What's a good way to run periodic tasks using Rx, with a single concurrent execution restriction?

Question

I want to run periodic tasks in with a restriction that at most only one execution of a method is running at any given time.

I was experimenting with Rx, but I am no

Answer 1

You are on the right track, you can use Select + Concat to flatten out the observable and limit the number of inflight requests (Note: if your task takes longer than the interval time, then they will start to stack up since they can't execute fast enough):

var source = Observable.Interval(TimeSpan.FromMilliseconds(100))
          //I assume you are doing async work since you want to limit concurrency
          .Select(_ => Observable.FromAsync(() => DoSomethingAsync()))
          //This is equivalent to calling Merge(1)
          .Concat();

source.Subscribe(/*Handle the result of each operation*/);