Enforce an async method to be called once

Question

Say I have a class that needs to perform some async initialization using an InitializeAsync() method. I want to make sure that the initialization is performed only once. If

Answer 1

Yes. Use Stephen Cleary's AsyncLazy (available on the AsyncEx nuget):

private static readonly AsyncLazy myResource = new AsyncLazy(
    async () => 
    { 
        var ret = new MyResource(); 
        await ret.InitAsync(); 
        return ret; 
    }
);

public async Task UseResource()
{
    MyResource resource = await myResource;
    // ...
}

Or the visual studio SDK's AsyncLazy if you prefer a Microsoft implementation.