Hello!
On Mon, Jan 31, 2000 at 09:11:14PM +0100, Wojciech Moczydlowski, Jr wrote:
> [...]
> main = do
> socket <- listenOn (PortNumber (mkPortNumber 6665))
> (handle, hn) <- accept socket
> putStrLn hn" - it's just supposed to say who called and exit.
> Nevertheless, when I try to run it again, it says:
> "Fail: resource busy
> Action: bindSocket
> Reason: Address already in use".
I believe, bindSocket is called from listenOn:
listenOn :: PortID -- Port Identifier
-> IO Socket -- Connected Socket
listenOn (Service serv) = [...]
listenOn (PortNumber port) = do
proto <- getProtocolNumber "tcp"
sock <- socket AF_INET Stream proto
bindSocket sock (SockAddrInet port iNADDR_ANY)
listen sock maxListenQueue
return sock
[...]
There should be a call to
SocketPrim.setSocketOption sock SocketPrim.ReuseAddr 1
before bindSocket.
*wink* to the GHC team :-)
There's an analogous idiom in C/C++ which is almost never wrong to
use, and often forgotten/not thought of in the beginning of writing
a network server.
> [...]
Regards, Hannah.
