socket with coroutine

socket_with_coroutine.lua

local socket = require('socket')

local threads = {}

local function receive(conn)
  conn:settimeout(0)
	local s, status = conn:receive(1024)
	if status == 'timeout' then
		coroutine.yield(conn)
	end
	return s, status
end

function echo(host, port, msg)
	local c = assert(socket.connect(host, port))
	local count = 0
	c:send( msg )
	while true do
		local s, status = receive(c)
		count = count + #s
		if status == 'closed' then
			break
		else
			print(s)
		end
	end
end


local function get(host, port, msg)
	local co = coroutine.create( function ()
		echo(host, port, msg)
	end)
	table.insert(threads, co)
end

local function dispatcher()
	while true do
		local n = #(threads)
		if n == 0 then break end
		local connections = {}
		for i = 1, n do
			local status, res = coroutine.resume(threads[i])
			if not res then
				table.remove(threads, i)
				break
			else -- timeout
				table.insert(connections, res)
			end
		end
		if #connections == n then
			socket.select(connections)
		end
	end
end


local host = "192.168.0.9"
local port = 3245
get(host, port, "hello, this the 1st message")
get(host, port, "hello again, this the 2nd message")

dispatcher()      -- main loop