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

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

open job
open result

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