lua coroutine 异步转同步

local Thread = require("llthreads2.ex")
local socket = require("socket")
local http = require("socket.http")
 
taskList = {}
 
function startHttpRequestTask(url, callback)
  print("startHttpRequest", url)
  local task = Thread.new(function(url)
    local http = require("socket.http")
    local ltn12 = require("ltn12")
    print("request", url)
    local t = {}
    local respt = http.request{
      url = url,
      sink = ltn12.sink.table(t)
    }
    return table.concat(t)
  end, url)
  task:start()
  taskList[#taskList + 1] = {task = task, callback = callback}
end
 
function AsyncHttpRequest(url)
  local coro = coroutine.running()
  print("load :", url)
  startHttpRequestTask(url, function(result) coroutine.resume(coro, result) end)
end
 
function update()
  if #taskList > 0 then
    for idx = #taskList, 1, -1 do
      local taskInfo = taskList[idx]
 
      local task = taskInfo.task
      if not task:alive() then
        local ok, ret = task:join()
        local callback = taskInfo.callback
        print("task done")
        callback(ret)
        table.remove(taskList, idx)
      end
    end
    return true
  else
    print("all task complete")
    return false
  end
end
 
function cofunction()
  print("start")
  local dataList = {"http://www.baidu.com", "http://www.python.com", "http://www.sina.cn"}
  for idx, data in ipairs(dataList) do
    local param = data
    print("loadAsync:", param)
    local res = coroutine.yield(AsyncHttpRequest(param))
    print("task result:", string.sub(res, 1, 100) .. "...")
  end
end
 
co = coroutine.create(cofunction)
print(coroutine.resume(co))
 
function loop()
  while update() do
    socket.sleep(1.0 / 60)
    --print("update")
  end
end
 
loop()