FileStream.FlushAsync(true), can it exist?

[jhudsoncedaron]

While we can't completely become async this idea of push everything large to async is still kicking around in our codebase. On attempting one, discovered a case where FileSream.Flush(true) is called; would need an async version as that's where the actual jam is.

I don't know if this even can exist.

[gfoidl]

Do you mean FileStream.FlushAsync?
It's already around for some time.

[jhudsoncedaron]

@gfoidl: Definitely not. FileStream.Flush(true) is a special function not on stream that does not return until the block is written all the way through to the disk.

[svick]

This was previously discussed at #28444, where @stephentoub said:

And as to my knowledge there's no asynchronous equivalent at the OS level exposed for flushToDisk==true, I wouldn't want to expose a FlushAsync(true)… if a developer wants to Task.Run(() => Flush(true)), they can do so.