Nonblocking TCP Sockets/Http Requests?

Hello,

I'm in the process of creating an addon that needs to have some form of internet communication to function. I have all of the communication done, but am getting a blocked UI whenever waiting for a response. 

I am new to LUA and was just wondering if there was any form of asynchronous callbacks / background thread that can be done.

Here's what the code looks like now..

function printItemPrices(itemID)
	 local tcp = assert(socket.tcp())
     tcp:connect(host, port)
	 tcp:send("GET /AHPrice/GetNamePriceForID.aspx?id=" .. itemID .. " HTTP/1.0\r\n\r\n")
	
	 lastLine = ''
	
	 local loopCount = 0
	
	 --This is where i am freezing
	 while true do
		 local s, status, partial = tcp:receive()
		 lastLine = s or partial
		 if status == "closed" or status == "Socket is not connected" then break end
	 end
	 tcp:close()
	 tcp:shutdown("both")
	 if (string.match(lastLine, ",")) then
		  --handle response
	 end
	
 end

Thanks!

tcp:settimeout(1)

repeat
    local result, error = tcp:connect()
    -- check the error here to see if the error was a timeout or something else

    -- this passes control back to the scheduler so that other code can run,
    -- without this you will still block the UI thread.
    coroutine.yield()
until result == 1

There's a really good chapter in the Lua book on coroutines which has this problem as an example. https://www.lua.org/pil/9.4.html

Based on what Iryoku wrote, it sounds like socket.select won't work as it's intended, but the chapter is worth reading anyway.

you must remember that(if i recall correctly) windowers lua is 5.1 while the latest version is 5.3 so do be careful of what you look up

The online version of the Lua book was written for Lua 5.0. The coroutines chapter is still relevant, except for the use of the table.getn function. I was not clear: the function socket.select works as it should, but is an inexpensive way of blocking a program, which is not what ScaryMonster wants to do. If he needs a quick rundown of coroutines, that chapter is a good source.

Thanks all! I am just now able to get back to this and will report back which solution works best for me.