async Task TryProcessNextMessage()
{
var parallelOperation = _parallelOperationsManager.TryBegin();
if (!parallelOperation.CanContinue())
{
await _backoffStrategy.WaitAsync(_cancellationToken);
return;
}
try
{
using (parallelOperation)
using (var context = new TransactionContextWithOwningBus(_owningBus))
{
var transportMessage = await ReceiveTransportMessage(_cancellationToken, context);
if (transportMessage == null)
{
context.Dispose();
// get out quickly if we're shutting down
if (_cancellationToken.IsCancellationRequested || _busDisposalCancellationToken.IsCancellationRequested)
{
return;
}
// no need for another thread to rush in and discover that there is no message
//parallelOperation.Dispose();
await _backoffStrategy.WaitNoMessageAsync(_cancellationToken);
return;
}
_backoffStrategy.Reset();
try
{
AmbientTransactionContext.SetCurrent(context);
await ProcessMessage(context, transportMessage);
}
finally
{
AmbientTransactionContext.SetCurrent(null);
}
}
}
catch (OperationCanceledException) when(_cancellationToken.IsCancellationRequested || _busDisposalCancellationToken.IsCancellationRequested)
{
// we're shutting down
}
catch (Exception exception)
{
_log.Error(exception, "Unhandled exception in worker {workerName}", Name);
}
}