http-test.lua

local client = require 'http.client'
local fiber = require 'fiber'
local yaml = require 'yaml'

local uris = {
    'http://httpbin.org/get?1',
    'http://httpbin.org/get?2',
    'http://httpbin.org/get?3',
    'http://httpbin.org/get?4',
    'http://httpbin.org/get?5',
}

local max_parallel = 3

local results = fiber.channel()
local active = 0
local fibers = {}
local n = 0
for i=1, max_parallel do
    fiber.create(function()
        while true do
            n = n + 1
            local uri = uris[n]
            print("fetch ", uri)
            if not uri then break end

            active = active + 1
            print("Start request in", i, n, "active", active)
            local res = client.get(uri)
            print("End request in", i, res.status, "active", active)
            results:put(res)
            active = active - 1

            if active == 0 then
                results:close()
            end
        end
    end)
end

local res = {}
repeat
    local result = results:get()
    print("Got from results", result and result.status)
    table.insert(res, result)
until not result

-- here we have all results in res

os.exit()