[wcoenen]

.NET has futures and continuations, see Task[1].

I haven't used tasks heavily yet so I'm not sure how to implement everything in your example. But I believe it's all possible.

Async/await is "just" syntactic sugar for tasks. So I'm not sure what you mean by "still blocking from the perspective of the caller". When you call an async method, you get back a Task. When you use await on a task, the compiler rewrites your code to introduce continuations. If you need some more powerful Task features hidden by the syntactic sugar, you always still have the option of using tasks explicitly.

[1] http://msdn.microsoft.com/en-us/library/dd321424.aspx

[SideburnsOfDoom]

The interesting thing about async / await is that for the coder, the code looks linear, but it doesn't execute that way. So a gap is opened up between "the perspective of the coder" and the perspective of the machine.

I think that bad_user means that if you await one client.GetStringAsync then await a second client.GetStringAsync, the second GetStringAsync only starts after the first one completes, so the first get "blocks" the second, "from the perspective of the caller". I.e no parallelism.

Of course, you don't have to do that. Code elsewhere in this thread.