git.iko.soy/distributed-process
on 56e5305 help sign in
4 files changed+100−2
since splitsnapshots
unifiedsplit
distributed-process.cabal+1 src/Control/Distributed/Process/Internal/ThreadPool.hs+78 src/Control/Distributed/Process/Internal/Types.hs+3 src/Control/Distributed/Process/Node.hs+18−2
distributed-process.cabal+1
@@ -68,6 +68,7 @@ Library
6868 Control.Distributed.Process.Internal.StrictContainerAccessors,
6969 Control.Distributed.Process.Internal.StrictList,
7070 Control.Distributed.Process.Internal.StrictMVar,
71+ Control.Distributed.Process.Internal.ThreadPool,
7172 Control.Distributed.Process.Internal.Types,
7273 Control.Distributed.Process.Internal.WeakTQueue,
7374 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
137137 , modifyMVar
138138 , modifyMVar_
139139 )
140+import Control.Distributed.Process.Internal.ThreadPool
140141import Control.Distributed.Process.Internal.WeakTQueue (TQueue)
141142import Control.Distributed.Static (RemoteTable, Closure)
142143import qualified Control.Distributed.Process.Internal.StrictContainerAccessors as DAC (mapMaybe)
@@ -267,6 +268,8 @@ data LocalNode = LocalNode
267268 -- | Runtime lookup table for supporting closures
268269 -- TODO: this should be part of the CH state, not the local endpoint state
269270 , remoteTable :: !RemoteTable
271+ -- The pool of threads and queues to send messages
272+ , localSendPool :: ThreadPool NodeId ThreadId
270273 }
271274
272275data ImplicitReconnect = WithImplicitReconnect | NoImplicitReconnect
src/Control/Distributed/Process/Node.hs+18−2
@@ -91,6 +91,12 @@ import Control.Distributed.Process.Internal.StrictMVar
9191 , putMVar
9292 , takeMVar
9393 )
94+import Control.Distributed.Process.Internal.ThreadPool
95+ ( newThreadPool
96+ , submitTask
97+ , lookupWorker
98+ , ThreadPool
99+ )
94100import Control.Concurrent.Chan (newChan, writeChan, readChan)
95101import qualified Control.Concurrent.MVar as MVar (newEmptyMVar, takeMVar)
96102import Control.Concurrent.STM
@@ -264,12 +270,14 @@ createBareLocalNode endPoint rtable = do
264270 , _localConnections = Map.empty
265271 }
266272 ctrlChan <- newChan
273+ sendPool <- newThreadPool
267274 let node = LocalNode { localNodeId = NodeId $ NT.address endPoint
268275 , localEndPoint = endPoint
269276 , localState = state
270277 , localCtrlChan = ctrlChan
271278 , localEventBus = MxEventBusInitialising
272279 , remoteTable = rtable
280+ , localSendPool = sendPool
273281 }
274282 tracedNode <- startMxAgent node
275283
@@ -613,6 +621,8 @@ handleIncomingMessages node = go initConnectionState
613621 , ctrlMsgSignal = Died nid DiedDisconnect
614622 }
615623 let notLost k = not (k `Set.member` (st ^. incomingFrom theirAddr))
624+ liftIO $ lookupWorker (localSendPool node) (NodeId theirAddr)
625+ >>= maybe (return ()) killThread
616626 closeImplicitReconnections node nid
617627 go ( (incomingFrom theirAddr ^= Set.empty)
618628 . (incoming ^: Map.filterWithKey (const . notLost))
@@ -669,6 +679,12 @@ data NCState = NCState
669679 , _registeredOnNodes :: !(Map ProcessId [(NodeId,Int)])
670680 }
671681
682+submitSendPool :: LocalNode -> NodeId -> IO () -> IO ()
683+submitSendPool node nid task = submitTask (localSendPool node) fork nid task
684+ where
685+ fork io =
686+ forkIO $ io `Exception.catch` \(NodeClosedException _) -> return ()
687+
672688newtype NC a = NC { unNC :: StateT NCState (ReaderT LocalNode IO) a }
673689 deriving ( Applicative
674690 , Functor
@@ -704,7 +720,7 @@ ncSendToProcessAndTrace shouldTrace pid msg = do
704720 node <- ask
705721 if processNodeId pid == localNodeId node
706722 then ncEffectLocalSendAndTrace shouldTrace node pid msg
707− else liftIO $ sendBinary node
723+ else liftIO $ submitSendPool node (processNodeId pid) $ sendBinary node
708724 (NodeIdentifier $ localNodeId node)
709725 (NodeIdentifier $ processNodeId pid)
710726 WithImplicitReconnect
@@ -717,7 +733,7 @@ ncSendToNode to msg = do
717733 node <- ask
718734 liftIO $ if to == localNodeId node
719735 then writeChan (localCtrlChan node) $! msg
720− else sendBinary node
736+ else submitSendPool node to $ sendBinary node
721737 (NodeIdentifier $ localNodeId node)
722738 (NodeIdentifier to)
723739 WithImplicitReconnect