trigger: keep state of if a trigger is currently registered

[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread-events.c

diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c
index d3b6cd855da47b872ae11e7fa3cbc4446e8de6a3..ec4d56bce7d9ec78c6c6926e256e376f59b6297a 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -1139,9 +1139,10 @@ int notification_thread_client_subscribe(struct notification_client *client,
         * at this point so that conditions that are already TRUE result
         * in a notification being sent out.
         *
-        * The client_list's trigger is used without locking the list itself.
-        * This is correct since the list doesn't own the trigger and the
-        * object is immutable.
+        * Note the iteration on all triggers which share an identical
+        * `condition` than the one to which the client is registering. This is
+        * done to ensure that the client receives a distinct notification for
+        * all triggers that have a `notify` action that have this condition.
         */
        pthread_mutex_lock(&client_list->lock);
        cds_list_for_each_entry(trigger_ht_element,
@@ -1151,6 +1152,7 @@ int notification_thread_client_subscribe(struct notification_client *client,
                        WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting.");
                        ret = -1;
                        free(client_list_element);
+                       pthread_mutex_unlock(&client_list->lock);
                        goto end;
                }
        }
@@ -2691,6 +2693,9 @@ int handle_notification_thread_command_register_trigger(
                goto error_free_ht_element;
        }
 
+       /* From this point consider the trigger registered. */
+       lttng_trigger_set_as_registered(trigger);
+
        /*
         * Some triggers might need a tracer notifier depending on its
         * condition and actions.
@@ -2890,6 +2895,11 @@ error_free_ht_element:
        }
 error:
        if (free_trigger) {
+               /*
+                * Other objects might have a reference to the trigger, mark it
+                * as unregistered.
+                */
+               lttng_trigger_set_as_unregistered(trigger);
                lttng_trigger_destroy(trigger);
        }
 end:
@@ -2971,6 +2981,12 @@ int handle_notification_thread_command_unregister_trigger(
                cmd_reply = LTTNG_OK;
        }
 
+       trigger_ht_element = caa_container_of(triggers_ht_node,
+                       struct lttng_trigger_ht_element, node);
+
+       /* From this point, consider the trigger unregistered no matter what. */
+       lttng_trigger_set_as_unregistered(trigger_ht_element->trigger);
+
        /* Remove trigger from channel_triggers_ht. */
        cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list,
                        channel_triggers_ht_node) {
@@ -2993,9 +3009,6 @@ int handle_notification_thread_command_unregister_trigger(
                teardown_tracer_notifier(state, trigger);
        }
 
-       trigger_ht_element = caa_container_of(triggers_ht_node,
-                       struct lttng_trigger_ht_element, node);
-
        if (is_trigger_action_notify(trigger)) {
                /*
                 * Remove and release the client list from
@@ -4333,7 +4346,7 @@ int notification_client_list_send_evaluation(
                        }
                }
 
-               if (client->uid != lttng_credentials_get_uid(trigger_creds) && client->gid != lttng_credentials_get_gid(trigger_creds)) {
+               if (client->uid != lttng_credentials_get_uid(trigger_creds)) {
                        DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this trigger");
                        goto skip_client;
                }
@@ -4521,13 +4534,6 @@ int dispatch_one_event_notifier_notification(struct notification_thread_state *s
                        struct notification_trigger_tokens_ht_element,
                        node);
 
-       if (!lttng_trigger_should_fire(element->trigger)) {
-               ret = 0;
-               goto end_unlock;
-       }
-
-       lttng_trigger_fire(element->trigger);
-
        trigger_status = lttng_trigger_get_name(element->trigger, &trigger_name);
        assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 
@@ -4839,12 +4845,6 @@ int handle_notification_thread_channel_sample(
                        goto put_list;
                }
 
-               if (!lttng_trigger_should_fire(trigger)) {
-                       goto put_list;
-               }
-
-               lttng_trigger_fire(trigger);
-
                /*
                 * Ownership of `evaluation` transferred to the action executor
                 * no matter the result.