private void SendFrame(AshFrame ashFrame)
{
switch (ashFrame.GetFrameType())
{
case AshFrame.FrameType.ACK:
_statsTxAcks++;
break;
case AshFrame.FrameType.DATA:
_statsTxData++;
// Set the frame number
((AshFrameData)ashFrame).SetFrmNum(_frmNum);
_frmNum = (_frmNum + 1) & 0x07;
// DATA frames need to go into a sent queue so we can retry if needed
_sentQueue.Enqueue((AshFrameData)ashFrame);
break;
case AshFrame.FrameType.NAK:
_statsTxNaks++;
break;
default:
break;
}
OutputFrame(ashFrame);
}
private void OutputFrame(AshFrame ashFrame)
{
ashFrame.SetAckNum(_ackNum);
Log.Debug("--> TX ASH frame: {Frame}", ashFrame);
// Send the data
int[] data = ashFrame.GetOutputBuffer();
byte[] bytes = new byte[data.Length];
for (int i = 0; i < data.Length; i++)
{
bytes[i] = (byte)data[i];
}
_port.Write(bytes);
// Only start the timer for data and reset frames
if (ashFrame is AshFrameData || ashFrame is AshFrameRst)
{
_sentTime = DateTime.Now;
StartRetryTimer();
}
}
private void ParserTaskLoop()
{
Log.Debug("AshFrameHandler parser task started");
int exceptionCnt = 0;
while (!_parserCancellationToken.IsCancellationRequested)
{
try
{
int[] packetData = GetPacket();
if (packetData == null)
{
continue;
}
AshFrame packet = AshFrame.CreateFromInput(packetData);
AshFrame responseFrame = null;
if (packet == null)
{
Log.Debug("<-- RX ASH error: BAD PACKET {Frame}", FrameToString(packetData));
// Send a NAK
responseFrame = new AshFrameNak(_ackNum);
}
else
{
Log.Debug("<-- RX ASH frame: {Frame}", packet.ToString());
// Reset the exception counter
exceptionCnt = 0;
// Extract the flags for DATA/ACK/NAK frames
switch (packet.GetFrameType())
{
case AshFrame.FrameType.DATA:
_statsRxData++;
// Always use the ackNum - even if this frame is discarded
AckSentQueue(packet.GetAckNum());
AshFrameData dataPacket = (AshFrameData)packet;
// Check for out of sequence frame number
if (packet.GetFrmNum() == _ackNum)
{
// Frame was in sequence - prepare the response
_ackNum = (_ackNum + 1) & 0x07;
responseFrame = new AshFrameAck(_ackNum);
// Get the EZSP frame
EzspFrameResponse response = EzspFrame.CreateHandler(dataPacket.GetDataBuffer());
Log.Verbose("ASH RX EZSP: {Response}", response);
if (response == null)
{
Log.Debug("ASH: No frame handler created for {Packet}", packet);
}
else
{
NotifyTransactionComplete(response);
HandleIncomingFrame(response);
}
}
else if (!dataPacket.GetReTx())
{
// Send a NAK - this is out of sequence and not a retransmission
Log.Debug("ASH: Frame out of sequence - expected {Expected}, received {Received}", _ackNum, packet.GetFrmNum());
responseFrame = new AshFrameNak(_ackNum);
}
else
{
// Send an ACK - this was out of sequence but was a retransmission
responseFrame = new AshFrameAck(_ackNum);
}
break;
case AshFrame.FrameType.ACK:
_statsRxAcks++;
AckSentQueue(packet.GetAckNum());
break;
case AshFrame.FrameType.NAK:
_statsRxNaks++;
SendRetry();
break;
case AshFrame.FrameType.RSTACK:
// Stack has been reset!
HandleReset((AshFrameRstAck)packet);
break;
case AshFrame.FrameType.ERROR:
// Stack has entered FAILED state
HandleError((AshFrameError)packet);
break;
default:
break;
}
}
// Due to possible I/O buffering, it is important to note that the Host could receive several
// valid or invalid frames after triggering a reset of the NCP. The Host must discard all frames
// and errors until a valid RSTACK frame is received.
if (!_stateConnected)
{
continue;
}
// Send the next frame
// Note that ASH protocol requires the host always sends an ack.
// Piggybacking on data packets is not allowed
if (responseFrame != null)
{
SendFrame(responseFrame);
}
SendNextFrame();
}
catch (Exception e)
{
Log.Error(e, "AshFrameHandler Exception: ", e);
if (exceptionCnt++ > 10)
{
Log.Error("AshFrameHandler exception count exceeded: {Exception}");
_parserCancellationToken.Cancel();
}
}
}
Log.Debug("AshFrameHandler exited.");
}