protected override async Task <MessageProcessingResult> DispatchMessage(TransportMessage message, long taskId, CancellationToken token, ITransactionContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context), "ITransactionContext context == null");
}
var stepContext = new IncomingStepContext(message, context);
await _pipelineInvoker.Invoke(stepContext);
return(new MessageProcessingResult {
isRollBack = false
});
}
async Task ProcessMessage(TransactionContext context, TransportMessage transportMessage)
{
try
{
AmbientTransactionContext.SetCurrent(context);
var stepContext = new IncomingStepContext(transportMessage, context);
await _pipelineInvoker.Invoke(stepContext);
try
{
await context.Complete();
}
catch (Exception exception)
{
_log.Error(exception, "An error occurred when attempting to complete the transaction context");
}
}
catch (OperationCanceledException exception)
{
context.Abort();
_log.Error(exception, "Worker was aborted while handling message {messageLabel}", transportMessage.GetMessageLabel());
}
catch (Exception exception)
{
context.Abort();
_log.Error(exception, "Unhandled exception while handling message {messageLabel}", transportMessage.GetMessageLabel());
}
finally
{
AmbientTransactionContext.SetCurrent(null);
}
}
async void TryReceiveNewMessage()
{
using (var operation = _parallelOperationsManager.TryBegin())
{
// if we didn't get to do our thing, pause the thread a very short while to avoid thrashing too much
if (!operation.CanContinue())
{
Thread.Sleep(10);
return;
}
using (var transactionContext = new DefaultTransactionContext())
{
AmbientTransactionContext.Current = transactionContext;
try
{
var message = await TryReceiveTransportMessage(transactionContext);
if (message == null)
{
// no message: finish the tx and wait....
await transactionContext.Complete();
await _backoffStrategy.Wait();
return;
}
// we got a message, so we reset the backoff strategy
_backoffStrategy.Reset();
var context = new IncomingStepContext(message, transactionContext);
var stagedReceiveSteps = _pipeline.ReceivePipeline();
await _pipelineInvoker.Invoke(context, stagedReceiveSteps);
try
{
await transactionContext.Complete();
}
catch (Exception exception)
{
_log.Error(exception, "An error occurred when attempting to complete the transaction context");
}
}
catch (Exception exception)
{
// we should not end up here unless something is off....
_log.Error(exception, "Unhandled exception in thread worker - the pipeline didn't handle its own errors (this is bad)");
Thread.Sleep(100);
}
finally
{
AmbientTransactionContext.Current = null;
}
}
}
}
async void TryProcessMessage()
{
using (var op = _parallelOperationsManager.TryBegin())
{
if (!op.CanContinue())
{
Thread.Sleep(10);
return;
}
using (var transactionContext = new DefaultTransactionContext())
{
AmbientTransactionContext.Current = transactionContext;
try
{
var message = await _transport.Receive(transactionContext);
if (message == null)
{
// finish the tx and wait....
await transactionContext.Complete();
await _backoffHelper.Wait();
return;
}
_backoffHelper.Reset();
var context = new IncomingStepContext(message, transactionContext);
transactionContext.Items[StepContext.StepContextKey] = context;
var stagedReceiveSteps = _pipeline.ReceivePipeline();
await _pipelineInvoker.Invoke(context, stagedReceiveSteps);
await transactionContext.Complete();
}
catch (Exception exception)
{
_log.Error(exception, "Unhandled exception in thread worker");
}
finally
{
AmbientTransactionContext.Current = null;
}
}
}
}
async Task ProcessMessage(TransactionContext context, TransportMessage transportMessage)
{
try
{
context.Items["OwningBus"] = _owningBus;
AmbientTransactionContext.SetCurrent(context);
var incomingSteps = _pipeline.ReceivePipeline();
var stepContext = new IncomingStepContext(transportMessage, context);
await _pipelineInvoker.Invoke(stepContext, incomingSteps);
try
{
await context.Complete();
}
catch (Exception exception)
{
_log.Error(exception, "An error occurred when attempting to complete the transaction context");
}
}
catch (ThreadAbortException exception)
{
context.Abort();
_log.Error(exception, $"Worker was killed while handling message {transportMessage.GetMessageLabel()}");
}
catch (Exception exception)
{
context.Abort();
_log.Error(exception, $"Unhandled exception while handling message {transportMessage.GetMessageLabel()}");
}
finally
{
AmbientTransactionContext.SetCurrent(null);
}
}
async Task SendUsingTransactionContext(IEnumerable <string> destinationAddresses, Message logicalMessage, ITransactionContext transactionContext)
{
var context = new OutgoingStepContext(logicalMessage, transactionContext, new DestinationAddresses(destinationAddresses));
await _pipelineInvoker.Invoke(context, _pipeline.SendPipeline());
}
async void TryReceiveNewMessage()
{
using (var operation = _parallelOperationsManager.TryBegin())
{
// if we didn't get to do our thing, let the OS decide what to do next.... we don't hog the processor
if (!operation.CanContinue())
{
Thread.Yield();
return;
}
using (var transactionContext = new DefaultTransactionContext())
{
transactionContext.Items["CancellationToken"] = _cancellationTokenSource.Token;
transactionContext.Items["OwningBus"] = _owningBus;
AmbientTransactionContext.Current = transactionContext;
try
{
var result = await TryReceiveTransportMessage(transactionContext, _cancellationTokenSource.Token);
if (result.Exception != null)
{
if (result.Exception is TaskCanceledException || result.Exception is OperationCanceledException)
{
// this is normal - we're being shut down so we just return quickly
transactionContext.Dispose();
return;
}
_log.Warn("An error occurred when attempting to receive transport message: {0}", result.Exception);
// error: finish the tx and wait....
transactionContext.Dispose();
await _backoffStrategy.WaitError();
return;
}
var message = result.TransportMessage;
if (message == null)
{
// no message: finish the tx and wait....
await transactionContext.Complete();
transactionContext.Dispose();
await _backoffStrategy.Wait();
return;
}
// we got a message, so we reset the backoff strategy
_backoffStrategy.Reset();
var context = new IncomingStepContext(message, transactionContext);
var stagedReceiveSteps = _pipeline.ReceivePipeline();
await _pipelineInvoker.Invoke(context, stagedReceiveSteps);
try
{
await transactionContext.Complete();
}
catch (Exception exception)
{
_log.Error(exception, "An error occurred when attempting to complete the transaction context");
}
}
catch (Exception exception)
{
// we should not end up here unless something is off....
_log.Error(exception, "Unhandled exception in thread worker - the pipeline didn't handle its own errors (this is bad)");
Thread.Sleep(100);
}
finally
{
AmbientTransactionContext.Current = null;
}
}
}
}
