ToListAsync() does not complete at all

Question

I want to execute some queries async. But when I debug through the code, most times when an ToListAsync() is called the program stops. There is no visible exception, and the

Answer 1

From the comments:

It is a wpf application. The commands are within an async method. I call this from a non-async method using var result = LoadAsync.Result();

Right there, thats a deadlock. The DispatcherSynchronizationContext tries to marshal the continuation (everything after the first await) back onto the dispatcher (UI) thread, which is currently blocked by the call to LoadAsync.Result

The solution:

1. await at the top of your call stack by making your method return an async Task instead of using Task.Result:

   await LoadAsync();
   

2. If you absolutely cant change the method at the top of of the stack to async Task and for some obscure reason have to still call Task.Result, use ConfigureAwait(false) when awating your inner async methods. This will tell the sync context to explicitly not attempt to marshal work back to the dispatcher thread:

   var res1 = await context.Address().Where(...).ToListAsync().ConfigureAwait(false);
   var res2 = await context.Person().Where(...).ToListAsync().ConfigureAwait(false);
   var res3 = await context.Rule().Where(...).ToListAsync().ConfigureAwait(false);