Re: multithread.lua - file from book PiL 5.1

[edxxgardo@...]

Thanks Roberto. I'll give it a try.


Sent from my iPhone

On 10/09/2012, at 20:36, Roberto Ierusalimschy <roberto@inf.puc-rio.br> wrote:

>> I just started to learn this very nice language. Even though I checked
>> around, I did not find any that can solve my problem.
>> I took the file in the subject from the Lua web site:
>> 
>> http://www.inf.puc-rio.br/~roberto/book/code/multithread.lua.html
> 
> Note that this file is quite old; it is for Lua 5.0 and for the first
> edition of the Lua book. Lua socket changed a while since then. The
> attached version should work OK with Lua 5.1 and the current version
> of Lua socket.
> 
> -- Roberto
> 
> --------------------------------------------------------
> local socket = require "socket"
> 
> 
> function receive (connection)
>  connection:settimeout(0)      -- do not block
>  local s, status, partial = connection:receive(2^10)
>  if status == "timeout" then
>    coroutine.yield(connection)
>  end
>  return s or partial, status
> end
> 
> function download (host, file)
>  local c = assert(socket.connect(host, 80))
>  local count = 0    -- counts number of bytes read
>  c:send("GET " .. file .. " HTTP/1.0\r\n\r\n")
>  while true do
>    local s, status = receive(c)
>    count = count + #s
>    if status == "closed" then break end
>  end
>  c:close()
>  print(file, count)
> end
> 
> 
> 
> threads = {}    -- list of all live threads
> 
> function get (host, file)
>  -- create coroutine
>  local co = coroutine.create(function ()
>    download(host, file)
>  end)
>  -- insert it in the list
>  table.insert(threads, co)
> end
> 
> function dispatch ()
>  local i = 1
>  local timedout = {}
>  while true do
>    if threads[i] == nil then   -- no more threads?
>      if threads[1] == nil then break end
>      i = 1                     -- restart the loop
>      timedout = {}
>    end
>    local status, res = coroutine.resume(threads[i])
>    if not res then    -- thread finished its task?
>      table.remove(threads, i)
>    else               -- time out
>      i = i + 1
>      timedout[#timedout + 1] = res
>      if #timedout == #threads then    -- all threads blocked?
>        socket.select(timedout)
>      end
>    end
>  end
> end
> 
> 
> host = "www.w3.org"
> 
> get(host, "/TR/html401/html40.txt")
> get(host, "/TR/2002/REC-xhtml1-20020801/xhtml1.pdf")
> get(host, "/TR/REC-html32.html")
> get(host, "/TR/2000/REC-DOM-Level-2-Core-20001113/DOM2-Core.txt")
> 
> dispatch()   -- main loop
> 
>