Lua simple thread pool

threadpool.lua

local create            = coroutine.create
local resume            = coroutine.resume
local running           = coroutine.running
local status            = coroutine.status
local wrap              = coroutine.wrap
local yield             = coroutine.yield
local tinsert           = table.insert
local tremove           = table.remove

local PREPARE_CONFIRM   = {}
local _ThreadPool 		= {}


local function returnwithrecycle(thread, ...)
    if #_ThreadPool < 100 then tinsert(_ThreadPool, thread) end -- recyle the thread
    yield(...)
end

local function preparefunc(thread, func, ...)
    returnwithrecycle(thread, func(...))
end

local function recyclethread(thread)
    while true do preparefunc(thread, yield(PREPARE_CONFIRM)) end
end

local function newrecyclethread()
    local thread        = tremove(_ThreadPool)

    -- Check Re-usable
    if thread then for i= 1, 3 do if thread() == PREPARE_CONFIRM then return thread end end end

    -- Create the new thread
    thread              = wrap(recyclethread)
    thread(thread)    -- pass the thread to be recycled
    return thread
end

function ThreadCall(func, ...)
    local thread        = newrecyclethread()
    return thread(func, ...)
end

print(
    ThreadCall(function(...) print(coroutine.running(), ...) return 1 end, 1, 2, 3)
)

print(
    ThreadCall(function(...) print(coroutine.running(), ...) return 2 end, 4, 5, 6)
)