/// <summary>
/// TBD
/// </summary>
/// <typeparam name="T">TBD</typeparam>
/// <param name="self">TBD</param>
/// <param name="messageFactory">Factory method that creates a message that can encapsulate the 'Sender' IActorRef</param>
/// <param name="timeout">TBD</param>
/// <param name="cancellationToken">TBD</param>
/// <exception cref="ArgumentException">
/// This exception is thrown if the system can't resolve the target provider.
/// </exception>
/// <returns>TBD</returns>
public static Task <T> Ask <T>(this ICanTell self, Func <IActorRef, object> messageFactory, TimeSpan?timeout, CancellationToken cancellationToken)
{
IActorRefProvider provider = ResolveProvider(self);
if (provider == null)
{
throw new ArgumentException("Unable to resolve the target Provider", nameof(self));
}
var result = TaskEx.NonBlockingTaskCompletionSource <T>();
CancellationTokenSource timeoutCancellation = null;
timeout = timeout ?? provider.Settings.AskTimeout;
CancellationTokenRegistration?ctr1 = null;
CancellationTokenRegistration?ctr2 = null;
if (timeout != Timeout.InfiniteTimeSpan && timeout.Value > default(TimeSpan))
{
timeoutCancellation = new CancellationTokenSource();
ctr1 = timeoutCancellation.Token.Register(() =>
{
result.TrySetException(new AskTimeoutException($"Timeout after {timeout} seconds"));
});
timeoutCancellation.CancelAfter(timeout.Value);
}
if (cancellationToken.CanBeCanceled)
{
ctr2 = cancellationToken.Register(() => result.TrySetCanceled());
}
var future = provider.CreateFutureRef(result);
var path = future.Path;
//The future actor needs to be unregistered in the temp container
_ = result.Task.ContinueWith(t =>
{
provider.UnregisterTempActor(path);
ctr1?.Dispose();
ctr2?.Dispose();
timeoutCancellation?.Dispose();
}, TaskContinuationOptions.ExecuteSynchronously);
//The future actor needs to be registered in the temp container
provider.RegisterTempActor(future, path);
var message = messageFactory(future);
self.Tell(message, future);
return(result.Task);
}