+ CDS_INIT_LIST_HEAD(&wait_node->head);
+
+ /* Create application object if socket is CMD. */
+ wait_node->app = ust_app_create(&ust_cmd->reg_msg,
+ ust_cmd->sock);
+ if (!wait_node->app) {
+ ret = close(ust_cmd->sock);
+ if (ret < 0) {
+ PERROR("close ust sock dispatch %d", ust_cmd->sock);
+ }
+ lttng_fd_put(1, LTTNG_FD_APPS);
+ free(wait_node);
+ free(ust_cmd);
+ continue;
+ }
+ /*
+ * Add application to the wait queue so we can set the notify
+ * socket before putting this object in the global ht.
+ */
+ cds_list_add(&wait_node->head, &wait_queue.head);
+ wait_queue.count++;
+
+ free(ust_cmd);
+ /*
+ * We have to continue here since we don't have the notify
+ * socket and the application MUST be added to the hash table
+ * only at that moment.
+ */
+ continue;
+ } else {
+ /*
+ * Look for the application in the local wait queue and set the
+ * notify socket if found.
+ */
+ cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
+ &wait_queue.head, head) {
+ health_code_update();
+ if (wait_node->app->pid == ust_cmd->reg_msg.pid) {
+ wait_node->app->notify_sock = ust_cmd->sock;
+ cds_list_del(&wait_node->head);
+ wait_queue.count--;
+ app = wait_node->app;
+ free(wait_node);
+ DBG3("UST app notify socket %d is set", ust_cmd->sock);
+ break;
+ }
+ }
+
+ /*
+ * With no application at this stage the received socket is
+ * basically useless so close it before we free the cmd data
+ * structure for good.
+ */
+ if (!app) {
+ ret = close(ust_cmd->sock);
+ if (ret < 0) {
+ PERROR("close ust sock dispatch %d", ust_cmd->sock);
+ }
+ lttng_fd_put(1, LTTNG_FD_APPS);
+ }
+ free(ust_cmd);
+ }
+
+ if (app) {
+ /*
+ * @session_lock_list
+ *
+ * Lock the global session list so from the register up to the
+ * registration done message, no thread can see the application
+ * and change its state.
+ */
+ session_lock_list();
+ rcu_read_lock();
+
+ /*
+ * Add application to the global hash table. This needs to be
+ * done before the update to the UST registry can locate the
+ * application.
+ */
+ ust_app_add(app);
+
+ /* Set app version. This call will print an error if needed. */
+ (void) ust_app_version(app);
+
+ /* Send notify socket through the notify pipe. */
+ ret = send_socket_to_thread(apps_cmd_notify_pipe[1],
+ app->notify_sock);
+ if (ret < 0) {
+ rcu_read_unlock();
+ session_unlock_list();
+ /* No notify thread, stop the UST tracing. */
+ goto error;
+ }
+
+ /*
+ * Update newly registered application with the tracing
+ * registry info already enabled information.
+ */
+ update_ust_app(app->sock);
+
+ /*
+ * Don't care about return value. Let the manage apps threads
+ * handle app unregistration upon socket close.
+ */
+ (void) ust_app_register_done(app->sock);
+
+ /*
+ * Even if the application socket has been closed, send the app
+ * to the thread and unregistration will take place at that
+ * place.
+ */
+ ret = send_socket_to_thread(apps_cmd_pipe[1], app->sock);
+ if (ret < 0) {
+ rcu_read_unlock();
+ session_unlock_list();
+ /* No apps. thread, stop the UST tracing. */
+ goto error;
+ }
+
+ rcu_read_unlock();
+ session_unlock_list();