public async Task Start()
{
try
{
OutputConsumer = new LibuvOutputConsumer(Output, Thread, _socket, ConnectionId, Log);
StartReading();
Exception inputError = null;
Exception outputError = null;
try
{
// This *must* happen after socket.ReadStart
// The socket output consumer is the only thing that can close the connection. If the
// output pipe is already closed by the time we start then it's fine since, it'll close gracefully afterwards.
await OutputConsumer.WriteOutputAsync();
}
catch (UvException ex)
{
// The connection reset/error has already been logged by LibuvOutputConsumer
if (ex.StatusCode == LibuvConstants.ECANCELED)
{
// Connection was aborted.
}
else if (LibuvConstants.IsConnectionReset(ex.StatusCode))
{
// Don't cause writes to throw for connection resets.
inputError = new ConnectionResetException(ex.Message, ex);
}
else
{
inputError = ex;
outputError = ex;
}
}
finally
{
// Now, complete the input so that no more reads can happen
Input.Complete(inputError ?? _abortReason ?? new ConnectionAbortedException());
Output.Complete(outputError);
// Make sure it isn't possible for a paused read to resume reading after calling uv_close
// on the stream handle
Input.CancelPendingFlush();
// Send a FIN
Log.ConnectionWriteFin(ConnectionId);
// We're done with the socket now
_socket.Dispose();
ThreadPool.QueueUserWorkItem(state => ((LibuvConnection)state).CancelConnectionClosedToken(), this);
}
}
catch (Exception e)
{
Log.LogCritical(0, e, $"{nameof(LibuvConnection)}.{nameof(Start)}() {ConnectionId}");
}
}
private Exception LogAndWrapReadError(UvException uvError)
{
if (uvError.StatusCode == LibuvConstants.ECANCELED)
{
// The operation was canceled by the server not the client. No need for additional logs.
return(new ConnectionAbortedException(uvError.Message, uvError));
}
else if (LibuvConstants.IsConnectionReset(uvError.StatusCode))
{
// Log connection resets at a lower (Debug) level.
Log.ConnectionReset(ConnectionId);
return(new ConnectionResetException(uvError.Message, uvError));
}
else
{
Log.ConnectionError(ConnectionId, uvError);
return(new IOException(uvError.Message, uvError));
}
}
/// <summary>
/// Handles an incoming connection
/// </summary>
/// <param name="listenSocket">Socket being used to listen on</param>
/// <param name="status">Connection status</param>
private void OnConnection(UvStreamHandle listenSocket, int status)
{
UvStreamHandle acceptSocket = null;
try
{
acceptSocket = CreateAcceptSocket();
listenSocket.Accept(acceptSocket);
DispatchConnection(acceptSocket);
}
catch (UvException ex) when(LibuvConstants.IsConnectionReset(ex.StatusCode))
{
Log.ConnectionReset("(null)");
acceptSocket?.Dispose();
}
catch (UvException ex)
{
Log.LogError(0, ex, "Listener.OnConnection");
acceptSocket?.Dispose();
}
}
private void ReadStartCallback(UvStreamHandle handle, int status)
{
if (status < 0)
{
if (status != LibuvConstants.EOF)
{
Thread.Loop.Libuv.Check(status, out var ex);
Log.LogError(0, ex, "DispatchPipe.ReadStart");
}
DispatchPipe.Dispose();
return;
}
if (_closed || DispatchPipe.PendingCount() == 0)
{
return;
}
var acceptSocket = CreateAcceptSocket();
try
{
DispatchPipe.Accept(acceptSocket);
// REVIEW: This task should be tracked by the server for graceful shutdown
// Today it's handled specifically for http but not for aribitrary middleware
_ = HandleConnectionAsync(acceptSocket);
}
catch (UvException ex) when(LibuvConstants.IsConnectionReset(ex.StatusCode))
{
Log.ConnectionReset("(null)");
acceptSocket.Dispose();
}
catch (UvException ex)
{
Log.LogError(0, ex, "DispatchPipe.Accept");
acceptSocket.Dispose();
}
}
private void LogWriteInfo(int status, Exception error)
{
if (error == null)
{
_log.ConnectionWriteCallback(_connectionId, status);
}
else
{
// Log connection resets at a lower (Debug) level.
if (status == LibuvConstants.ECANCELED)
{
// Connection was aborted.
}
else if (LibuvConstants.IsConnectionReset(status))
{
_log.ConnectionReset(_connectionId);
}
else
{
_log.ConnectionError(_connectionId, error);
}
}
}
protected async Task HandleConnectionAsync(UvStreamHandle socket)
{
try
{
IPEndPoint remoteEndPoint = null;
IPEndPoint localEndPoint = null;
if (socket is UvTcpHandle tcpHandle)
{
try
{
remoteEndPoint = tcpHandle.GetPeerIPEndPoint();
localEndPoint = tcpHandle.GetSockIPEndPoint();
}
catch (UvException ex) when(LibuvConstants.IsConnectionReset(ex.StatusCode))
{
TransportContext.Log.ConnectionReset("(null)");
socket.Dispose();
return;
}
}
var connection = new LibuvConnection(socket, TransportContext.Log, Thread, remoteEndPoint, localEndPoint);
var middlewareTask = TransportContext.ConnectionDispatcher.OnConnection(connection);
var transportTask = connection.Start();
await transportTask;
await middlewareTask;
connection.Dispose();
}
catch (Exception ex)
{
TransportContext.Log.LogCritical(ex, $"Unexpected exception in {nameof(ListenerContext)}.{nameof(HandleConnectionAsync)}.");
}
}