public virtual void Read()
{
while (_isMonitoring)
{
try
{
if (_cancellationTokenSource != null && _cancellationTokenSource.IsCancellationRequested)
{
_cancellationTokenSource.Token.ThrowIfCancellationRequested();
}
// Sometimes the serial port lib will throw an exception and read past the end of the queue if a
// status changes while data is being written. We just ignore these bytes.
var b = Reader.ReadByte();
ReadBuffer.Enqueue(b);
DataAvailable(false);
}
catch (OperationCanceledException ex)
{
_cancellationTokenSource.Dispose();
_cancellationTokenSource = null;
_isMonitoring = false;
Debug.WriteLine($"Read Cancelled Exception: {ex.Message}");
}
}
private void Init()
{
Writer = () =>
{
while (Executing)
{
if (WriteBuffer.Count > 0)
{
lock (WriteBuffer)
{
if (WriteBuffer.Count > 0)
{
var e = WriteBuffer.Dequeue();
//Debug.WriteLine($"Computer reads {e}");
return(e);
}
Thread.Sleep(1);
}
}
}
return(-1);
};
Reader = l =>
{
lock (ReadBuffer)
{
//Debug.WriteLine($"Computer writes {l}");
ReadBuffer.Enqueue(l);
}
};
}
protected virtual async void ReadLongRunningTask()
{
while (true)
{
if (_readCancellationTokenSource != null && _readCancellationTokenSource.IsCancellationRequested)
{
Logging.Logger?.LogDebug("[{Function}]:[{PrinterName}] Read Long-Running Task Cancellation was requested.", $"{this}.{MethodBase.GetCurrentMethod().Name}", PrinterName);
break;
}
await Task.Delay(100);
if (Reader == null)
{
continue;
}
if (!IsConnected)
{
continue;
}
try
{
// Sometimes the serial port lib will throw an exception and read past the end of the queue if a
// status changes while data is being written. We just ignore these bytes.
var b = Reader.BaseStream.ReadByte();
if (b >= 0 && b <= 255)
{
ReadBuffer.Enqueue((byte)b);
DataAvailable();
}
}
//catch (OperationCanceledException ex)
//{
// try
// {
// _readCancellationTokenSource.Dispose();
// _readCancellationTokenSource = null;
// //_isMonitoring = false;
// }
// catch
// {
// Logging.Logger?.LogDebug("[{Function}]:[{PrinterName}] Swallowing OperationCanceledException... secondary issue during dispose of cancellation token.");
// }
// Logging.Logger?.LogDebug("[{Function}]:[{PrinterName}] Swallowing OperationCanceledException... this is used to turn off status monitoring.");
//}
catch (Exception ex)
{ // Swallow the exception
//Logging.Logger?.LogDebug("[{Function}]:[{PrinterName}] Swallowing generic read exception... sometimes happens with serial port printers.", $"{this}.{MethodBase.GetCurrentMethod().Name}", PrinterName);
}
}
}
