private void OnClientConnected(object sender, MqttClientConnectedEventArgs eventArgs)
{
MqttTrace.Information(nameof(MqttServer), $"Client '{eventArgs.Identifier}': Connected.");
ClientConnected?.Invoke(this, eventArgs);
Task.Run(() => _clientSessionsManager.RunClientSessionAsync(eventArgs), _cancellationTokenSource.Token);
}
private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var mqttPacket = await _adapter.ReceivePacketAsync(TimeSpan.Zero);
MqttTrace.Information(nameof(MqttClient), $"Received <<< {mqttPacket}");
Task.Run(() => ProcessReceivedPacket(mqttPacket), cancellationToken).Forget();
}
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while receiving packets.");
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
await DisconnectInternalAsync();
}
}
private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var mqttPacket = await _adapter.ReceivePacketAsync(TimeSpan.Zero);
MqttTrace.Information(nameof(MqttClient), $"Received <<< {mqttPacket}");
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
Task.Run(() => ProcessReceivedPacketAsync(mqttPacket), cancellationToken);
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
}
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while receiving packets.");
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
await DisconnectInternalAsync();
}
}
private async Task SendKeepAliveMessagesAsync(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start sending keep alive packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
await Task.Delay(_options.KeepAlivePeriod, cancellationToken);
await SendAndReceiveAsync <MqttPingRespPacket>(new MqttPingReqPacket());
}
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
}
catch (Exception exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "Error while sending/receiving keep alive packets.");
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped sending keep alive packets.");
await DisconnectInternalAsync();
}
}
private async Task DisconnectInternalAsync()
{
var cts = _cancellationTokenSource;
if (cts == null || cts.IsCancellationRequested)
{
return;
}
cts.Cancel(false);
cts.Dispose();
_cancellationTokenSource = null;
try
{
await _adapter.DisconnectAsync(_options.DefaultCommunicationTimeout).ConfigureAwait(false);
MqttTrace.Information(nameof(MqttClient), "Disconnected from adapter.");
}
catch (Exception exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "Error while disconnecting from adapter.");
}
finally
{
Disconnected?.Invoke(this, EventArgs.Empty);
}
}
public async Task <MqttBasePacket> ReceivePacketAsync(TimeSpan timeout)
{
MqttBasePacket packet;
if (timeout > TimeSpan.Zero)
{
var workerTask = _serializer.DeserializeAsync(_channel);
var timeoutTask = Task.Delay(timeout);
var hasTimeout = Task.WhenAny(timeoutTask, workerTask) == timeoutTask;
if (hasTimeout)
{
throw new MqttCommunicationTimedOutException();
}
packet = workerTask.Result;
}
else
{
packet = await _serializer.DeserializeAsync(_channel);
}
if (packet == null)
{
throw new MqttProtocolViolationException("Received malformed packet.");
}
MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), $"RX <<< {packet}");
return(packet);
}
public void Stop()
{
_cancellationTokenSource?.Cancel();
_cancellationTokenSource = null;
_adapter.ClientConnected -= OnClientConnected;
_adapter.Stop();
_clientSessionsManager.Clear();
MqttTrace.Information(nameof(MqttServer), "Stopped.");
}
public void Start()
{
if (_cancellationTokenSource != null)
{
throw new InvalidOperationException("The MQTT server is already started.");
}
_cancellationTokenSource = new CancellationTokenSource();
_adapter.ClientConnected += OnClientConnected;
_adapter.Start(_options);
MqttTrace.Information(nameof(MqttServer), "Started.");
}
public void Stop()
{
_cancellationTokenSource?.Cancel(false);
_cancellationTokenSource?.Dispose();
_cancellationTokenSource = null;
foreach (var adapter in _adapters)
{
adapter.ClientConnected -= OnClientConnected;
adapter.Stop();
}
_clientSessionsManager.Clear();
MqttTrace.Information(nameof(MqttServer), "Stopped.");
}
public async Task <MqttBasePacket> ReceivePacketAsync(TimeSpan timeout, CancellationToken cancellationToken)
{
try
{
ReceivedMqttPacket receivedMqttPacket;
if (timeout > TimeSpan.Zero)
{
receivedMqttPacket = await ReceiveAsync(_channel.RawReceiveStream, cancellationToken).TimeoutAfter(timeout).ConfigureAwait(false);
}
else
{
receivedMqttPacket = await ReceiveAsync(_channel.ReceiveStream, cancellationToken).ConfigureAwait(false);
}
if (cancellationToken.IsCancellationRequested)
{
throw new TaskCanceledException();
}
var packet = PacketSerializer.Deserialize(receivedMqttPacket);
if (packet == null)
{
throw new MqttProtocolViolationException("Received malformed packet.");
}
MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), "RX <<< {0}", packet);
return(packet);
}
catch (TaskCanceledException)
{
throw;
}
catch (MqttCommunicationTimedOutException)
{
throw;
}
catch (MqttCommunicationException)
{
throw;
}
catch (Exception exception)
{
throw new MqttCommunicationException(exception);
}
}
public async Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, IEnumerable <MqttBasePacket> packets)
{
try
{
lock (_channel)
{
foreach (var packet in packets)
{
MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), "TX >>> {0} [Timeout={1}]", packet, timeout);
var writeBuffer = PacketSerializer.Serialize(packet);
_sendTask = _sendTask.ContinueWith(p => _channel.SendStream.WriteAsync(writeBuffer, 0, writeBuffer.Length, cancellationToken).ConfigureAwait(false), cancellationToken);
}
}
await _sendTask; // configure await false generates stackoverflow
if (timeout > TimeSpan.Zero)
{
await _channel.SendStream.FlushAsync(cancellationToken).TimeoutAfter(timeout).ConfigureAwait(false);
}
else
{
await _channel.SendStream.FlushAsync(cancellationToken).ConfigureAwait(false);
}
}
catch (TaskCanceledException)
{
throw;
}
catch (MqttCommunicationTimedOutException)
{
throw;
}
catch (MqttCommunicationException)
{
throw;
}
catch (Exception exception)
{
throw new MqttCommunicationException(exception);
}
}
public async Task RunAsync(string identifier, MqttApplicationMessage willApplicationMessage, IMqttCommunicationAdapter adapter)
{
if (adapter == null)
{
throw new ArgumentNullException(nameof(adapter));
}
_willApplicationMessage = willApplicationMessage;
try
{
_identifier = identifier;
Adapter = adapter;
_cancellationTokenSource = new CancellationTokenSource();
_messageQueue.Start(adapter);
while (!_cancellationTokenSource.IsCancellationRequested)
{
var packet = await adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
await HandleIncomingPacketAsync(packet).ConfigureAwait(false);
}
}
catch (MqttCommunicationException)
{
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClientSession), exception, "Client '{0}': Unhandled exception while processing client packets.", _identifier);
}
finally
{
if (willApplicationMessage != null)
{
_publishPacketReceivedCallback(this, _willApplicationMessage.ToPublishPacket());
}
_messageQueue.Stop();
_cancellationTokenSource.Cancel();
Adapter = null;
MqttTrace.Information(nameof(MqttClientSession), "Client '{0}': Disconnected.", _identifier);
}
}
private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
StartProcessReceivedPacket(packet, cancellationToken);
}
}
catch (TaskCanceledException)
{
}
catch (MqttCommunicationException exception)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Unhandled exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
}
}
private async Task SendKeepAliveMessagesAsync(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start sending keep alive packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
await Task.Delay(_options.KeepAlivePeriod, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
await SendAndReceiveAsync <MqttPingRespPacket>(new MqttPingReqPacket()).ConfigureAwait(false);
}
}
catch (TaskCanceledException)
{
}
catch (MqttCommunicationException exception)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication exception while sending/receiving keep alive packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
catch (Exception exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "Unhandled exception while sending/receiving keep alive packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped sending keep alive packets.");
}
}
private async Task ProcessReceivedPacketAsync(MqttBasePacket packet)
{
try
{
MqttTrace.Information(nameof(MqttClient), "Received <<< {0}", packet);
if (packet is MqttPingReqPacket)
{
await SendAsync(new MqttPingRespPacket());
return;
}
if (packet is MqttDisconnectPacket)
{
await DisconnectAsync();
return;
}
if (packet is MqttPublishPacket publishPacket)
{
await ProcessReceivedPublishPacket(publishPacket);
return;
}
if (packet is MqttPubRelPacket pubRelPacket)
{
await ProcessReceivedPubRelPacket(pubRelPacket);
return;
}
_packetDispatcher.Dispatch(packet);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Unhandled exception while processing received packet.");
}
}
public async Task SendPacketAsync(MqttBasePacket packet, TimeSpan timeout)
{
MqttTrace.Information(nameof(MqttChannelCommunicationAdapter), $"TX >>> {packet} [Timeout={timeout}]");
bool hasTimeout;
try
{
var task = _serializer.SerializeAsync(packet, _channel);
hasTimeout = await Task.WhenAny(Task.Delay(timeout), task) != task;
}
catch (Exception exception)
{
throw new MqttCommunicationException(exception);
}
if (hasTimeout)
{
throw new MqttCommunicationTimedOutException();
}
}