Trying System.Threading.Channels

SimulateSub.fs

open System
open System.Threading
open System.Threading.Channels
open FSharp.Control

let channel =
    Channel.CreateUnbounded<int>(UnboundedChannelOptions(SingleWriter=true, SingleReader=true))

let mutable cnt = 0
let timerEvent _ =
    cnt <- cnt + 1
    channel.Writer.WriteAsync(cnt).AsTask() |> Async.AwaitTask |> Async.Start

#nowarn "40"
let rec asq =
    asyncSeq {
        yield channel.Reader.ReadAsync().AsTask() |> Async.AwaitTask
        yield! asq 
    }

[<EntryPoint>]
let main _ =
    let timer = new Timer(TimerCallback(timerEvent))
    timer.Change(0, 1000) |> ignore
    
    asq
    |> AsyncSeq.mapAsync id
    |> AsyncSeq.iter (fun i -> Console.WriteLine(sprintf "%d" i))
    |> Async.Start
    
    Console.ReadLine() |> ignore
    0