private async Task <SendMessageResult> sendMessageAsync(ReadOnlyMemory <byte> message, ProtocolType protocol, int timeout, CancellationToken cancellationToken)
{
SendMessageResult result = new SendMessageResult
{
Bytes = 0,
Packets = 0,
};
ReadOnlyMemory <byte> modbusTcpMessage = buildTcpMessage(message, protocol);
try
{
result.Bytes += await _client.SendAsync(modbusTcpMessage, timeout, cancellationToken);
result.Packets += 1;
}
catch (ObjectDisposedException)
{
throw new UnitronicsException("Failed to Send " + protocol + " Message to Unitronics PLC '" + RemoteHost + ":" + Port + "' - The underlying Socket Connection has been Closed");
}
catch (TimeoutException)
{
throw new UnitronicsException("Failed to Send " + protocol + " Message within the Timeout Period to Unitronics PLC '" + RemoteHost + ":" + Port + "'");
}
catch (System.Net.Sockets.SocketException e)
{
throw new UnitronicsException("Failed to Send " + protocol + " Message to Unitronics PLC '" + RemoteHost + ":" + Port + "'", e);
}
return(result);
}
public async Task <ProcessMessageResult> ProcessMessageAsync(ReadOnlyMemory <byte> requestMessage, ProtocolType protocol, byte unitId, int timeout, int retries, CancellationToken cancellationToken)
{
int attempts = 0;
Memory <byte> responseMessage = new Memory <byte>();
int bytesSent = 0;
int packetsSent = 0;
int bytesReceived = 0;
int packetsReceived = 0;
DateTime startTimestamp = DateTime.UtcNow;
while (attempts <= retries)
{
try
{
if (!_semaphore.Wait(0))
{
await _semaphore.WaitAsync(cancellationToken);
}
if (attempts > 0)
{
await destroyAndInitializeClient(timeout, cancellationToken);
}
// Send the Message
SendMessageResult sendResult = await sendMessageAsync(requestMessage, protocol, timeout, cancellationToken);
bytesSent += sendResult.Bytes;
packetsSent += sendResult.Packets;
// Receive a Response
ReceiveMessageResult receiveResult = await receiveMessageAsync(protocol, timeout, cancellationToken);
bytesReceived += receiveResult.Bytes;
packetsReceived += receiveResult.Packets;
responseMessage = receiveResult.Message;
break;
}
catch (Exception)
{
if (attempts >= retries)
{
throw;
}
}
finally
{
_semaphore.Release();
}
// Increment the Attempts
attempts++;
}
return(new ProcessMessageResult
{
BytesSent = bytesSent,
PacketsSent = packetsSent,
BytesReceived = bytesReceived,
PacketsReceived = packetsReceived,
Duration = DateTime.UtcNow.Subtract(startTimestamp).TotalMilliseconds,
ResponseMessage = responseMessage,
});
}
