+/*
+ * Setup the base event notifier group.
+ *
+ * Return 0 on success else a negative value either an errno code or a
+ * LTTng-UST error code.
+ */
+int ust_app_setup_event_notifier_group(struct ust_app *app)
+{
+ int ret;
+ int event_pipe_write_fd;
+ struct lttng_ust_object_data *event_notifier_group = NULL;
+ enum lttng_error_code lttng_ret;
+
+ assert(app);
+
+ /* Get the write side of the pipe. */
+ event_pipe_write_fd = lttng_pipe_get_writefd(
+ app->event_notifier_group.event_pipe);
+
+ pthread_mutex_lock(&app->sock_lock);
+ ret = ustctl_create_event_notifier_group(app->sock,
+ event_pipe_write_fd, &event_notifier_group);
+ pthread_mutex_unlock(&app->sock_lock);
+ if (ret < 0) {
+ if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) {
+ ERR("Failed to create application event notifier group: ret = %d, app socket fd = %d, event_pipe_write_fd = %d",
+ ret, app->sock, event_pipe_write_fd);
+ } else {
+ DBG("Failed to create application event notifier group (application is dead): app socket fd = %d",
+ app->sock);
+ }
+
+ goto error;
+ }
+
+ lttng_ret = notification_thread_command_add_tracer_event_source(
+ notification_thread_handle,
+ lttng_pipe_get_readfd(app->event_notifier_group.event_pipe),
+ LTTNG_DOMAIN_UST);
+ if (lttng_ret != LTTNG_OK) {
+ ERR("Failed to add tracer event source to notification thread");
+ ret = - 1;
+ goto error;
+ }
+
+ /* Assign handle only when the complete setup is valid. */
+ app->event_notifier_group.object = event_notifier_group;
+ return ret;
+
+error:
+ ustctl_release_object(app->sock, app->event_notifier_group.object);
+ free(app->event_notifier_group.object);
+ return ret;
+}
+