public async Task <TaskSeriesCommandResult> ExecuteAsync(CancellationToken cancellationToken)
{
TimeSpan delay;
try
{
UpdateReceipt updateReceipt = await _queue.UpdateMessageAsync(_message.MessageId, _message.PopReceipt, visibilityTimeout : _visibilityTimeout, cancellationToken : cancellationToken).ConfigureAwait(false);
_message = _message.Update(updateReceipt);
_onUpdateReceipt?.Invoke(updateReceipt);
// The next execution should occur after a normal delay.
delay = _speedupStrategy.GetNextDelay(executionSucceeded: true);
}
catch (RequestFailedException exception)
{
// For consistency, the exceptions handled here should match PollQueueCommand.DeleteMessageAsync.
if (exception.IsServerSideError())
{
// The next execution should occur more quickly (try to update the visibility before it expires).
delay = _speedupStrategy.GetNextDelay(executionSucceeded: false);
}
if (exception.IsBadRequestPopReceiptMismatch())
{
// There's no point to executing again. Once the pop receipt doesn't match, we've permanently lost
// ownership.
delay = Timeout.InfiniteTimeSpan;
}
else if (exception.IsNotFoundMessageOrQueueNotFound() ||
exception.IsConflictQueueBeingDeletedOrDisabled())
{
// There's no point to executing again. Once the message or queue is deleted, we've permanently lost
// ownership.
// For queue disabled, in theory it's possible the queue could be re-enabled, but the scenarios here
// are currently unclear.
delay = Timeout.InfiniteTimeSpan;
}
else
{
throw;
}
}
return(new TaskSeriesCommandResult(wait: Task.Delay(delay, cancellationToken)));
}
internal async Task ProcessMessageAsync(QueueMessage message, TimeSpan visibilityTimeout, CancellationToken cancellationToken)
{
try
{
if (!await _queueProcessor.BeginProcessingMessageAsync(message, cancellationToken).ConfigureAwait(false))
{
return;
}
FunctionResult result = null;
Action <UpdateReceipt> onUpdateReceipt = updateReceipt => { message = message.Update(updateReceipt); };
using (ITaskSeriesTimer timer = CreateUpdateMessageVisibilityTimer(_queue, message, visibilityTimeout, _exceptionHandler, onUpdateReceipt))
{
timer.Start();
result = await _triggerExecutor.ExecuteAsync(message, cancellationToken).ConfigureAwait(false);
await timer.StopAsync(cancellationToken).ConfigureAwait(false);
}
// Use a different cancellation token for shutdown to allow graceful shutdown.
// Specifically, don't cancel the completion or update of the message itself during graceful shutdown.
// Only cancel completion or update of the message if a non-graceful shutdown is requested via _shutdownCancellationTokenSource.
await _queueProcessor.CompleteProcessingMessageAsync(message, result, _shutdownCancellationTokenSource.Token).ConfigureAwait(false);
}
catch (TaskCanceledException)
{
// Don't fail the top-level task when an inner task cancels.
}
catch (OperationCanceledException)
{
// Don't fail the top-level task when an inner task cancels.
}
catch (Exception exception)
{
// Immediately report any unhandled exception from this background task.
// (Don't capture the exception as a fault of this Task; that would delay any exception reporting until
// Stop is called, which might never happen.)
#pragma warning disable AZC0103 // Do not wait synchronously in asynchronous scope.
_exceptionHandler.OnUnhandledExceptionAsync(ExceptionDispatchInfo.Capture(exception)).GetAwaiter().GetResult();
#pragma warning restore AZC0103 // Do not wait synchronously in asynchronous scope.
}
}