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
)
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
,
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
);
312 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
314 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
315 session_name
, get_action_name(action
),
316 get_trigger_name(work_item
->trigger
));
317 lttng_action_increase_execution_failure_count(action
);
318 goto error_unlock_list
;
321 session_lock(session
);
322 if (session
->destroyed
) {
323 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
324 session
->name
, session
->id
,
325 get_action_name(action
),
326 get_trigger_name(work_item
->trigger
));
327 goto error_unlock_session
;
330 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
331 goto error_unlock_session
;
334 cmd_ret
= (lttng_error_code
) cmd_start_trace(session
);
337 DBG("Successfully started session `%s` on behalf of trigger `%s`",
338 session_name
, get_trigger_name(work_item
->trigger
));
340 case LTTNG_ERR_TRACE_ALREADY_STARTED
:
341 DBG("Attempted to start session `%s` on behalf of trigger `%s` but it was already started",
342 session_name
, get_trigger_name(work_item
->trigger
));
345 WARN("Failed to start session `%s` on behalf of trigger `%s`: %s",
346 session_name
, get_trigger_name(work_item
->trigger
),
347 lttng_strerror(-cmd_ret
));
348 lttng_action_increase_execution_failure_count(action
);
352 error_unlock_session
:
353 session_unlock(session
);
354 session_put(session
);
356 session_unlock_list();
361 static int action_executor_stop_session_handler(
362 struct action_executor
*executor
,
363 const struct action_work_item
*work_item
,
364 struct action_work_subitem
*item
)
367 const char *session_name
;
368 enum lttng_action_status action_status
;
369 struct ltt_session
*session
;
370 enum lttng_error_code cmd_ret
;
371 struct lttng_action
*action
= item
->action
;
373 action_status
= lttng_action_stop_session_get_session_name(
374 action
, &session_name
);
375 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
376 ERR("Failed to get session name from `%s` action",
377 get_action_name(action
));
383 * Validate if, at the moment the action was queued, the target session
384 * existed. If not, skip the action altogether.
386 if (!item
->context
.session_id
.is_set
) {
387 DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
388 session_name
, get_action_name(action
),
389 get_trigger_name(work_item
->trigger
));
390 lttng_action_increase_execution_failure_count(action
);
395 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
397 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
398 session_name
, get_action_name(action
),
399 get_trigger_name(work_item
->trigger
));
400 lttng_action_increase_execution_failure_count(action
);
401 goto error_unlock_list
;
404 session_lock(session
);
405 if (session
->destroyed
) {
406 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
407 session
->name
, session
->id
,
408 get_action_name(action
),
409 get_trigger_name(work_item
->trigger
));
410 goto error_unlock_session
;
413 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
414 goto error_unlock_session
;
417 cmd_ret
= (lttng_error_code
) cmd_stop_trace(session
);
420 DBG("Successfully stopped session `%s` on behalf of trigger `%s`",
421 session_name
, get_trigger_name(work_item
->trigger
));
423 case LTTNG_ERR_TRACE_ALREADY_STOPPED
:
424 DBG("Attempted to stop session `%s` on behalf of trigger `%s` but it was already stopped",
425 session_name
, get_trigger_name(work_item
->trigger
));
428 WARN("Failed to stop session `%s` on behalf of trigger `%s`: %s",
429 session_name
, get_trigger_name(work_item
->trigger
),
430 lttng_strerror(-cmd_ret
));
431 lttng_action_increase_execution_failure_count(action
);
435 error_unlock_session
:
436 session_unlock(session
);
437 session_put(session
);
439 session_unlock_list();
444 static int action_executor_rotate_session_handler(
445 struct action_executor
*executor
,
446 const struct action_work_item
*work_item
,
447 struct action_work_subitem
*item
)
450 const char *session_name
;
451 enum lttng_action_status action_status
;
452 struct ltt_session
*session
;
453 enum lttng_error_code cmd_ret
;
454 struct lttng_action
*action
= item
->action
;
456 action_status
= lttng_action_rotate_session_get_session_name(
457 action
, &session_name
);
458 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
459 ERR("Failed to get session name from `%s` action",
460 get_action_name(action
));
466 * Validate if, at the moment the action was queued, the target session
467 * existed. If not, skip the action altogether.
469 if (!item
->context
.session_id
.is_set
) {
470 DBG("Session `%s` was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
471 session_name
, get_action_name(action
),
472 get_trigger_name(work_item
->trigger
));
473 lttng_action_increase_execution_failure_count(action
);
478 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
480 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
481 session_name
, get_action_name(action
),
482 get_trigger_name(work_item
->trigger
));
483 lttng_action_increase_execution_failure_count(action
);
484 goto error_unlock_list
;
487 session_lock(session
);
488 if (session
->destroyed
) {
489 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
490 session
->name
, session
->id
,
491 get_action_name(action
),
492 get_trigger_name(work_item
->trigger
));
493 goto error_unlock_session
;
496 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
497 goto error_unlock_session
;
500 cmd_ret
= (lttng_error_code
) cmd_rotate_session(session
, NULL
, false,
501 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED
);
504 DBG("Successfully started rotation of session `%s` on behalf of trigger `%s`",
505 session_name
, get_trigger_name(work_item
->trigger
));
507 case LTTNG_ERR_ROTATION_PENDING
:
508 DBG("Attempted to start a rotation of session `%s` on behalf of trigger `%s` but a rotation is already ongoing",
509 session_name
, get_trigger_name(work_item
->trigger
));
510 lttng_action_increase_execution_failure_count(action
);
512 case LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP
:
513 case LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR
:
514 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",
515 session_name
, get_trigger_name(work_item
->trigger
));
518 WARN("Failed to start a rotation of session `%s` on behalf of trigger `%s`: %s",
519 session_name
, get_trigger_name(work_item
->trigger
),
520 lttng_strerror(-cmd_ret
));
521 lttng_action_increase_execution_failure_count(action
);
525 error_unlock_session
:
526 session_unlock(session
);
527 session_put(session
);
529 session_unlock_list();
534 static int action_executor_snapshot_session_handler(
535 struct action_executor
*executor
,
536 const struct action_work_item
*work_item
,
537 struct action_work_subitem
*item
)
540 const char *session_name
;
541 enum lttng_action_status action_status
;
542 struct ltt_session
*session
;
543 lttng_snapshot_output default_snapshot_output
;
544 const struct lttng_snapshot_output
*snapshot_output
=
545 &default_snapshot_output
;
546 enum lttng_error_code cmd_ret
;
547 struct lttng_action
*action
= item
->action
;
549 default_snapshot_output
.max_size
= UINT64_MAX
;
552 * Validate if, at the moment the action was queued, the target session
553 * existed. If not, skip the action altogether.
555 if (!item
->context
.session_id
.is_set
) {
556 DBG("Session was not present at the moment the work item was enqueued for `%s` action of trigger `%s`",
557 get_action_name(action
),
558 get_trigger_name(work_item
->trigger
));
559 lttng_action_increase_execution_failure_count(action
);
563 action_status
= lttng_action_snapshot_session_get_session_name(
564 action
, &session_name
);
565 if (action_status
!= LTTNG_ACTION_STATUS_OK
) {
566 ERR("Failed to get session name from `%s` action",
567 get_action_name(action
));
572 action_status
= lttng_action_snapshot_session_get_output(
573 action
, &snapshot_output
);
574 if (action_status
!= LTTNG_ACTION_STATUS_OK
&&
575 action_status
!= LTTNG_ACTION_STATUS_UNSET
) {
576 ERR("Failed to get output from `%s` action",
577 get_action_name(action
));
583 session
= session_find_by_id(LTTNG_OPTIONAL_GET(item
->context
.session_id
));
585 DBG("Failed to find session `%s` by name while executing `%s` action of trigger `%s`",
586 session_name
, get_action_name(action
),
587 get_trigger_name(work_item
->trigger
));
588 lttng_action_increase_execution_failure_count(action
);
589 goto error_unlock_list
;
592 session_lock(session
);
593 if (session
->destroyed
) {
594 DBG("Session `%s` with id = %" PRIu64
" is flagged as destroyed. Skipping: action = `%s`, trigger = `%s`",
595 session
->name
, session
->id
,
596 get_action_name(action
),
597 get_trigger_name(work_item
->trigger
));
598 goto error_unlock_session
;
601 if (!is_trigger_allowed_for_session(work_item
->trigger
, session
)) {
602 goto error_unlock_session
;
605 cmd_ret
= (lttng_error_code
) cmd_snapshot_record(session
, snapshot_output
, 0);
608 DBG("Successfully recorded snapshot of session `%s` on behalf of trigger `%s`",
609 session_name
, get_trigger_name(work_item
->trigger
));
612 WARN("Failed to record snapshot of session `%s` on behalf of trigger `%s`: %s",
613 session_name
, get_trigger_name(work_item
->trigger
),
614 lttng_strerror(-cmd_ret
));
615 lttng_action_increase_execution_failure_count(action
);
619 error_unlock_session
:
620 session_unlock(session
);
621 session_put(session
);
623 session_unlock_list();
628 static int action_executor_list_handler(struct action_executor
*executor
,
629 const struct action_work_item
*work_item
,
630 struct action_work_subitem
*item
)
632 ERR("Execution of a list action by the action executor should never occur");
636 static int action_executor_generic_handler(struct action_executor
*executor
,
637 const struct action_work_item
*work_item
,
638 struct action_work_subitem
*item
)
641 struct lttng_action
*action
= item
->action
;
642 const enum lttng_action_type action_type
= lttng_action_get_type(action
);
644 LTTNG_ASSERT(action_type
!= LTTNG_ACTION_TYPE_UNKNOWN
);
646 lttng_action_increase_execution_request_count(action
);
647 if (!lttng_action_should_execute(action
)) {
648 DBG("Policy prevented execution of action `%s` of trigger `%s` action work item %" PRIu64
,
649 get_action_name(action
),
650 get_trigger_name(work_item
->trigger
),
656 lttng_action_increase_execution_count(action
);
657 DBG("Executing action `%s` of trigger `%s` action work item %" PRIu64
,
658 get_action_name(action
),
659 get_trigger_name(work_item
->trigger
),
661 ret
= action_executors
[action_type
](executor
, work_item
, item
);
666 static int action_work_item_execute(struct action_executor
*executor
,
667 struct action_work_item
*work_item
)
672 DBG("Starting execution of action work item %" PRIu64
" of trigger `%s`",
673 work_item
->id
, get_trigger_name(work_item
->trigger
));
675 count
= lttng_dynamic_array_get_count(&work_item
->subitems
);
676 for (i
= 0; i
< count
; i
++) {
677 struct action_work_subitem
*item
;
679 item
= (action_work_subitem
*) lttng_dynamic_array_get_element(&work_item
->subitems
, i
);
680 ret
= action_executor_generic_handler(
681 executor
, work_item
, item
);
687 DBG("Completed execution of action work item %" PRIu64
" of trigger `%s`",
688 work_item
->id
, get_trigger_name(work_item
->trigger
));
692 static void action_work_item_destroy(struct action_work_item
*work_item
)
694 lttng_trigger_put(work_item
->trigger
);
695 lttng_evaluation_destroy(work_item
->evaluation
);
696 notification_client_list_put(work_item
->client_list
);
697 lttng_dynamic_array_reset(&work_item
->subitems
);
701 static void *action_executor_thread(void *_data
)
703 struct action_executor
*executor
= (action_executor
*) _data
;
705 LTTNG_ASSERT(executor
);
707 health_register(the_health_sessiond
,
708 HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR
);
710 rcu_register_thread();
713 DBG("Entering work execution loop");
714 pthread_mutex_lock(&executor
->work
.lock
);
715 while (!executor
->should_quit
) {
717 struct action_work_item
*work_item
;
719 health_code_update();
720 if (executor
->work
.pending_count
== 0) {
722 DBG("No work items enqueued, entering wait");
723 pthread_cond_wait(&executor
->work
.cond
,
724 &executor
->work
.lock
);
725 DBG("Woke-up from wait");
730 /* Pop item from front of the list with work lock held. */
731 work_item
= cds_list_first_entry(&executor
->work
.list
,
732 struct action_work_item
, list_node
);
733 cds_list_del(&work_item
->list_node
);
734 executor
->work
.pending_count
--;
737 * Work can be performed without holding the work lock,
738 * allowing new items to be queued.
740 pthread_mutex_unlock(&executor
->work
.lock
);
742 /* Execute item only if a trigger is registered. */
743 lttng_trigger_lock(work_item
->trigger
);
744 if (!lttng_trigger_is_registered(work_item
->trigger
)) {
745 const char *trigger_name
= NULL
;
746 uid_t trigger_owner_uid
;
747 enum lttng_trigger_status trigger_status
;
749 trigger_name
= get_trigger_name(work_item
->trigger
);
751 trigger_status
= lttng_trigger_get_owner_uid(
752 work_item
->trigger
, &trigger_owner_uid
);
753 LTTNG_ASSERT(trigger_status
== LTTNG_TRIGGER_STATUS_OK
);
755 DBG("Work item skipped since the associated trigger is no longer registered: work item id = %" PRIu64
", trigger name = `%s`, trigger owner uid = %d",
756 work_item
->id
, trigger_name
,
757 (int) trigger_owner_uid
);
762 ret
= action_work_item_execute(executor
, work_item
);
765 lttng_trigger_unlock(work_item
->trigger
);
766 action_work_item_destroy(work_item
);
772 health_code_update();
773 pthread_mutex_lock(&executor
->work
.lock
);
776 if (executor
->should_quit
) {
777 pthread_mutex_unlock(&executor
->work
.lock
);
779 DBG("Left work execution loop");
781 health_code_update();
783 rcu_thread_offline();
784 rcu_unregister_thread();
785 health_unregister(the_health_sessiond
);
790 static bool shutdown_action_executor_thread(void *_data
)
792 struct action_executor
*executor
= (action_executor
*) _data
;
794 pthread_mutex_lock(&executor
->work
.lock
);
795 executor
->should_quit
= true;
796 pthread_cond_signal(&executor
->work
.cond
);
797 pthread_mutex_unlock(&executor
->work
.lock
);
801 static void clean_up_action_executor_thread(void *_data
)
803 struct action_executor
*executor
= (action_executor
*) _data
;
805 LTTNG_ASSERT(cds_list_empty(&executor
->work
.list
));
807 pthread_mutex_destroy(&executor
->work
.lock
);
808 pthread_cond_destroy(&executor
->work
.cond
);
812 struct action_executor
*action_executor_create(
813 struct notification_thread_handle
*handle
)
815 struct action_executor
*executor
= (action_executor
*) zmalloc(sizeof(*executor
));
821 CDS_INIT_LIST_HEAD(&executor
->work
.list
);
822 pthread_cond_init(&executor
->work
.cond
, NULL
);
823 pthread_mutex_init(&executor
->work
.lock
, NULL
);
824 executor
->notification_thread_handle
= handle
;
826 executor
->thread
= lttng_thread_create(THREAD_NAME
,
827 action_executor_thread
, shutdown_action_executor_thread
,
828 clean_up_action_executor_thread
, executor
);
833 void action_executor_destroy(struct action_executor
*executor
)
835 struct action_work_item
*work_item
, *tmp
;
837 /* TODO Wait for work list to drain? */
838 lttng_thread_shutdown(executor
->thread
);
839 pthread_mutex_lock(&executor
->work
.lock
);
840 if (executor
->work
.pending_count
!= 0) {
842 " trigger action%s still queued for execution and will be discarded",
843 executor
->work
.pending_count
,
844 executor
->work
.pending_count
== 1 ? " is" :
848 cds_list_for_each_entry_safe (
849 work_item
, tmp
, &executor
->work
.list
, list_node
) {
850 WARN("Discarding action work item %" PRIu64
851 " associated to trigger `%s`",
852 work_item
->id
, get_trigger_name(work_item
->trigger
));
853 cds_list_del(&work_item
->list_node
);
854 action_work_item_destroy(work_item
);
856 pthread_mutex_unlock(&executor
->work
.lock
);
857 lttng_thread_put(executor
->thread
);
860 /* RCU read-lock must be held by the caller. */
861 enum action_executor_status
action_executor_enqueue_trigger(
862 struct action_executor
*executor
,
863 struct lttng_trigger
*trigger
,
864 struct lttng_evaluation
*evaluation
,
865 const struct lttng_credentials
*object_creds
,
866 struct notification_client_list
*client_list
)
869 enum action_executor_status executor_status
= ACTION_EXECUTOR_STATUS_OK
;
870 const uint64_t work_item_id
= executor
->next_work_item_id
++;
871 struct action_work_item
*work_item
;
874 LTTNG_ASSERT(trigger
);
876 pthread_mutex_lock(&executor
->work
.lock
);
877 /* Check for queue overflow. */
878 if (executor
->work
.pending_count
>= MAX_QUEUED_WORK_COUNT
) {
879 /* Most likely spammy, remove if it is the case. */
880 DBG("Refusing to enqueue action for trigger (overflow): trigger name = `%s`, work item id = %" PRIu64
,
881 get_trigger_name(trigger
), work_item_id
);
882 executor_status
= ACTION_EXECUTOR_STATUS_OVERFLOW
;
886 work_item
= (action_work_item
*) zmalloc(sizeof(*work_item
));
888 PERROR("Failed to allocate action executor work item: trigger name = `%s`",
889 get_trigger_name(trigger
));
890 executor_status
= ACTION_EXECUTOR_STATUS_ERROR
;
894 lttng_trigger_get(trigger
);
896 const bool reference_acquired
=
897 notification_client_list_get(client_list
);
899 LTTNG_ASSERT(reference_acquired
);
902 work_item
->id
= work_item_id
;
903 work_item
->trigger
= trigger
;
905 /* Ownership transferred to the work item. */
906 work_item
->evaluation
= evaluation
;
909 work_item
->client_list
= client_list
;
910 work_item
->object_creds
.is_set
= !!object_creds
;
912 work_item
->object_creds
.value
= *object_creds
;
915 CDS_INIT_LIST_HEAD(&work_item
->list_node
);
917 /* Build the array of action work subitems for the passed trigger. */
918 lttng_dynamic_array_init(&work_item
->subitems
,
919 sizeof(struct action_work_subitem
),
920 action_work_subitem_destructor
);
922 ret
= populate_subitem_array_from_trigger(
923 trigger
, &work_item
->subitems
);
925 ERR("Failed to populate work item sub items on behalf of trigger: trigger name = `%s`",
926 get_trigger_name(trigger
));
927 executor_status
= ACTION_EXECUTOR_STATUS_ERROR
;
931 cds_list_add_tail(&work_item
->list_node
, &executor
->work
.list
);
932 executor
->work
.pending_count
++;
933 DBG("Enqueued action for trigger: trigger name = `%s`, work item id = %" PRIu64
,
934 get_trigger_name(trigger
), work_item_id
);
939 pthread_cond_signal(&executor
->work
.cond
);
942 pthread_mutex_unlock(&executor
->work
.lock
);
943 lttng_evaluation_destroy(evaluation
);
944 return executor_status
;
947 static int add_action_to_subitem_array(struct lttng_action
*action
,
948 struct lttng_dynamic_array
*subitems
)
951 enum lttng_action_type type
= lttng_action_get_type(action
);
952 const char *session_name
= NULL
;
953 enum lttng_action_status status
;
954 struct action_work_subitem subitem
= {
957 .session_id
= LTTNG_OPTIONAL_INIT_UNSET
,
961 LTTNG_ASSERT(action
);
962 LTTNG_ASSERT(subitems
);
964 if (type
== LTTNG_ACTION_TYPE_LIST
) {
965 unsigned int count
, i
;
967 status
= lttng_action_list_get_count(action
, &count
);
968 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
970 for (i
= 0; i
< count
; i
++) {
971 struct lttng_action
*inner_action
= NULL
;
973 inner_action
= lttng_action_list_borrow_mutable_at_index(
975 LTTNG_ASSERT(inner_action
);
976 ret
= add_action_to_subitem_array(
977 inner_action
, subitems
);
984 * Go directly to the end since there is no need to add the
985 * list action by itself to the subitems array.
990 /* Gather execution context. */
992 case LTTNG_ACTION_TYPE_NOTIFY
:
994 case LTTNG_ACTION_TYPE_START_SESSION
:
995 status
= lttng_action_start_session_get_session_name(
996 action
, &session_name
);
997 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
999 case LTTNG_ACTION_TYPE_STOP_SESSION
:
1000 status
= lttng_action_stop_session_get_session_name(
1001 action
, &session_name
);
1002 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1004 case LTTNG_ACTION_TYPE_ROTATE_SESSION
:
1005 status
= lttng_action_rotate_session_get_session_name(
1006 action
, &session_name
);
1007 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1009 case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION
:
1010 status
= lttng_action_snapshot_session_get_session_name(
1011 action
, &session_name
);
1012 LTTNG_ASSERT(status
== LTTNG_ACTION_STATUS_OK
);
1014 case LTTNG_ACTION_TYPE_LIST
:
1015 case LTTNG_ACTION_TYPE_UNKNOWN
:
1023 * Fetch the session execution context info as needed.
1024 * Note that we could decide to not add an action for which we know the
1025 * execution will not happen (i.e no session exists for that name). For
1026 * now we leave the decision to skip to the action executor for sake of
1027 * simplicity and consistency.
1029 if (session_name
!= NULL
) {
1030 uint64_t session_id
;
1033 * Instantaneous sampling of the session id if present.
1035 * This method is preferred over `sessiond_find_by_name` then
1036 * fetching the session'd id since `sessiond_find_by_name`
1037 * requires the session list lock to be taken.
1039 * Taking the session list lock can lead to a deadlock
1040 * between the action executor and the notification thread
1041 * (caller of add_action_to_subitem_array). It is okay if the
1042 * session state changes between the enqueuing time and the
1043 * execution time. The execution context is validated at
1046 if (sample_session_id_by_name(session_name
, &session_id
)) {
1047 LTTNG_OPTIONAL_SET(&subitem
.context
.session_id
,
1052 /* Get a reference to the action. */
1053 lttng_action_get(action
);
1054 subitem
.action
= action
;
1056 ret
= lttng_dynamic_array_add_element(subitems
, &subitem
);
1058 ERR("Failed to add work subitem to the subitem array");
1059 lttng_action_put(action
);
1068 static int populate_subitem_array_from_trigger(struct lttng_trigger
*trigger
,
1069 struct lttng_dynamic_array
*subitems
)
1071 struct lttng_action
*action
;
1073 action
= lttng_trigger_get_action(trigger
);
1074 LTTNG_ASSERT(action
);
1076 return add_action_to_subitem_array(action
, subitems
);