asynchronous - When does a C# Task actually start?

Question

When does a Task actually start?

public void DoSomething() {
    Task myTask = DoSomethingAsync();

    Task.WaitAll(new[] { myTask }, 2000);
}

public async Task DoSomethingAsync() {
    await SomethingElse();
}

Does it start immediately when initializing it in Task myTask = DoSomethingAsync(); or does it start when you say to wait for it in Task.WaitAll(new[] { myTask }, 2000); ?

Answer 1

Calling an async method returns a hot task, a task that has already been started. So there is no actual code necessary to force it to run.

According MSDN (thanks to Stephen Cleary) the Task-based Asynchronous Pattern (TAP) pattern requires returned tasks to be hot. That means that all tasks, except those created with new Task will be hot.

From the referenced article:

Tasks that are created by the public Task constructors are referred to as cold tasks... All other tasks begin their life cycle in a hot state.