Hello, all! Can somebody please explain, what is the best way of using CURL with several threads? I wrote simple client, which tries to authenticate against HTTP server. With running this client, it starts to eat memory insanely (and I know this code is far, far away of even being close to be called good one ) ========================================================================================= module NTLMTest where import System.IO import Network.Curl import Control.Concurrent import Control.Concurrent.Chan type ResponseState = Either Bool String type RespChannel = Chan ResponseState delay = 500 * 1000 isResponseOk :: String -> CurlResponse -> ResponseState isResponseOk username response = case respCurlCode response of CurlOK -> Left True _ -> Right $ username ++ " => " ++ respStatusLine response ++ " :: " ++ (show . respStatus $ response) checkAuthResponse :: RespChannel -> String -> String -> String -> IO () checkAuthResponse state user passwd url = do response <- curlGetResponse_ url [CurlHttpAuth [HttpAuthAny], CurlUserPwd $ user ++ ":" ++ passwd] writeChan state $ isResponseOk user response threadDelay $ delay runHTTPThread :: RespChannel -> (String,String) -> IO () runHTTPThread state (user,passwd) = checkAuthResponse state user passwd url url = "http://localhost:8082/" credentials = map (\i -> ("user" ++ show i,"123456")) [1..21] main = withCurlDo $ do chan <- newChan :: IO (RespChannel) mapM_ ( \cred -> forkIO $ runHTTPThread chan cred ) credentials dumpChannel chan $ length credentials main where dumpChannel :: RespChannel -> Int -> IO () dumpChannel _chan n | n == 0 = return () | otherwise = do state <- readChan _chan case state of (Left _) -> return () --putStrLn "OK" (Right err) -> putStrLn err dumpChannel _chan $ n-1 ========================================================================================= If I get rid of forkIO - it stops at 40-50 megabytes and don't raise memory usage anymore. Also, I noticed that (either because of buffering, or may be something else) results are appearing on console much slower than if I simply use "wget" with looping in shell script. JMeter also reports awesome speed, so server can authenticate tens of concurrent users per second (thus it's not server or connection bandwidth issue). Hopefully, someone could help me in overcoming my ignorance :) -- Eugene N Dzhurinsky