如何解锁wgetch？

我在客户端有一个线程接收来自服务器的消息,主线程接收来自用户的输入,但是当第一个线程收到shutdown命令时,主线程在执行关闭之前等待来自客户端的一个密钥.

我的问题是：有没有办法解除主线程上的wgetch,使其不等待密钥并执行关闭？

代码：

void *trata_fifo(void *dados) {

int i;

RESPONSE resp;
char namepipe[MAX];

sprintf(namepipe,CLIENT_FIFO,getpid());
mkfifo(namepipe,0600);
fd_res = open(namepipe,O_RDWR);


do {
    i = read(fd_res,&resp,sizeof (RESPONSE));

        drawGame(resp);
        if (resp.command == 3) {
            wclear(info_win);
            box(info_win,0);
            wattron(info_win,A_REVERSE | A_BOLD);
            mvwprintw(info_win,2,4,"Score");
            mvwprintw(info_win,5," %d ",resp.points);
            mvwprintw(info_win,6,"Bombinhas");
            mvwprintw(info_win,8,resp.bombinha);
            mvwprintw(info_win,10,"Megabombas");
            mvwprintw(info_win,12,resp.megaBomba);
            wrefresh(info_win);
        }

        if (resp.command == 4) {//here
            SHUTDOWN = true;
            write(STDIN_FILENO,NULL,0);//i tried this,but its not working
        }
        if (resp.command == 5) {
            SHUTDOWN = true;
        }
    }

} while (!SHUTDOWN);

close(fd_res);
pthread_exit(NULL);

    }


    int main() {

REQUEST client;
pthread_t tarefa;
int highlight = 1,choice = 0,opt;

int startx = 0,starty = 0;

signal(SIGINT,handleSignalCli);
signal(SIGUSR1,handleSignalCli);
signal(SIGALRM,handleSignalCli);



if (access(SERVER_FIFO,F_OK) != 0) //Verificar se servidor esta correndo
{
    perror("[ERROR] Server ins't running...!/n");
    exit(EXIT_FAILURE);
}

if (pthread_create(&tarefa,trata_fifo,NULL) != 0) {
    fprintf(stderr,"[ERROR] Creating Threadn");
    exit(EXIT_FAILURE);
}

fd = open(SERVER_FIFO,O_WRONLY);
if (!fd) {
    perror("[ERROR] Opening Server Fifo...!n");
    exit(EXIT_FAILURE);
}

    /*...*/
while (!SHUTDOWN) {
    cbreak();
    keypad(game_win,TRUE);
    noecho();
    client.command = 3;
    client.tecla = wgetch(game_win);
    res = write(fd,&client,sizeof (client));
}

close(fd);
pthread_join(tarefa,NULL);

delwin(game_win);
delwin(main_win);
endwin();

exit(0);

    }

PS：resp.comand = 4表示服务器正在踢出播放器/客户端.
抱歉英文不好:)