How to dispose TransactionScope in cancelable async/await?

Question

I\'m trying to use the new async/await feature to asynchronously work with a DB. As some of the requests can be lengthy, I want to be able to cancel them. The issue I\'m run

Answer 1

The problem stems from the fact that I was prototyping the code in a console application, which I did not reflect in the question.

The way async/await continues to execute the code after await is dependent on the presence of SynchronizationContext.Current, and console application don't have one by default, which means the continuation gets executed using the current TaskScheduler, which is a ThreadPool, so it (potentially?) executes on a different thread.

Thus one simply needs to have a SynchronizationContext that will ensure TransactionScope is disposed on the same thread it was created. WinForms and WPF applications will have it by default, while console applications can either use a custom one, or borrow DispatcherSynchronizationContext from WPF.

Here are two great blog posts that explain the mechanics in detail:
Await, SynchronizationContext, and Console Apps
Await, SynchronizationContext, and Console Apps: Part 2