Use onException for exception cleanup, and mask async exceptions

diff --git a/System/Event/Thread.hs b/System/Event/Thread.hs
index 4c2170d..72343d9 100644 (file)
--- a/System/Event/Thread.hs
+++ b/System/Event/Thread.hs
@@ -10,7 +10,6 @@ module System.Event.Thread
     , registerDelay
     ) where
 
     , registerDelay
     ) where
 

-import Control.Exception (SomeException, catch, throw)

 import Data.IORef (IORef, newIORef, readIORef, writeIORef)
 import Data.Maybe (Maybe(..))
 import Foreign.C.Error (eBADF, errnoToIOError)
 import Data.IORef (IORef, newIORef, readIORef, writeIORef)
 import Data.Maybe (Maybe(..))
 import Foreign.C.Error (eBADF, errnoToIOError)

@@ -19,6 +18,7 @@ import GHC.Base
 import GHC.Conc.Sync (TVar, ThreadId, ThreadStatus(..), atomically, forkIO,
                       labelThread, modifyMVar_, newTVar, sharedCAF,
                       threadStatus, writeTVar)
 import GHC.Conc.Sync (TVar, ThreadId, ThreadStatus(..), atomically, forkIO,
                       labelThread, modifyMVar_, newTVar, sharedCAF,
                       threadStatus, writeTVar)

+import GHC.IO (mask_, onException)

 import GHC.IO.Exception (ioError)
 import GHC.MVar (MVar, newEmptyMVar, newMVar, putMVar, takeMVar)
 import GHC.Real (fromIntegral)
 import GHC.IO.Exception (ioError)
 import GHC.MVar (MVar, newEmptyMVar, newMVar, putMVar, takeMVar)
 import GHC.Real (fromIntegral)

@@ -36,12 +36,11 @@ import System.Posix.Types (Fd)
 -- when the delay has expired, but the thread will never continue to
 -- run /earlier/ than specified.
 threadDelay :: Int -> IO ()
 -- when the delay has expired, but the thread will never continue to
 -- run /earlier/ than specified.
 threadDelay :: Int -> IO ()

-threadDelay usecs = do
+threadDelay usecs = mask_ $ do

   Just mgr <- readIORef eventManager
   m <- newEmptyMVar
   reg <- registerTimeout mgr usecs (putMVar m ())
   Just mgr <- readIORef eventManager
   m <- newEmptyMVar
   reg <- registerTimeout mgr usecs (putMVar m ())

-  takeMVar m `catch` \(e::SomeException) ->
-    M.unregisterTimeout mgr reg >> throw e
+  takeMVar m `onException` M.unregisterTimeout mgr reg

 
 -- | Set the value of returned TVar to True after a given number of
 -- microseconds. The caveats associated with threadDelay also apply.
 
 -- | Set the value of returned TVar to True after a given number of
 -- microseconds. The caveats associated with threadDelay also apply.

@@ -86,12 +85,11 @@ closeFdWith close fd = do
   M.closeFd mgr close fd
 
 threadWait :: Event -> Fd -> IO ()
   M.closeFd mgr close fd
 
 threadWait :: Event -> Fd -> IO ()

-threadWait evt fd = do
+threadWait evt fd = mask_ $ do

   m <- newEmptyMVar
   Just mgr <- readIORef eventManager
   reg <- registerFd mgr (\reg e -> unregisterFd_ mgr reg >> putMVar m e) fd evt
   m <- newEmptyMVar
   Just mgr <- readIORef eventManager
   reg <- registerFd mgr (\reg e -> unregisterFd_ mgr reg >> putMVar m e) fd evt

-  evt' <- takeMVar m `catch` \(e::SomeException) ->
-            unregisterFd_ mgr reg >> throw e
+  evt' <- takeMVar m `onException` unregisterFd_ mgr reg

   if evt' `eventIs` evtClose
     then ioError $ errnoToIOError "threadWait" eBADF Nothing Nothing
     else return ()
   if evt' `eventIs` evtClose
     then ioError $ errnoToIOError "threadWait" eBADF Nothing Nothing
     else return ()