[Haskell-cafe] network-conduit failing to close sockets

[Felipe Almeida Lessa]

2012/2/1 Ertugrul Söylemez <es at ertes.de>:
> Hello there,
>
> I have tried to implement a simple echo server using the network-conduit
> library version 0.2.1.  This is the code:
>
>    module Main where
>
>    import Data.Conduit
>    import Data.Conduit.Network
>
>    main :: IO ()
>    main = runTCPServer (ServerSettings 4000 Nothing) ($$)
>
> It works, but at some point it dies with too many open files, even
> though I never open two connections simultaneously:
>
>    % ./echo-server
>    echo-server: accept: resource exhausted (Too many open files)
>
> Apparently it fails to close the sockets properly.  This is the client
> side code I have used for testing in GHCi:
>
>    > :m Network Control.Monad System.IO
>    > replicateM_ 512 (connectTo "127.0.0.1" (PortNumber 4000) >>=
>                       hClose)
>
> I'm running the action once, then wait a few seconds to give the server
> a chance to close the handles.  Then I run it again, causing the server
> program to die with the above mentioned error message.
>
> Am I doing something wrong or is this a bug in network-conduit?

This part of network-conduit is very new so bugs are expected.
Michael, it seems that runTCPServer [1] should setup a release key on
the ResourceT in order to close the socket after app finishes, right?

Cheers! =)

[1] http://hackage.haskell.org/packages/archive/network-conduit/0.2.1/doc/html/src/Data-Conduit-Network.html#runTCPServer

-- 
Felipe.