/// <inheritdoc />
protected override Task StopInternalAsync()
{
// Simple lock here to guard start and stop phase
TcpListener?lastListener = null;
TcpClient? lastSendSocket = null;
lock (_startStopLock)
{
if (!_isRunning)
{
throw new InvalidOperationException($"Unable to stop {nameof(TcpPassiveByteStreamHandler)} for port {this.ListeningPort}: This object is stopped already!");
}
_isRunning = false;
_runningLoopCounter++;
if (_runningLoopCounter > RUNNING_LOOP_COUNTER_MAX)
{
_runningLoopCounter = 1;
}
lastListener = _currentListener;
lastSendSocket = _currentSendSocket;
_currentListener = null;
_currentSendSocket = null;
}
// Dispose previous sockets
TcpAsyncUtil.SafeStop(ref lastListener);
TcpAsyncUtil.SafeDispose(ref lastSendSocket);
this.Log(LoggingMessageType.Info, "TCP communication stopped");
return(Task.CompletedTask);
}
/// <inheritdoc />
protected override Task StopInternalAsync()
{
// Simple lock here to guard start and stop phase
UdpClient?lastSendSocket = null;
lock (_startStopLock)
{
if (!_isRunning)
{
throw new InvalidOperationException(
$"Unable to stop {nameof(TcpActiveByteStreamHandler)} for host {this.RemoteHost} and port {this.RemotePort}: This object is stopped already!");
}
_isRunning = false;
_connState = ConnectionState.Stopped;
_runningLoopCounter++;
if (_runningLoopCounter > RUNNING_LOOP_COUNTER_MAX)
{
_runningLoopCounter = 1;
}
lastSendSocket = _udpClient;
_udpClient = null;
}
// Dispose previous sockets
TcpAsyncUtil.SafeDispose(ref lastSendSocket);
this.Log(LoggingMessageType.Info, "UDP communication stopped");
return(Task.CompletedTask);
}
private async void RunConnectionMainLoop(int loopId)
{
this.Log(LoggingMessageType.Info, "TcpCommunicator started in passive mode");
// Start main loop
TcpClient?lastClient = null;
CancellationTokenSource?lastCancelTokenSource = null;
TcpListener? tcpListener = null;
var reconnectErrorCount = 0;
while (loopId == _runningLoopCounter)
{
if (tcpListener == null)
{
this.ActualListeningPort = this.ListeningPort;
try
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("Creating TcpListener socket for port {0}...", this.ListeningPort));
}
tcpListener = new TcpListener(this.ListeningIPAddress, this.ListeningPort);
tcpListener.Start();
this.ActualListeningPort = (ushort)((IPEndPoint)tcpListener.LocalEndpoint).Port;
reconnectErrorCount = 0;
_currentListener = tcpListener;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("TcpListener created for port {0}", this.ActualListeningPort));
}
}
catch (Exception ex)
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format("Error while creating TcpListener for port {0}: {1}", this.ActualListeningPort, ex.Message),
exception: ex);
}
_currentListener = null;
TcpAsyncUtil.SafeStop(ref tcpListener);
TcpAsyncUtil.SafeDispose(ref _currentSendSocket);
await this.WaitByReconnectWaitTimeAsync(reconnectErrorCount)
.ConfigureAwait(false);
reconnectErrorCount++;
}
if (tcpListener == null)
{
continue;
}
}
// Wait for incoming connection
TcpClient? actTcpClient = null;
IPEndPoint?actPartnerEndPoint = null;
IPEndPoint?actLocalEndPoint = null;
try
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("Listening for incoming connections on port {0}...",
this.ActualListeningPort));
}
actTcpClient = await tcpListener.AcceptTcpClientAsync()
.ConfigureAwait(false);
actLocalEndPoint = (IPEndPoint)actTcpClient.Client.LocalEndPoint !;
actPartnerEndPoint = (IPEndPoint)actTcpClient.Client.RemoteEndPoint !;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format(
"Got new connection on listening port {0}. Connection established between {1} and {2}",
this.ActualListeningPort, actLocalEndPoint.ToString(), actPartnerEndPoint.ToString()));
}
}
catch (ObjectDisposedException)
{
// Stop may be called in the meanwhile
if (!_isRunning)
{
continue;
}
if (loopId != _runningLoopCounter)
{
continue;
}
}
catch (Exception ex)
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format("Error while listening for incoming connections on port {0}: {1}", this.ActualListeningPort, ex.Message),
exception: ex);
}
TcpAsyncUtil.SafeStop(ref tcpListener);
TcpAsyncUtil.SafeDispose(ref _currentSendSocket);
await this.WaitByReconnectWaitTimeAsync(reconnectErrorCount)
.ConfigureAwait(false);
reconnectErrorCount++;
}
if (tcpListener == null)
{
continue;
}
if (actTcpClient == null)
{
continue;
}
// New connection request coming in... close the previous one
if (lastClient != null)
{
lastCancelTokenSource !.Cancel();
lastCancelTokenSource = null;
lastClient = null;
}
// Register new client
_currentSendSocket = actTcpClient;
lastClient = actTcpClient;
lastCancelTokenSource = new CancellationTokenSource();
// Run receive loop for this client (we don't have to await this because we a listening for a new connection request)
#pragma warning disable 4014
this.RunReceiveLoopAsync(
lastClient, lastClient.Client,
actLocalEndPoint !, actPartnerEndPoint !, lastCancelTokenSource.Token);
#pragma warning restore 4014
}
if (tcpListener != null)
{
TcpAsyncUtil.SafeStop(ref tcpListener);
}
}
/// <summary>
/// Internal method which reacts on incoming bytes on the currently active socket connection.
/// Only one of this connection is active at one time.
/// </summary>
protected async Task RunReceiveLoopAsync(IDisposable parentDisposable, Socket socket, IPEndPoint localEndPoint, IPEndPoint partnerEndPoint, CancellationToken cancelToken)
{
parentDisposable.MustNotBeNull(nameof(parentDisposable));
socket.MustNotBeNull(nameof(socket));
localEndPoint.MustNotBeNull(nameof(localEndPoint));
partnerEndPoint.MustNotBeNull(nameof(partnerEndPoint));
_lastSuccessfulConnectTimestampUtc = DateTime.UtcNow;
var localEndPointStr = localEndPoint.ToString();
var partnerEndPointStr = partnerEndPoint.ToString();
var newConnection = true;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("Starting receive loop for connection {0} to {1}", localEndPointStr, partnerEndPointStr));
}
var receiveBuffer = new byte[this.ReceiveBufferSize];
while (!cancelToken.IsCancellationRequested)
{
int lastReceiveResult;
try
{
// Read next bytes
#if NETSTANDARD2_0
var receiveTask = socket.ReceiveAsync(new ArraySegment <byte>(receiveBuffer), SocketFlags.None);
if (receiveTask.IsCompleted)
{
lastReceiveResult = receiveTask.Result;
}
else if (this.ReceiveTimeout == TimeSpan.Zero)
{
lastReceiveResult = await receiveTask
.ConfigureAwait(false);
}
else
{
var timeoutTask = Task.Delay(this.ReceiveTimeout);
await Task.WhenAny(receiveTask, timeoutTask)
.ConfigureAwait(false);
if (receiveTask.IsCompleted)
{
lastReceiveResult = receiveTask.Result;
}
else
{
_ = receiveTask.ContinueWith(s_dummyReceiveContinuation);
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format(
"Timeout while receiving from {0}!",
partnerEndPointStr));
}
break;
}
}
#else
var receiveTaskStruct = socket.ReceiveAsync(new Memory <byte>(receiveBuffer), SocketFlags.None);
if (receiveTaskStruct.IsCompleted)
{
lastReceiveResult = receiveTaskStruct.Result;
}
else if (this.ReceiveTimeout == TimeSpan.Zero)
{
lastReceiveResult = await receiveTaskStruct
.ConfigureAwait(false);
}
else
{
var receiveTask = receiveTaskStruct.AsTask();
var timeoutTask = Task.Delay(this.ReceiveTimeout);
await Task.WhenAny(receiveTask, timeoutTask)
.ConfigureAwait(false);
if (receiveTask.IsCompleted)
{
lastReceiveResult = receiveTask.Result;
}
else
{
_ = receiveTask.ContinueWith(s_dummyReceiveContinuation);
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format(
"Timeout while receiving from {0}!",
partnerEndPointStr));
}
break;
}
}
#endif
// Reset receive result if we where canceled already
if (lastReceiveResult == 0)
{
this.Log(LoggingMessageType.Info, "Connection closed by remote partner");
}
else if (cancelToken.IsCancellationRequested)
{
this.Log(LoggingMessageType.Info, "Connection canceled by local program");
lastReceiveResult = 0;
}
else
{
_lastSuccessfulReceiveTimestampUtc = DateTime.UtcNow;
}
}
catch (ObjectDisposedException)
{
break;
}
catch (SocketException socketException)
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format(
"Error while receiving bytes from {0}: (Code: {1}) {2}",
partnerEndPointStr,
socketException.SocketErrorCode.ToString(),
socketException.Message),
exception: socketException);
}
break;
}
catch (Exception ex)
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format(
"Error while receiving bytes from {0}: {1}",
partnerEndPointStr,
ex.Message),
exception: ex);
}
break;
}
if (lastReceiveResult <= 0)
{
break;
}
this.ProcessReceivedBytes(newConnection, receiveBuffer, lastReceiveResult);
newConnection = false;
}
// Ensure that the socket is closed after ending this method
TcpAsyncUtil.SafeDispose(parentDisposable);
}
private async void RunConnectionMainLoop(int loopId)
{
this.Log(LoggingMessageType.Info, "TcpCommunicator started in active mode");
var reconnectErrorCount = 0;
var remoteAddressStr = this.RemoteHost;
while (loopId == _runningLoopCounter)
{
TcpClient?newClient = null;
try
{
_connState = ConnectionState.Connecting;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("Connecting to host {0} on port {1}", remoteAddressStr,
this.RemotePort));
}
newClient = new TcpClient();
if (!ReferenceEquals(this.RemoteIPAddress, IPAddress.None))
{
await newClient.ConnectAsync(this.RemoteIPAddress, this.RemotePort);
}
else
{
await newClient.ConnectAsync(this.RemoteHost, this.RemotePort);
}
_currentClient = newClient;
reconnectErrorCount = 0;
_connState = ConnectionState.Connected;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Info,
StringBuffer.Format("Successfully connected to host {0} on port {1}", remoteAddressStr,
this.RemotePort));
}
}
catch (Exception ex)
{
TcpAsyncUtil.SafeDispose(ref newClient);
_currentClient = null;
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format("Error while connecting to host {0} on port {1}: {2}",
remoteAddressStr, this.RemotePort, ex.Message),
exception: ex);
}
_connState = ConnectionState.Connecting;
await this.WaitByReconnectWaitTimeAsync(reconnectErrorCount)
.ConfigureAwait(false);
reconnectErrorCount++;
}
if (_currentClient == null)
{
continue;
}
// Normal receive loop handling
try
{
await this.RunReceiveLoopAsync(
_currentClient, _currentClient.Client,
(IPEndPoint)_currentClient.Client.LocalEndPoint !,
(IPEndPoint)_currentClient.Client.RemoteEndPoint !, CancellationToken.None);
}
catch (Exception ex)
{
if (this.IsLoggerSet)
{
this.Log(
LoggingMessageType.Error,
StringBuffer.Format(
"Error while running receive loop for host {0} on port {1}: {2}",
remoteAddressStr, this.RemotePort, ex.Message),
exception: ex);
}
}
// Client gets already disposed in receive loop
_currentClient = null;
}
}
