IOCTL_FARC_GET_RXSTATUS
Purpose: check out if any packets have been received
Parameter:
IN: -
OUT: UCHAR (size of output buffer > = 1 byte)
Comment:
This function returns 0, if no unread packets available otherwise 1.
Possible errors (see also Error codes):
E_FARC_INVALID_HANDLE
E_FARC_BUFFER_TOO_SMALL
Example:
Note, that the following example is only a fragment. It is recommended,
that the driver is opened in asynchronous mode and a handle to the driver
is available.
OVERLAPPED overlapped;
DWORD read, err;
BOOL ret;
UCHAR rxStatus;
overlapped.Offset = 0;
overlapped.OffsetHigh = 0;
overlapped.hEvent = CreateEvent(NULL,
TRUE, FALSE, NULL);
...
ret = DeviceIoControl(drvhandle,
IOCTL_FARC_GET_RXSTATUS,
NULL, 0,
&rxStatus,
sizeof(rxStatus),
&read,
&overlapped);
if (!ret)
{
err = GetLastError();
if (err == E_FARC_PENDING)
{
ret
= GetOverlappedResult(drvhandle, &overlapped, &read, TRUE);
if
(!ret)
{
err = GetLastError();
// do errorhandling here
}
}
else
{
//
other error occured, perhaps wrong handle
}
}
if (rxStatus)
{
// some unread packets
available;
}
...