discard """
  output: '''0
1
2
3
4
5
6
7
8'''
  sortoutput: true
"""

import threadpool, locks

var echoLock: Lock
initLock echoLock

proc f(a: openArray[int]) =
  for x in a:
    withLock echoLock:
      echo x

proc f(a: int) =
  withLock echoLock:
    echo a

proc main() =
  var a: array[0..9, int] = [0,1,2,3,4,5,6,7,8,9]
  parallel:
    spawn f(a[0..2])
    #spawn f(a[16..30])
    var i = 3
    while i <= 8:
      spawn f(a[i])
      spawn f(a[i+1])
      inc i, 2
      # is correct here

main()