add numSparks :: IO Int (#4167)

[ghc-base.git] / Control / Concurrent.hs

diff --git a/Control/Concurrent.hs b/Control/Concurrent.hs
index 2d9cf57..6122a10 100644 (file)
--- a/Control/Concurrent.hs
+++ b/Control/Concurrent.hs
@@ -28,6 +28,7 @@ module Control.Concurrent (
 
         forkIO,
 #ifdef __GLASGOW_HASKELL__
+        forkIOUnmasked,
         killThread,
         throwTo,
 #endif
@@ -98,9 +99,9 @@ import Control.Exception.Base as Exception
 #ifdef __GLASGOW_HASKELL__
 import GHC.Exception
 import GHC.Conc         ( ThreadId(..), myThreadId, killThread, yield,
-                          threadDelay, forkIO, childHandler )
+                          threadDelay, forkIO, forkIOUnmasked, childHandler )
 import qualified GHC.Conc
-import GHC.IO           ( IO(..), unsafeInterleaveIO )
+import GHC.IO           ( IO(..), unsafeInterleaveIO, unsafeUnmask )
 import GHC.IORef        ( newIORef, readIORef, writeIORef )
 import GHC.Base
 
@@ -357,13 +358,15 @@ failNonThreaded = fail $ "RTS doesn't support multiple OS threads "
 forkOS action0
     | rtsSupportsBoundThreads = do
         mv <- newEmptyMVar
-        b <- Exception.blocked
+        b <- Exception.getMaskingState
         let
-            -- async exceptions are blocked in the child if they are blocked
+            -- async exceptions are masked in the child if they are masked
             -- in the parent, as for forkIO (see #1048). forkOS_createThread
-            -- creates a thread with exceptions blocked by default.
-            action1 | b = action0
-                    | otherwise = unblock action0
+            -- creates a thread with exceptions masked by default.
+            action1 = case b of
+                        Unmasked -> unsafeUnmask action0
+                        MaskedInterruptible -> action0
+                        MaskedUninterruptible -> uninterruptibleMask_ action0
 
             action_plus = Exception.catch action1 childHandler
 
@@ -430,7 +433,10 @@ runInUnboundThread action = do
     if bound
         then do
             mv <- newEmptyMVar
-            forkIO (Exception.try action >>= putMVar mv)
+            b <- blocked
+            _ <- mask $ \restore -> forkIO $
+              Exception.try (if b then action else restore action) >>=
+              putMVar mv
             takeMVar mv >>= \ei -> case ei of
                 Left exception -> Exception.throw (exception :: SomeException)
                 Right result -> return result
@@ -453,7 +459,8 @@ threadWaitRead fd
   -- and this only works with -threaded.
   | threaded  = withThread (waitFd fd 0)
   | otherwise = case fd of
-                  0 -> do hWaitForInput stdin (-1); return ()
+                  0 -> do _ <- hWaitForInput stdin (-1)
+                          return ()
                         -- hWaitForInput does work properly, but we can only
                         -- do this for stdin since we know its FD.
                   _ -> error "threadWaitRead requires -threaded on Windows, or use System.IO.hWaitForInput"
@@ -478,7 +485,7 @@ foreign import ccall unsafe "rtsSupportsBoundThreads" threaded :: Bool
 withThread :: IO a -> IO a
 withThread io = do
   m <- newEmptyMVar
-  forkIO $ try io >>= putMVar m
+  _ <- mask_ $ forkIO $ try io >>= putMVar m
   x <- takeMVar m
   case x of
     Right a -> return a
@@ -486,9 +493,8 @@ withThread io = do
 
 waitFd :: Fd -> CInt -> IO ()
 waitFd fd write = do
-   throwErrnoIfMinus1 "fdReady" $
+   throwErrnoIfMinus1_ "fdReady" $
         fdReady (fromIntegral fd) write (fromIntegral iNFINITE) 0
-   return ()
 
 iNFINITE :: CInt
 iNFINITE = 0xFFFFFFFF -- urgh