int device_fd = -1;
static int listen_fd = -1;
static int request_fd = -1;
static int data_fd = -1;
static int write_fd = -1;
static int state = 0;
int device_fd = -1;
static int listen_fd = -1;
static int request_fd = -1;
static int data_fd = -1;
static int write_fd = -1;
static int state = 0;