+% ------------------------------------------------------------------------------
+% $Id: PrelHandle.lhs,v 1.63 2000/11/07 10:42:56 simonmar Exp $
%
-% (c) The AQUA Project, Glasgow University, 1994-1996
+% (c) The AQUA Project, Glasgow University, 1994-2000
%
\section[PrelHandle]{Module @PrelHandle@}
\begin{code}
{-# OPTIONS -fno-implicit-prelude -#include "cbits/stgio.h" #-}
-#include "error.h"
-
+#include "cbits/stgerror.h"
+#ifndef __HUGS__ /* Hugs just includes this in PreludeBuiltin so no header needed */
module PrelHandle where
+import PrelArr
import PrelBase
-import PrelArr ( newVar, readVar, writeVar, ByteArray )
+import PrelAddr ( Addr, nullAddr )
+import PrelByteArr ( ByteArray(..) )
import PrelRead ( Read )
import PrelList ( span )
import PrelIOBase
import PrelMaybe ( Maybe(..) )
+import PrelException
+import PrelEnum
+import PrelNum ( toBig, Integer(..), Num(..) )
+import PrelShow
import PrelAddr ( Addr, nullAddr )
-import PrelBounded () -- get at Bounded Int instance.
-import PrelNum ( toInteger )
-import Ix
+import PrelReal ( toInteger )
+import PrelPack ( packString )
+#ifndef __PARALLEL_HASKELL__
+import PrelWeak ( addForeignFinalizer )
+#endif
+
+import PrelConc
#ifndef __PARALLEL_HASKELL__
-import PrelForeign ( ForeignObj, makeForeignObj, writeForeignObj )
+import PrelForeign ( makeForeignObj, mkForeignObj )
#endif
-import PrelConc -- concurrent only
+#endif /* ndef(__HUGS__) */
+
+#ifdef __HUGS__
+#define __CONCURRENT_HASKELL__
+#define stToIO id
+#endif
+
+#ifndef __PARALLEL_HASKELL__
+#define FILE_OBJECT ForeignObj
+#else
+#define FILE_OBJECT Addr
+#endif
\end{code}
+\begin{code}
+mkBuffer__ :: FILE_OBJECT -> Int -> IO ()
+mkBuffer__ fo sz_in_bytes = do
+ chunk <-
+ case sz_in_bytes of
+ 0 -> return nullAddr -- this has the effect of overwriting the pointer to the old buffer.
+ _ -> do
+ chunk <- malloc sz_in_bytes
+ if chunk == nullAddr
+ then ioException (IOError Nothing ResourceExhausted "mkBuffer__" "not enough virtual memory")
+ else return chunk
+ setBuf fo chunk sz_in_bytes
+\end{code}
%*********************************************************
%* *
\begin{code}
{-# INLINE newHandle #-}
-{-# INLINE readHandle #-}
-{-# INLINE writeHandle #-}
-newHandle :: Handle__ -> IO Handle
-readHandle :: Handle -> IO Handle__
-writeHandle :: Handle -> Handle__ -> IO ()
-
-#if defined(__CONCURRENT_HASKELL__)
+newHandle :: Handle__ -> IO Handle
-- Use MVars for concurrent Haskell
newHandle hc = newMVar hc >>= \ h ->
return (Handle h)
+\end{code}
+
+%*********************************************************
+%* *
+\subsection{@withHandle@ operations}
+%* *
+%*********************************************************
-readHandle (Handle h) = takeMVar h
-writeHandle (Handle h) hc = putMVar h hc
+In the concurrent world, handles are locked during use. This is done
+by wrapping an MVar around the handle which acts as a mutex over
+operations on the handle.
-#else
+To avoid races, we use the following bracketing operations. The idea
+is to obtain the lock, do some operation and replace the lock again,
+whether the operation succeeded or failed. We also want to handle the
+case where the thread receives an exception while processing the IO
+operation: in these cases we also want to relinquish the lock.
--- Use ordinary MutableVars for non-concurrent Haskell
-newHandle hc = stToIO (newVar hc >>= \ h ->
- return (Handle h))
+There are three versions of @withHandle@: corresponding to the three
+possible combinations of:
-readHandle (Handle h) = stToIO (readVar h)
-writeHandle (Handle h) hc = stToIO (writeVar h hc)
+ - the operation may side-effect the handle
+ - the operation may return a result
+If the operation generates an error or an exception is raised, the
+orignal handle is always replaced [ this is the case at the moment,
+but we might want to revisit this in the future --SDM ].
+
+\begin{code}
+withHandle :: Handle -> (Handle__ -> IO (Handle__,a)) -> IO a
+{-# INLINE withHandle #-}
+withHandle (Handle h) act =
+ block $ do
+ h_ <- takeMVar h
+ (h',v) <- catchException (act h_) (\ ex -> putMVar h h_ >> throw ex)
+ putMVar h h'
+ return v
+
+withHandle_ :: Handle -> (Handle__ -> IO a) -> IO a
+{-# INLINE withHandle_ #-}
+withHandle_ (Handle h) act =
+ block $ do
+ h_ <- takeMVar h
+ v <- catchException (act h_) (\ ex -> putMVar h h_ >> throw ex)
+ putMVar h h_
+ return v
+
+withHandle__ :: Handle -> (Handle__ -> IO Handle__) -> IO ()
+{-# INLINE withHandle__ #-}
+withHandle__ (Handle h) act =
+ block $ do
+ h_ <- takeMVar h
+ h' <- catchException (act h_) (\ ex -> putMVar h h_ >> throw ex)
+ putMVar h h'
+ return ()
+\end{code}
+
+nullFile__ is only used for closed handles, plugging it in as a null
+file object reference.
+
+\begin{code}
+nullFile__ :: FILE_OBJECT
+nullFile__ =
+#ifndef __PARALLEL_HASKELL__
+ unsafePerformIO (makeForeignObj nullAddr (return ()))
+#else
+ nullAddr
#endif
+
+mkClosedHandle__ :: Handle__
+mkClosedHandle__ =
+ Handle__ { haFO__ = nullFile__,
+ haType__ = ClosedHandle,
+ haBufferMode__ = NoBuffering,
+ haFilePath__ = "closed file",
+ haBuffers__ = []
+ }
+\end{code}
+
+%*********************************************************
+%* *
+\subsection{Handle Finalizers}
+%* *
+%*********************************************************
+
+\begin{code}
+stdHandleFinalizer :: Handle -> IO ()
+stdHandleFinalizer (Handle hdl) = do
+ handle <- takeMVar hdl
+ let fo = haFO__ handle
+ freeStdFileObject fo
+ freeBuffers (haBuffers__ handle)
+
+handleFinalizer :: Handle -> IO ()
+handleFinalizer (Handle hdl) = do
+ handle <- takeMVar hdl
+ let fo = haFO__ handle
+ freeFileObject fo
+ freeBuffers (haBuffers__ handle)
+
+freeBuffers [] = return ()
+freeBuffers (b:bs) = do { free b; freeBuffers bs }
+
+foreign import "libHS_cbits" "freeStdFileObject" unsafe
+ freeStdFileObject :: FILE_OBJECT -> IO ()
+foreign import "libHS_cbits" "freeFileObject" unsafe
+ freeFileObject :: FILE_OBJECT -> IO ()
+foreign import "free" unsafe
+ free :: Addr -> IO ()
\end{code}
%*********************************************************
or output channel respectively. The third manages output to the
standard error channel. These handles are initially open.
+
\begin{code}
stdin, stdout, stderr :: Handle
stdout = unsafePerformIO (do
- rc <- _ccall_ getLock 1 1 -- ConcHask: SAFE, won't block
- case rc of
+ rc <- getLock (1::Int) (1::Int) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __CONCURRENT_HASKELL__
- fo <- _ccall_ openStdFile 1 1{-flush on close-} 0{-writeable-} -- ConcHask: SAFE, won't block
-#else
- fo <- _ccall_ openStdFile 1 (1{-flush on close-} + 128{-don't block on I/O-})
- 0{-writeable-} -- ConcHask: SAFE, won't block
-#endif
+ fo <- openStdFile (1::Int)
+ (0::Int){-writeable-} -- ConcHask: SAFE, won't block
#ifndef __PARALLEL_HASKELL__
- fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
+ fo <- mkForeignObj fo
+ -- I know this is deprecated, but I couldn't bring myself
+ -- to move fixIO into the prelude just so I could use makeForeignObj.
+ -- --SDM
#endif
+
+#ifdef __HUGS__
+/* I dont care what the Haskell report says, in an interactive system,
+ * stdout should be unbuffered by default.
+ */
+ let bm = NoBuffering
+#else
(bm, bf_size) <- getBMode__ fo
mkBuffer__ fo bf_size
- newHandle (Handle__ fo WriteHandle bm "stdout")
- _ -> do ioError <- constructError "stdout"
- newHandle (mkErrorHandle__ ioError)
+#endif
+ hdl <- newHandle (Handle__ fo WriteHandle bm "stdout" [])
+
+#ifndef __PARALLEL_HASKELL__
+ addForeignFinalizer fo (stdHandleFinalizer hdl)
+#endif
+ return hdl
+
+ _ -> constructErrorAndFail "stdout"
)
stdin = unsafePerformIO (do
- rc <- _ccall_ getLock 0 0 -- ConcHask: SAFE, won't block
- case rc of
+ rc <- getLock (0::Int) (0::Int) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __CONCURRENT_HASKELL__
- fo <- _ccall_ openStdFile 0 0{-don't flush on close -} 1{-readable-} -- ConcHask: SAFE, won't block
-#else
- fo <- _ccall_ openStdFile 0 (0{-flush on close-} + 128{-don't block on I/O-})
- 1{-readable-} -- ConcHask: SAFE, won't block
-#endif
+ fo <- openStdFile (0::Int)
+ (1::Int){-readable-} -- ConcHask: SAFE, won't block
#ifndef __PARALLEL_HASKELL__
- fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
+ fo <- mkForeignObj fo
#endif
(bm, bf_size) <- getBMode__ fo
mkBuffer__ fo bf_size
- hdl <- newHandle (Handle__ fo ReadHandle bm "stdin")
+ hdl <- newHandle (Handle__ fo ReadHandle bm "stdin" [])
-- when stdin and stdout are both connected to a terminal, ensure
- -- that anything buffered on stdout is flushed prior to reading from stdin.
- --
+ -- that anything buffered on stdout is flushed prior to reading from
+ -- stdin.
+#ifndef __PARALLEL_HASKELL__
+ addForeignFinalizer fo (stdHandleFinalizer hdl)
+#endif
hConnectTerms stdout hdl
return hdl
- _ -> do ioError <- constructError "stdin"
- newHandle (mkErrorHandle__ ioError)
+ _ -> constructErrorAndFail "stdin"
)
stderr = unsafePerformIO (do
- rc <- _ccall_ getLock 2 1 -- ConcHask: SAFE, won't block
- case rc of
+ rc <- getLock (2::Int) (1::Int){-writeable-} -- ConcHask: SAFE, won't block
+ case (rc::Int) of
0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __CONCURRENT_HASKELL__
- fo <- _ccall_ openStdFile 2 1{-flush on close-} 0{-writeable-} -- ConcHask: SAFE, won't block
-#else
- fo <- _ccall_ openStdFile 2 (1{-flush on close-} + 128{-don't block on I/O-})
- 0{-writeable-} -- ConcHask: SAFE, won't block
-#endif
+ fo <- openStdFile (2::Int)
+ (0::Int){-writeable-} -- ConcHask: SAFE, won't block
#ifndef __PARALLEL_HASKELL__
- fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
+ fo <- mkForeignObj fo
+#endif
+ hdl <- newHandle (Handle__ fo WriteHandle NoBuffering "stderr" [])
+ -- when stderr and stdout are both connected to a terminal, ensure
+ -- that anything buffered on stdout is flushed prior to writing to
+ -- stderr.
+#ifndef __PARALLEL_HASKELL__
+ addForeignFinalizer fo (stdHandleFinalizer hdl)
#endif
- newHandle (Handle__ fo WriteHandle NoBuffering "stderr")
- _ -> do ioError <- constructError "stderr"
- newHandle (mkErrorHandle__ ioError)
+ hConnectTo stdout hdl
+ return hdl
+
+ _ -> constructErrorAndFail "stderr"
)
\end{code}
openFileEx :: FilePath -> IOModeEx -> IO Handle
openFileEx f m = do
- fo <- _ccall_ openFile f file_mode binary flush_on_close -- ConcHask: SAFE, won't block
+ fo <- primOpenFile (packString f)
+ (file_mode::Int)
+ (binary::Int) -- ConcHask: SAFE, won't block
if fo /= nullAddr then do
#ifndef __PARALLEL_HASKELL__
- fo <- makeForeignObj fo ((``&freeFileObject'')::Addr)
+ fo <- mkForeignObj fo
#endif
(bm, bf_size) <- getBMode__ fo
mkBuffer__ fo bf_size
- newHandle (Handle__ fo htype bm f)
+ hdl <- newHandle (Handle__ fo htype bm f [])
+#ifndef __PARALLEL_HASKELL__
+ addForeignFinalizer fo (handleFinalizer hdl)
+#endif
+ return hdl
else do
constructErrorAndFailWithInfo "openFile" f
where
(imo, binary) =
case m of
- BinaryMode imo -> (imo, 1)
- TextMode imo -> (imo, 0)
-
-#ifndef __CONCURRENT_HASKELL__
- file_mode = file_mode'
-#else
- file_mode = file_mode' + 128{-Don't block on I/O-}
-#endif
+ BinaryMode bmo -> (bmo, 1)
+ TextMode tmo -> (tmo, 0)
- (flush_on_close, file_mode') =
+ file_mode =
case imo of
- AppendMode -> (1, 0)
- WriteMode -> (1, 1)
- ReadMode -> (0, 2)
- ReadWriteMode -> (1, 3)
+ AppendMode -> 0
+ WriteMode -> 1
+ ReadMode -> 2
+ ReadWriteMode -> 3
htype = case imo of
ReadMode -> ReadHandle
\begin{code}
hClose :: Handle -> IO ()
-hClose handle = do
- handle_ <- readHandle handle
+hClose handle =
+ withHandle__ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hClose" handle
+ ClosedHandle -> return handle_
_ -> do
- rc <- _ccall_ closeFile (haFO__ handle_) 1{-flush if you can-} -- ConcHask: SAFE, won't block
+ rc <- closeFile (haFO__ handle_)
+ (1::Int){-flush if you can-} -- ConcHask: SAFE, won't block
{- We explicitly close a file object so that we can be told
if there were any errors. Note that after @hClose@
has been performed, the ForeignObj embedded in the Handle
is still lying around in the heap, so care is taken
to avoid closing the file object when the ForeignObj
- is finalised. (we overwrite the file ptr in the underlying
+ is finalized. (we overwrite the file ptr in the underlying
FileObject with a NULL as part of closeFile())
-}
- if rc == 0
- then
- writeHandle handle (handle_{ haType__ = ClosedHandle,
- haFO__ = nullFile__ })
- else do
- writeHandle handle handle_
- constructErrorAndFail "hClose"
+ if (rc /= 0)
+ then constructErrorAndFail "hClose"
+
+ -- free the spare buffers (except the handle buffer)
+ -- associated with this handle.
+ else do freeBuffers (haBuffers__ handle_)
+ return (handle_{ haType__ = ClosedHandle,
+ haBuffers__ = [] })
\end{code}
Computation $hClose hdl$ makes handle {\em hdl} closed. Before the
%*********************************************************
%* *
-\subsection[EOF]{Detecting the End of Input}
+\subsection[FileSize]{Detecting the size of a file}
%* *
%*********************************************************
\begin{code}
hFileSize :: Handle -> IO Integer
-hFileSize handle = do
- handle_ <- readHandle handle
+hFileSize handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hFileSize" handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hFileSize" handle
- other ->
+ ClosedHandle -> ioe_closedHandle "hFileSize" handle
+ SemiClosedHandle -> ioe_closedHandle "hFileSize" handle
+#ifdef __HUGS__
+ _ -> do
+ mem <- primNewByteArray 8{-sizeof_int64-}
+ rc <- fileSize_int64 (haFO__ handle_) mem -- ConcHask: SAFE, won't block
+ if rc == 0 then do
+ result <- primReadInt64Array mem 0
+ return (primInt64ToInteger result)
+ else
+ constructErrorAndFail "hFileSize"
+#else
+ _ ->
-- HACK! We build a unique MP_INT of the right shape to hold
-- a single unsigned word, and we let the C routine
-- change the data bits
--
- -- For some reason, this fails to typecheck if converted to a do
- -- expression --SDM
- _casm_ ``%r = 1;'' >>= \(I# hack#) ->
- case int2Integer# hack# of
- result@(J# _ _ d#) -> do
- rc <- _ccall_ fileSize (haFO__ handle_) d# -- ConcHask: SAFE, won't block
- writeHandle handle handle_
- if rc == 0 then
- return result
+ case int2Integer# 1# of
+ (# s, d #) -> do
+ rc <- fileSize (haFO__ handle_) d -- ConcHask: SAFE, won't block
+ if rc == (0::Int) then
+ return (J# s d)
else
constructErrorAndFail "hFileSize"
+#endif
\end{code}
+%*********************************************************
+%* *
+\subsection[EOF]{Detecting the End of Input}
+%* *
+%*********************************************************
+
+
For a readable handle {\em hdl}, @hIsEOF hdl@ returns
@True@ if no further input can be taken from @hdl@ or for a
physical file, if the current I/O position is equal to the length of
\begin{code}
hIsEOF :: Handle -> IO Bool
hIsEOF handle = do
- handle_ <- wantReadableHandle "hIsEOF" handle
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ fileEOF fo) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
+ rc <- mayBlockRead "hIsEOF" handle fileEOF
case rc of
0 -> return False
1 -> return True
hSetBuffering handle mode =
case mode of
BlockBuffering (Just n)
- | n <= 0 -> fail (IOError (Just handle)
+ | n <= 0 -> ioException
+ (IOError (Just handle)
InvalidArgument
"hSetBuffering"
- ("illegal buffer size " ++ showsPrec 9 n [])) -- 9 => should be parens'ified.
- _ -> do
- handle_ <- readHandle handle
+ ("illegal buffer size " ++ showsPrec 9 n []))
+ -- 9 => should be parens'ified.
+ _ ->
+ withHandle__ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hSetBuffering" handle
+ ClosedHandle -> ioe_closedHandle "hSetBuffering" handle
_ -> do
{- Note:
- we flush the old buffer regardless of whether
of semi-closed handles to change [sof 6/98]
-}
let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ setBuffering fo bsize) -- ConcHask: UNSAFE, may block
+ rc <- mayBlock fo (setBuffering fo bsize) -- ConcHask: UNSAFE, may block
if rc == 0
then do
- writeHandle handle (handle_{ haBufferMode__ = mode })
+ return (handle_{ haBufferMode__ = mode })
else do
-- Note: failure to change the buffer size will cause old buffer to be flushed.
- writeHandle handle handle_
constructErrorAndFail "hSetBuffering"
where
bsize :: Int
\begin{code}
hFlush :: Handle -> IO ()
-hFlush handle = do
- handle_ <- wantWriteableHandle "hFlush" handle
+hFlush handle =
+ wantWriteableHandle "hFlush" handle $ \ handle_ -> do
let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ flushFile fo) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
+ rc <- mayBlock fo (flushFile fo) -- ConcHask: UNSAFE, may block
if rc == 0 then
return ()
else
data HandlePosn
= HandlePosn
Handle -- Q: should this be a weak or strong ref. to the handle?
- Int
+ -- [what's the winning argument for it not being strong? --sof]
+ HandlePosition
+
+instance Eq HandlePosn where
+ (HandlePosn h1 p1) == (HandlePosn h2 p2) = p1==p2 && h1==h2
+
+ -- HandlePosition is the Haskell equivalent of POSIX' off_t.
+ -- We represent it as an Integer on the Haskell side, but
+ -- cheat slightly in that hGetPosn calls upon a C helper
+ -- that reports the position back via (merely) an Int.
+type HandlePosition = Integer
+
+mkHandlePosn :: Handle -> HandlePosition -> HandlePosn
+mkHandlePosn h p = HandlePosn h p
data SeekMode = AbsoluteSeek | RelativeSeek | SeekFromEnd
deriving (Eq, Ord, Ix, Enum, Read, Show)
\begin{code}
hGetPosn :: Handle -> IO HandlePosn
-hGetPosn handle = do
- handle_ <- wantSeekableHandle "hGetPosn" handle
- posn <- _ccall_ getFilePosn (haFO__ handle_) -- ConcHask: SAFE, won't block
- writeHandle handle handle_
- if posn /= -1 then
- return (HandlePosn handle posn)
+hGetPosn handle =
+ wantSeekableHandle "hGetPosn" handle $ \ handle_ -> do
+ posn <- getFilePosn (haFO__ handle_) -- ConcHask: SAFE, won't block
+ if posn /= -1 then do
+ return (mkHandlePosn handle (fromInt posn))
else
constructErrorAndFail "hGetPosn"
hSetPosn :: HandlePosn -> IO ()
-hSetPosn (HandlePosn handle posn) = do
- handle_ <- wantSeekableHandle "hSetPosn" handle -- not as silly as it looks: the handle may have been closed in the meantime.
+hSetPosn (HandlePosn handle i@(S# _)) = hSetPosn (HandlePosn handle (toBig i))
+hSetPosn (HandlePosn handle (J# s# d#)) =
+ wantSeekableHandle "hSetPosn" handle $ \ handle_ -> do
+ -- not as silly as it looks: the handle may have been closed in the meantime.
let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ setFilePosn fo posn) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
- if rc == 0 then
+ rc <- mayBlock fo (setFilePosn fo (I# s#) d#) -- ConcHask: UNSAFE, may block
+ if rc == 0 then do
return ()
else
constructErrorAndFail "hSetPosn"
The action @hSeek hdl mode i@ sets the position of handle
@hdl@ depending on @mode@. If @mode@ is
-\begin{itemize}
-\item[{\bf AbsoluteSeek}] The position of @hdl@ is set to @i@.
-\item[{\bf RelativeSeek}] The position of @hdl@ is set to offset @i@ from
-the current position.
-\item[{\bf SeekFromEnd}] The position of @hdl@ is set to offset @i@ from
-the end of the file.
-\end{itemize}
-Some handles may not be seekable (see @hIsSeekable@), or only support a
-subset of the possible positioning operations (e.g. it may only be
-possible to seek to the end of a tape, or to a positive offset from
-the beginning or current position).
+ * AbsoluteSeek - The position of @hdl@ is set to @i@.
+ * RelativeSeek - The position of @hdl@ is set to offset @i@ from
+ the current position.
+ * SeekFromEnd - The position of @hdl@ is set to offset @i@ from
+ the end of the file.
+
+Some handles may not be seekable (see @hIsSeekable@), or only
+support a subset of the possible positioning operations (e.g. it may
+only be possible to seek to the end of a tape, or to a positive
+offset from the beginning or current position).
It is not possible to set a negative I/O position, or for a physical
file, an I/O position beyond the current end-of-file.
Note:
- - when seeking using @SeekFromEnd@, positive offsets (>=0) means seeking
- at or past EOF.
+ - when seeking using @SeekFromEnd@, positive offsets (>=0) means
+ seeking at or past EOF.
- relative seeking on buffered handles can lead to non-obvious results.
\begin{code}
hSeek :: Handle -> SeekMode -> Integer -> IO ()
-hSeek handle mode offset@(J# _ s# d#) = do
- handle_ <- wantSeekableHandle "hSeek" handle
+#ifdef __HUGS__
+hSeek handle mode offset =
+ wantSeekableHandle "hSeek" handle $ \ handle_ -> do
let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ seekFile fo whence (I# s#) d#) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
- if rc == 0 then
+ rc <- mayBlock fo (seekFile fo whence (primIntegerToInt64 offset)) -- ConcHask: UNSAFE, may block
+#else
+hSeek handle mode i@(S# _) = hSeek handle mode (toBig i)
+hSeek handle mode (J# s# d#) =
+ wantSeekableHandle "hSeek" handle $ \ handle_ -> do
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (seekFile fo whence (I# s#) d#) -- ConcHask: UNSAFE, may block
+#endif
+ if rc == 0 then do
return ()
else
constructErrorAndFail "hSeek"
\begin{code}
hIsOpen :: Handle -> IO Bool
-hIsOpen handle = do
- handle_ <- readHandle handle
+hIsOpen handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- return False
- SemiClosedHandle -> do
- writeHandle handle handle_
- return False
- _ -> do
- writeHandle handle handle_
- return True
+ ClosedHandle -> return False
+ SemiClosedHandle -> return False
+ _ -> return True
hIsClosed :: Handle -> IO Bool
-hIsClosed handle = do
- handle_ <- readHandle handle
+hIsClosed handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- return True
- _ -> do
- writeHandle handle handle_
- return False
+ ClosedHandle -> return True
+ _ -> return False
{- not defined, nor exported, but mentioned
here for documentation purposes:
-}
hIsReadable :: Handle -> IO Bool
-hIsReadable handle = do
- handle_ <- readHandle handle
+hIsReadable handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsReadable" handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsReadable" handle
- htype -> do
- writeHandle handle handle_
- return (isReadable htype)
+ ClosedHandle -> ioe_closedHandle "hIsReadable" handle
+ SemiClosedHandle -> ioe_closedHandle "hIsReadable" handle
+ htype -> return (isReadable htype)
where
isReadable ReadHandle = True
isReadable ReadWriteHandle = True
isReadable _ = False
hIsWritable :: Handle -> IO Bool
-hIsWritable handle = do
- handle_ <- readHandle handle
+hIsWritable handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsWritable" handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsWritable" handle
- htype -> do
- writeHandle handle handle_
- return (isWritable htype)
+ ClosedHandle -> ioe_closedHandle "hIsWritable" handle
+ SemiClosedHandle -> ioe_closedHandle "hIsWritable" handle
+ htype -> return (isWritable htype)
where
isWritable AppendHandle = True
isWritable WriteHandle = True
isWritable _ = False
-#ifndef __PARALLEL_HASKELL__
-getBMode__ :: ForeignObj -> IO (BufferMode, Int)
-#else
-getBMode__ :: Addr -> IO (BufferMode, Int)
-#endif
+getBMode__ :: FILE_OBJECT -> IO (BufferMode, Int)
getBMode__ fo = do
- rc <- _ccall_ getBufferMode fo -- ConcHask: SAFE, won't block
+ rc <- getBufferMode fo -- ConcHask: SAFE, won't block
case (rc::Int) of
0 -> return (NoBuffering, 0)
-1 -> return (LineBuffering, default_buffer_size)
n -> return (BlockBuffering (Just n), n)
where
default_buffer_size :: Int
- default_buffer_size = (``BUFSIZ'' - 1)
+ default_buffer_size = const_BUFSIZ
\end{code}
Querying how a handle buffers its data:
\begin{code}
hGetBuffering :: Handle -> IO BufferMode
-hGetBuffering handle = do
- handle_ <- readHandle handle
+hGetBuffering handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hGetBuffering" handle
- _ -> do
+ ClosedHandle -> ioe_closedHandle "hGetBuffering" handle
+ _ ->
{-
We're being non-standard here, and allow the buffering
of a semi-closed handle to be queried. -- sof 6/98
-}
- let v = haBufferMode__ handle_
- writeHandle handle handle_
- return v -- could be stricter..
-
+ return (haBufferMode__ handle_) -- could be stricter..
\end{code}
\begin{code}
hIsSeekable :: Handle -> IO Bool
-hIsSeekable handle = do
- handle_ <- readHandle handle
+hIsSeekable handle =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsSeekable" handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "hIsSeekable" handle
- AppendHandle -> do
- writeHandle handle handle_
- return False
- other -> do
- rc <- _ccall_ seekFileP (haFO__ handle_) -- ConcHask: SAFE, won't block
- writeHandle handle handle_
- case rc of
+ ClosedHandle -> ioe_closedHandle "hIsSeekable" handle
+ SemiClosedHandle -> ioe_closedHandle "hIsSeekable" handle
+ AppendHandle -> return False
+ _ -> do
+ rc <- seekFileP (haFO__ handle_) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
0 -> return False
1 -> return True
_ -> constructErrorAndFail "hIsSeekable"
\begin{code}
hSetEcho :: Handle -> Bool -> IO ()
-hSetEcho hdl on = do
- isT <- hIsTerminalDevice hdl
+hSetEcho handle on = do
+ isT <- hIsTerminalDevice handle
if not isT
then return ()
- else do
- handle_ <- readHandle hdl
+ else
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle hdl handle_
- fail ioError
- ClosedHandle -> do
- writeHandle hdl handle_
- ioe_closedHandle "hSetEcho" hdl
- other -> do
- rc <- _ccall_ setTerminalEcho (haFO__ handle_) (if on then 1 else 0) -- ConcHask: SAFE, won't block
- writeHandle hdl handle_
- if rc /= -1
+ ClosedHandle -> ioe_closedHandle "hSetEcho" handle
+ _ -> do
+ rc <- setTerminalEcho (haFO__ handle_) (if on then 1 else 0) -- ConcHask: SAFE, won't block
+ if rc /= ((-1)::Int)
then return ()
else constructErrorAndFail "hSetEcho"
hGetEcho :: Handle -> IO Bool
-hGetEcho hdl = do
- isT <- hIsTerminalDevice hdl
+hGetEcho handle = do
+ isT <- hIsTerminalDevice handle
if not isT
then return False
- else do
- handle_ <- readHandle hdl
+ else
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle hdl handle_
- fail ioError
- ClosedHandle -> do
- writeHandle hdl handle_
- ioe_closedHandle "hGetEcho" hdl
- other -> do
- rc <- _ccall_ getTerminalEcho (haFO__ handle_) -- ConcHask: SAFE, won't block
- writeHandle hdl handle_
- case rc of
+ ClosedHandle -> ioe_closedHandle "hGetEcho" handle
+ _ -> do
+ rc <- getTerminalEcho (haFO__ handle_) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
1 -> return True
0 -> return False
_ -> constructErrorAndFail "hSetEcho"
hIsTerminalDevice :: Handle -> IO Bool
-hIsTerminalDevice hdl = do
- handle_ <- readHandle hdl
- case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle hdl handle_
- fail ioError
- ClosedHandle -> do
- writeHandle hdl handle_
- ioe_closedHandle "hIsTerminalDevice" hdl
- other -> do
- rc <- _ccall_ isTerminalDevice (haFO__ handle_) -- ConcHask: SAFE, won't block
- writeHandle hdl handle_
- case rc of
+hIsTerminalDevice handle = do
+ withHandle_ handle $ \ handle_ -> do
+ case haType__ handle_ of
+ ClosedHandle -> ioe_closedHandle "hIsTerminalDevice" handle
+ _ -> do
+ rc <- isTerminalDevice (haFO__ handle_) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
1 -> return True
0 -> return False
_ -> constructErrorAndFail "hIsTerminalDevice"
hConnectTo hW hR = hConnectHdl_ hW hR 0{-connect regardless-}
hConnectHdl_ :: Handle -> Handle -> Int -> IO ()
-hConnectHdl_ hW hR is_tty = do
- hW_ <- wantWriteableHandle "hConnectTo" hW
- hR_ <- wantReadableHandle "hConnectTo" hR
- _ccall_ setConnectedTo (haFO__ hR_) (haFO__ hW_) is_tty -- ConcHask: SAFE, won't block
- writeHandle hR hR_
- writeHandle hW hW_
-
+hConnectHdl_ hW hR is_tty =
+ wantRWHandle "hConnectTo" hW $ \ hW_ ->
+ wantRWHandle "hConnectTo" hR $ \ hR_ -> do
+ setConnectedTo (haFO__ hR_) (haFO__ hW_) is_tty -- ConcHask: SAFE, won't block
\end{code}
As an extension, we also allow characters to be pushed back.
\begin{code}
hUngetChar :: Handle -> Char -> IO ()
-hUngetChar handle c = do
- handle_ <- wantReadableHandle "hLookAhead" handle
- rc <- _ccall_ ungetChar (haFO__ handle_) c -- ConcHask: SAFE, won't block
- writeHandle handle handle_
- if rc == (-1)
+hUngetChar handle c =
+ wantReadableHandle "hLookAhead" handle $ \ handle_ -> do
+ rc <- ungetChar (haFO__ handle_) c -- ConcHask: SAFE, won't block
+ if rc == ((-1)::Int)
then constructErrorAndFail "hUngetChar"
else return ()
-- in one go, read file into an externally allocated buffer.
slurpFile :: FilePath -> IO (Addr, Int)
slurpFile fname = do
- hdl <- openFile fname ReadMode
- sz <- hFileSize hdl
+ handle <- openFile fname ReadMode
+ sz <- hFileSize handle
if sz > toInteger (maxBound::Int) then
- fail (userError "slurpFile: file too big")
+ ioError (userError "slurpFile: file too big")
else do
let sz_i = fromInteger sz
- chunk <- _ccall_ allocMemory__ (sz_i::Int)
+ chunk <- malloc sz_i
if chunk == nullAddr
then do
- hClose hdl
+ hClose handle
constructErrorAndFail "slurpFile"
else do
- handle_ <- readHandle hdl
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ readChunk fo chunk sz_i) -- ConcHask: UNSAFE, may block.
- writeHandle hdl handle_
- hClose hdl
- if rc < 0
+ rc <- withHandle_ handle ( \ handle_ -> do
+ let fo = haFO__ handle_
+ mayBlock fo (readChunk fo chunk 0 sz_i) -- ConcHask: UNSAFE, may block.
+ )
+ hClose handle
+ if rc < (0::Int)
then constructErrorAndFail "slurpFile"
else return (chunk, rc)
-hFillBufBA :: Handle -> ByteArray Int -> Int -> IO Int
-hFillBufBA handle buf sz
- | sz <= 0 = fail (IOError (Just handle)
- InvalidArgument
- "hFillBufBA"
- ("illegal buffer size " ++ showsPrec 9 sz [])) -- 9 => should be parens'ified.
- | otherwise = do
- handle_ <- wantReadableHandle "hFillBufBA" handle
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ readChunk fo buf sz) -- ConcHask: UNSAFE, may block.
- writeHandle handle handle_
- if rc >= 0
- then return rc
- else constructErrorAndFail "hFillBufBA"
-
-hFillBuf :: Handle -> Addr -> Int -> IO Int
-hFillBuf handle buf sz
- | sz <= 0 = fail (IOError (Just handle)
- InvalidArgument
- "hFillBuf"
- ("illegal buffer size " ++ showsPrec 9 sz [])) -- 9 => should be parens'ified.
- | otherwise = do
- handle_ <- wantReadableHandle "hFillBuf" handle
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ readChunk fo buf sz) -- ConcHask: UNSAFE, may block.
- writeHandle handle handle_
- if rc >= 0
- then return rc
- else constructErrorAndFail "hFillBuf"
-
-\end{code}
-
-The @hPutBuf hdl buf len@ action writes an already packed sequence of
-bytes to the file/channel managed by @hdl@ - non-standard.
-
-\begin{code}
-hPutBuf :: Handle -> Addr -> Int -> IO ()
-hPutBuf handle buf len = do
- handle_ <- wantWriteableHandle "hPutBuf" handle
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ writeBuf fo buf len) -- ConcHask: UNSAFE, may block.
- writeHandle handle handle_
- if rc == 0
- then return ()
- else constructErrorAndFail "hPutBuf"
-
-hPutBufBA :: Handle -> ByteArray Int -> Int -> IO ()
-hPutBufBA handle buf len = do
- handle_ <- wantWriteableHandle "hPutBufBA" handle
- let fo = haFO__ handle_
- rc <- mayBlock fo (_ccall_ writeBufBA fo buf len) -- ConcHask: UNSAFE, may block.
- writeHandle handle handle_
- if rc == 0
- then return ()
- else constructErrorAndFail "hPutBuf"
\end{code}
Sometimes it's useful to get at the file descriptor that
\begin{code}
getHandleFd :: Handle -> IO Int
-getHandleFd handle = do
- handle_ <- readHandle handle
+getHandleFd handle =
+ withHandle_ handle $ \ handle_ -> do
case (haType__ handle_) of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle "getHandleFd" handle
+ ClosedHandle -> ioe_closedHandle "getHandleFd" handle
_ -> do
- fd <- _ccall_ getFileFd (haFO__ handle_)
- writeHandle handle handle_
+ fd <- getFileFd (haFO__ handle_)
return fd
\end{code}
ioeGetErrorString :: IOError -> String
ioeGetHandle :: IOError -> Maybe Handle
-ioeGetHandle (IOError h _ _ _) = h
-ioeGetErrorString (IOError _ iot _ str) =
+ioeGetHandle (IOException (IOError h _ _ _)) = h
+ioeGetHandle _ = error "IO.ioeGetHandle: not an IO error"
+
+ioeGetErrorString (IOException (IOError _ iot _ str)) =
case iot of
EOF -> "end of file"
_ -> str
+ioeGetErrorString _ = error "IO.ioeGetErrorString: not an IO error"
-ioeGetFileName (IOError _ _ _ str) =
+ioeGetFileName (IOException (IOError _ _ _ str)) =
case span (/=':') str of
- (fs,[]) -> Nothing
+ (_,[]) -> Nothing
(fs,_) -> Just fs
+ioeGetFileName _ = error "IO.ioeGetFileName: not an IO error"
+\end{code}
+
+'Top-level' IO actions want to catch exceptions (e.g., forkIO and
+PrelMain.mainIO) and report them - topHandler is the exception
+handler they should use for this:
+\begin{code}
+-- make sure we handle errors while reporting the error!
+-- (e.g. evaluating the string passed to 'error' might generate
+-- another error, etc.)
+topHandler :: Bool -> Exception -> IO ()
+topHandler bombOut err = catchException (real_handler bombOut err) (topHandler bombOut)
+
+real_handler :: Bool -> Exception -> IO ()
+real_handler bombOut ex =
+ case ex of
+ AsyncException StackOverflow -> reportStackOverflow bombOut
+ ErrorCall s -> reportError bombOut s
+ other -> reportError bombOut (showsPrec 0 other "\n")
+
+reportStackOverflow :: Bool -> IO ()
+reportStackOverflow bombOut = do
+ (hFlush stdout) `catchException` (\ _ -> return ())
+ callStackOverflowHook
+ if bombOut then
+ stg_exit 2
+ else
+ return ()
+
+reportError :: Bool -> String -> IO ()
+reportError bombOut str = do
+ (hFlush stdout) `catchException` (\ _ -> return ())
+ let bs@(ByteArray _ len _) = packString str
+ writeErrString addrOf_ErrorHdrHook bs len
+ if bombOut then
+ stg_exit 1
+ else
+ return ()
+
+foreign import ccall "addrOf_ErrorHdrHook" unsafe
+ addrOf_ErrorHdrHook :: Addr
+
+foreign import ccall "writeErrString__" unsafe
+ writeErrString :: Addr -> ByteArray Int -> Int -> IO ()
+
+-- SUP: Are the hooks allowed to re-enter Haskell land? If yes, remove the unsafe below.
+foreign import ccall "stackOverflow" unsafe
+ callStackOverflowHook :: IO ()
+
+foreign import ccall "stg_exit" unsafe
+ stg_exit :: Int -> IO ()
\end{code}
+
A number of operations want to get at a readable or writeable handle, and fail
if it isn't:
\begin{code}
-wantReadableHandle :: String -> Handle -> IO Handle__
-wantReadableHandle fun handle = do
- handle_ <- readHandle handle
+wantReadableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
+wantReadableHandle fun handle act =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- AppendHandle -> do
- writeHandle handle handle_
- fail not_readable_error
- WriteHandle -> do
- writeHandle handle handle_
- fail not_readable_error
- other -> return handle_
+ ClosedHandle -> ioe_closedHandle fun handle
+ SemiClosedHandle -> ioe_closedHandle fun handle
+ AppendHandle -> ioException not_readable_error
+ WriteHandle -> ioException not_readable_error
+ _ -> act handle_
where
not_readable_error =
IOError (Just handle) IllegalOperation fun
("handle is not open for reading")
-wantWriteableHandle :: String -> Handle -> IO Handle__
-wantWriteableHandle fun handle = do
- handle_ <- readHandle handle
- case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- ReadHandle -> do
- writeHandle handle handle_
- fail not_writeable_error
- other -> return handle_
+wantWriteableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
+wantWriteableHandle fun handle act =
+ withHandle_ handle $ \ handle_ ->
+ checkWriteableHandle fun handle handle_ (act handle_)
+
+wantWriteableHandle_ :: String -> Handle -> (Handle__ -> IO (Handle__, a)) -> IO a
+wantWriteableHandle_ fun handle act =
+ withHandle handle $ \ handle_ ->
+ checkWriteableHandle fun handle handle_ (act handle_)
+
+checkWriteableHandle fun handle handle_ act
+ = case haType__ handle_ of
+ ClosedHandle -> ioe_closedHandle fun handle
+ SemiClosedHandle -> ioe_closedHandle fun handle
+ ReadHandle -> ioError not_writeable_error
+ _ -> act
where
not_writeable_error =
- IOError (Just handle) IllegalOperation fun
- ("handle is not open for writing")
+ IOException (IOError (Just handle) IllegalOperation fun
+ ("handle is not open for writing"))
-wantSeekableHandle :: String -> Handle -> IO Handle__
-wantSeekableHandle fun handle = do
- handle_ <- readHandle handle
+wantRWHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
+wantRWHandle fun handle act =
+ withHandle_ handle $ \ handle_ -> do
case haType__ handle_ of
- ErrorHandle ioError -> do
- writeHandle handle handle_
- fail ioError
- ClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- SemiClosedHandle -> do
- writeHandle handle handle_
- ioe_closedHandle fun handle
- AppendHandle -> do
- writeHandle handle handle_
- fail not_seekable_error
- _ -> return handle_
- where
- not_seekable_error =
- IOError (Just handle)
- IllegalOperation fun
- ("handle is not seekable")
+ ClosedHandle -> ioe_closedHandle fun handle
+ SemiClosedHandle -> ioe_closedHandle fun handle
+ _ -> act handle_
+wantSeekableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
+wantSeekableHandle fun handle act =
+ withHandle_ handle $ \ handle_ -> do
+ case haType__ handle_ of
+ ClosedHandle -> ioe_closedHandle fun handle
+ SemiClosedHandle -> ioe_closedHandle fun handle
+ _ -> act handle_
\end{code}
Internal function for creating an @IOError@ representing the
\begin{code}
ioe_closedHandle :: String -> Handle -> IO a
-ioe_closedHandle fun h = fail (IOError (Just h) IllegalOperation fun "handle is closed")
+ioe_closedHandle fun h = ioError (IOException (IOError (Just h) IllegalOperation fun
+ "handle is closed"))
\end{code}
Internal helper functions for Concurrent Haskell implementation
of IO:
\begin{code}
-#ifndef __PARALLEL_HASKELL__
-mayBlock :: ForeignObj -> IO Int -> IO Int
-#else
-mayBlock :: Addr -> IO Int -> IO Int
-#endif
-
-#ifndef __CONCURRENT_HASKELL__
-mayBlock _ act = act
-#else
+mayBlock :: FILE_OBJECT -> IO Int -> IO Int
mayBlock fo act = do
rc <- act
case rc of
-5 -> do -- (possibly blocking) read
- fd <- _ccall_ getFileFd fo
+ fd <- getFileFd fo
threadWaitRead fd
- _ccall_ clearNonBlockingIOFlag__ fo -- force read to happen this time.
mayBlock fo act -- input available, re-try
-6 -> do -- (possibly blocking) write
- fd <- _ccall_ getFileFd fo
+ fd <- getFileFd fo
threadWaitWrite fd
- _ccall_ clearNonBlockingIOFlag__ fo -- force write to happen this time.
mayBlock fo act -- output possible
-7 -> do -- (possibly blocking) write on connected handle
- fd <- _ccall_ getConnFileFd fo
+ fd <- getConnFileFd fo
threadWaitWrite fd
- _ccall_ clearConnNonBlockingIOFlag__ fo -- force write to happen this time.
mayBlock fo act -- output possible
_ -> do
- _ccall_ setNonBlockingIOFlag__ fo -- reset file object.
- _ccall_ setConnNonBlockingIOFlag__ fo -- reset (connected) file object.
return rc
+data MayBlock a
+ = BlockRead Int
+ | BlockWrite Int
+ | NoBlock a
+
+mayBlockRead :: String -> Handle -> (FILE_OBJECT -> IO Int) -> IO Int
+mayBlockRead fname handle fn = do
+ r <- wantReadableHandle fname handle $ \ handle_ -> do
+ let fo = haFO__ handle_
+ rc <- fn fo
+ case rc of
+ -5 -> do -- (possibly blocking) read
+ fd <- getFileFd fo
+ return (BlockRead fd)
+ -6 -> do -- (possibly blocking) write
+ fd <- getFileFd fo
+ return (BlockWrite fd)
+ -7 -> do -- (possibly blocking) write on connected handle
+ fd <- getConnFileFd fo
+ return (BlockWrite fd)
+ _ ->
+ if rc >= 0
+ then return (NoBlock rc)
+ else constructErrorAndFail fname
+ case r of
+ BlockRead fd -> do
+ threadWaitRead fd
+ mayBlockRead fname handle fn
+ BlockWrite fd -> do
+ threadWaitWrite fd
+ mayBlockRead fname handle fn
+ NoBlock c -> return c
+
+mayBlockRead' :: String -> Handle
+ -> (FILE_OBJECT -> IO Int)
+ -> (FILE_OBJECT -> Int -> IO a)
+ -> IO a
+mayBlockRead' fname handle fn io = do
+ r <- wantReadableHandle fname handle $ \ handle_ -> do
+ let fo = haFO__ handle_
+ rc <- fn fo
+ case rc of
+ -5 -> do -- (possibly blocking) read
+ fd <- getFileFd fo
+ return (BlockRead fd)
+ -6 -> do -- (possibly blocking) write
+ fd <- getFileFd fo
+ return (BlockWrite fd)
+ -7 -> do -- (possibly blocking) write on connected handle
+ fd <- getConnFileFd fo
+ return (BlockWrite fd)
+ _ ->
+ if rc >= 0
+ then do a <- io fo rc
+ return (NoBlock a)
+ else constructErrorAndFail fname
+ case r of
+ BlockRead fd -> do
+ threadWaitRead fd
+ mayBlockRead' fname handle fn io
+ BlockWrite fd -> do
+ threadWaitWrite fd
+ mayBlockRead' fname handle fn io
+ NoBlock c -> return c
+
+mayBlockWrite :: String -> Handle -> (FILE_OBJECT -> IO Int) -> IO Int
+mayBlockWrite fname handle fn = do
+ r <- wantWriteableHandle fname handle $ \ handle_ -> do
+ let fo = haFO__ handle_
+ rc <- fn fo
+ case rc of
+ -5 -> do -- (possibly blocking) read
+ fd <- getFileFd fo
+ return (BlockRead fd)
+ -6 -> do -- (possibly blocking) write
+ fd <- getFileFd fo
+ return (BlockWrite fd)
+ -7 -> do -- (possibly blocking) write on connected handle
+ fd <- getConnFileFd fo
+ return (BlockWrite fd)
+ _ ->
+ if rc >= 0
+ then return (NoBlock rc)
+ else constructErrorAndFail fname
+ case r of
+ BlockRead fd -> do
+ threadWaitRead fd
+ mayBlockWrite fname handle fn
+ BlockWrite fd -> do
+ threadWaitWrite fd
+ mayBlockWrite fname handle fn
+ NoBlock c -> return c
+\end{code}
+
+Foreign import declarations of helper functions:
+
+\begin{code}
+
+#ifdef __HUGS__
+type Bytes = PrimByteArray RealWorld
+#else
+type Bytes = ByteArray#
+#endif
+
+foreign import "libHS_cbits" "inputReady" unsafe
+ inputReady :: FILE_OBJECT -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "fileGetc" unsafe
+ fileGetc :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "fileLookAhead" unsafe
+ fileLookAhead :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "readBlock" unsafe
+ readBlock :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "readLine" unsafe
+ readLine :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "readChar" unsafe
+ readChar :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "writeFileObject" unsafe
+ writeFileObject :: FILE_OBJECT -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "filePutc" unsafe
+ filePutc :: FILE_OBJECT -> Char -> IO Int{-ret code-}
+foreign import "libHS_cbits" "write_" unsafe
+ write_ :: FILE_OBJECT -> Addr -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "getBufStart" unsafe
+ getBufStart :: FILE_OBJECT -> Int -> IO Addr
+foreign import "libHS_cbits" "getWriteableBuf" unsafe
+ getWriteableBuf :: FILE_OBJECT -> IO Addr
+foreign import "libHS_cbits" "getBuf" unsafe
+ getBuf :: FILE_OBJECT -> IO Addr
+foreign import "libHS_cbits" "getBufWPtr" unsafe
+ getBufWPtr :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "setBufWPtr" unsafe
+ setBufWPtr :: FILE_OBJECT -> Int -> IO ()
+foreign import "libHS_cbits" "closeFile" unsafe
+ closeFile :: FILE_OBJECT -> Int{-Flush-} -> IO Int{-ret code-}
+foreign import "libHS_cbits" "fileEOF" unsafe
+ fileEOF :: FILE_OBJECT -> IO Int{-ret code-}
+foreign import "libHS_cbits" "setBuffering" unsafe
+ setBuffering :: FILE_OBJECT -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "flushFile" unsafe
+ flushFile :: FILE_OBJECT -> IO Int{-ret code-}
+foreign import "libHS_cbits" "flushConnectedBuf" unsafe
+ flushConnectedBuf :: FILE_OBJECT -> IO ()
+foreign import "libHS_cbits" "getBufferMode" unsafe
+ getBufferMode :: FILE_OBJECT -> IO Int{-ret code-}
+#ifdef __HUGS__
+foreign import "libHS_cbits" "seekFile_int64" unsafe
+ seekFile :: FILE_OBJECT -> Int -> Int64 -> IO Int
+#else
+foreign import "libHS_cbits" "seekFile" unsafe
+ seekFile :: FILE_OBJECT -> Int -> Int -> Bytes -> IO Int
+#endif
+
+foreign import "libHS_cbits" "seekFileP" unsafe
+ seekFileP :: FILE_OBJECT -> IO Int{-ret code-}
+foreign import "libHS_cbits" "setTerminalEcho" unsafe
+ setTerminalEcho :: FILE_OBJECT -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "getTerminalEcho" unsafe
+ getTerminalEcho :: FILE_OBJECT -> IO Int{-ret code-}
+foreign import "libHS_cbits" "isTerminalDevice" unsafe
+ isTerminalDevice :: FILE_OBJECT -> IO Int{-ret code-}
+foreign import "libHS_cbits" "setConnectedTo" unsafe
+ setConnectedTo :: FILE_OBJECT -> FILE_OBJECT -> Int -> IO ()
+foreign import "libHS_cbits" "ungetChar" unsafe
+ ungetChar :: FILE_OBJECT -> Char -> IO Int{-ret code-}
+foreign import "libHS_cbits" "readChunk" unsafe
+ readChunk :: FILE_OBJECT -> Addr -> Int -> Int -> IO Int{-ret code-}
+foreign import "libHS_cbits" "getFileFd" unsafe
+ getFileFd :: FILE_OBJECT -> IO Int{-fd-}
+#ifdef __HUGS__
+foreign import "libHS_cbits" "fileSize_int64" unsafe
+ fileSize_int64 :: FILE_OBJECT -> Bytes -> IO Int{-ret code-}
+#else
+foreign import "libHS_cbits" "fileSize" unsafe
+ fileSize :: FILE_OBJECT -> Bytes -> IO Int{-ret code-}
#endif
+
+foreign import "libHS_cbits" "getFilePosn" unsafe
+ getFilePosn :: FILE_OBJECT -> IO Int
+foreign import "libHS_cbits" "setFilePosn" unsafe
+ setFilePosn :: FILE_OBJECT -> Int -> ByteArray# -> IO Int
+foreign import "libHS_cbits" "getConnFileFd" unsafe
+ getConnFileFd :: FILE_OBJECT -> IO Int{-fd-}
+foreign import "libHS_cbits" "getLock" unsafe
+ getLock :: Int{-Fd-} -> Int{-exclusive-} -> IO Int{-return code-}
+foreign import "libHS_cbits" "openStdFile" unsafe
+ openStdFile :: Int{-fd-} -> Int{-Readable?-} -> IO Addr{-file obj-}
+foreign import "libHS_cbits" "openFile" unsafe
+ primOpenFile :: ByteArray Int{-CString-}
+ -> Int{-How-}
+ -> Int{-Binary-}
+ -> IO Addr {-file obj-}
+foreign import "libHS_cbits" "const_BUFSIZ" unsafe
+ const_BUFSIZ :: Int
+
+foreign import "libHS_cbits" "setBinaryMode__" unsafe
+ setBinaryMode :: FILE_OBJECT -> Int -> IO Int
\end{code}
projects / ghc-hetmet.git / blobdiff