transient 0.1.0.2 → 0.1.0.3

raw patch · 4 files changed

+16/−79 lines, 4 filesdep ~base

Dependency ranges changed: base

Files

• Main.hs +5/−4
• src/Transient/Base.hs +9/−5
• src/Transient/EVars.hs +0/−68
• transient.cabal +2/−2

@@ -320,14 +320,15 @@ pubSub=  do
   option "pubs" "an example of publish-subscribe using Event Vars (EVars)"
   v  <- newEVar  :: TransIO (EVar String)
-  v' <- newEVar
+
+  v' <- newEVar 
   subscribe v v' <|> publish v v'
-  liftIO $ putStrLn ".............."
   where
-
+      
   publish v v'= do
     liftIO $ putStrLn "Enter a message to publish"
-    msg <-   input(const True)
+    msg <-  input(const True)
+
     writeEVar v msg
     liftIO $ putStrLn "after writing first EVar\n"
     writeEVar v' $ "second " ++ msg

@@ -62,12 +62,13 @@                                   }
                                   deriving Typeable
 
+
 type P= IORef
 newp= newIORef
 
 
 --(=:) :: P a  -> (a -> a) -> IO()
-(=:) n f= liftIO $ atomicModifyIORef' n $  \v ->  ((f v),())
+(=:) n f= liftIO $ atomicModifyIORef n $  \v ->  ((f v),())
 
 addr x= show $ unsafePerformIO $ do
        st <- makeStableName $! x
@@ -282,8 +283,8 @@ 
 -- * Threads
 
-waitQSemB sem= atomicModifyIORef' sem $ \n -> if n > 0 then(n-1,True) else (n,False)
-signalQSemB sem= atomicModifyIORef' sem  $ \n ->  (n + 1,())
+waitQSemB sem= atomicModifyIORef sem $ \n -> if n > 0 then(n-1,True) else (n,False)
+signalQSemB sem= atomicModifyIORef sem  $ \n ->  (n + 1,())
 
 -- | set the maximun number of threads for a procedure. It is useful for the
 threads :: Int -> TransientIO a -> TransientIO a
@@ -475,7 +476,7 @@ 
          if dofork
             then  do
-                 th <- forkFinally proc $ \me -> do
+                 th <- forkFinally1 proc $ \me -> do
                          case me of -- !> "THREAD ENDED" of
                           Left  e -> do
                            when (fromException e /= Just ThreadKilled)$ liftIO $ print e
@@ -505,7 +506,10 @@ 
             else proc  -- !> "NO THREAD"
 
-
+forkFinally1 :: IO a -> (Either SomeException a -> IO ()) -> IO ThreadId
+forkFinally1 action and_then =
+  mask $ \restore ->
+    forkIO $ try (restore action) >>= and_then
 
 free th env= do
   if isNothing $ parent env

@@ -1,68 +0,0 @@-{-# LANGUAGE DeriveDataTypeable #-}
-module Transient.EVars where
-
-import Transient.Base
-import qualified Data.Map as M
-import Data.Typeable
-
-import Control.Concurrent
-import Control.Applicative
-import Data.IORef
-import Control.Monad.IO.Class
-import Control.Monad.State
-
-newtype EVars= EVars  (IORef (M.Map Int [EventF]))  deriving Typeable
-
-data EVar a= EVar Int (IORef (Maybe a))
-
--- * Evars are event vars. `writeEVar` trigger the execution of all the continuations associated to the  `readEVar` of this variable
--- (the code that is after them) as  stack: the most recent reads are executed first.
---
--- It is like the publish-subscribe pattern but without inversion of control, since a readEVar can be inserted at any place in the
--- Transient flow.
---
--- EVars are created upstream and can be used to communicate two sub-threads of the monad. Following the Transient philosophy they 
--- do not block his own thread if used with alternative operators, unlike the IORefs and TVars. And unlike STM vars, that are composable,
--- they wait for their respective events, while TVars execute the whole expression when any variable is modified.
--- 
--- The execution continues after the writeEVar when all subscribers have been executed.
---
--- see https://www.fpcomplete.com/user/agocorona/publish-subscribe-variables-transient-effects-v
--- 
-
-
-newEVar ::  TransientIO (EVar a)
-newEVar  = Transient $ do
-   EVars ref <- getSessionData `onNothing`  do
-                            ref <- liftIO $ newIORef M.empty
-                            setSData $ EVars ref
-                            return  (EVars ref) 
-   id <- genNewId
-   ref <- liftIO $ newIORef Nothing
-   return . Just $ EVar id ref
-
-readEVar :: EVar a -> TransIO a
-readEVar (EVar id ref1)= Transient $ do 
-   mr <- liftIO $ readIORef ref1
-   case mr of
-     Just _ -> return mr
-     Nothing -> do
-         cont <- getCont
-         EVars ref <- getSessionData `onNothing` error "No Events context"
-         map <- liftIO $ readIORef ref
-         let Just conts=  M.lookup  id map <|> Just []
-         liftIO $ writeIORef ref $  M.insert id (cont:conts) map
-         return Nothing
-         
-writeEVar (EVar id ref1) x= Transient $ do
-   EVars ref <- getSessionData `onNothing`  error "No Events context" 
-   liftIO $ writeIORef ref1 $ Just x
-   map <- liftIO $ readIORef ref
-   let Just conts= M.lookup id map <|> Just []
-   mapM runCont conts 
-   liftIO $ writeIORef ref1 Nothing
-   return $ Just ()
- 
-
-
-

@@ -2,7 +2,7 @@ synopsis: A monad for extensible effects and primitives for unrestricted composability of applications
 homepage: http://www.fpcomplete.com/user/agocorona
 bug-reports: https://github.com/agocorona/transient/issues
-version: 0.1.0.2
+version: 0.1.0.3
 cabal-version: >=1.10
 build-type: Simple
 license: GPL-3
@@ -20,7 +20,7 @@                    directory -any, filepath -any, stm -any, HTTP -any, network -any,
                    transformers -any, process -any, network-info -any
 
-    exposed-modules: Transient.Indeterminism Transient.Base Transient.EVars
+    exposed-modules: Transient.Indeterminism Transient.Base
                      Transient.Backtrack Transient.Move Transient.Logged
     exposed: True
     buildable: True