+listener_t *start_listener(int port);
+
+client_t *client_register(int fd, run_client_t runner, void *data);
+void client_delete(client_t **client);
+void client_release(client_t *client);
+
+void client_io_none(client_t *client);
+void client_io_rw(client_t *client);
+void client_io_ro(client_t *client);
+
+ssize_t client_read(client_t *client);
+buffer_t *client_input_buffer(client_t *client);
+buffer_t *client_output_buffer(client_t *client);
+void *client_data(client_t *client);