+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
-----------------------------------------------------------------------------
-- |
-- Module : Control.Concurrent
import GHC.Conc ( ThreadId(..), myThreadId, killThread, yield,
threadDelay, forkIO, childHandler )
import qualified GHC.Conc
-import GHC.TopHandler ( reportStackOverflow, reportError )
-import GHC.IOBase ( IO(..) )
-import GHC.IOBase ( unsafeInterleaveIO )
-import GHC.IOBase ( newIORef, readIORef, writeIORef )
+import GHC.IO ( IO(..), unsafeInterleaveIO )
+import GHC.IORef ( newIORef, readIORef, writeIORef )
import GHC.Base
import System.Posix.Types ( Fd )
#ifdef mingw32_HOST_OS
import Foreign.C
import System.IO
-import GHC.Handle
#endif
#endif
foreign import ccall "forkOS_entry" forkOS_entry_reimported
:: StablePtr (IO ()) -> IO ()
+forkOS_entry :: StablePtr (IO ()) -> IO ()
forkOS_entry stableAction = do
action <- deRefStablePtr stableAction
action
foreign import ccall forkOS_createThread
:: StablePtr (IO ()) -> IO CInt
+failNonThreaded :: IO a
failNonThreaded = fail $ "RTS doesn't support multiple OS threads "
++"(use ghc -threaded when linking)"
if bound
then do
mv <- newEmptyMVar
- forkIO (Exception.try action >>= putMVar mv)
- takeMVar mv >>= \either -> case either of
+ b <- blocked
+ _ <- block $ forkIO $
+ Exception.try (if b then action else unblock action) >>=
+ putMVar mv
+ takeMVar mv >>= \ei -> case ei of
Left exception -> Exception.throw (exception :: SomeException)
Right result -> return result
else action
-- 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"
withThread :: IO a -> IO a
withThread io = do
m <- newEmptyMVar
- forkIO $ try io >>= putMVar m
+ _ <- block $ forkIO $ try io >>= putMVar m
x <- takeMVar m
case x of
Right a -> return a
waitFd :: Fd -> CInt -> IO ()
waitFd fd write = do
- throwErrnoIfMinus1 "fdReady" $
+ throwErrnoIfMinus1_ "fdReady" $
fdReady (fromIntegral fd) write (fromIntegral iNFINITE) 0
- return ()
-iNFINITE = 0xFFFFFFFF :: CInt -- urgh
+iNFINITE :: CInt
+iNFINITE = 0xFFFFFFFF -- urgh
foreign import ccall safe "fdReady"
fdReady :: CInt -> CInt -> CInt -> CInt -> IO CInt
The "System.IO" library manages multiplexing in its own way. On
Windows systems it uses @safe@ foreign calls to ensure that
threads doing I\/O operations don't block the whole runtime,
- whereas on Unix systems all the currently blocked I\/O reqwests
+ whereas on Unix systems all the currently blocked I\/O requests
are managed by a single thread (the /IO manager thread/) using
@select@.