Hello, communion people!
I have a problem and ask for an advice.
I'm dealing with sockets on *Linux* platform (Network.Socket). The problem
is that I can't fully control timeout for (connect :: Socket -> SockAddr ->
IO ()) operation.
On my system the timeout is - 3 seconds - I want to be able to change that
in run-time. Well I managed to find out how to make it LESS THAN 3 seconds -
using System.Timeout. But how to make timeout bigger (for example 9 seconds)
is a mystery.
(Notice: in order to achieve 9 seconds timeout - just repeating *connect* 3
times won't be effective for long-slow-way-connections. So it's not a
solution.)
The source code of Network.Socket.connect, taken from darcs:
---------------------------------
-- Connecting a socket
--
-- Make a connection to an already opened socket on a given machine
-- and port. assumes that we have already called createSocket,
-- otherwise it will fail.
--
-- This is the dual to $bindSocket$. The {\em server} process will
-- usually bind to a port number, the {\em client} will then connect
-- to the same port number. Port numbers of user applications are
-- normally agreed in advance, otherwise we must rely on some meta
-- protocol for telling the other side what port number we have been
-- allocated.
connect :: Socket -- Unconnected Socket
-> SockAddr -- Socket address stuff
-> IO ()
connect sock@(MkSocket s _family _stype _protocol socketStatus) addr = do
modifyMVar_ socketStatus $ \currentStatus -> do
if currentStatus /= NotConnected
then
ioError (userError ("connect: can't peform connect on socket in status "
++
show currentStatus))
else do
withSockAddr addr $ \p_addr sz -> do
let connectLoop = do
r <- c_connect s p_addr (fromIntegral sz)
if r == -1
then do
rc <- c_getLastError
case rc of
10093 -> do -- WSANOTINITIALISED
withSocketsDo (return ())
r <- c_connect s p_addr (fromIntegral sz)
if r == -1
then (c_getLastError >>= throwSocketError "connect")
else return r
_ -> throwSocketError "connect" rc
else return r
connectBlocked = do
#if !defined(__HUGS__)
threadWaitWrite (fromIntegral s)
#endif
err <- getSocketOption sock SoError
if (err == 0)
then return 0
else do ioError (errnoToIOError "connect"
(Errno (fromIntegral err))
Nothing Nothing)
connectLoop
return Connected
---------------------------------
I know that controlling timeout is somehow connected to select(2) (I'm
currently investigating this matter...), but it's not in the Network or
Network.Socket libs (but in the libs that they FFI with).
Hope I won't have to rewrite these low-level functions.... >__<
Could anybody, please share some experience on how to adjust timeout for
*connect*?
Thanks in advance,
Best regards,
Belka
--
View this message in context:
http://www.nabble.com/controlling-timeout-for-Network.Socket.connect---how--tp22139581p22139581.html
Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
