var
  thr: array[0..3, system.TThread[tuple[id: int, incoming: TChannel[int], outgoing: TChannel[float]]]]
  job: TChannel[int]
  result: TChannel[float]

proc threadFunc(channels: tuple[id: int, incoming: TChannel[int], outgoing: TChannel[float]]) {.thread.} =
  while true:
    var i : int
    channels.incoming.recv()
    echo("got i: ", i, " in thread: ", channel.id)
    var o: float
    o = i*0.5
    channels.outgoing.send(o)

for i in 0..high(thr):
  createThread(thr[i], threadFunc, (i, job, result))
  while true:
    job.send(3)
joinThreads(thr)