internal async Task TimerLoopAsync(TimerAwaitable timer)
{
timer.Start();
using (timer)
{
// await returns True until `timer.Stop()` is called in the `finally` block of `ReceiveLoop`
while (await timer)
{
try
{
// Ping server
var response = await _session.SendRequestAsync(StreamingRequest.CreateGet("/api/version"), _disconnectCts.Token).ConfigureAwait(false);
if (!IsSuccessResponse(response))
{
Log.ClientKeepAliveFail(_logger, _url, response.StatusCode);
IsConnected = false;
Disconnected?.Invoke(this, new DisconnectedEventArgs()
{
Reason = $"Received failure from server heartbeat: {response.StatusCode}."
});
}
else
{
Log.ClientKeepAliveSucceed(_logger, _url);
}
}
#pragma warning disable CA1031 // Do not catch general exception types
catch (Exception e)
#pragma warning restore CA1031 // Do not catch general exception types
{
Log.ClientKeepAliveFail(_logger, _url, 0, e);
IsConnected = false;
Disconnected?.Invoke(this, new DisconnectedEventArgs()
{
Reason = $"Received failure from server heartbeat: {e}."
});
}
}
}
}
internal async Task ConnectInternalAsync(Func <WebSocketTransport, Task> connectFunc, CancellationToken cancellationToken)
{
CheckDisposed();
TimerAwaitable timer = null;
Task timerTask = null;
try
{
// Pipes
_duplexPipePair = DuplexPipe.CreateConnectionPair(PipeOptions.Default, PipeOptions.Default);
// Transport
var transport = new WebSocketTransport(_duplexPipePair.Application, _logger);
// Application
_transportHandler = new TransportHandler(_duplexPipePair.Transport, _logger);
// Session
_session = new StreamingSession(_requestHandler, _transportHandler, _logger, cancellationToken);
// Set up cancellation
_disconnectCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
// Start transport and application
var transportTask = connectFunc(transport);
var applicationTask = _transportHandler.ListenAsync(_disconnectCts.Token);
var combinedTask = Task.WhenAll(transportTask, applicationTask);
Log.ClientStarted(_logger, _url ?? string.Empty);
// 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 ?? string.Empty);
}
