+
+enum lttng_trigger_status lttng_trigger_set_firing_policy(
+ struct lttng_trigger *trigger,
+ enum lttng_trigger_firing_policy policy_type,
+ uint64_t threshold)
+{
+ enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK;
+ assert(trigger);
+
+ if (threshold < 1) {
+ ret = LTTNG_TRIGGER_STATUS_INVALID;
+ goto end;
+ }
+
+ trigger->firing_policy.type = policy_type;
+ trigger->firing_policy.threshold = threshold;
+
+end:
+ return ret;
+}
+
+enum lttng_trigger_status lttng_trigger_get_firing_policy(
+ const struct lttng_trigger *trigger,
+ enum lttng_trigger_firing_policy *policy_type,
+ uint64_t *threshold)
+{
+ enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK;
+
+ if (!trigger || !policy_type || !threshold) {
+ status = LTTNG_TRIGGER_STATUS_INVALID;
+ goto end;
+ }
+
+ *policy_type = trigger->firing_policy.type;
+ *threshold = trigger->firing_policy.threshold;
+
+end:
+ return status;
+}
+
+LTTNG_HIDDEN
+bool lttng_trigger_should_fire(const struct lttng_trigger *trigger)
+{
+ bool ready_to_fire = false;
+
+ assert(trigger);
+
+ switch (trigger->firing_policy.type) {
+ case LTTNG_TRIGGER_FIRING_POLICY_EVERY_N:
+ if (trigger->firing_policy.current_count < trigger->firing_policy.threshold) {
+ ready_to_fire = true;
+ }
+ break;
+ case LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N:
+ if (trigger->firing_policy.current_count < trigger->firing_policy.threshold) {
+ ready_to_fire = true;
+ }
+ break;
+ default:
+ abort();
+ };
+
+ return ready_to_fire;
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_fire(struct lttng_trigger *trigger)
+{
+ assert(trigger);
+
+ trigger->firing_policy.current_count++;
+
+ switch (trigger->firing_policy.type) {
+ case LTTNG_TRIGGER_FIRING_POLICY_EVERY_N:
+ if (trigger->firing_policy.current_count == trigger->firing_policy.threshold) {
+ trigger->firing_policy.current_count = 0;
+ }
+
+ break;
+ case LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N:
+ /*
+ * TODO:
+ * As an optimisation, deactivate the trigger condition and
+ * remove any checks in the traced application or kernel since
+ * the trigger will never fire again.
+ */
+ break;
+ default:
+ abort();
+ };
+}
+
+LTTNG_HIDDEN
+enum lttng_domain_type lttng_trigger_get_underlying_domain_type_restriction(
+ const struct lttng_trigger *trigger)
+{
+ enum lttng_domain_type type = LTTNG_DOMAIN_NONE;
+ const struct lttng_event_rule *event_rule;
+ enum lttng_condition_status c_status;
+ enum lttng_condition_type c_type;
+
+ assert(trigger);
+ assert(trigger->condition);
+
+ c_type = lttng_condition_get_type(trigger->condition);
+ assert (c_type != LTTNG_CONDITION_TYPE_UNKNOWN);
+
+ switch (c_type) {
+ case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ /* Apply to any domain. */
+ type = LTTNG_DOMAIN_NONE;
+ break;
+ case LTTNG_CONDITION_TYPE_ON_EVENT:
+ /* Return the domain of the event rule. */
+ c_status = lttng_condition_on_event_get_rule(
+ trigger->condition, &event_rule);
+ assert(c_status == LTTNG_CONDITION_STATUS_OK);
+ type = lttng_event_rule_get_domain_type(event_rule);
+ break;
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+ /* Return the domain of the channel being monitored. */
+ c_status = lttng_condition_buffer_usage_get_domain_type(
+ trigger->condition, &type);
+ assert(c_status == LTTNG_CONDITION_STATUS_OK);
+ break;
+ default:
+ abort();
+ }
+
+ return type;
+}
+
+/*
+ * Generate bytecode related to the trigger.
+ * On success LTTNG_OK. On error, returns lttng_error code.
+ */
+LTTNG_HIDDEN
+enum lttng_error_code lttng_trigger_generate_bytecode(
+ struct lttng_trigger *trigger,
+ const struct lttng_credentials *creds)
+{
+ enum lttng_error_code ret;
+ struct lttng_condition *condition = NULL;
+
+ condition = lttng_trigger_get_condition(trigger);
+ if (!condition) {
+ ret = LTTNG_ERR_INVALID_TRIGGER;
+ goto end;
+ }
+
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_ON_EVENT:
+ {
+ struct lttng_event_rule *event_rule;
+ const enum lttng_condition_status condition_status =
+ lttng_condition_on_event_borrow_rule_mutable(
+ condition, &event_rule);
+
+ assert(condition_status == LTTNG_CONDITION_STATUS_OK);
+
+ /* Generate the filter bytecode. */
+ ret = lttng_event_rule_generate_filter_bytecode(
+ event_rule, creds);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+
+ /* Generate the capture bytecode. */
+ ret = lttng_condition_on_event_generate_capture_descriptor_bytecode(
+ condition);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+
+ ret = LTTNG_OK;
+ break;
+ }
+ default:
+ ret = LTTNG_OK;
+ break;
+ }
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+struct lttng_trigger *lttng_trigger_copy(const struct lttng_trigger *trigger)
+{
+ int ret;
+ struct lttng_payload copy_buffer;
+ struct lttng_trigger *copy = NULL;
+
+ lttng_payload_init(©_buffer);
+
+ ret = lttng_trigger_serialize(trigger, ©_buffer);
+ if (ret < 0) {
+ goto end;
+ }
+
+ {
+ struct lttng_payload_view view =
+ lttng_payload_view_from_payload(
+ ©_buffer, 0, -1);
+ ret = lttng_trigger_create_from_payload(
+ &view, ©);
+ if (ret < 0) {
+ copy = NULL;
+ goto end;
+ }
+ }
+
+end:
+ lttng_payload_reset(©_buffer);
+ return copy;
+}
+
+
+static
+bool action_type_needs_tracer_notifier(enum lttng_action_type action_type)
+{
+ switch (action_type) {
+ case LTTNG_ACTION_TYPE_NOTIFY:
+ case LTTNG_ACTION_TYPE_START_SESSION:
+ case LTTNG_ACTION_TYPE_STOP_SESSION:
+ case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION:
+ case LTTNG_ACTION_TYPE_ROTATE_SESSION:
+ return true;
+ case LTTNG_ACTION_TYPE_INCREMENT_VALUE:
+ return false;
+ case LTTNG_ACTION_TYPE_GROUP:
+ case LTTNG_ACTION_TYPE_UNKNOWN:
+ default:
+ abort();
+ }
+}
+
+static
+bool action_needs_tracer_notifier(const struct lttng_action *action)
+{
+ bool needs_tracer_notifier = false;
+ unsigned int i, count;
+ enum lttng_action_status action_status;
+ enum lttng_action_type action_type;
+
+ assert(action);
+ /* If there is only one action. Check if it needs a tracer notifier. */
+ action_type = lttng_action_get_type(action);
+ if (action_type != LTTNG_ACTION_TYPE_GROUP) {
+ needs_tracer_notifier = action_type_needs_tracer_notifier(
+ action_type);
+ goto end;
+ }
+
+ /*
+ * Iterate over all the actions of the action group and check if any of
+ * them needs a tracer notifier.
+ */
+ action_status = lttng_action_group_get_count(action, &count);
+ assert(action_status == LTTNG_ACTION_STATUS_OK);
+ for (i = 0; i < count; i++) {
+ const struct lttng_action *inner_action =
+ lttng_action_group_get_at_index(action, i);
+
+ action_type = lttng_action_get_type(inner_action);
+ if (action_type_needs_tracer_notifier(action_type)) {
+ needs_tracer_notifier = true;
+ goto end;
+ }
+ }
+
+end:
+ return needs_tracer_notifier;
+}
+
+LTTNG_HIDDEN
+bool lttng_trigger_needs_tracer_notifier(const struct lttng_trigger *trigger)
+{
+ bool needs_tracer_notifier = false;
+ const struct lttng_condition *condition =
+ lttng_trigger_get_const_condition(trigger);
+ const struct lttng_action *action =
+ lttng_trigger_get_const_action(trigger);
+
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_ON_EVENT:
+ needs_tracer_notifier = action_needs_tracer_notifier(action);
+ goto end;
+ case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ goto end;
+ case LTTNG_CONDITION_TYPE_UNKNOWN:
+ default:
+ abort();
+ }
+end:
+ return needs_tracer_notifier;
+}