2 * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 * SPDX-License-Identifier: GPL-2.0-only
8 #include "action-executor.h"
10 #include "health-sessiond.h"
11 #include "lttng-sessiond.h"
12 #include "notification-thread-internal.h"
15 #include <common/dynamic-array.h>
16 #include <common/macros.h>
17 #include <common/optional.h>
18 #include <lttng/action/action-internal.h>
19 #include <lttng/action/list-internal.h>
20 #include <lttng/action/list.h>
21 #include <lttng/action/notify-internal.h>
22 #include <lttng/action/notify.h>
23 #include <lttng/action/rotate-session.h>
24 #include <lttng/action/snapshot-session.h>
25 #include <lttng/action/start-session.h>
26 #include <lttng/action/stop-session.h>
27 #include <lttng/condition/evaluation.h>
28 #include <lttng/condition/event-rule-matches-internal.h>
29 #include <lttng/lttng-error.h>
30 #include <lttng/trigger/trigger-internal.h>
34 #include <urcu/list.h>
36 #define THREAD_NAME "Action Executor"
37 #define MAX_QUEUED_WORK_COUNT 8192
40 * A work item is composed of a dynamic array of sub-items which
41 * represent a flattened, and augmented, version of a trigger's actions.
43 * We cannot rely solely on the trigger's actions since each action can have an
44 * execution context we need to comply with.
46 * The notion of execution context is required since for some actions the
47 * associated object are referenced by name and not by id. This can lead to
48 * a number of ambiguities when executing an action work item.
50 * For example, let's take a simple trigger such as:
51 * - condition: ust event a
52 * - action: start session S
54 * At time T, session S exists.
55 * At T + 1, the event A is hit.
56 * At T + 2, the tracer event notification is received and the work item is
57 * queued. Here session S have an id of 1.
58 * At T + 3, the session S is destroyed and a new session S is created, with a
59 * resulting id of 200.
60 * At T +4, the work item is popped from the queue and begin execution and will
61 * start session S with an id of 200 instead of the session S id 1 that was
62 * present at the queuing phase.
64 * The context to be respected is the one when the work item is queued. If the
65 * execution context is not the same at the moment of execution, we skip the
66 * execution of that sub-item.
68 * It is the same policy in regards to the validity of the associated
69 * trigger object at the moment of execution, if the trigger is found to be
70 * unregistered, the execution is skipped.
73 struct action_work_item
{
77 * The actions to be executed with their respective execution context.
78 * See struct `action_work_subitem`.
80 struct lttng_dynamic_array subitems
;
82 /* Execution context data */
83 struct lttng_trigger
*trigger
;
84 struct lttng_evaluation
*evaluation
;
85 struct notification_client_list
*client_list
;
86 LTTNG_OPTIONAL(struct lttng_credentials
) object_creds
;
87 struct cds_list_head list_node
;
90 struct action_work_subitem
{
91 struct lttng_action
*action
;
93 /* Used by actions targeting a session. */
94 LTTNG_OPTIONAL(uint64_t) session_id
;
98 struct action_executor
{
99 struct lttng_thread
*thread
;
100 struct notification_thread_handle
*notification_thread_handle
;
102 uint64_t pending_count
;
103 struct cds_list_head list
;
105 pthread_mutex_t lock
;
108 uint64_t next_work_item_id
;
112 * Only return non-zero on a fatal error that should shut down the action
115 typedef int (*action_executor_handler
)(struct action_executor
*executor
,
116 const struct action_work_item
*,
117 struct action_work_subitem
*item
);
119 static int action_executor_notify_handler(struct action_executor
*executor
,
120 const struct action_work_item
*,
121 struct action_work_subitem
*);
122 static int action_executor_start_session_handler(
123 struct action_executor
*executor
,
124 const struct action_work_item
*,
125 struct action_work_subitem
*);
126 static int action_executor_stop_session_handler(
127 struct action_executor
*executor
,
128 const struct action_work_item
*,
129 struct action_work_subitem
*);
130 static int action_executor_rotate_session_handler(
131 struct action_executor
*executor
,
132 const struct action_work_item
*,
133 struct action_work_subitem
*);
134 static int action_executor_snapshot_session_handler(
135 struct action_executor
*executor
,
136 const struct action_work_item
*,
137 struct action_work_subitem
*);
138 static int action_executor_list_handler(struct action_executor
*executor
,
139 const struct action_work_item
*,
140 struct action_work_subitem
*);
141 static int action_executor_generic_handler(struct action_executor
*executor
,
142 const struct action_work_item
*,
143 struct action_work_subitem
*);
145 static const action_executor_handler action_executors
[] = {
146 action_executor_notify_handler
,
147 action_executor_start_session_handler
,
148 action_executor_stop_session_handler
,
149 action_executor_rotate_session_handler
,
150 action_executor_snapshot_session_handler
,
151 action_executor_list_handler
,
154 /* Forward declaration */
155 static int add_action_to_subitem_array(struct lttng_action
*action
,
156 struct lttng_dynamic_array
*subitems
);
158 static int populate_subitem_array_from_trigger(struct lttng_trigger
*trigger
,
159 struct lttng_dynamic_array
*subitems
);
161 static void action_work_subitem_destructor(void *element
)
163 struct action_work_subitem
*subitem
= (action_work_subitem
*) element
;
165 lttng_action_put(subitem
->action
);
168 static const char *get_action_name(const struct lttng_action
*action
)
170 const enum lttng_action_type action_type
= lttng_action_get_type(action
);
172 LTTNG_ASSERT(action_type
!= LTTNG_ACTION_TYPE_UNKNOWN
);
174 return lttng_action_type_string(action_type
);
177 /* Check if this trigger allowed to interect with a given session. */
178 static bool is_trigger_allowed_for_session(const struct lttng_trigger
*trigger
,
179 struct ltt_session
*session
)
181 bool is_allowed
= false;
182 const struct lttng_credentials session_creds
= {
183 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session
->uid
),
184 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session
->gid
),
186 /* Can never be NULL. */
187 const struct lttng_credentials
*trigger_creds
=
188 lttng_trigger_get_credentials(trigger
);
190 is_allowed
= (lttng_credentials_is_equal_uid(trigger_creds
, &session_creds
)) ||
191 (lttng_credentials_get_uid(trigger_creds
) == 0);
193 WARN("Trigger is not allowed to interact with session `%s`: session uid = %ld, session gid = %ld, trigger uid = %ld",
195 (long int) session
->uid
,
196 (long int) session
->gid
,
197 (long int) lttng_credentials_get_uid(trigger_creds
));
203 static const char *get_trigger_name(const struct lttng_trigger
*trigger
)
205 const char *trigger_name
;
206 enum lttng_trigger_status trigger_status
;
208 trigger_status
= lttng_trigger_get_name(trigger
, &trigger_name
);
209 switch (trigger_status
) {
210 case LTTNG_TRIGGER_STATUS_OK
:
212 case LTTNG_TRIGGER_STATUS_UNSET
:
213 trigger_name
= "(anonymous)";
216 trigger_name
= "(failed to get name)";
223 static int client_handle_transmission_status(
224 struct notification_client
*client
,
225 enum client_transmission_status status
,
229 struct action_executor
*executor
= (action_executor
*) user_data
;
230 bool update_communication
= true;
233 case CLIENT_TRANSMISSION_STATUS_COMPLETE
:
234 DBG("Successfully sent full notification to client, client_id = %" PRIu64
,
236 update_communication
= false;
238 case CLIENT_TRANSMISSION_STATUS_QUEUED
:
239 DBG("Queued notification in client outgoing buffer, client_id = %" PRIu64
,
242 case CLIENT_TRANSMISSION_STATUS_FAIL
:
243 DBG("Communication error occurred while sending notification to client, client_id = %" PRIu64
,
247 ERR("Fatal error encoutered while sending notification to client, client_id = %" PRIu64
,
253 if (!update_communication
) {
257 /* Safe to read client's id without locking as it is immutable. */
258 ret
= notification_thread_client_communication_update(
259 executor
->notification_thread_handle
, client
->id
,
265 static int action_executor_notify_handler(struct action_executor
*executor
,
266 const struct action_work_item
*work_item
,
267 struct action_work_subitem
*item
__attribute__((unused
)))
269 return notification_client_list_send_evaluation(work_item
->client_list
,
271 work_item
->evaluation
,
272 work_item
->object_creds
.is_set
?
273 &(work_item
->object_creds
.value
) :
275 client_handle_transmission_status
, executor
);
278 static int action_executor_start_session_handler(
279 struct action_executor
*executor
__attribute__((unused
)),
280 const struct action_work_item
*work_item
,
281 struct action_work_subitem
*item
)
284 const char *session_name
;
285 enum lttng_action_status action_status
;
286 struct ltt_session
*session
;
287 enum lttng_error_code cmd_ret
;
288 struct lttng_action
*action
= item
->action
;
290 action_status
= lttng_action_start_session_get_session_name(
291 action
, &session_name
);
292 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
293 ERR("Failed to get session name from `%s` action",
294 get_action_name(action
));
300 * Validate if at the moment of the action was queued the session
301 * existed. If not skip the action altogether.
303 if (!item
->context
.session_id
.is_set
) {
304 DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
305 session_name
, get_action_name(action
),
306 get_trigger_name(work_item
->trigger
));
307 lttng_action_increase_execution_failure_count(action
);
313 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
315 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
316 session_name
, get_action_name(action
),
317 get_trigger_name(work_item
->trigger
));
318 lttng_action_increase_execution_failure_count(action
);
319 goto error_unlock_list
;
322 session_lock(session
);
323 if (session
->destroyed
) {
324 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
325 session
->name
, session
->id
,
326 get_action_name(action
),
327 get_trigger_name(work_item
->trigger
));
328 goto error_unlock_session
;
331 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
332 goto error_unlock_session
;
335 cmd_ret
= (lttng_error_code
) cmd_start_trace(session
);
338 DBG("Successfully started session `%s` on behalf of trigger `%s`",
339 session_name
, get_trigger_name(work_item
->trigger
));
341 case LTTNG_ERR_TRACE_ALREADY_STARTED
:
342 DBG("Attempted to start session `%s` on behalf of trigger `%s` but it was already started",
343 session_name
, get_trigger_name(work_item
->trigger
));
346 WARN("Failed to start session `%s` on behalf of trigger `%s`: %s",
347 session_name
, get_trigger_name(work_item
->trigger
),
348 lttng_strerror(-cmd_ret
));
349 lttng_action_increase_execution_failure_count(action
);
353 error_unlock_session
:
354 session_unlock(session
);
355 session_put(session
);
358 session_unlock_list();
363 static int action_executor_stop_session_handler(
364 struct action_executor
*executor
__attribute__((unused
)),
365 const struct action_work_item
*work_item
,
366 struct action_work_subitem
*item
)
369 const char *session_name
;
370 enum lttng_action_status action_status
;
371 struct ltt_session
*session
;
372 enum lttng_error_code cmd_ret
;
373 struct lttng_action
*action
= item
->action
;
375 action_status
= lttng_action_stop_session_get_session_name(
376 action
, &session_name
);
377 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
378 ERR("Failed to get session name from `%s` action",
379 get_action_name(action
));
385 * Validate if, at the moment the action was queued, the target session
386 * existed. If not, skip the action altogether.
388 if (!item
->context
.session_id
.is_set
) {
389 DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
390 session_name
, get_action_name(action
),
391 get_trigger_name(work_item
->trigger
));
392 lttng_action_increase_execution_failure_count(action
);
398 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
400 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
401 session_name
, get_action_name(action
),
402 get_trigger_name(work_item
->trigger
));
403 lttng_action_increase_execution_failure_count(action
);
404 goto error_unlock_list
;
407 session_lock(session
);
408 if (session
->destroyed
) {
409 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
410 session
->name
, session
->id
,
411 get_action_name(action
),
412 get_trigger_name(work_item
->trigger
));
413 goto error_unlock_session
;
416 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
417 goto error_unlock_session
;
420 cmd_ret
= (lttng_error_code
) cmd_stop_trace(session
);
423 DBG("Successfully stopped session `%s` on behalf of trigger `%s`",
424 session_name
, get_trigger_name(work_item
->trigger
));
426 case LTTNG_ERR_TRACE_ALREADY_STOPPED
:
427 DBG("Attempted to stop session `%s` on behalf of trigger `%s` but it was already stopped",
428 session_name
, get_trigger_name(work_item
->trigger
));
431 WARN("Failed to stop session `%s` on behalf of trigger `%s`: %s",
432 session_name
, get_trigger_name(work_item
->trigger
),
433 lttng_strerror(-cmd_ret
));
434 lttng_action_increase_execution_failure_count(action
);
438 error_unlock_session
:
439 session_unlock(session
);
440 session_put(session
);
443 session_unlock_list();
448 static int action_executor_rotate_session_handler(
449 struct action_executor
*executor
__attribute__((unused
)),
450 const struct action_work_item
*work_item
,
451 struct action_work_subitem
*item
)
454 const char *session_name
;
455 enum lttng_action_status action_status
;
456 struct ltt_session
*session
;
457 enum lttng_error_code cmd_ret
;
458 struct lttng_action
*action
= item
->action
;
460 action_status
= lttng_action_rotate_session_get_session_name(
461 action
, &session_name
);
462 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
463 ERR("Failed to get session name from `%s` action",
464 get_action_name(action
));
470 * Validate if, at the moment the action was queued, the target session
471 * existed. If not, skip the action altogether.
473 if (!item
->context
.session_id
.is_set
) {
474 DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
475 session_name
, get_action_name(action
),
476 get_trigger_name(work_item
->trigger
));
477 lttng_action_increase_execution_failure_count(action
);
483 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
485 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
486 session_name
, get_action_name(action
),
487 get_trigger_name(work_item
->trigger
));
488 lttng_action_increase_execution_failure_count(action
);
489 goto error_unlock_list
;
492 session_lock(session
);
493 if (session
->destroyed
) {
494 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
495 session
->name
, session
->id
,
496 get_action_name(action
),
497 get_trigger_name(work_item
->trigger
));
498 goto error_unlock_session
;
501 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
502 goto error_unlock_session
;
505 cmd_ret
= (lttng_error_code
) cmd_rotate_session(session
, NULL
, false,
506 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED
);
509 DBG("Successfully started rotation of session `%s` on behalf of trigger `%s`",
510 session_name
, get_trigger_name(work_item
->trigger
));
512 case LTTNG_ERR_ROTATION_PENDING
:
513 DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation is already ongoing",
514 session_name
, get_trigger_name(work_item
->trigger
));
515 lttng_action_increase_execution_failure_count(action
);
517 case LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP
:
518 case LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR
:
519 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",
520 session_name
, get_trigger_name(work_item
->trigger
));
523 WARN("Failed to start a rotation of session `%s` on behalf of trigger `%s`: %s",
524 session_name
, get_trigger_name(work_item
->trigger
),
525 lttng_strerror(-cmd_ret
));
526 lttng_action_increase_execution_failure_count(action
);
530 error_unlock_session
:
531 session_unlock(session
);
532 session_put(session
);
535 session_unlock_list();
540 static int action_executor_snapshot_session_handler(
541 struct action_executor
*executor
__attribute__((unused
)),
542 const struct action_work_item
*work_item
,
543 struct action_work_subitem
*item
)
546 const char *session_name
;
547 enum lttng_action_status action_status
;
548 struct ltt_session
*session
;
549 lttng_snapshot_output default_snapshot_output
;
550 const struct lttng_snapshot_output
*snapshot_output
=
551 &default_snapshot_output
;
552 enum lttng_error_code cmd_ret
;
553 struct lttng_action
*action
= item
->action
;
555 default_snapshot_output
.max_size
= UINT64_MAX
;
558 * Validate if, at the moment the action was queued, the target session
559 * existed. If not, skip the action altogether.
561 if (!item
->context
.session_id
.is_set
) {
562 DBG("Session was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
563 get_action_name(action
),
564 get_trigger_name(work_item
->trigger
));
565 lttng_action_increase_execution_failure_count(action
);
569 action_status
= lttng_action_snapshot_session_get_session_name(
570 action
, &session_name
);
571 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
572 ERR("Failed to get session name from `%s` action",
573 get_action_name(action
));
578 action_status
= lttng_action_snapshot_session_get_output(
579 action
, &snapshot_output
);
580 if (action_status
!= LTTNG_ACTION_STATUS_OK
&&
581 action_status
!= LTTNG_ACTION_STATUS_UNSET
) {
582 ERR("Failed to get output from `%s` action",
583 get_action_name(action
));
590 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
592 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
593 session_name
, get_action_name(action
),
594 get_trigger_name(work_item
->trigger
));
595 lttng_action_increase_execution_failure_count(action
);
596 goto error_unlock_list
;
599 session_lock(session
);
600 if (session
->destroyed
) {
601 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
602 session
->name
, session
->id
,
603 get_action_name(action
),
604 get_trigger_name(work_item
->trigger
));
605 goto error_unlock_session
;
608 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
609 goto error_unlock_session
;
612 cmd_ret
= (lttng_error_code
) cmd_snapshot_record(session
, snapshot_output
, 0);
615 DBG("Successfully recorded snapshot of session `%s` on behalf of trigger `%s`",
616 session_name
, get_trigger_name(work_item
->trigger
));
619 WARN("Failed to record snapshot of session `%s` on behalf of trigger `%s`: %s",
620 session_name
, get_trigger_name(work_item
->trigger
),
621 lttng_strerror(-cmd_ret
));
622 lttng_action_increase_execution_failure_count(action
);
626 error_unlock_session
:
627 session_unlock(session
);
628 session_put(session
);
631 session_unlock_list();
636 static int action_executor_list_handler(
637 struct action_executor
*executor
__attribute__((unused
)),
638 const struct action_work_item
*work_item
__attribute__((unused
)),
639 struct action_work_subitem
*item
__attribute__((unused
)))
641 ERR("Execution of a list action by the action executor should never occur");
645 static int action_executor_generic_handler(struct action_executor
*executor
,
646 const struct action_work_item
*work_item
,
647 struct action_work_subitem
*item
)
650 struct lttng_action
*action
= item
->action
;
651 const enum lttng_action_type action_type
= lttng_action_get_type(action
);
653 LTTNG_ASSERT(action_type
!= LTTNG_ACTION_TYPE_UNKNOWN
);
655 lttng_action_increase_execution_request_count(action
);
656 if (!lttng_action_should_execute(action
)) {
657 DBG("Policy prevented execution of action `%s` of trigger `%s` action work item %" PRIu64
,
658 get_action_name(action
),
659 get_trigger_name(work_item
->trigger
),
665 lttng_action_increase_execution_count(action
);
666 DBG("Executing action `%s` of trigger `%s` action work item %" PRIu64
,
667 get_action_name(action
),
668 get_trigger_name(work_item
->trigger
),
670 ret
= action_executors
[action_type
](executor
, work_item
, item
);
675 static int action_work_item_execute(struct action_executor
*executor
,
676 struct action_work_item
*work_item
)
681 DBG("Starting execution of action work item %" PRIu64
" of trigger `%s`",
682 work_item
->id
, get_trigger_name(work_item
->trigger
));
684 count
= lttng_dynamic_array_get_count(&work_item
->subitems
);
685 for (i
= 0; i
< count
; i
++) {
686 struct action_work_subitem
*item
;
688 item
= (action_work_subitem
*) lttng_dynamic_array_get_element(&work_item
->subitems
, i
);
689 ret
= action_executor_generic_handler(
690 executor
, work_item
, item
);
696 DBG("Completed execution of action work item %" PRIu64
" of trigger `%s`",
697 work_item
->id
, get_trigger_name(work_item
->trigger
));
701 static void action_work_item_destroy(struct action_work_item
*work_item
)
703 lttng_trigger_put(work_item
->trigger
);
704 lttng_evaluation_destroy(work_item
->evaluation
);
705 notification_client_list_put(work_item
->client_list
);
706 lttng_dynamic_array_reset(&work_item
->subitems
);
710 static void *action_executor_thread(void *_data
)
712 struct action_executor
*executor
= (action_executor
*) _data
;
714 LTTNG_ASSERT(executor
);
716 health_register(the_health_sessiond
,
717 HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR
);
719 rcu_register_thread();
722 DBG("Entering work execution loop");
723 pthread_mutex_lock(&executor
->work
.lock
);
724 while (!executor
->should_quit
) {
726 struct action_work_item
*work_item
;
728 health_code_update();
729 if (executor
->work
.pending_count
== 0) {
731 DBG("No work items enqueued, entering wait");
732 pthread_cond_wait(&executor
->work
.cond
,
733 &executor
->work
.lock
);
734 DBG("Woke-up from wait");
739 /* Pop item from front of the list with work lock held. */
740 work_item
= cds_list_first_entry(&executor
->work
.list
,
741 struct action_work_item
, list_node
);
742 cds_list_del(&work_item
->list_node
);
743 executor
->work
.pending_count
--;
746 * Work can be performed without holding the work lock,
747 * allowing new items to be queued.
749 pthread_mutex_unlock(&executor
->work
.lock
);
751 /* Execute item only if a trigger is registered. */
752 lttng_trigger_lock(work_item
->trigger
);
753 if (!lttng_trigger_is_registered(work_item
->trigger
)) {
754 const char *trigger_name
= NULL
;
755 uid_t trigger_owner_uid
;
756 enum lttng_trigger_status trigger_status
;
758 trigger_name
= get_trigger_name(work_item
->trigger
);
760 trigger_status
= lttng_trigger_get_owner_uid(
761 work_item
->trigger
, &trigger_owner_uid
);
762 LTTNG_ASSERT(trigger_status
== LTTNG_TRIGGER_STATUS_OK
);
764 DBG("Work item skipped since the associated trigger is no longer registered: work item id = %" PRIu64
", trigger name = `%s`, trigger owner uid = %d",
765 work_item
->id
, trigger_name
,
766 (int) trigger_owner_uid
);
771 ret
= action_work_item_execute(executor
, work_item
);
774 lttng_trigger_unlock(work_item
->trigger
);
775 action_work_item_destroy(work_item
);
781 health_code_update();
782 pthread_mutex_lock(&executor
->work
.lock
);
785 if (executor
->should_quit
) {
786 pthread_mutex_unlock(&executor
->work
.lock
);
788 DBG("Left work execution loop");
790 health_code_update();
792 rcu_thread_offline();
793 rcu_unregister_thread();
794 health_unregister(the_health_sessiond
);
799 static bool shutdown_action_executor_thread(void *_data
)
801 struct action_executor
*executor
= (action_executor
*) _data
;
803 pthread_mutex_lock(&executor
->work
.lock
);
804 executor
->should_quit
= true;
805 pthread_cond_signal(&executor
->work
.cond
);
806 pthread_mutex_unlock(&executor
->work
.lock
);
810 static void clean_up_action_executor_thread(void *_data
)
812 struct action_executor
*executor
= (action_executor
*) _data
;
814 LTTNG_ASSERT(cds_list_empty(&executor
->work
.list
));
816 pthread_mutex_destroy(&executor
->work
.lock
);
817 pthread_cond_destroy(&executor
->work
.cond
);
821 struct action_executor
*action_executor_create(
822 struct notification_thread_handle
*handle
)
824 struct action_executor
*executor
= (action_executor
*) zmalloc(sizeof(*executor
));
830 CDS_INIT_LIST_HEAD(&executor
->work
.list
);
831 pthread_cond_init(&executor
->work
.cond
, NULL
);
832 pthread_mutex_init(&executor
->work
.lock
, NULL
);
833 executor
->notification_thread_handle
= handle
;
835 executor
->thread
= lttng_thread_create(THREAD_NAME
,
836 action_executor_thread
, shutdown_action_executor_thread
,
837 clean_up_action_executor_thread
, executor
);
842 void action_executor_destroy(struct action_executor
*executor
)
844 struct action_work_item
*work_item
, *tmp
;
846 /* TODO Wait for work list to drain? */
847 lttng_thread_shutdown(executor
->thread
);
848 pthread_mutex_lock(&executor
->work
.lock
);
849 if (executor
->work
.pending_count
!= 0) {
851 " trigger action%s still queued for execution and will be discarded",
852 executor
->work
.pending_count
,
853 executor
->work
.pending_count
== 1 ? " is" :
857 cds_list_for_each_entry_safe (
858 work_item
, tmp
, &executor
->work
.list
, list_node
) {
859 WARN("Discarding action work item %" PRIu64
860 " associated to trigger `%s`",
861 work_item
->id
, get_trigger_name(work_item
->trigger
));
862 cds_list_del(&work_item
->list_node
);
863 action_work_item_destroy(work_item
);
865 pthread_mutex_unlock(&executor
->work
.lock
);
866 lttng_thread_put(executor
->thread
);
869 /* RCU read-lock must be held by the caller. */
870 enum action_executor_status
action_executor_enqueue_trigger(
871 struct action_executor
*executor
,
872 struct lttng_trigger
*trigger
,
873 struct lttng_evaluation
*evaluation
,
874 const struct lttng_credentials
*object_creds
,
875 struct notification_client_list
*client_list
)
878 enum action_executor_status executor_status
= ACTION_EXECUTOR_STATUS_OK
;
879 const uint64_t work_item_id
= executor
->next_work_item_id
++;
880 struct action_work_item
*work_item
;
883 LTTNG_ASSERT(trigger
);
884 ASSERT_RCU_READ_LOCKED();
886 pthread_mutex_lock(&executor
->work
.lock
);
887 /* Check for queue overflow. */
888 if (executor
->work
.pending_count
>= MAX_QUEUED_WORK_COUNT
) {
889 /* Most likely spammy, remove if it is the case. */
890 DBG("Refusing to enqueue action for trigger (overflow): trigger name = `%s`, work item id = %" PRIu64
,
891 get_trigger_name(trigger
), work_item_id
);
892 executor_status
= ACTION_EXECUTOR_STATUS_OVERFLOW
;
896 work_item
= (action_work_item
*) zmalloc(sizeof(*work_item
));
898 PERROR("Failed to allocate action executor work item: trigger name = `%s`",
899 get_trigger_name(trigger
));
900 executor_status
= ACTION_EXECUTOR_STATUS_ERROR
;
904 lttng_trigger_get(trigger
);
906 const bool reference_acquired
=
907 notification_client_list_get(client_list
);
909 LTTNG_ASSERT(reference_acquired
);
912 work_item
->id
= work_item_id
;
913 work_item
->trigger
= trigger
;
915 /* Ownership transferred to the work item. */
916 work_item
->evaluation
= evaluation
;
919 work_item
->client_list
= client_list
;
920 work_item
->object_creds
.is_set
= !!object_creds
;
922 work_item
->object_creds
.value
= *object_creds
;
925 CDS_INIT_LIST_HEAD(&work_item
->list_node
);
927 /* Build the array of action work subitems for the passed trigger. */
928 lttng_dynamic_array_init(&work_item
->subitems
,
929 sizeof(struct action_work_subitem
),
930 action_work_subitem_destructor
);
932 ret
= populate_subitem_array_from_trigger(
933 trigger
, &work_item
->subitems
);
935 ERR("Failed to populate work item sub items on behalf of trigger: trigger name = `%s`",
936 get_trigger_name(trigger
));
937 executor_status
= ACTION_EXECUTOR_STATUS_ERROR
;
941 cds_list_add_tail(&work_item
->list_node
, &executor
->work
.list
);
942 executor
->work
.pending_count
++;
943 DBG("Enqueued action for trigger: trigger name = `%s`, work item id = %" PRIu64
,
944 get_trigger_name(trigger
), work_item_id
);
949 pthread_cond_signal(&executor
->work
.cond
);
952 pthread_mutex_unlock(&executor
->work
.lock
);
953 lttng_evaluation_destroy(evaluation
);
954 return executor_status
;
957 static int add_action_to_subitem_array(struct lttng_action
*action
,
958 struct lttng_dynamic_array
*subitems
)
961 enum lttng_action_type type
= lttng_action_get_type(action
);
962 const char *session_name
= NULL
;
963 enum lttng_action_status status
;
964 struct action_work_subitem subitem
= {
967 .session_id
= LTTNG_OPTIONAL_INIT_UNSET
,
971 LTTNG_ASSERT(action
);
972 LTTNG_ASSERT(subitems
);
974 if (type
== LTTNG_ACTION_TYPE_LIST
) {
975 unsigned int count
, i
;
977 status
= lttng_action_list_get_count(action
, &count
);
978 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
980 for (i
= 0; i
< count
; i
++) {
981 struct lttng_action
*inner_action
= NULL
;
983 inner_action
= lttng_action_list_borrow_mutable_at_index(
985 LTTNG_ASSERT(inner_action
);
986 ret
= add_action_to_subitem_array(
987 inner_action
, subitems
);
994 * Go directly to the end since there is no need to add the
995 * list action by itself to the subitems array.
1000 /* Gather execution context. */
1002 case LTTNG_ACTION_TYPE_NOTIFY
:
1004 case LTTNG_ACTION_TYPE_START_SESSION
:
1005 status
= lttng_action_start_session_get_session_name(
1006 action
, &session_name
);
1007 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1009 case LTTNG_ACTION_TYPE_STOP_SESSION
:
1010 status
= lttng_action_stop_session_get_session_name(
1011 action
, &session_name
);
1012 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1014 case LTTNG_ACTION_TYPE_ROTATE_SESSION
:
1015 status
= lttng_action_rotate_session_get_session_name(
1016 action
, &session_name
);
1017 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1019 case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION
:
1020 status
= lttng_action_snapshot_session_get_session_name(
1021 action
, &session_name
);
1022 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1024 case LTTNG_ACTION_TYPE_LIST
:
1025 case LTTNG_ACTION_TYPE_UNKNOWN
:
1033 * Fetch the session execution context info as needed.
1034 * Note that we could decide to not add an action for which we know the
1035 * execution will not happen (i.e no session exists for that name). For
1036 * now we leave the decision to skip to the action executor for sake of
1037 * simplicity and consistency.
1039 if (session_name
!= NULL
) {
1040 uint64_t session_id
;
1043 * Instantaneous sampling of the session id if present.
1045 * This method is preferred over `sessiond_find_by_name` then
1046 * fetching the session'd id since `sessiond_find_by_name`
1047 * requires the session list lock to be taken.
1049 * Taking the session list lock can lead to a deadlock
1050 * between the action executor and the notification thread
1051 * (caller of add_action_to_subitem_array). It is okay if the
1052 * session state changes between the enqueuing time and the
1053 * execution time. The execution context is validated at
1056 if (sample_session_id_by_name(session_name
, &session_id
)) {
1057 LTTNG_OPTIONAL_SET(&subitem
.context
.session_id
,
1062 /* Get a reference to the action. */
1063 lttng_action_get(action
);
1064 subitem
.action
= action
;
1066 ret
= lttng_dynamic_array_add_element(subitems
, &subitem
);
1068 ERR("Failed to add work subitem to the subitem array");
1069 lttng_action_put(action
);
1078 static int populate_subitem_array_from_trigger(struct lttng_trigger
*trigger
,
1079 struct lttng_dynamic_array
*subitems
)
1081 struct lttng_action
*action
;
1083 action
= lttng_trigger_get_action(trigger
);
1084 LTTNG_ASSERT(action
);
1086 return add_action_to_subitem_array(action
, subitems
);