Serial Port File Descriptor close() Delay - c++

Question

I have an application that interfaces with serial ports. Sometimes when I close a serial port using close(int fd), the call to close() takes 30 seconds or so.
Is there a way I can configure the system to forgo this delay when closing the file descriptor?
I open my port by fd = open(addr, O_RDWR );
Most of the code configuing the port is shown below:
rc = tcgetattr(fd, &opts);
if(rc)
{
printf("TC get attr failed %d \n", errno);
return rc;
}
// Configure parity
opts.c_cflag &= ~PARENB;
if(com_port->parity_)
{
opts.c_cflag |= PARENB;
if(com_port->parity_ >1)
{
opts.c_cflag = PARODD;
}
}
// Configure stop bits
opts.c_cflag &= ~CSTOPB; // Clear stop bit for default setting
switch(com_port->stop_bit_)
{
case 1:
//default is 1 stop bit for POSIX
break;
case 2:
opts.c_cflag |= CSTOPB;
break;
default:
//Use the default setting for POSIX
printf("Warning using default stop bit\n");
break;
}
// Configure bytes size
opts.c_cflag &= ~CSIZE; // Clear byte size bit
opts.c_cflag |= (CS8); // Set byte size bit
// Configure flow control
opts.c_cflag &= ~CRTSCTS; // flow control disabled
opts.c_cflag |= CREAD | CLOCAL; // allow read and ignore ctrl lines
// Disable canonical mode
opts.c_lflag &= ~ICANON;
// Disable echoing
opts.c_lflag &= ~ECHO;
opts.c_lflag &= ~ECHOE;
opts.c_lflag &= ~ECHONL;
// Disable signal chars
opts.c_lflag &= ~ISIG;
// Disable flow control
opts.c_iflag &= ~(IXON | IXOFF | IXANY);
// Disable special handling
opts.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL);
// Configure output modes
opts.c_oflag &= ~OPOST;
opts.c_oflag &= ~ONLCR;
// Default timeouts
opts.c_cc[VTIME] = 10;
opts.c_cc[VMIN] = 0;
I close the file with this code:
int CloseSerialPort(SerComPort* com_port)
{
if(com_port->port_handle_ > 0)
{
tcflush(com_port->port_handle_ TCIOFLUSH);
}
return close(com_port->port_handle_);
}