+ * Enable a single agent event for a given UST session.
+ *
+ * Return LTTNG_OK on success or else a LTTNG_ERR* code.
+ */
+int event_agent_enable(struct ltt_ust_session *usess,
+ struct agent *agt,
+ struct lttng_event *event,
+ struct lttng_bytecode *filter,
+ char *filter_expression)
+{
+ assert(usess);
+ assert(event);
+ assert(agt);
+
+ DBG("Enabling agent event: event pattern = '%s', session id = %" PRIu64 ", loglevel type = %d, loglevel = %d, filter expression = '%s'",
+ event->name, usess->id, event->loglevel_type,
+ event->loglevel,
+ filter_expression ? filter_expression : "(none)");
+
+ return agent_enable(agt, event, filter, filter_expression);
+}
+
+/*
+ * Enable a single agent event for a trigger.
+ *
+ * Return LTTNG_OK on success or else a LTTNG_ERR* code.
+ */
+int trigger_agent_enable(const struct lttng_trigger *trigger, struct agent *agt)
+{
+ int ret;
+ enum lttng_condition_status c_status;
+ enum lttng_trigger_status t_status;
+ enum lttng_domain_type d_type;
+ const struct lttng_condition *condition;
+ const struct lttng_event_rule *rule;
+ const char *filter_expression;
+ char *filter_expression_copy = NULL;
+ const struct lttng_bytecode *filter_bytecode;
+ struct lttng_bytecode *filter_bytecode_copy = NULL;
+ struct lttng_event *event = NULL;
+ uid_t trigger_owner_uid = 0;
+ const char *trigger_name;
+
+ assert(trigger);
+ assert(agt);
+
+ t_status = lttng_trigger_get_name(trigger, &trigger_name);
+ if (t_status != LTTNG_TRIGGER_STATUS_OK) {
+ trigger_name = "(unnamed)";
+ }
+
+ t_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner_uid);
+ assert(t_status == LTTNG_TRIGGER_STATUS_OK);
+
+ condition = lttng_trigger_get_const_condition(trigger);
+
+ assert(lttng_condition_get_type(condition) ==
+ LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
+
+ c_status = lttng_condition_event_rule_get_rule(condition, &rule);
+ assert(c_status == LTTNG_CONDITION_STATUS_OK);
+
+ assert(lttng_event_rule_get_type(rule) ==
+ LTTNG_EVENT_RULE_TYPE_TRACEPOINT);
+
+ d_type = lttng_event_rule_get_domain_type(rule);
+ assert(d_type == agt->domain);
+
+ event = lttng_event_rule_generate_lttng_event(rule);
+ if (!event) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Get the internal filter expression and bytecode. */
+ filter_expression = lttng_event_rule_get_filter(rule);
+ if (filter_expression) {
+ filter_expression_copy = strdup(filter_expression);
+ if (!filter_expression_copy) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Get the filter bytecode */
+ filter_bytecode = lttng_event_rule_get_filter_bytecode(rule);
+ if (filter_bytecode) {
+ filter_bytecode_copy =
+ lttng_bytecode_copy(filter_bytecode);
+ if (!filter_bytecode_copy) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+ }
+
+ DBG("Enabling agent event from trigger: trigger name = '%s', trigger owner uid = %d, token = %" PRIu64,
+ trigger_name, trigger_owner_uid,
+ lttng_trigger_get_tracer_token(trigger));
+
+ ret = agent_enable(agt, event, filter_bytecode_copy,
+ filter_expression_copy);
+ /* Ownership was passed even in case of error. */
+ filter_expression_copy = NULL;
+ filter_bytecode_copy = NULL;
+
+end:
+ free(filter_expression_copy);
+ free(filter_bytecode_copy);
+ free(event);
+ return ret;
+}
+
+/*
+ * Return the default event name associated with the provided UST domain. Return
+ * NULL on error.