+static
+void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
+{
+ struct lttng_event_notifier_enabler *event_notifier_enabler;
+ struct lttng_kernel_event_notifier_private *event_notifier_priv;
+
+ list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
+ lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
+
+ /*
+ * For each event_notifier, if at least one of its enablers is enabled,
+ * we enable the event_notifier, else we disable it.
+ */
+ list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
+ struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
+ struct lttng_enabler_ref *enabler_ref;
+ struct lttng_kernel_bytecode_runtime *runtime;
+ int enabled = 0, has_enablers_without_filter_bytecode = 0;
+ int nr_filters = 0, nr_captures = 0;
+
+ switch (event_notifier_priv->parent.instrumentation) {
+ case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
+ case LTTNG_KERNEL_ABI_SYSCALL:
+ /* Enable event_notifiers */
+ list_for_each_entry(enabler_ref,
+ &event_notifier_priv->parent.enablers_ref_head, node) {
+ if (enabler_ref->ref->enabled) {
+ enabled = 1;
+ break;
+ }
+ }
+ break;
+
+ default:
+ /* Not handled with sync. */
+ continue;
+ }
+
+ WRITE_ONCE(event_notifier->parent.enabled, enabled);
+ /*
+ * Sync tracepoint registration with event_notifier enabled
+ * state.
+ */
+ if (enabled) {
+ if (!event_notifier_priv->parent.registered)
+ register_event_notifier(event_notifier);
+ } else {
+ if (event_notifier_priv->parent.registered)
+ _lttng_event_notifier_unregister(event_notifier);
+ }
+
+ /* Check if has enablers without bytecode enabled */
+ list_for_each_entry(enabler_ref,
+ &event_notifier_priv->parent.enablers_ref_head, node) {
+ if (enabler_ref->ref->enabled
+ && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
+ has_enablers_without_filter_bytecode = 1;
+ break;
+ }
+ }
+ event_notifier_priv->parent.has_enablers_without_filter_bytecode =
+ has_enablers_without_filter_bytecode;
+
+ /* Enable filters */
+ list_for_each_entry(runtime,
+ &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
+ lttng_bytecode_sync_state(runtime);
+ nr_filters++;
+ }
+ WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
+ !(has_enablers_without_filter_bytecode || !nr_filters));
+
+ /* Enable captures */
+ list_for_each_entry(runtime,
+ &event_notifier_priv->capture_bytecode_runtime_head, node) {
+ lttng_bytecode_sync_state(runtime);
+ nr_captures++;
+ }
+ WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
+ }
+}
+