import std/[locks, lists, strutils, os]

var L: Lock

proc threadFunc(interval: tuple[a,b: int]) {.thread.} =
  for i in interval.a..interval.b:
    acquire(L) # lock stdout
    echo i
    release(L)

proc test() =
  var thr = newSeqOfCap[Thread[tuple[a,b: int]]](2)
  initLock(L)

  for i in 0..parseInt(paramStr(1)): # Use dynamic number of threads
    thr.setLen thr.len + 1
    createThread(thr[thr.high], threadFunc, (i*10, i*10+5)) # Create thread into already allocated memory

  for thread in thr.mitems: # mitems is used here because we don't want a copy (Nim will fail to compile without it)
    joinThread(thread) # Join all threads one by one

  deinitLock(L)
  # `thr` will be deallocated here, along with all the nodes

test()