/// <summary>
/// This method causes the communication listener to close. Close is a terminal state and
/// this method allows the communication listener to transition to this state in a
/// graceful manner.
/// </summary>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns>
/// A <see cref="T:System.Threading.Tasks.Task">Task</see> that represents outstanding operation.
/// </returns>
public async Task CloseAsync(CancellationToken cancellationToken)
{
WriteLog("Service Bus Communication Listener closing");
IsClosing = true;
_stopProcessingMessageTokenSource.Cancel();
//Wait for Message processing to complete..
await Task.WhenAny(
// Timeout task.
Task.Delay(CloseTimeout, cancellationToken),
// Wait for all processing messages to finish by stealing semaphore entries.
Task.Run(() =>
{
for (int i = 0; i < (MaxConcurrentCalls ?? 1); i++)
{
// ReSharper disable once AccessToDisposedClosure
// ReSharper disable once EmptyGeneralCatchClause
try { ProcessingMessage.Wait(cancellationToken); }
catch { }
}
}, cancellationToken));
ProcessingMessage.Dispose();
await CloseImplAsync(cancellationToken);
}
/// <summary>
/// Will pass an incoming message to the <see cref="Receiver"/> for processing.
/// </summary>
/// <param name="message"></param>
/// <param name="cancellationToken"></param>
protected async Task ReceiveMessageAsync(Message message, CancellationToken cancellationToken)
{
try
{
ProcessingMessage.Wait(cancellationToken);
var combined = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, StopProcessingMessageToken).Token;
await Receiver.ReceiveMessageAsync(message, combined);
}
finally
{
ProcessingMessage.Release();
}
}
/// <summary>
/// Will pass an incoming message to the <see cref="Receiver"/> for processing.
/// </summary>
/// <param name="message"></param>
/// <param name="cancellationToken"></param>
protected async Task ReceiveMessageAsync(Message message, CancellationToken cancellationToken)
{
try
{
if (IsClosing)
{
// We want the thread to sleep and not return immediately.
// Returning immediately could increment the message fail count and send it to dead letter.
Thread.Sleep(CloseTimeout);
return;
}
ProcessingMessage.Wait(cancellationToken);
var combined = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, StopProcessingMessageToken).Token;
await Receiver.ReceiveMessageAsync(message, combined);
}
finally
{
ProcessingMessage.Release();
}
}