I'm using a BluetoothClient on a background thread to poll for a BT client and connect once there. My thread's code looks something like this:
while (true)
{
try
{
using (var client = new BluetoothClient { InquiryLength = TimeSpan.FromSeconds(INQUIRY_MAX_DURATION)} )
{
var curAddr = ...;
var ep = new BluetoothEndPoint(curAddr, BluetoothService.SerialPort);
client.Connect(ep);
if (client.Connected)
{
using(var stream = client.GetStream())
{
try
{
//Do stuff on stream
}
catch(IOException) { }
}
}
}
}
catch (PlatformNotSupportedException)
{
Thread.Sleep(STACK_NOT_FOUND_RETRY_INTERVAL);
}
catch (SocketException ex)
{
Thread.Sleep(CONNECTION_FAILED_RETRY_INTERVAL);
}
}
This does connect and work correctly on the most computers, including the MS Surface with windows 8.1 Pro as long as it does not enter suspend. If I disable the surface and leave it alone for a while so it enters suspend, after turning on all Connect() attempts are throwing a SocketException saying the was invalid. It only recovers if I close and restart the app.
This condition does NOT happen if I set aircraft mode or pull the Bluetooth dongle on a PC, it seems to happen exclusively after the tablet's suspend. It seems not to matter whether the system has entered suspend in a connected or disconnected state.
What can I do to avoid this state or recover properly?
EDIT: API sniffing shows that an "WSAEINVAL" error is constantly thrown by the unmanaged WSAConnect function.
