46228c2 · distributed-process

git.iko.soy/distributed-process

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Fix for DP-110. The NC does not block anymore on network operations.

46228c2Facundo Domínguez11 years ago

distributed-process.cabal+1

compare with master

unifiedsplit

@@ -69,6 +69,7 @@ Library

69 Control.Distributed.Process.Internal.StrictContainerAccessors,

70 Control.Distributed.Process.Internal.StrictList,

71 Control.Distributed.Process.Internal.StrictMVar,

72+ Control.Distributed.Process.Internal.ThreadPool,

72 Control.Distributed.Process.Internal.Types,

73 Control.Distributed.Process.Internal.Types,

73 Control.Distributed.Process.Internal.WeakTQueue,

74 Control.Distributed.Process.Internal.WeakTQueue,

74 Control.Distributed.Process.Management,

75 Control.Distributed.Process.Management,

src/Control/Distributed/Process/Internal/ThreadPool.hsnew file+78

@@ -0,0 +1,78 @@

1+-- | An implementation of a pool of threads

2+--

3+{-# LANGUAGE RecursiveDo #-}

4+module Control.Distributed.Process.Internal.ThreadPool

5+ ( newThreadPool

6+ , submitTask

7+ , lookupWorker

8+ , ThreadPool

9+ ) where

10+

11+import Control.Exception

12+import Control.Monad

13+import Data.IORef

14+import qualified Data.Map as Map

15+

16+

17+-- | A pool of worker threads that execute tasks.

18+--

19+-- Each worker thread is named with a key @k@. Tasks are submitted to a

20+-- specific worker using its key. While the worker is busy the tasks are queued.

21+-- When there are no more queued tasks the worker ceases to exist.

22+--

23+-- The next time a task is submitted the worker will be respawned.

24+--

25+newtype ThreadPool k w = ThreadPool (IORef (Map.Map k (Maybe (IO ()), w)))

26+

27+-- Each worker has an entry in the map with a closure that contains all

28+-- queued actions fot it.

29+--

30+-- No entry in the map is kept for defunct workers.

31+

32+-- | Creates a pool with no workers.

33+newThreadPool :: IO (ThreadPool k w)

34+newThreadPool = fmap ThreadPool $ newIORef Map.empty

35+

36+-- | @submitTask pool fork k task@ submits a task for the worker @k@.

37+--

38+-- If worker @k@ is busy, then the task is queued until the worker is available.

39+--

40+-- If worker @k@ does not exist, then the given @fork@ operation is used to

41+-- spawn the worker. @fork@ returns whatever information is deemed useful for

42+-- later retrieval via 'lookupWorker'.

43+--

44+submitTask :: Ord k

45+ => ThreadPool k w

46+ -> (IO () -> IO w)

47+ -> k -> IO () -> IO ()

48+submitTask (ThreadPool mapRef) fork k task = mdo

49+ m' <- join $ atomicModifyIORef mapRef $ \m ->

50+ case Map.lookup k m of

51+ -- There is no worker for this key, create one.

52+ Nothing -> ( m'

53+ , do w <- fork $ flip onException terminateWorker $ do

54+ task

55+ continue

56+ return $ Map.insert k (Nothing, w) m

57+ )

58+ -- Queue an action for the existing worker.

59+ Just (mp, w) ->

60+ (m', return $ Map.insert k (Just $ maybe task (>> task) mp, w) m)

61+ return ()

62+ where

63+ continue = join $ atomicModifyIORef mapRef $ \m ->

64+ case Map.lookup k m of

65+ -- Execute the next batch of queued actions.

66+ Just (Just p, w) -> (Map.insert k (Nothing, w) m, p >> continue)

67+ -- There are no more queued actions. Terminate the worker.

68+ Just (Nothing, w) -> (Map.delete k m, return ())

69+ -- The worker key was removed already (?)

70+ Nothing -> (m, return ())

71+ -- Remove the worker key regardless of whether there are more queued

72+ -- actions.

73+ terminateWorker = atomicModifyIORef mapRef $ \m -> (Map.delete k m, ())

74+

75+-- | Looks up a worker with the given key.

76+lookupWorker :: Ord k => ThreadPool k w -> k -> IO (Maybe w)

77+lookupWorker (ThreadPool mapRef) k =

78+ atomicModifyIORef mapRef $ \m -> (m, fmap snd $ Map.lookup k m)

src/Control/Distributed/Process/Internal/Types.hs+3

@@ -137,6 +137,7 @@ import Control.Distributed.Process.Internal.StrictMVar

137 , modifyMVar

138 , modifyMVar_

139 )

140+import Control.Distributed.Process.Internal.ThreadPool

140import Control.Distributed.Process.Internal.WeakTQueue (TQueue)

141import Control.Distributed.Process.Internal.WeakTQueue (TQueue)

141import Control.Distributed.Static (RemoteTable, Closure)

142import Control.Distributed.Static (RemoteTable, Closure)

142import qualified Control.Distributed.Process.Internal.StrictContainerAccessors as DAC (mapMaybe)

143import qualified Control.Distributed.Process.Internal.StrictContainerAccessors as DAC (mapMaybe)

@@ -266,6 +267,8 @@ data LocalNode = LocalNode

266 -- | Runtime lookup table for supporting closures

267 -- | Runtime lookup table for supporting closures

267 -- TODO: this should be part of the CH state, not the local endpoint state

268 -- TODO: this should be part of the CH state, not the local endpoint state

268 , remoteTable :: !RemoteTable

269 , remoteTable :: !RemoteTable

270+ -- The pool of threads and queues to send messages

271+ , localSendPool :: ThreadPool NodeId ThreadId

269 }

272 }

270

273

271data ImplicitReconnect = WithImplicitReconnect | NoImplicitReconnect

274data ImplicitReconnect = WithImplicitReconnect | NoImplicitReconnect

src/Control/Distributed/Process/Node.hs+24−7

@@ -83,6 +83,12 @@ import Control.Distributed.Process.Internal.StrictMVar

83 , putMVar

84 , takeMVar

85 )

86+import Control.Distributed.Process.Internal.ThreadPool

87+ ( newThreadPool

88+ , submitTask

89+ , lookupWorker

90+ , ThreadPool

91+ )

86import Control.Concurrent.Chan (newChan, writeChan, readChan)

92import Control.Concurrent.Chan (newChan, writeChan, readChan)

87import qualified Control.Concurrent.MVar as MVar (newEmptyMVar, takeMVar)

93import qualified Control.Concurrent.MVar as MVar (newEmptyMVar, takeMVar)

88import Control.Concurrent.STM

94import Control.Concurrent.STM

@@ -249,12 +255,14 @@ createBareLocalNode endPoint rtable = do

249 , _localConnections = Map.empty

255 , _localConnections = Map.empty

250 }

256 }

251 ctrlChan <- newChan

257 ctrlChan <- newChan

258+ sendPool <- newThreadPool

252 let node = LocalNode { localNodeId = NodeId $ NT.address endPoint

259 let node = LocalNode { localNodeId = NodeId $ NT.address endPoint

253 , localEndPoint = endPoint

260 , localEndPoint = endPoint

254 , localState = state

261 , localState = state

255 , localCtrlChan = ctrlChan

262 , localCtrlChan = ctrlChan

256 , localEventBus = MxEventBusInitialising

263 , localEventBus = MxEventBusInitialising

257 , remoteTable = rtable

264 , remoteTable = rtable

265+ , localSendPool = sendPool

258 }

266 }

259 tracedNode <- startMxAgent node

267 tracedNode <- startMxAgent node

260

268

@@ -580,6 +588,8 @@ handleIncomingMessages node = go initConnectionState

580 , ctrlMsgSignal = Died nid DiedDisconnect

588 , ctrlMsgSignal = Died nid DiedDisconnect

581 }

589 }

582 let notLost k = not (k `Set.member` (st ^. incomingFrom theirAddr))

590 let notLost k = not (k `Set.member` (st ^. incomingFrom theirAddr))

591+ liftIO $ lookupWorker (localSendPool node) (NodeId theirAddr)

592+ >>= maybe (return ()) killThread

583 closeImplicitReconnections node nid

593 closeImplicitReconnections node nid

584 go ( (incomingFrom theirAddr ^= Set.empty)

594 go ( (incomingFrom theirAddr ^= Set.empty)

585 . (incoming ^: Map.filterWithKey (const . notLost))

595 . (incoming ^: Map.filterWithKey (const . notLost))

@@ -634,6 +644,12 @@ data NCState = NCState

634 , _registeredOnNodes :: !(Map ProcessId [(NodeId,Int)])

644 , _registeredOnNodes :: !(Map ProcessId [(NodeId,Int)])

635 }

645 }

636

646

647+submitSendPool :: LocalNode -> NodeId -> IO () -> IO ()

648+submitSendPool node nid task = submitTask (localSendPool node) fork nid task

649+ where

650+ fork io =

651+ forkIO $ io `Exception.catch` \(NodeClosedException _) -> return ()

652+

637newtype NC a = NC { unNC :: StateT NCState (ReaderT LocalNode IO) a }

653newtype NC a = NC { unNC :: StateT NCState (ReaderT LocalNode IO) a }

638 deriving ( Applicative

654 deriving ( Applicative

639 , Functor

655 , Functor

@@ -644,11 +660,12 @@ newtype NC a = NC { unNC :: StateT NCState (ReaderT LocalNode IO) a }

644 )

660 )

645

661

646initNCState :: NCState

662initNCState :: NCState

647−initNCState = NCState { _links = Map.empty

663+initNCState = NCState

664+ { _links = Map.empty

648− , _monitors = Map.empty

665+ , _monitors = Map.empty

649− , _registeredHere = Map.empty

666+ , _registeredHere = Map.empty

650− , _registeredOnNodes = Map.empty

667+ , _registeredOnNodes = Map.empty

651− }

668+ }

652

669

653-- | Thrown in response to the user invoking 'kill' (see Primitives.hs). This

670-- | Thrown in response to the user invoking 'kill' (see Primitives.hs). This

654-- type is deliberately not exported so it cannot be caught explicitly.

671-- type is deliberately not exported so it cannot be caught explicitly.

@@ -666,7 +683,7 @@ ncSendToProcess pid msg = do

666 node <- ask

683 node <- ask

667 if processNodeId pid == localNodeId node

684 if processNodeId pid == localNodeId node

668 then ncEffectLocalSend node pid msg

685 then ncEffectLocalSend node pid msg

669− else liftIO $ sendBinary node

686+ else liftIO $ submitSendPool node (processNodeId pid) $ sendBinary node

670 (NodeIdentifier $ localNodeId node)

687 (NodeIdentifier $ localNodeId node)

671 (NodeIdentifier $ processNodeId pid)

688 (NodeIdentifier $ processNodeId pid)

672 WithImplicitReconnect

689 WithImplicitReconnect

@@ -679,7 +696,7 @@ ncSendToNode to msg = do

679 node <- ask

696 node <- ask

680 liftIO $ if to == localNodeId node

697 liftIO $ if to == localNodeId node

681 then writeChan (localCtrlChan node) $! msg

698 then writeChan (localCtrlChan node) $! msg

682− else sendBinary node

699+ else submitSendPool node to $ sendBinary node

683 (NodeIdentifier $ localNodeId node)

700 (NodeIdentifier $ localNodeId node)

684 (NodeIdentifier to)

701 (NodeIdentifier to)

685 WithImplicitReconnect

702 WithImplicitReconnect