trigger/action executor: move trigger registration state change to client thread

[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 827cf2c1459f5ee4cb683ac3fd5b0699ab5d9b82..90fdadd61280bc2452063931ad1c7ca1fc837f8b 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -353,6 +353,8 @@ const char *notification_command_type_str(
                return "REMOVE_TRACER_EVENT_SOURCE";
        case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS:
                return "LIST_TRIGGERS";
+       case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER:
+               return "GET_TRIGGER";
        case NOTIFICATION_COMMAND_TYPE_QUIT:
                return "QUIT";
        case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE:
@@ -2280,6 +2282,69 @@ end:
        return ret;
 }
 
+static inline void get_trigger_info_for_log(const struct lttng_trigger *trigger,
+               const char **trigger_name,
+               uid_t *trigger_owner_uid)
+{
+       enum lttng_trigger_status trigger_status;
+
+       trigger_status = lttng_trigger_get_name(trigger, trigger_name);
+       switch (trigger_status) {
+       case LTTNG_TRIGGER_STATUS_OK:
+               break;
+       case LTTNG_TRIGGER_STATUS_UNSET:
+               *trigger_name = "(unset)";
+               break;
+       default:
+               abort();
+       }
+
+       trigger_status = lttng_trigger_get_owner_uid(trigger,
+                       trigger_owner_uid);
+       assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+}
+
+static int handle_notification_thread_command_get_trigger(
+               struct notification_thread_state *state,
+               const struct lttng_trigger *trigger,
+               struct lttng_trigger **registered_trigger,
+               enum lttng_error_code *_cmd_result)
+{
+       int ret = -1;
+       struct cds_lfht_iter iter;
+       struct lttng_trigger_ht_element *trigger_ht_element;
+       enum lttng_error_code cmd_result = LTTNG_ERR_TRIGGER_NOT_FOUND;
+       const char *trigger_name;
+       uid_t trigger_owner_uid;
+
+       rcu_read_lock();
+
+       cds_lfht_for_each_entry(
+                       state->triggers_ht, &iter, trigger_ht_element, node) {
+               if (lttng_trigger_is_equal(
+                                   trigger, trigger_ht_element->trigger)) {
+                       /* Take one reference on the return trigger. */
+                       *registered_trigger = trigger_ht_element->trigger;
+                       lttng_trigger_get(*registered_trigger);
+                       ret = 0;
+                       cmd_result = LTTNG_OK;
+                       goto end;
+               }
+       }
+
+       /* Not a fatal error if the trigger is not found. */
+       get_trigger_info_for_log(trigger, &trigger_name, &trigger_owner_uid);
+       ERR("Failed to retrieve registered version of trigger: trigger name = '%s', trigger owner uid = %d",
+                       trigger_name, (int) trigger_owner_uid);
+
+       ret = 0;
+
+end:
+       rcu_read_unlock();
+       *_cmd_result = cmd_result;
+       return ret;
+}
+
 static
 bool condition_is_supported(struct lttng_condition *condition)
 {
@@ -2693,6 +2758,9 @@ 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.
@@ -2892,6 +2960,11 @@ 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:
@@ -2973,6 +3046,9 @@ 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);
+
        /* Remove trigger from channel_triggers_ht. */
        cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list,
                        channel_triggers_ht_node) {
@@ -2995,9 +3071,6 @@ 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
@@ -3127,6 +3200,16 @@ int handle_notification_thread_command(
                cmd->reply_code = LTTNG_OK;
                ret = 1;
                goto end;
+       case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER:
+       {
+               struct lttng_trigger *trigger = NULL;
+
+               ret = handle_notification_thread_command_get_trigger(state,
+                               cmd->parameters.get_trigger.trigger, &trigger,
+                               &cmd->reply_code);
+               cmd->reply.get_trigger.trigger = trigger;
+               break;
+       }
        case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE:
        {
                const enum client_transmission_status client_status =
@@ -4523,13 +4606,6 @@ 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);
 
@@ -4841,12 +4917,6 @@ 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.