{-# LANGUAGE TypeSynonymInstances, MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances, UndecidableInstances #-} {- -------------------------------------------------------------------------------- -- -- Copyright (C) 2008 Martin Sulzmann, Edmund Lam. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Isaac Jones nor the names of other contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -} module MultiSetRewrite.StoreRepresentation where -- An actual representation of the store import IO import Data.IORef import Control.Concurrent import Control.Concurrent.STM import System.IO.Unsafe import Data.List import qualified MultiSetRewrite.ConcurrentList as L import qualified MultiSetRewrite.ConcurrentBag as B import MultiSetRewrite.Base import MultiSetRewrite.RuleSyntax import MultiSetRewrite.RuleCompiler ---------------------------------------- -- primitives for hashing messages type HashIdx = Int data HashOp msg = HashOp { numberOfTables :: HashIdx , hashMsg :: msg -> HashIdx } -- store representation data Store msg = Store { msgTable :: [B.Bag (InternalMsg msg)], hashOp :: HashOp msg } type Location msg = IORef (L.List (InternalMsg msg)) -- we need the location (pointer ref) of the message in internal form -- for quick access (eg logical delete) -- internal details of the store distribution = 7 -- we assume that store is -- a bag of linked lists -- NOTE: we could assume a different distribution for -- the individual messages -- The run-time distribution is currently monolithic -- We simply take the threadId 'mod' distribution instance (EMatch msg, Eq msg, Show msg) => RuleCompiler (Store msg) msg (Location msg) HashIdx (B.Iterator (InternalMsg msg)) where --atomicVerifyAndDeleteCnt :: Store msg -> Code_RHS a -- -> [(Check (Location msg),IO (Maybe (Code_RHS a)))] -> IO (Maybe (Code_RHS a)) -- we don't need the store here, but otherwise the method's type is ambiguous atomicVerifyAndDeleteCnt _ body checks = let -- reverify that all verify fields are True reVerify [] = return True reVerify (n:ns) = do let n' = case n of Verify n -> n VerifyAndDelete n -> n b <- readTVar n' if b then reVerify ns else return False -- set verify fields to False -- only those which actually need to be deleted (the simp heads) setFalse [] = return () setFalse ((Verify _):ns) = setFalse ns setFalse ((VerifyAndDelete n):ns) = do writeTVar n False setFalse ns -- accumulates all deletes (only simp heads) accDeletes [] = return () accDeletes ((Verify _,_):ns) = accDeletes ns accDeletes ((VerifyAndDelete msg,_):ns) = do node <- readIORef msg writeIORef msg (L.DelNode {L.verify = L.verify node, L.next = L.next node}) accDeletes ns -- in case of failure, pick the continuation of the node -- which failed (the earliest from left to right) checkNode (msg,cnt) = do node <- readIORef msg b <- atomically $ readTVar (L.verify node) if b then return Nothing else return (Just cnt) pickCont [] = error "pickCont: impossible, there must be a failed node" pickCont (c:rest) = do let (msg,cnt) = case c of (Verify msg, cnt) -> (msg, cnt) (VerifyAndDelete msg, cnt) -> (msg, cnt) res <- checkNode (msg,cnt) case res of Nothing -> pickCont rest Just cnt -> cnt in do ns <- -- extract the to be verified fields mapM (\ (m,_) -> case m of Verify msg -> do node <- readIORef msg return (Verify (L.verify node)) VerifyAndDelete msg -> do node <- readIORef msg return (VerifyAndDelete (L.verify node)) ) checks -- perform atomic re-verification -- check that nodes are still there, and if successful -- set their flags to False -- we continue by actually deleting the nodes followed by -- executing the body -- otherwise, we abort and pick the continuation of the first -- node which couldn't be reverified next <- atomically $ (do r <- reVerify ns if r then do setFalse ns return (return (Just (do {accDeletes checks; body}))) else retry ) `orElse` return (pickCont checks) next --getIndex :: Store msg -> msg -> IO HashIdx getIndex act m = return ((hashMsg (hashOp act)) m) --initSearch :: Store msg -> HashIdx -> IO (B.Iterator (InternalMsg msg)) initSearch act idx = do let bag = (msgTable act) !! (idx -1) t_id <- myThreadId let no = threadIdToInt t_id let bagEntryIdx = no `mod` distribution it <- B.newIterator bag bagEntryIdx return it -- we use the iterator to scan through the queue --nextMsg :: Store msg -> (B.Iterator (InternalMsg msg)) -> IO (Maybe (Location msg)) nextMsg act curIterator = do res <- B.iterateBag curIterator return res --extractMsg :: Location msg -> IO (Maybe (InternalMsg msg)) extractMsg ptr = do node <- readIORef ptr case node of L.Node {} -> return (Just (L.val node)) _ -> return Nothing printMsg _ ptr = do do m <- readIORef ptr return (show (L.val m)) printReachMsg _ it = error "TODO" -- HACK!!!!! -- FIX -- length "ThreadId " = 9 threadIdToInt x = read (drop 9 (show x)) :: Int newStore :: (EMatch msg, Eq msg, Show msg) => HashOp msg -> IO (Store msg) newStore hash = do let n = numberOfTables hash mt <- mapM (\ _ -> B.newBag (distribution-1)) [1..n] -- distribution starts with 0 !!! return (Store {msgTable = mt, hashOp = hash}) compileRulePattern :: (EMatch msg, Eq msg, Show msg) => [([MatchTask msg], Code_RHS ())] -> [CompClause (Store msg) (Location msg) ()] compileRulePattern prog = let build [] = [] build ((tasks,body):rest) = (compileCnt body tasks) ++ (build rest) in build prog -- adds the message in external format and -- returns (added) message in internal format -- this is the format we need to perform the search addMsg :: (EMatch msg, Eq msg, Show msg) => (Store msg) -> msg -> IO (Location msg) addMsg (Store {msgTable = mt, hashOp = hash}) msg = do new_tag <- newTag let new_msg = InternalMsg {message = msg, msg_tag = new_tag} let hashIdx = (hashMsg hash) msg let bag = mt !! (hashIdx - 1) t_id <- myThreadId let no = threadIdToInt t_id let bagEntryIdx = no `mod` distribution loc <- B.addToBag bag bagEntryIdx new_msg return loc executeRules :: (EMatch msg, Eq msg, Show msg) => Store msg -> Location msg -> [CompClause (Store msg) (Location msg) ()] -> IO (Maybe (Code_RHS ())) executeRules store active_msg prog = select store active_msg prog