NServiceBus.ExpiredTimeoutsPoller.SpinOnce C# (CSharp) Method

        internal async Task SpinOnce(CancellationToken cancellationToken)
        {
            if (NextRetrieval > currentTimeProvider() || cancellationToken.IsCancellationRequested)
            {
                return;
            }

            Logger.DebugFormat("Polling for timeouts at {0}.", currentTimeProvider());
            var timeoutChunk = await timeoutsFetcher.GetNextChunk(startSlice).ConfigureAwait(false);

            foreach (var timeoutData in timeoutChunk.DueTimeouts)
            {
                if (cancellationToken.IsCancellationRequested)
                {
                    return;
                }

                if (startSlice < timeoutData.DueTime)
                {
                    startSlice = timeoutData.DueTime;
                }

                var dispatchRequest = ControlMessageFactory.Create(MessageIntentEnum.Send);

                dispatchRequest.Headers["Timeout.Id"] = timeoutData.Id;

                var transportOperation = new TransportOperation(dispatchRequest, new UnicastAddressTag(dispatcherAddress));
                await dispatcher.Dispatch(new TransportOperations(transportOperation), new TransportTransaction(), new ContextBag()).ConfigureAwait(false);
            }

            lock (lockObject)
            {
                var nextTimeToQuery = timeoutChunk.NextTimeToQuery;

                // we cap the next retrieval to max 1 minute this will make sure that we trip the circuit breaker if we
                // loose connectivity to our storage. This will also make sure that timeouts added (during migration) direct to storage
                // will be picked up after at most 1 minute
                var maxNextRetrieval = currentTimeProvider() + MaxNextRetrievalDelay;

                NextRetrieval = nextTimeToQuery > maxNextRetrieval ? maxNextRetrieval : nextTimeToQuery;

                Logger.DebugFormat("Polling next retrieval is at {0}.", NextRetrieval.ToLocalTime());
            }

            circuitBreaker.Success();
        }