What happens if I don't await a task?

Question

Consider this example:

var task = DoSomething()
bool ready = await DoSomethingElse();
if (!ready) 
  return null;

var value = await DoThirdThing(); // depends o         


        

Answer 1

Follow-up: Is there a neat way to make sure task is awaited?

If you need individual, more fine-grained than TaskScheduler.UnobservedTaskException control over exceptions thrown by the tasks you don't await, there is a handy tool for that: async void methods.

Your code might look like this:

static async void Observe(Task task)
{        
    // use try/catch here if desired so;

    // otherwise, exceptions will be thrown out-of-band, i.e.
    // via SyncronizationContext.Post or 
    // via ThreadPool.QueueUSerWorkItem (if there's no sync. context) 

    await task; 
}

// ...

var taskObserved = false;
var task = DoSomething()
try
{
    bool ready = await DoSomethingElse();
    if (!ready) 
      return null;

    var value = await DoThirdThing(); // depends on DoSomethingElse
    taskObserved = true;
    return value + await task;
 }
 finally
 {
     if (!taskObserved)
        Observe(task);
 }

Some more details can be found here and here.