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-rw-r--r--2019/23.hs221
1 files changed, 130 insertions, 91 deletions
diff --git a/2019/23.hs b/2019/23.hs
index 054b53a..77baccf 100644
--- a/2019/23.hs
+++ b/2019/23.hs
@@ -1,111 +1,150 @@
--- Part 2: 17281 is too high
-
-{-# LANGUAGE TupleSections #-}
module Main where
-import Data.Foldable (toList)
-import qualified Data.Map.Strict as Map
-import Data.Maybe
-import qualified Data.Sequence as S
+import qualified Data.Array as A
+import Control.Concurrent
+import Control.Concurrent.STM
+import Control.Monad
+import qualified Data.IntSet as IntSet
-import Debug.Trace
+-- import Debug.Trace
import Input
import IntCode
-safeLast :: [a] -> Maybe a
-safeLast [] = Nothing
-safeLast [x] = Just x
-safeLast (_:xs) = safeLast xs
-
-data Computer
- = Computer { cCont :: Continuation
- , cQueue :: S.Seq Integer }
-
-queueAdd :: Message -> Computer -> Computer
-queueAdd (Message _ x y) comp = comp { cQueue = cQueue comp S.|> x S.|> y }
-
-queueAdds :: [Message] -> Computer -> Computer
-queueAdds msgs comp = foldr queueAdd comp msgs
-
-data Message = Message Int Integer Integer
- deriving (Show)
+data Message = Message Int Integer Integer deriving (Show)
+data CompIn = CompRecvMsg Message | IdlePoll | Quit deriving (Show)
+data CompOut = CompSendMsg Int Message | Idle Int deriving (Show)
+data NatIn = NatRecvMsg Message | NetworkIdle deriving (Show)
+data NatOut = NatSendMsg Message | Answer Integer deriving (Show)
parseMessages :: [Integer] -> [Message]
parseMessages [] = []
parseMessages (to:x:y:rest) = Message (fromIntegral to) x y : parseMessages rest
parseMessages _ = error "Non-3-blocked output"
-runComputer :: Computer -> ([Message], Computer)
-runComputer (Computer cont queue) =
- let queue' = if null queue then [-1] else toList queue
- (cont', output) = either id ((undefined,) . snd) (runContinue cont queue')
- in (parseMessages output, Computer cont' mempty)
-
-step :: Map.Map Int Computer -> Int -> ([Message], Map.Map Int Computer)
-step network cid =
- let (msgs, computer') = runComputer (network Map.! cid)
- network' = foldr (\msg@(Message to _ _) -> Map.adjust (queueAdd msg) to)
- (Map.insert cid computer' network)
- msgs
- in (msgs, network')
-
-runUntilNAT :: Map.Map Int Computer -> Int -> Message
-runUntilNAT network cid =
- let (msgs, network') = step network cid
- in case [msg | msg@(Message 255 _ _) <- msgs] of
- msg:_ -> msg
- [] -> runUntilNAT network' ((cid + 1) `mod` 50)
-
--- NAT (last recv'd msg (with to=0)) (last Y value sent to 0) (number of idle computers)
-data NAT = NAT (Maybe Message) (Maybe Integer) Int
-
-initNAT :: NAT
-initNAT = NAT Nothing Nothing 0
-
-natNotify :: NAT -> Int -> [Message] -> S.Seq Integer -> NAT
-natNotify (NAT origBin zeroY idle) from msgs queue =
- let recv = [msg | msg@(Message 255 _ _) <- msgs]
- newBin = safeLast (maybeToList origBin ++ [Message 0 x y | Message _ x y <- recv])
- idle' = if null msgs && S.null queue then idle + 1 else 0
- in -- (if not (null recv) then trace ("NAT received " ++ show recv ++ " from " ++ show from) else id) $
- (if idle' >= 50 then trace "idle!" else id) $
- NAT newBin zeroY idle'
-
-natPoll :: NAT -> Either Integer ([Message], NAT)
--- natPoll (NAT _ _ idle) | traceShow ("poll", idle) False = undefined
-natPoll (NAT (Just bin) zeroY idle) | idle >= 50 =
- case (bin, zeroY) of
- (Message 0 _ y, Just y') | y == y' -> Left y
- (Message 0 _ y, _) -> Right ([bin], NAT Nothing (Just y) 0)
- (_, _) -> Right ([bin], NAT Nothing zeroY 0)
-natPoll nat@(NAT _ _ _) = Right ([], nat)
-
-traceMessages :: [(Int, Message)] -> a -> a
-traceMessages = flip (foldr (\(from, Message to x y) -> trace ("Message " ++ show from ++ " -> " ++ show to ++ ": [" ++ show x ++ "," ++ show y ++ "]")))
-
-runWithNAT :: NAT -> Map.Map Int Computer -> Int -> Integer
-runWithNAT nat network cid =
- -- trace ("runWithNAT cid=" ++ show cid) $
- let (msgs, network') = step network cid
- nat' = natNotify nat cid msgs (cQueue (network Map.! cid))
- in trace ("step " ++ show cid ++ " in: " ++ show (cQueue (network Map.! cid)) ++ ", out: " ++ show msgs) $
- traceMessages (map (cid,) msgs) $
- case natPoll nat' of
- Left res -> res
- Right (natout, nat'') ->
- -- (if not (null natout) then trace ("NAT sent " ++ show natout) else id) $
- traceMessages (map (-1,) natout) $
- runWithNAT nat'' (Map.adjust (queueAdds natout) 0 network') ((cid + 1) `mod` 50)
+chanFunnel :: (a -> c) -> TChan a -> (b -> c) -> TChan b -> IO (ThreadId, TChan c)
+chanFunnel f1 in1Chan f2 in2Chan = do
+ outChan <- atomically $ newTChan
+ th1 <- forkIO $ forever $ atomically (readTChan in1Chan) >>= atomically . writeTChan outChan . f1
+ th2 <- forkIO $ forever $ atomically (readTChan in2Chan) >>= atomically . writeTChan outChan . f2
+ th <- forkFinally (forever yield) (const $ killThread th1 >> killThread th2)
+ return (th, outChan)
+
+threadComputer :: Int -> [Integer] -> TChan CompIn -> TChan CompOut -> IO ()
+threadComputer myid nicProgram inChan outChan =
+ case runInterruptible nicProgram [fromIntegral myid] of
+ Left (cont, output) -> sendMsgs output >> loop cont
+ Right _ -> undefined
+ where
+ loop :: Continuation -> IO ()
+ loop cont = do
+ incoming <- atomically $ readTChan inChan
+ case incoming of
+ CompRecvMsg (Message _ x y) -> do
+ (cont', output) <-
+ case runContinue cont [x, y] of
+ Left pair -> return pair
+ Right (_, out) -> do
+ putStrLn $ "!! Computer " ++ show myid ++ ": intcode terminated! (in recvmsg)"
+ return (undefined, out)
+ sendMsgs output
+ loop cont'
+ IdlePoll -> do
+ (cont', output) <-
+ case runContinue cont [-1] of
+ Left pair -> return pair
+ Right (_, out) -> do
+ putStrLn $ "!! Computer " ++ show myid ++ ": intcode terminated! (in idlepoll)"
+ return (undefined, out)
+ if null output
+ then atomically $ writeTChan outChan (Idle myid)
+ else sendMsgs output
+ loop cont'
+ Quit ->
+ return ()
+
+ sendMsgs :: [Integer] -> IO ()
+ sendMsgs output = atomically $ sequence_ [writeTChan outChan (CompSendMsg myid msg)
+ | msg <- parseMessages output]
+
+threadNAT :: TChan NatIn -> TChan NatOut -> TVar (Maybe Integer) -> IO ()
+threadNAT inChan outChan part1 = loop Nothing Nothing
+ where
+ loop :: Maybe Message -> Maybe Integer -> IO ()
+ loop msave mlastY = do
+ incoming <- atomically $ readTChan inChan
+ case incoming of
+ NatRecvMsg msg@(Message _ _ y) -> do
+ -- Set 'part1' to contain the first y value ever sent to the NAT
+ atomically $ modifyTVar' part1 (\m -> case m of
+ Just _ -> m
+ Nothing -> Just y)
+ loop (Just msg) mlastY
+ NetworkIdle -> do
+ -- traceM "NAT: network idle received"
+ case (msave, mlastY) of
+ (Just (Message _ _ y), Just y') | y == y' ->
+ atomically $ writeTChan outChan (Answer y)
+ (Just (Message _ x y), _) -> do
+ atomically $ writeTChan outChan (NatSendMsg (Message 0 x y))
+ loop Nothing (Just y)
+ (Nothing, _) -> do
+ putStrLn "!! NAT deadlock: network idle but no message queued in NAT!"
+ atomically $ writeTChan outChan (Answer (-1))
+
+arbitrator :: TChan (Either NatOut CompOut) -> A.Array Int (TChan CompIn) -> TChan NatIn -> IO Integer
+arbitrator inChan compChans natChan = loop Nothing
+ where
+ loop :: Maybe IntSet.IntSet -> IO Integer
+ loop midle = do
+ yield
+ incoming <- atomically $ tryReadTChan inChan
+ case incoming of
+ Just (Left (NatSendMsg msg)) ->
+ sendMsg (-1) msg >> loop Nothing
+ Just (Left (Answer y)) -> do
+ sequence_ [atomically $ writeTChan chan Quit | chan <- A.elems compChans]
+ return y
+ Just (Right (CompSendMsg from msg)) ->
+ sendMsg from msg >> loop Nothing
+ Just (Right (Idle from)) ->
+ case midle of
+ Just idle ->
+ let idle' = IntSet.insert from idle
+ in if IntSet.size idle' == 50
+ then atomically (writeTChan natChan NetworkIdle) >> loop Nothing
+ else loop (Just idle')
+ Nothing ->
+ loop midle
+ Nothing -> do
+ -- traceM "ar: Sending deadlock poll"
+ sequence_ [atomically $ writeTChan chan IdlePoll | chan <- A.elems compChans]
+ loop (Just IntSet.empty)
+
+ sendMsg :: Int -> Message -> IO ()
+ -- sendMsg from msg | trace ("ar: send " ++ show from ++ " -> " ++ show msg) False = undefined
+ sendMsg _ msg@(Message 255 _ _) = atomically $ writeTChan natChan (NatRecvMsg msg)
+ sendMsg _ msg@(Message to _ _) = atomically $ writeTChan (compChans A.! to) (CompRecvMsg msg)
main :: IO ()
main = do
nicProgram <- parse . head <$> getInput 23
- let initComputer i = Computer (initialContinuation nicProgram) (S.singleton (fromIntegral i))
- initNetwork = Map.fromList [(i, initComputer i) | i <- [0..49]]
- Message _ _ y = runUntilNAT initNetwork 0
- print y
+ part1 <- atomically $ newTVar Nothing
+
+ compChans <- atomically $ A.listArray (0, 49) <$> sequence (replicate 50 newTChan)
+ compOutChan <- atomically $ newTChan
+ natChan <- atomically $ newTChan
+ natOutChan <- atomically $ newTChan
+ (_, collectChan) <- chanFunnel Left natOutChan Right compOutChan
+
+ _ <- sequence [forkIO (threadComputer i nicProgram (compChans A.! i) compOutChan)
+ | i <- [0..49]]
- print (runWithNAT initNAT initNetwork 0)
+ _ <- forkIO (threadNAT natChan natOutChan part1)
+
+ y <- arbitrator collectChan compChans natChan
+ Just part1y <- atomically (readTVar part1)
+ print part1y
+ print y