c# What is a .NET Mutex? https://msdn.microsoft.com/en-us/library/system.threading.mutex(v=vs.110).aspx a primitive .NET type one thread owns it at a time WaitOne(int) blocks the calling thread returns true when
f# A simple example of using an Observable in F# open System; open System.Timers; open System.Threading.Tasks; let t1 = new Timer(float 500); let disposable = t1.Elapsed |> Observable.map(fun _ -> "t1") |> Observable.subscribe(fun s