public override sealed Task ConnectAsync(EndPoint remoteAddress, EndPoint localAddress)
{
// todo: handle cancellation
AbstractSocketChannel ch = this.Channel;
if (!ch.Open)
{
return(this.CreateClosedChannelExceptionTask());
}
try
{
if (ch.connectPromise != null)
{
throw new InvalidOperationException("connection attempt already made");
}
bool wasActive = this.channel.Active;
if (ch.DoConnect(remoteAddress, localAddress))
{
this.FulfillConnectPromise(wasActive);
return(TaskEx.Completed);
}
else
{
if (!wasActive)
{
ch.SetState(StateFlags.ActivationPending);
}
ch.connectPromise = new TaskCompletionSource(remoteAddress);
// Schedule connect timeout.
TimeSpan connectTimeout = ch.Configuration.ConnectTimeout;
if (connectTimeout > TimeSpan.Zero)
{
CancellationTokenSource cts = ch.connectCancellation = new CancellationTokenSource();
ch.EventLoop.Schedule(
c =>
{
// todo: make static / cache delegate?..
var self = (AbstractSocketChannel)c;
// todo: call Socket.CancelConnectAsync(...)
TaskCompletionSource promise = ch.connectPromise;
var cause =
new ConnectTimeoutException("connection timed out: " + remoteAddress);
if (promise != null && promise.TrySetException(cause))
{
self.CloseAsync();
}
},
this.channel,
connectTimeout,
cts.Token);
}
ch.connectPromise.Task.ContinueWith(t =>
{
if (ch.connectCancellation != null)
{
ch.connectCancellation.Cancel();
}
ch.connectPromise = null;
this.channel.CloseAsync();
},
TaskContinuationOptions.OnlyOnCanceled | TaskContinuationOptions.ExecuteSynchronously);
return(ch.connectPromise.Task);
}
}
catch (Exception ex)
{
this.CloseIfClosed();
return(TaskEx.FromException(this.AnnotateConnectException(ex, remoteAddress)));
}
}
