Announcement: AsyncEx Stable Release

A lot of my posts have to do with asynchronous code one way or another. Along the way, I’ve compiled a lot of useful helper classes into a library called Nito.AsyncEx.

Today I am pleased to announce that the first public, official release of AsyncEx has gone live. Try it out and see what you think! (And go ahead and yell at me if it’s broken).

Release Notes

With this first stable release of AsyncEx, I restructured the DLL and NuGet packages slightly (details on the library homepage). I also had to make some difficult decisions about cutting some of the APIs that were most likely to change in the future.

Redesigned Features

These types have gone through a redesign since the last prerelease:

• The old AsyncWaitQueue (which was possibly the worst API I’ve ever written) was completely reworked into a properly-designed IAsyncWaitQueue.
• TaskCompletionNotifier has also been redesigned and renamed to NotifyTaskCompletion. This was more of a minor correction in the design.

Semantic Changes

The AsyncFactory FromApm methods now propagate exceptions directly from Begin* methods. This matches TaskFactory.FromAsync behavior, so it should be less surprising for new adopters.

Moving Stuff Around

• Moved synchronous task extensions (e.g., Task.WaitAndUnwrapException) into namespace Nito.AsyncEx.Synchronous because they are normally not needed.
• Moved dataflow support into a separate Nito.AsyncEx.Dataflow NuGet package. So if you upgrade and all your dataflow support breaks, you’ll need to download the new NuGet package.

Removed and Probably Not Coming Back

The awaitable interfaces (IAwaitable, IAwaiter, and friends) have been removed. They are only helpful (but not required) in some advanced custom awaitable situations and they don’t properly support ICriticalNotifyCompletion.

TaskFactory.With has also been removed. While this API makes sense, it just isn’t that helpful.

Removed but Will Probably Come Back after They Bake a Bit More

• Custom types derived from Task (TaskBase, TaskBaseWithCompletion). These are useful conceptually but need some more API work and testing.
• ETW tracing. All ETW tracing has been disabled for this release; I’m working on making the ETW tracing more consistent across all types. ETW tracing will definitely be supported in a future release.

New features

• Added several more CancellationTokenHelpers: None, Canceled, and Timeout.
• Finished Task.Then implementations.