/// <summary>
/// Opens the <see cref="StreamingConnection"/> and listens for incoming requests, which will
/// be assembled and sent to the provided <see cref="RequestHandler"/>.
/// </summary>
/// <param name="requestHandler"><see cref="RequestHandler"/> to which incoming requests will be sent.</param>
/// <param name="cancellationToken"><see cref="CancellationToken"/> that signals the need to stop the connection.
/// Once the token is cancelled, the connection will be gracefully shut down, finishing pending sends and receives.</param>
/// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
public virtual async Task ListenAsync(RequestHandler requestHandler, CancellationToken cancellationToken = default)
{
if (requestHandler == null)
{
throw new ArgumentNullException(nameof(requestHandler));
}
var duplexPipePair = DuplexPipe.CreateConnectionPair(PipeOptions.Default, PipeOptions.Default);
// Create transport and application
_transport = CreateStreamingTransport(duplexPipePair.Application);
var application = new TransportHandler(duplexPipePair.Transport, Logger);
// Create session
_session = new StreamingSession(requestHandler, application, Logger, cancellationToken);
// Start transport and application
var transportTask = _transport.ConnectAsync(cancellationToken);
var applicationTask = application.ListenAsync(cancellationToken);
var tasks = new List <Task> {
transportTask, applicationTask
};
// Signal that session is ready to be used
_sessionInitializedTask.SetResult(true);
// Let application and transport run
await Task.WhenAll(tasks).ConfigureAwait(false);
}
private async Task ConnectImplAsync(Func <StreamingTransport, Task> connectFunc, CancellationToken cancellationToken)
{
CheckDisposed();
TimerAwaitable timer = null;
Task timerTask = null;
try
{
// Pipes
var duplexPipePair = DuplexPipe.CreateConnectionPair(PipeOptions.Default, PipeOptions.Default);
// Transport
_transport = CreateStreamingTransport(duplexPipePair.Application);
// Application
_application = new TransportHandler(duplexPipePair.Transport, Logger);
// Session
_session = new StreamingSession(_requestHandler, _application, Logger, cancellationToken);
// Set up cancellation
_disconnectCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
// Start transport and application
var transportTask = connectFunc(_transport);
var applicationTask = _application.ListenAsync(_disconnectCts.Token);
var combinedTask = Task.WhenAll(transportTask, applicationTask);
Log.ClientStarted(Logger, _url);
// Periodic task: keep alive
// Disposed with `timer.Stop()` in the finally block below
if (_keepAlive.HasValue)
{
timer = new TimerAwaitable(_keepAlive.Value, _keepAlive.Value);
timerTask = TimerLoopAsync(timer);
}
// We are connected!
IsConnected = true;
// Block until transport or application ends.
await combinedTask.ConfigureAwait(false);
// Signal that we're done
_disconnectCts.Cancel();
Log.ClientTransportApplicationCompleted(Logger, _url);
}
finally
{
timer?.Stop();
if (timerTask != null)
{
await timerTask.ConfigureAwait(false);
}
}
Log.ClientCompleted(Logger, _url);
}
