816 | health_unregister(the_health_sessiond); |
f2b3ef9f | 817 | |
cd9adb8b | 818 | return nullptr; |
f2b3ef9f JG |
819 | } |
820 | ||
821 | static bool shutdown_action_executor_thread(void *_data) | |
822 | { | |
7966af57 | 823 | struct action_executor *executor = (action_executor *) _data; |
f2b3ef9f | 824 | |
8db3acaf | 825 | pthread_mutex_lock(&executor->work.lock); |
f2b3ef9f JG |
826 | executor->should_quit = true; |
827 | pthread_cond_signal(&executor->work.cond); | |
8db3acaf | 828 | pthread_mutex_unlock(&executor->work.lock); |
f2b3ef9f JG |
829 | return true; |
830 | } | |
831 | ||
832 | static void clean_up_action_executor_thread(void *_data) | |
833 | { | |
7966af57 | 834 | struct action_executor *executor = (action_executor *) _data; |
f2b3ef9f | 835 | |
a0377dfe | 836 | LTTNG_ASSERT(cds_list_empty(&executor->work.list)); |
f2b3ef9f JG |
837 | |
838 | pthread_mutex_destroy(&executor->work.lock); | |
839 | pthread_cond_destroy(&executor->work.cond); | |
840 | free(executor); | |
841 | } | |
842 | ||
28ab034a | 843 | struct action_executor *action_executor_create(struct notification_thread_handle *handle) |
f2b3ef9f | 844 | { |
64803277 | 845 | struct action_executor *executor = zmalloc<action_executor>(); |
f2b3ef9f JG |
846 | |
847 | if (!executor) { | |
848 | goto end; | |
849 | } | |
850 | ||
851 | CDS_INIT_LIST_HEAD(&executor->work.list); | |
cd9adb8b JG |
852 | pthread_cond_init(&executor->work.cond, nullptr); |
853 | pthread_mutex_init(&executor->work.lock, nullptr); | |
f2b3ef9f JG |
854 | executor->notification_thread_handle = handle; |
855 | ||
856 | executor->thread = lttng_thread_create(THREAD_NAME, | |
28ab034a JG |
857 | action_executor_thread, |
858 | shutdown_action_executor_thread, | |
859 | clean_up_action_executor_thread, | |
860 | executor); | |
f2b3ef9f JG |
861 | end: |
862 | return executor; | |
863 | } | |
864 | ||
865 | void action_executor_destroy(struct action_executor *executor) | |
866 | { | |
867 | struct action_work_item *work_item, *tmp; | |
868 | ||
869 | /* TODO Wait for work list to drain? */ | |
870 | lttng_thread_shutdown(executor->thread); | |
871 | pthread_mutex_lock(&executor->work.lock); | |
872 | if (executor->work.pending_count != 0) { | |
873 | WARN("%" PRIu64 | |
28ab034a JG |
874 | " trigger action%s still queued for execution and will be discarded", |
875 | executor->work.pending_count, | |
876 | executor->work.pending_count == 1 ? " is" : "s are"); | |
f2b3ef9f JG |
877 | } |
878 | ||
28ab034a JG |
879 | cds_list_for_each_entry_safe (work_item, tmp, &executor->work.list, list_node) { |
880 | WARN("Discarding action work item %" PRIu64 " associated to trigger `%s`", | |
881 | work_item->id, | |
882 | get_trigger_name(work_item->trigger)); | |
f2b3ef9f JG |
883 | cds_list_del(&work_item->list_node); |
884 | action_work_item_destroy(work_item); | |
885 | } | |
886 | pthread_mutex_unlock(&executor->work.lock); | |
887 | lttng_thread_put(executor->thread); | |
888 | } | |
889 | ||
890 | /* RCU read-lock must be held by the caller. */ | |
28ab034a JG |
891 | enum action_executor_status |
892 | action_executor_enqueue_trigger(struct action_executor *executor, | |
893 | struct lttng_trigger *trigger, | |
894 | struct lttng_evaluation *evaluation, | |
895 | const struct lttng_credentials *object_creds, | |
896 | struct notification_client_list *client_list) | |
f2b3ef9f | 897 | { |
72365501 | 898 | int ret; |
f2b3ef9f JG |
899 | enum action_executor_status executor_status = ACTION_EXECUTOR_STATUS_OK; |
900 | const uint64_t work_item_id = executor->next_work_item_id++; | |
901 | struct action_work_item *work_item; | |
902 | bool signal = false; | |
72365501 | 903 | |
a0377dfe | 904 | LTTNG_ASSERT(trigger); |
48b7cdc2 | 905 | ASSERT_RCU_READ_LOCKED(); |
72365501 | 906 | |
f2b3ef9f JG |
907 | pthread_mutex_lock(&executor->work.lock); |
908 | /* Check for queue overflow. */ | |
909 | if (executor->work.pending_count >= MAX_QUEUED_WORK_COUNT) { | |
910 | /* Most likely spammy, remove if it is the case. */ | |
72365501 | 911 | DBG("Refusing to enqueue action for trigger (overflow): trigger name = `%s`, work item id = %" PRIu64, |
28ab034a JG |
912 | get_trigger_name(trigger), |
913 | work_item_id); | |
f2b3ef9f JG |
914 | executor_status = ACTION_EXECUTOR_STATUS_OVERFLOW; |
915 | goto error_unlock; | |
916 | } | |
917 | ||
64803277 | 918 | work_item = zmalloc<action_work_item>(); |
f2b3ef9f | 919 | if (!work_item) { |
4ec6f5b6 | 920 | PERROR("Failed to allocate action executor work item: trigger name = `%s`", |
28ab034a | 921 | get_trigger_name(trigger)); |
f2b3ef9f JG |
922 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
923 | goto error_unlock; | |
924 | } | |
925 | ||
926 | lttng_trigger_get(trigger); | |
927 | if (client_list) { | |
28ab034a | 928 | const bool reference_acquired = notification_client_list_get(client_list); |
f2b3ef9f | 929 | |
a0377dfe | 930 | LTTNG_ASSERT(reference_acquired); |
f2b3ef9f JG |
931 | } |
932 | ||
7966af57 SM |
933 | work_item->id = work_item_id; |
934 | work_item->trigger = trigger; | |
f2b3ef9f | 935 | |
7966af57 SM |
936 | /* Ownership transferred to the work item. */ |
937 | work_item->evaluation = evaluation; | |
cd9adb8b | 938 | evaluation = nullptr; |
be65f802 | 939 | |
7966af57 SM |
940 | work_item->client_list = client_list; |
941 | work_item->object_creds.is_set = !!object_creds; | |
942 | if (object_creds) { | |
943 | work_item->object_creds.value = *object_creds; | |
944 | } | |
945 | ||
946 | CDS_INIT_LIST_HEAD(&work_item->list_node); | |
947 | ||
be65f802 JG |
948 | /* Build the array of action work subitems for the passed trigger. */ |
949 | lttng_dynamic_array_init(&work_item->subitems, | |
28ab034a JG |
950 | sizeof(struct action_work_subitem), |
951 | action_work_subitem_destructor); | |
be65f802 | 952 | |
28ab034a | 953 | ret = populate_subitem_array_from_trigger(trigger, &work_item->subitems); |
be65f802 JG |
954 | if (ret) { |
955 | ERR("Failed to populate work item sub items on behalf of trigger: trigger name = `%s`", | |
28ab034a | 956 | get_trigger_name(trigger)); |
be65f802 JG |
957 | executor_status = ACTION_EXECUTOR_STATUS_ERROR; |
958 | goto error_unlock; | |
959 | } | |
960 | ||
f2b3ef9f JG |
961 | cds_list_add_tail(&work_item->list_node, &executor->work.list); |
962 | executor->work.pending_count++; | |
72365501 | 963 | DBG("Enqueued action for trigger: trigger name = `%s`, work item id = %" PRIu64, |
28ab034a JG |
964 | get_trigger_name(trigger), |
965 | work_item_id); | |
f2b3ef9f JG |
966 | signal = true; |
967 | ||
968 | error_unlock: | |
f2b3ef9f JG |
969 | if (signal) { |
970 | pthread_cond_signal(&executor->work.cond); | |
971 | } | |
972 | ||
be65f802 | 973 | pthread_mutex_unlock(&executor->work.lock); |
f2b3ef9f JG |
974 | lttng_evaluation_destroy(evaluation); |
975 | return executor_status; | |
976 | } | |
72365501 JR |
977 | |
978 | static int add_action_to_subitem_array(struct lttng_action *action, | |
28ab034a | 979 | struct lttng_dynamic_array *subitems) |
72365501 | 980 | { |
da247508 | 981 | int ret = 0; |
72365501 | 982 | enum lttng_action_type type = lttng_action_get_type(action); |
cd9adb8b | 983 | const char *session_name = nullptr; |
72365501 JR |
984 | enum lttng_action_status status; |
985 | struct action_work_subitem subitem = { | |
cd9adb8b | 986 | .action = nullptr, |
72365501 JR |
987 | .context = { |
988 | .session_id = LTTNG_OPTIONAL_INIT_UNSET, | |
989 | }, | |
990 | }; | |
991 | ||
a0377dfe FD |
992 | LTTNG_ASSERT(action); |
993 | LTTNG_ASSERT(subitems); | |
72365501 | 994 | |
7c2fae7c | 995 | if (type == LTTNG_ACTION_TYPE_LIST) { |
b17ed2ad | 996 | for (auto inner_action : lttng::ctl::action_list_view(action)) { |
a0377dfe | 997 | LTTNG_ASSERT(inner_action); |
2460203a | 998 | |
28ab034a | 999 | ret = add_action_to_subitem_array(inner_action, subitems); |
72365501 JR |
1000 | if (ret) { |
1001 | goto end; | |
1002 | } | |
1003 | } | |
1004 | ||
1005 | /* | |
1006 | * Go directly to the end since there is no need to add the | |
7c2fae7c | 1007 | * list action by itself to the subitems array. |
72365501 JR |
1008 | */ |
1009 | goto end; | |
1010 | } | |
1011 | ||
1012 | /* Gather execution context. */ | |
1013 | switch (type) { | |
1014 | case LTTNG_ACTION_TYPE_NOTIFY: | |
1015 | break; | |
1016 | case LTTNG_ACTION_TYPE_START_SESSION: | |
28ab034a | 1017 | status = lttng_action_start_session_get_session_name(action, &session_name); |
a0377dfe | 1018 | LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK); |
72365501 JR |
1019 | break; |
1020 | case LTTNG_ACTION_TYPE_STOP_SESSION: | |
28ab034a | 1021 | status = lttng_action_stop_session_get_session_name(action, &session_name); |
a0377dfe | 1022 | LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK); |
72365501 JR |
1023 | break; |
1024 | case LTTNG_ACTION_TYPE_ROTATE_SESSION: | |
28ab034a | 1025 | status = lttng_action_rotate_session_get_session_name(action, &session_name); |
a0377dfe | 1026 | LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK); |
72365501 JR |
1027 | break; |
1028 | case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION: | |
28ab034a | 1029 | status = lttng_action_snapshot_session_get_session_name(action, &session_name); |
a0377dfe | 1030 | LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK); |
72365501 | 1031 | break; |
7c2fae7c | 1032 | case LTTNG_ACTION_TYPE_LIST: |
72365501 JR |
1033 | case LTTNG_ACTION_TYPE_UNKNOWN: |
1034 | /* Fallthrough */ | |
1035 | default: | |
1036 | abort(); | |
1037 | break; | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * Fetch the session execution context info as needed. | |
1042 | * Note that we could decide to not add an action for which we know the | |
1043 | * execution will not happen (i.e no session exists for that name). For | |
1044 | * now we leave the decision to skip to the action executor for sake of | |
1045 | * simplicity and consistency. | |
1046 | */ | |
cd9adb8b | 1047 | if (session_name != nullptr) { |
e1bbf989 | 1048 | uint64_t session_id; |
72365501 | 1049 | |
e1bbf989 JR |
1050 | /* |
1051 | * Instantaneous sampling of the session id if present. | |
1052 | * | |
1053 | * This method is preferred over `sessiond_find_by_name` then | |
1054 | * fetching the session'd id since `sessiond_find_by_name` | |
1055 | * requires the session list lock to be taken. | |
1056 | * | |
1057 | * Taking the session list lock can lead to a deadlock | |
1058 | * between the action executor and the notification thread | |
1059 | * (caller of add_action_to_subitem_array). It is okay if the | |
1060 | * session state changes between the enqueuing time and the | |
1061 | * execution time. The execution context is validated at | |
1062 | * execution time. | |
1063 | */ | |
1064 | if (sample_session_id_by_name(session_name, &session_id)) { | |
28ab034a | 1065 | LTTNG_OPTIONAL_SET(&subitem.context.session_id, session_id); |
72365501 | 1066 | } |
72365501 JR |
1067 | } |
1068 | ||
1069 | /* Get a reference to the action. */ | |
1070 | lttng_action_get(action); | |
1071 | subitem.action = action; | |
1072 | ||
1073 | ret = lttng_dynamic_array_add_element(subitems, &subitem); | |
1074 | if (ret) { | |
1075 | ERR("Failed to add work subitem to the subitem array"); | |
1076 | lttng_action_put(action); | |
1077 | ret = -1; | |
1078 | goto end; | |
1079 | } | |
1080 | ||
1081 | end: | |
1082 | return ret; | |
1083 | } | |
1084 | ||
1085 | static int populate_subitem_array_from_trigger(struct lttng_trigger *trigger, | |
28ab034a | 1086 | struct lttng_dynamic_array *subitems) |
72365501 JR |
1087 | { |
1088 | struct lttng_action *action; | |
1089 | ||
1090 | action = lttng_trigger_get_action(trigger); | |
a0377dfe | 1091 | LTTNG_ASSERT(action); |
72365501 JR |
1092 | |
1093 | return add_action_to_subitem_array(action, subitems); | |
1094 | } |