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{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE CPP #-}
module Network.QueryResponse.TCP where
#ifdef THREAD_DEBUG
import Control.Concurrent.Lifted.Instrument
#else
import Control.Concurrent.Lifted
import GHC.Conc (labelThread)
#endif
import Control.Arrow
import Control.Concurrent.STM
import Control.Monad
import Data.ByteString (ByteString,hPut)
import Data.Function
import Data.Hashable
import Data.Maybe
import Data.Ord
import Data.Time.Clock.POSIX
import Data.Word
import Data.String (IsString(..))
import Network.BSD
import Network.Socket
import System.Timeout
import System.IO
import System.IO.Error
import DebugTag
import DebugUtil
import DPut
import Connection.Tcp (socketFamily)
import qualified Data.MinMaxPSQ as MM
import Network.QueryResponse
data TCPSession st
= PendingTCPSession
| TCPSession
{ tcpHandle :: Handle
, tcpState :: st
, tcpThread :: ThreadId
}
newtype TCPAddress = TCPAddress SockAddr
deriving (Eq,Ord,Show)
instance Hashable TCPAddress where
hashWithSalt salt (TCPAddress x) = case x of
SockAddrInet port addr -> hashWithSalt salt (fromIntegral port :: Word16,addr)
SockAddrInet6 port b c d -> hashWithSalt salt (fromIntegral port :: Word16,b,c,d)
_ -> 0
data TCPCache st = TCPCache
{ lru :: TVar (MM.MinMaxPSQ' TCPAddress (Down POSIXTime) (TCPSession st))
, tcpMax :: Int
}
-- This is a suitable /st/ parameter to 'TCPCache'
data SessionProtocol x y = SessionProtocol
{ streamGoodbye :: IO () -- ^ "Goodbye" protocol upon termination.
, streamDecode :: IO (Maybe x) -- ^ Parse inbound messages.
, streamEncode :: y -> IO () -- ^ Serialize outbound messages.
}
data StreamHandshake addr x y = StreamHandshake
{ streamHello :: addr -> Handle -> IO (SessionProtocol x y) -- ^ "Hello" protocol upon fresh connection.
, streamAddr :: addr -> SockAddr
}
killSession :: TCPSession st -> IO ()
killSession PendingTCPSession = return ()
killSession TCPSession{tcpThread=t} = killThread t
showStat :: IsString p => TCPSession st -> p
showStat r = case r of PendingTCPSession -> "pending."
TCPSession {} -> "established."
tcp_timeout :: Int
tcp_timeout = 10000000
acquireConnection :: MVar (Maybe (Either a (x, addr)))
-> TCPCache (SessionProtocol x y)
-> StreamHandshake addr x y
-> addr
-> Bool
-> IO (Maybe (y -> IO ()))
acquireConnection mvar tcpcache stream addr bDoCon = do
now <- getPOSIXTime
-- dput XTCP $ "acquireConnection 0 " ++ show (streamAddr stream addr)
entry <- atomically $ do
c <- readTVar (lru tcpcache)
let v = MM.lookup' (TCPAddress $ streamAddr stream addr) c
case v of
Nothing | bDoCon -> writeTVar (lru tcpcache)
$ MM.insert' (TCPAddress $ streamAddr stream addr) PendingTCPSession (Down now) c
| otherwise -> return ()
Just (tm, v) -> modifyTVar' (lru tcpcache) $ MM.insert' (TCPAddress $ streamAddr stream addr) v (Down now)
return v
-- dput XTCP $ "acquireConnection 1 " ++ show (streamAddr stream addr, fmap (second showStat) entry)
case entry of
Nothing -> fmap join $ forM (guard bDoCon) $ \() -> do
proto <- getProtocolNumber "tcp"
mh <- catchIOError (do h <- timeout tcp_timeout $ do
sock <- socket (socketFamily $ streamAddr stream addr) Stream proto
connect sock (streamAddr stream addr) `catchIOError` (\e -> close sock)
h <- socketToHandle sock ReadWriteMode
hSetBuffering h NoBuffering
return h
return h)
$ \e -> return Nothing
when (isNothing mh)
$ atomically $ modifyTVar' (lru tcpcache)
$ MM.delete (TCPAddress $ streamAddr stream addr)
ret <- fmap join $ forM mh $ \h -> do
mst <- catchIOError (Just <$> streamHello stream addr h)
(\e -> return Nothing)
case mst of
Nothing -> do
atomically $ modifyTVar' (lru tcpcache) $ MM.delete (TCPAddress $ streamAddr stream addr)
return Nothing
Just st -> do
dput XTCP $ "TCP Connected! " ++ show (streamAddr stream addr)
signal <- newTVarIO False
let showAddr a = show (streamAddr stream a)
rthread <- forkLabeled ("tcp:"++showAddr addr) $ do
atomically (readTVar signal >>= check)
fix $ \loop -> do
x <- streamDecode st
dput XTCP $ "TCP streamDecode " ++ show (streamAddr stream addr) ++ " --> " ++ maybe "Nothing" (const "got") x
case x of
Just u -> do
m <- timeout tcp_timeout $ putMVar mvar $ Just $ Right (u, addr)
when (isNothing m) $ do
dput XTCP $ "TCP "++show (streamAddr stream addr) ++ " dropped packet."
tryTakeMVar mvar
return ()
loop
Nothing -> do
dput XTCP $ "TCP disconnected: " ++ show (streamAddr stream addr)
do atomically $ modifyTVar' (lru tcpcache)
$ MM.delete (TCPAddress $ streamAddr stream addr)
c <- atomically $ readTVar (lru tcpcache)
now <- getPOSIXTime
forM_ (zip [1..] $ MM.toList c) $ \(i,MM.Binding (TCPAddress addr) r (Down tm)) -> do
dput XTCP $ unwords [show i ++ ".", "Still connected:", show addr, show (now - tm), showStat r]
mreport <- timeout tcp_timeout $ threadReport False -- XXX: Paranoid timeout
case mreport of
Just treport -> dput XTCP treport
Nothing -> dput XTCP "TCP ERROR: threadReport timed out."
hClose h
let v = TCPSession
{ tcpHandle = h
, tcpState = st
, tcpThread = rthread
}
t <- getPOSIXTime
retires <- atomically $ do
c <- readTVar (lru tcpcache)
let (rs,c') = MM.takeView (tcpMax tcpcache)
$ MM.insert' (TCPAddress $ streamAddr stream addr) v (Down t) c
writeTVar (lru tcpcache) c'
writeTVar signal True
return rs
forM_ retires $ \(MM.Binding (TCPAddress k) r _) -> void $ forkLabeled ("tcp-close:"++show k) $ do
dput XTCP $ "TCP dropped: " ++ show k
killSession r
case r of TCPSession {tcpState=st,tcpHandle=h} -> do
streamGoodbye st
hClose h
_ -> return ()
return $ Just $ streamEncode st
when (isNothing ret) $ do
atomically $ modifyTVar' (lru tcpcache) $ MM.delete (TCPAddress $ streamAddr stream addr)
return ret
Just (tm, PendingTCPSession)
| not bDoCon -> return Nothing
| otherwise -> fmap join $ timeout tcp_timeout $ atomically $ do
c <- readTVar (lru tcpcache)
let v = MM.lookup' (TCPAddress $ streamAddr stream addr) c
case v of
Just (_,TCPSession{tcpState=st}) -> return $ Just $ streamEncode st
Nothing -> return Nothing
_ -> retry
Just (tm, v@TCPSession {tcpState=st}) -> return $ Just $ streamEncode st
closeAll :: TCPCache (SessionProtocol x y) -> StreamHandshake addr x y -> IO ()
closeAll tcpcache stream = do
dput XTCP "TCP.closeAll called."
cache <- atomically $ swapTVar (lru tcpcache) MM.empty
forM_ (MM.toList cache) $ \(MM.Binding (TCPAddress addr) r tm) -> do
killSession r
case r of TCPSession{tcpState=st,tcpHandle=h} -> streamGoodbye st >> hClose h
_ -> return ()
-- Use a cache of TCP client connections for sending (and receiving) packets.
-- The boolean value prepended to the message allows the sender to specify
-- whether or not a new connection will be initiated if neccessary. If 'False'
-- is passed, then the packet will be sent only if there already exists a
-- connection.
tcpTransport :: Int -- ^ maximum number of TCP links to maintain.
-> StreamHandshake addr x y
-> IO (TCPCache (SessionProtocol x y), TransportA err addr x (Bool,y))
tcpTransport maxcon stream = do
msgvar <- newEmptyMVar
tcpcache <- atomically $ (`TCPCache` maxcon) <$> newTVar (MM.empty)
return $ (,) tcpcache Transport
{ awaitMessage = \f -> takeMVar msgvar >>= \x -> f x `catchIOError` (\e -> dput XTCP ("TCP transport stopped. " ++ show e) >> f Nothing)
, sendMessage = \addr (bDoCon,y) -> do
void . forkLabeled "tcp-send" $ do
msock <- acquireConnection msgvar tcpcache stream addr bDoCon
mapM_ ($ y) msock
`catchIOError` \e -> dput XTCP $ "TCP-send: " ++ show e
, closeTransport = closeAll tcpcache stream >> putMVar msgvar Nothing
}
|
