import threadpool, strformat, os, strutils, math
type
  Tree = ref object
    left: Tree
    right: Tree

proc deepCopy[T](x: var T, y: T) =
   x = y

proc check(t: Tree): int32 =
  result = 1
  if (t.left != nil and t.right != nil):
    result += check t.left
    result += check t.right

proc make(depth: int32): Tree =
  result = Tree(left: nil, right: nil)
  if depth > 0:
    result.left = make(depth - 1)
    result.right = make(depth - 1)

proc shortLived(depth: int32, iterations: int32): string =
  {.push experimental: "parallel".}
  var ts = newSeq[FlowVar[Tree]](iterations)
  parallel:
    for i in 0 .. ts.len-1:
      ts[i] = spawn make depth
  var sum = 0
  for t in ts:
    sum += check ^t
  {.pop.}
  &"{iterations}\t trees of depth {depth}\t check: {sum}"

let minDepth = 4
let maxDepth : int32 =
  if paramCount() == 0: 2
  else:
    try: parseInt(paramStr(1))
    except: 2

echo &"stretch tree of depth {maxDepth+1} check: {check(make(maxDepth+1))}"

let longLived = make maxDepth
let numMessages = int(maxDepth/2)

var messages = newSeq[string](numMessages+1)
for i in 2 .. int(maxDepth/2):
  let depth = int32(i*2)
  let iterations = int32(1 shl (maxDepth - depth + minDepth))
  echo iterations , " " , depth
  messages[i] = shortLived(depth, iterations)

echo messages
echo check longLived