await.fsx

let await (timeout: int) task =
    async {
        let evt = Event<_>()
        let! _ =
            async {
                do! Async.Sleep timeout
                evt.Trigger None
            } |> Async.StartChild

        let! _ =
            async {
                let! result = task
                evt.Trigger (Some result)
            } |> Async.StartChild

        return!
            evt.Publish
            |> Async.AwaitEvent
    }

async {
    do! Async.Sleep 10
    printfn "test"
    return 9
}
|> await 100
|> Async.RunSynchronously