.net - How to handle all unhandled exceptions when using Task Parallel Library?

Question

I'm using the TPL (Task Parallel Library) in .NET 4.0. I want to centralize the handling logic of all unhandled exceptions by using the Thread.GetDomain().UnhandledException event. However, in my application, the event is never fired for threads started with TPL code, e.g. Task.Factory.StartNew(...). The event is indeed fired if I use something like new Thread(threadStart).Start().

This MSDN article suggests to use Task.Wait() to catch the AggregateException when working with TPL, but that is not what I want because this mechanism is not "centralized" enough.

Does anyone experience same problem at all or is it just me? Do you have any solution for this?

Answer 1

I think TaskScheduler.UnobservedTaskException Event is what you want:

Occurs when a faulted Task's unobserved exception is about to trigger exception escalation policy, which, by default, would terminate the process.

So, this event is similar to DomainUnhandledException that you mentioned in your question but occurs only for tasks.

BTW note, that unobserved-exceptions policy (yeah, this is not an unobserved exceptions, MS guys invented new word ... again), changed from .NET 4.0 to .NET 4.5. In .NET 4.0 unobserved exception leads to process termination but in .NET 4.5 - don't. This is all because new async stuff that we'll have in C# 5 and VB 11.