loading classes

local tAPIsLoading = {}
function newClass(path)
    local _sPath = path
    local sName = fs.getName( _sPath )
    local n = 1
    while tAPIsLoading[sName] == true and n < 300 do
        n = n + 1
        sleep(0)
    end
    if n < 300 then
        tAPIsLoading[sName] = true

        local tEnv = {}
        setmetatable( tEnv, { __index = _G } )
        local fnAPI, err = loadfile( _sPath )
        if fnAPI then
            setfenv( fnAPI, tEnv )
            fnAPI()
        else
            printError( err )
            tAPIsLoading[sName] = nil
            return nil
        end

        local tAPI = {}
        for k,v in pairs( tEnv ) do
            tAPI[k] =  v
        end

        tAPIsLoading[sName] = nil
        return tAPI
    else
        return nil
    end
end